Q1 Fuselage comes up


Eugen Pilarski
 

The fuselage of Q1 is coming up from the foam and the stuff is very sandy :-))

Some picture from the progress .....

Eugen


 

Hi Eugen,
Very nice photos.
The only comment I might have is in regards to the contour edges.
From the  photos they look kinda sharp.  If I remember right the glass cloth likes rounded edges.
It doesn't like making sharp turns.  The only places I remember having sharp turns is where glass tapes were used for bulkheads and micro was used in the corners.
But that was a long time ago too.
Those currently building may have a better view of that.
Just my two cents. 
Keith
N494K


---------- Original Message ----------
From: "Eugen Pilarski" <interbus@...>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200

The fuselage of Q1 is coming up from the foam and the stuff is very sandy :-))

Some picture from the progress .....

Eugen







Rob de Bie
 

Very nice work indeed!! But I agree with Keith: the sharp corners are far from optimal. Your light vacuum will make sure that the glass fiber cloth will conform, so that's not the problem. But if you have a multiple ply laminate laid over a small radius, you will get high out-of-plane stresses if a bending moment is applied. Now whether there is a lot of bending moment in the fuselage skins, I don't know, they are probably secondary effects. But I would nevertheless increase the radius quite a bit.

As an example of out-of-plane stresses: imagine laminating a 90 angle with 10 cm / 4 inch legs, with 3 or 4 layers. If you would bend it so the angle gets smaller, the out-of-plane stresses will push the laminate plies against each other - no problem. But if you bend it so the angle gets bigger, the sign changes, and the out-of-plane stresses want to delaminate. Now do this same experiment with different radii, and you will see that the larger the radius, the stronger the specimen will be.

Rob

On 30 Mar 2021 13:43, Keith Welsh wrote:
Hi Eugen,
Very nice photos.
The only comment I might have is in regards to the contour edges.
From the  photos they look kinda sharp.  If I remember right the glass cloth likes rounded edges.
It doesn't like making sharp turns.  The only places I remember having sharp turns is where glass tapes were used for bulkheads and micro was used in the corners.
But that was a long time ago too.
Those currently building may have a better view of that.
Just my two cents.
Keith
N494K
---------- Original Message ----------
From: "Eugen Pilarski" <interbus@web.de>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200
The fuselage of Q1 is coming up from the foam and the stuff is very sandy :-))
Some picture from the progress .....
Eugen


Bruce Crain
 

Nice!  What engine will you use?  Yep you will get a lot of sanding in the process!  
Bruce


---------- Original Message ----------
From: "Eugen Pilarski" <interbus@...>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200

The fuselage of Q1 is coming up from the foam and the stuff is very sandy :-))

Some picture from the progress .....

Eugen







Jay Scheevel
 

Eugen,

Everyone is right about the sharp corners and the cloth wrapping them.
Guidelines on how much rounding of the corners is needed can be found here:
http://n8wq.scheevel.com/documents/RAF_composite_education_section_from_Q2Pl
ans.pdf

Also, the best way to round the corners in a very smooth way is to use a
spare piece of the foam as a sanding block. The foam will grind away on both
the block and the piece you are sanding and make a very nice curve (lots of
foam dust, so have a vacuum cleaner on hand).

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Rob de Bie
Sent: Tuesday, March 30, 2021 6:06 AM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Q1 Fuselage comes up

Very nice work indeed!! But I agree with Keith: the sharp corners are far
from optimal. Your light vacuum will make sure that the glass fiber cloth
will conform, so that's not the problem. But if you have a multiple ply
laminate laid over a small radius, you will get high out-of-plane stresses
if a bending moment is applied. Now whether there is a lot of bending moment
in the fuselage skins, I don't know, they are probably secondary effects.
But I would nevertheless increase the radius quite a bit.

As an example of out-of-plane stresses: imagine laminating a 90 angle with
10 cm / 4 inch legs, with
3 or 4 layers. If you would bend it so the angle gets smaller, the
out-of-plane stresses will push the laminate plies against each other - no
problem. But if you bend it so the angle gets bigger, the sign changes, and
the out-of-plane stresses want to delaminate. Now do this same experiment
with different radii, and you will see that the larger the radius, the
stronger the specimen will be.

Rob

On 30 Mar 2021 13:43, Keith Welsh wrote:
Hi Eugen,
Very nice photos.
The only comment I might have is in regards to the contour edges.
From the  photos they look kinda sharp.  If I remember right the glass
cloth likes rounded edges.
It doesn't like making sharp turns.  The only places I remember having
sharp turns is where glass
tapes were used for bulkheads and micro was used in the corners.
But that was a long time ago too.
Those currently building may have a better view of that.
Just my two cents.
Keith
N494K

---------- Original Message ----------
From: "Eugen Pilarski" <interbus@web.de>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200

The fuselage of Q1 is coming up from the foam and the stuff is very sandy
:-))

Some picture from the progress .....

Eugen







smeshno1@...
 

 A Vanguard V, Briggs and Stratton. They are used in auto racing....with of course modifications to the innards.

This is Briggs & Stratton Slingshot Racing
www.youtube.com


 

 I've also seen these run in micro drag racing...pushing the limits of the internals but that is the nature of 
drag racing. Circle track looking to endurance. The racer telling how little has to be done to keep on the
track for an entire season is remarkable. Valve springs and oil changes after 60 hard running races!  


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Tuesday, March 30, 2021 9:32 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Q1 Fuselage comes up
 
Nice!  What engine will you use?  Yep you will get a lot of sanding in the process!  
Bruce

---------- Original Message ----------
From: "Eugen Pilarski" <interbus@...>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200

The fuselage of Q1 is coming up from the foam and the stuff is very sandy :-))

Some picture from the progress .....

Eugen







Eugen Pilarski
 

Hi @all,

thanks for the hint about the corners and the necessary of form it with a sanding block. This area is manufactured exactly according to the plans, it’s listed in Page 7-6 Contouring, especially the section A-A, please find below a screen shot. 

Before the first layer will place on the fuselage all areas need to form with a sanding block for sure, like the Quickie construction plans indicate, the picture you received just show an intermediate state. Unfortunately, pictures from that time are very rare and scarce, and 40 years have passed since the first Q1 was built.

The foam for the Fuselage I use has a compressive strength of 0,27 Mpa or 2900 hPa, with my Vacuum bag I will not go lower then 500 hPa (Standard is 1013hPa). After I did a test piece with 3 layers on each side with the Vacuum bag go down to 200 hPa (Standar is 1013hPa), they was no issue with the foam, no deformation or damage and good bonding with the micro to the foam.

I did a short crossover of different foam and suppliers like Aircraft Spruce, Wicks and other European suppliers and choice the best one for my application. It is Airex C70.55 for Bulkheads, Bauder E33 for fuselage and Korff Styrofoam XPS billet for wing/Canard, all stuff comes from europe.  I have of course considered the recommendations from the LongEz and Cozy corner and followed them.  Please find below my investigation about Foam, glass and resin: https://aerobase.weebly.com/q1-bill-of-material---source--spec.html

The resin is a MGS L385 and H386 with aerospace approval, glass will be interglass with aerospace approval too. From my point of view, you have as an homebuilder to be on the safe side with the material and not save money at the wrong end, that’s the reason why I spend’s minimum 12 month to investigate the foam/glass/resin challenge. Unfortunately, I only know one Q1 and one LongEz builder in Europe personally and all the others unfortunately only via email/WebConf/Facebook. Here, too, those with direct building experience in europe of the patterns mentioned above are very rare or have already passed away. 

So let's keep the Quickie story alive and I welcome any comments, advice and hints from the community. 

The other question was about the engine for the Q1 and it will be a B&S Vanguard 679cc with standard 23hp include a belt drive, but with some modifications :-) 

Best regards from Germany

Eugen

P.S.: Next week I'm meeting with people from the boat manufacturing sector, the resin and glass fibre gods :-)  Maybe I can learn something from them, because they have really big vacuum bags :-) 


Am 30.03.2021 um 18:16 schrieb Jay Scheevel <jay@...>:

Eugen,

Everyone is right about the sharp corners and the cloth wrapping them.
Guidelines on how much rounding of the corners is needed can be found here:
http://n8wq.scheevel.com/documents/RAF_composite_education_section_from_Q2Pl
ans.pdf

Also, the best way to round the corners in a very smooth way is to use a
spare piece of the foam as a sanding block. The foam will grind away on both
the block and the piece you are sanding and make a very nice curve (lots of
foam dust, so have a vacuum cleaner on hand).

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Rob de Bie
Sent: Tuesday, March 30, 2021 6:06 AM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Q1 Fuselage comes up

Very nice work indeed!! But I agree with Keith: the sharp corners are far
from optimal. Your light vacuum will make sure that the glass fiber cloth
will conform, so that's not the problem. But if you have a multiple ply
laminate laid over a small radius, you will get high out-of-plane stresses
if a bending moment is applied. Now whether there is a lot of bending moment
in the fuselage skins, I don't know, they are probably secondary effects.
But I would nevertheless increase the radius quite a bit.

As an example of out-of-plane stresses: imagine laminating a 90 angle with
10 cm / 4 inch legs, with
3 or 4 layers. If you would bend it so the angle gets smaller, the
out-of-plane stresses will push the laminate plies against each other - no
problem. But if you bend it so the angle gets bigger, the sign changes, and
the out-of-plane stresses want to delaminate. Now do this same experiment
with different radii, and you will see that the larger the radius, the
stronger the specimen will be.

Rob

On 30 Mar 2021 13:43, Keith Welsh wrote:
Hi Eugen,
Very nice photos.
The only comment I might have is in regards to the contour edges.
From the  photos they look kinda sharp.  If I remember right the glass
cloth likes rounded edges.
It doesn't like making sharp turns.  The only places I remember having
sharp turns is where glass
tapes were used for bulkheads and micro was used in the corners.
But that was a long time ago too.
Those currently building may have a better view of that.
Just my two cents.
Keith
N494K

---------- Original Message ----------
From: "Eugen Pilarski" <interbus@...>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200

The fuselage of Q1 is coming up from the foam and the stuff is very sandy
:-))

Some picture from the progress .....

Eugen



















Robert Cringely
 

I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 


Rob de Bie
 

Eugen, sounds to me like you're doing a thorough job. The only remark I want to make is about the 0.27 MPa foam compressive strength. Some time ago I found a paper that showed how anisotropic XPS can be. You can download it here:


https://www.semanticscholar.org/paper/Finite-element-modeling-of-compression-behavior-of-Sadek-Fouad/c132caa718183ebfbf4dbbd08033f6e04fcbfe29

The authors measured Young's moduli of 6, 17 and 37 GPa, and compressive strengths of 0.18, 0.35 and 0.73 MPa for different directions!! I can see that the cells are oriented, but I never expected such extreme anisotropic behavior. It woke me up! I'm not saying that PVC or PU foam is equally anisotropic, but beware of this aspect. BTW, the Young's modulus is important for the buckling strength of the skin laminated on it, that's why I listed it first.

Here's another paper on XPS foam, that found far less extreme differences:


https://www.researchgate.net/publication/338241040_Measurement_of_the_Shear_Properties_of_Extruded_Polystyrene_Foam_by_In-Plane_Shear_and_Asymmetric_Four-Point_Bending_Tests

I did not compare the methods sufficiently to say whether errors were made, that would explain the big differences. It screams for doing some material tests yourself :-)

Rob

On 30 Mar 2021 22:08, Eugen Pilarski wrote:
Hi @all,
thanks for the hint about the corners and the necessary of form it with a sanding block. This area is manufactured exactly according to the plans, it’s listed in Page 7-6 Contouring, especially the section A-A, please find below a screen shot.
Before the first layer will place on the fuselage all areas need to form with a sanding block for sure, like the Quickie construction plans indicate, the picture you received just show an intermediate state. Unfortunately, pictures from that time are very rare and scarce, and 40 years have passed since the first Q1 was built.
The foam for the Fuselage I use has a compressive strength of 0,27 Mpa or 2900 hPa, with my Vacuum bag I will not go lower then 500 hPa (Standard is 1013hPa). After I did a test piece with 3 layers on each side with the Vacuum bag go down to 200 hPa (Standar is 1013hPa), they was no issue with the foam, no deformation or damage and good bonding with the micro to the foam.
I did a short crossover of different foam and suppliers like Aircraft Spruce, Wicks and other European suppliers and choice the best one for my application. It is Airex C70.55 for Bulkheads, Bauder E33 for fuselage and Korff Styrofoam XPS billet for wing/Canard, all stuff comes from europe.  I have of course considered the recommendations from the LongEz and Cozy corner and followed them.  Please find below my investigation about Foam, glass and resin: https://aerobase.weebly.com/q1-bill-of-material---source--spec.html <https://aerobase.weebly.com/q1-bill-of-material---source--spec.html>
The resin is a MGS L385 and H386 with aerospace approval, glass will be interglass with aerospace approval too. From my point of view, you have as an homebuilder to be on the safe side with the material and not save money at the wrong end, that’s the reason why I spend’s minimum 12 month to investigate the foam/glass/resin challenge. Unfortunately, I only know one Q1 and one LongEz builder in Europe personally and all the others unfortunately only via email/WebConf/Facebook. Here, too, those with direct building experience in europe of the patterns mentioned above are very rare or have already passed away.
So let's keep the Quickie story alive and I welcome any comments, advice and hints from the community.
The other question was about the engine for the Q1 and it will be a B&S Vanguard 679cc with standard 23hp include a belt drive, but with some modifications :-)
Best regards from Germany
Eugen
P.S.: Next week I'm meeting with people from the boat manufacturing sector, the resin and glass fibre gods :-)  Maybe I can learn something from them, because they have really big vacuum bags :-)

Am 30.03.2021 um 18:16 schrieb Jay Scheevel <jay@scheevel.com <mailto:jay@scheevel.com>>:

Eugen,

Everyone is right about the sharp corners and the cloth wrapping them.
Guidelines on how much rounding of the corners is needed can be found here:
http://n8wq.scheevel.com/documents/RAF_composite_education_section_from_Q2Pl <http://n8wq.scheevel.com/documents/RAF_composite_education_section_from_Q2Pl>
ans.pdf

Also, the best way to round the corners in a very smooth way is to use a
spare piece of the foam as a sanding block. The foam will grind away on both
the block and the piece you are sanding and make a very nice curve (lots of
foam dust, so have a vacuum cleaner on hand).

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Rob de Bie
Sent: Tuesday, March 30, 2021 6:06 AM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Q1 Fuselage comes up

Very nice work indeed!! But I agree with Keith: the sharp corners are far
from optimal. Your light vacuum will make sure that the glass fiber cloth
will conform, so that's not the problem. But if you have a multiple ply
laminate laid over a small radius, you will get high out-of-plane stresses
if a bending moment is applied. Now whether there is a lot of bending moment
in the fuselage skins, I don't know, they are probably secondary effects.
But I would nevertheless increase the radius quite a bit.

As an example of out-of-plane stresses: imagine laminating a 90 angle with
10 cm / 4 inch legs, with
3 or 4 layers. If you would bend it so the angle gets smaller, the
out-of-plane stresses will push the laminate plies against each other - no
problem. But if you bend it so the angle gets bigger, the sign changes, and
the out-of-plane stresses want to delaminate. Now do this same experiment
with different radii, and you will see that the larger the radius, the
stronger the specimen will be.

Rob

On 30 Mar 2021 13:43, Keith Welsh wrote:
Hi Eugen,
Very nice photos.
The only comment I might have is in regards to the contour edges.
From the  photos they look kinda sharp.  If I remember right the glass
cloth likes rounded edges.
It doesn't like making sharp turns.  The only places I remember having
sharp turns is where glass
tapes were used for bulkheads and micro was used in the corners.
But that was a long time ago too.
Those currently building may have a better view of that.
Just my two cents.
Keith
N494K

---------- Original Message ----------
From: "Eugen Pilarski" <interbus@web.de>
To: main@q-list.groups.io
Subject: [Q-List] Q1 Fuselage comes up
Date: Tue, 30 Mar 2021 10:19:05 +0200

The fuselage of Q1 is coming up from the foam and the stuff is very sandy
:-))

Some picture from the progress .....

Eugen
















smeshno1@...
 

 If the crankshaft is in question it should be pretty easy for any decent machine shop to cut a billet for you. The company that Nitrides the crankshafts for Corvair conversions are not outlandishly expensive, not afraid of Experimental aircraft engines (obviuously), and you'd have confidense your crankshaft that would be up to aircraft standard...have them cut all radii to .100". If you have to it is not difficult to clearance cut the rod big ends to accept the wide radii. 

  In my Corvair conversions one of my crankshafts is Standard and was Nitrided from GM.  My other engine I will have to ship to have it cut .010" undersize with the wide radii and then nitrided. Both engines are 2,7L...or..100hp. 

 First thought is the rods should be up to the task. I own an air cooled diesel generator/DC welder that uses a similar basic engine design. tuff as nails! I don't baby it at all and it is always there. Never a hickup.  I've also overhauled many a 1.5/1.6 VW diesel. I had a 1981 VW Caddy that I dropped in a 1.9 turboD (non electronic). The VW's have been successfully used in Europe in Experimental aircraft. The only issues reported is the exhaust odor..pretty ruff on the gizzard in choppy air. Might be a good idea to extend the exhaust pipe further aft.  

 It would be great to chat and to see your powerplant.. JP5 please!! no avgas thank you!!  

 I like titanium also partly because it anodizes very easily and any shade you like..the color stays stable too. Mini turbo..that is too kool!

Vern         


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Robert Cringely <bob@...>
Sent: Tuesday, March 30, 2021 3:48 PM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: Re: [Q-List] Q1 Fuselage comes up
 
I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 


Robert Cringely
 

I honor your heroic efforts, but my present solution, which is already in hand, sidesteps the crank issue while also raising the thrust line, which direct drive does not. These aren’t inverted Vs, so the prop clearance would be too little with direct drive. 

On Tue, Mar 30, 2021 at 2:45 PM <smeshno1@...> wrote:
 If the crankshaft is in question it should be pretty easy for any decent machine shop to cut a billet for you. The company that Nitrides the crankshafts for Corvair conversions are not outlandishly expensive, not afraid of Experimental aircraft engines (obviuously), and you'd have confidense your crankshaft that would be up to aircraft standard...have them cut all radii to .100". If you have to it is not difficult to clearance cut the rod big ends to accept the wide radii. 

  In my Corvair conversions one of my crankshafts is Standard and was Nitrided from GM.  My other engine I will have to ship to have it cut .010" undersize with the wide radii and then nitrided. Both engines are 2,7L...or..100hp. 

 First thought is the rods should be up to the task. I own an air cooled diesel generator/DC welder that uses a similar basic engine design. tuff as nails! I don't baby it at all and it is always there. Never a hickup.  I've also overhauled many a 1.5/1.6 VW diesel. I had a 1981 VW Caddy that I dropped in a 1.9 turboD (non electronic). The VW's have been successfully used in Europe in Experimental aircraft. The only issues reported is the exhaust odor..pretty ruff on the gizzard in choppy air. Might be a good idea to extend the exhaust pipe further aft.  

 It would be great to chat and to see your powerplant.. JP5 please!! no avgas thank you!!  

 I like titanium also partly because it anodizes very easily and any shade you like..the color stays stable too. Mini turbo..that is too kool!

Vern         


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Robert Cringely <bob@...>
Sent: Tuesday, March 30, 2021 3:48 PM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: Re: [Q-List] Q1 Fuselage comes up
 
I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 


smeshno1@...
 

Understood. 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Robert Cringely <bob@...>
Sent: Tuesday, March 30, 2021 5:48 PM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: Re: [Q-List] Q1 Fuselage comes up
 
I honor your heroic efforts, but my present solution, which is already in hand, sidesteps the crank issue while also raising the thrust line, which direct drive does not. These aren’t inverted Vs, so the prop clearance would be too little with direct drive. 

On Tue, Mar 30, 2021 at 2:45 PM <smeshno1@...> wrote:
 If the crankshaft is in question it should be pretty easy for any decent machine shop to cut a billet for you. The company that Nitrides the crankshafts for Corvair conversions are not outlandishly expensive, not afraid of Experimental aircraft engines (obviuously), and you'd have confidense your crankshaft that would be up to aircraft standard...have them cut all radii to .100". If you have to it is not difficult to clearance cut the rod big ends to accept the wide radii. 

  In my Corvair conversions one of my crankshafts is Standard and was Nitrided from GM.  My other engine I will have to ship to have it cut .010" undersize with the wide radii and then nitrided. Both engines are 2,7L...or..100hp. 

 First thought is the rods should be up to the task. I own an air cooled diesel generator/DC welder that uses a similar basic engine design. tuff as nails! I don't baby it at all and it is always there. Never a hickup.  I've also overhauled many a 1.5/1.6 VW diesel. I had a 1981 VW Caddy that I dropped in a 1.9 turboD (non electronic). The VW's have been successfully used in Europe in Experimental aircraft. The only issues reported is the exhaust odor..pretty ruff on the gizzard in choppy air. Might be a good idea to extend the exhaust pipe further aft.  

 It would be great to chat and to see your powerplant.. JP5 please!! no avgas thank you!!  

 I like titanium also partly because it anodizes very easily and any shade you like..the color stays stable too. Mini turbo..that is too kool!

Vern         


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Robert Cringely <bob@...>
Sent: Tuesday, March 30, 2021 3:48 PM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: Re: [Q-List] Q1 Fuselage comes up
 
I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 


Eugen Pilarski
 

Rob,

wow, a Diesel with a turbo!!! Sounds awesome!! Did you have a youtube channel or a website/facebok with more information? Its the weight about 55kg all In or just the engine? 

A other great engine manufacturer is Lifan, they copied the B&S engine with some improvements and a EFI system too. Please find below a link: https://www.lifancanada.ca/27hp-lifan-engine-elect-starter-2v78f-3.html

I got my information about the B&S conversation from Kevin Armstrong, he has build one of the engine (no, it was two after the first blow up based on a value/oil issue) on his trike. Please find below the link on you tube: https://www.youtube.com/watch?v=dy6Tg3ssJZc&t=105s

At first he chose the B&S Vanguard with 679cc and the second engine is B&S with 800cc. He did it all by him self and the upgrades comes from the US. The weight of the engine was all in around 30kg, so we are in the range that the Q1 could handle it.

If you want get in touch with kevin, send him a message and he will for sure share with you all the information/drawings/test result and soon.

Best regards

Eugen 


Am 30.03.2021 um 22:48 schrieb Robert Cringely <bob@...>:

I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 



Robert Cringely
 

My engine is 55kg all-up.The titanium parts hardly weigh anything. There are Q1s with 1835 VWs that weigh 75 kg, so I'm not too bothered. Keeping the CG in the right place is a matter of adding weight in the tail. I've converted to a heavier Aviation Products tailwheel with a rod spring for most of that. The lady in Ojai who makes those tailwheels (it's just one lady, all on her own, in her late father's old airplane factory kind of like a flying Miss Havisham from Great Expectations), she'll sell me the correct spring to dial it in when I finish carving my prop, which I should have done long ago, but it's my first three-blader and pretty daunting. There's a reason why only Craig Catto carves three-bladed wood props.


On Wed, Mar 31, 2021 at 2:44 AM Eugen Pilarski <interbus@...> wrote:
Rob,

wow, a Diesel with a turbo!!! Sounds awesome!! Did you have a youtube channel or a website/facebok with more information? Its the weight about 55kg all In or just the engine? 

A other great engine manufacturer is Lifan, they copied the B&S engine with some improvements and a EFI system too. Please find below a link: https://www.lifancanada.ca/27hp-lifan-engine-elect-starter-2v78f-3.html

I got my information about the B&S conversation from Kevin Armstrong, he has build one of the engine (no, it was two after the first blow up based on a value/oil issue) on his trike. Please find below the link on you tube: https://www.youtube.com/watch?v=dy6Tg3ssJZc&t=105s

At first he chose the B&S Vanguard with 679cc and the second engine is B&S with 800cc. He did it all by him self and the upgrades comes from the US. The weight of the engine was all in around 30kg, so we are in the range that the Q1 could handle it.

If you want get in touch with kevin, send him a message and he will for sure share with you all the information/drawings/test result and soon.

Best regards

Eugen 


Am 30.03.2021 um 22:48 schrieb Robert Cringely <bob@...>:

I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 



Tony Warnock
 

Guys,

Please keep us up to date on these developments!! I have two Q-1s I would like to install updated engines on. It initially planned for two strokes however if there is a modern four stroke alternative that is proving to be reliable and isn’t stupid heavy.......I’m definitely interested!! Especially the B&S!! The turbo diesel is exciting too!! Keep us informed on that project as well!!

Tony


On Mar 31, 2021, at 4:44 AM, Eugen Pilarski <interbus@...> wrote:

Rob,

wow, a Diesel with a turbo!!! Sounds awesome!! Did you have a youtube channel or a website/facebok with more information? Its the weight about 55kg all In or just the engine? 

A other great engine manufacturer is Lifan, they copied the B&S engine with some improvements and a EFI system too. Please find below a link: https://www.lifancanada.ca/27hp-lifan-engine-elect-starter-2v78f-3.html

I got my information about the B&S conversation from Kevin Armstrong, he has build one of the engine (no, it was two after the first blow up based on a value/oil issue) on his trike. Please find below the link on you tube: https://www.youtube.com/watch?v=dy6Tg3ssJZc&t=105s

At first he chose the B&S Vanguard with 679cc and the second engine is B&S with 800cc. He did it all by him self and the upgrades comes from the US. The weight of the engine was all in around 30kg, so we are in the range that the Q1 could handle it.

If you want get in touch with kevin, send him a message and he will for sure share with you all the information/drawings/test result and soon.

Best regards

Eugen 


Am 30.03.2021 um 22:48 schrieb Robert Cringely <bob@...>:

I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 



smeshno1@...
 

 Tony.. I am building a Frankenbird (2 seat tandem) but if you've seen the video on the racing team with the Vanguard it seems your search would be pretty easy to fulfill. You'd have one of your birds back in the air and...we'd love to see you at FOD in Enid this September. 

  If I weren't married, and already in progress, I would seriously considered this option. Years ago at North Little  Rock (KORK) airport where I learned to fly (and flew a lot of taildraggers also) I flew a Q1 with the original Onan.  The trees at the end of runway 35, which at the time the airport only had one runway, got REALLY large before I could get a positive rate of climb! A bit scary with the single handle 
mechanical brake on rollout also. BUT..if that aircraft had the extra HP the Vanguard offers and differential hydraulic brakes..maybe with a hoop main gear it would be a very economical and reliable travel machine.   


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Tony Warnock via groups.io <tony.warnock@...>
Sent: Monday, April 5, 2021 7:39 AM
To: main@q-list.groups.io <main@q-list.groups.io>
Subject: Re: [Q-List] Q1 Fuselage comes up
 
Guys,

Please keep us up to date on these developments!! I have two Q-1s I would like to install updated engines on. It initially planned for two strokes however if there is a modern four stroke alternative that is proving to be reliable and isn’t stupid heavy.......I’m definitely interested!! Especially the B&S!! The turbo diesel is exciting too!! Keep us informed on that project as well!!

Tony


On Mar 31, 2021, at 4:44 AM, Eugen Pilarski <interbus@...> wrote:

Rob,

wow, a Diesel with a turbo!!! Sounds awesome!! Did you have a youtube channel or a website/facebok with more information? Its the weight about 55kg all In or just the engine? 

A other great engine manufacturer is Lifan, they copied the B&S engine with some improvements and a EFI system too. Please find below a link: https://www.lifancanada.ca/27hp-lifan-engine-elect-starter-2v78f-3.html

I got my information about the B&S conversation from Kevin Armstrong, he has build one of the engine (no, it was two after the first blow up based on a value/oil issue) on his trike. Please find below the link on you tube: https://www.youtube.com/watch?v=dy6Tg3ssJZc&t=105s

At first he chose the B&S Vanguard with 679cc and the second engine is B&S with 800cc. He did it all by him self and the upgrades comes from the US. The weight of the engine was all in around 30kg, so we are in the range that the Q1 could handle it.

If you want get in touch with kevin, send him a message and he will for sure share with you all the information/drawings/test result and soon.

Best regards

Eugen 


Am 30.03.2021 um 22:48 schrieb Robert Cringely <bob@...>:

I like the idea of using the Briggs & Stratton Vanguard engine, especially since there is so much racing experience and aftermarket parts. I am installing a new engine in my Q1 and going in a similar -- though not identical -- direction. I'm replacing the 22-hp Super-Onan with a pretty generic two-cylinder 870 cc Chinese direct-injection diesel rated for 25 hp at 3600 rpm. I'm turbocharging the engine with a tiny IHI turbo (the smallest sold) and an intercooler. I'm aiming for a turbo-normalized 30 hp, which should give me some really interesting performance numbers at my 17,999-foot cruise altitude.

The engine is all aluminum and air-cooled. I've removed a bunch of extra parts and material like the OEM exhaust, intake, and fuel tank and have the weight down around 55 kg. The new parts are mainly titanium, but that's because we use titanium at my day job and have a welder who does beautiful work. Guessing that the crankshaft is a casting, I'm installing a 1-to-1 belt drive to isolate the prop loads while raising the thrust line. The engine, turbo, and intercooler come from China, the redrive is from India, so the complete powerplant (minus prop) was under $2000 including shipping.

I built the new engine so I can commute to work in San Luis Obispo, CA. My company is right at the airport there and I can even park inside. Presently I fly my Thorp T-18, which takes about 90 minutes for the 222 nm flight from Santa Rosa. I don't expect the Q to go any faster (or slower) than that, but hope to drop the fuel consumption from 10 gallons down to three. Even at 10 gallons it is cheaper to fly than to drive my car, in part because I skip the toll on the Golden Gate Bridge. 



David J. Gall
 

Eugen,

It appears that you machined a 45 degree bevel on the inside contouring of your fuselage sides and bottom. The section A-A you refer to shows a much more shallow bevel. You MAY encounter problems of break-through when contouring the outside of your fuselage. You WILL encounter an awkwardness when contouring the outside of the fuselage at the seatback bulkhead/main wing saddle area. The plans show the fuselage sides contoured to a "knife-edge" thickness of foam at the longerons (page 7-12, Station 70.0 and station 89.0) but immediately aft of the seatback bulkhead that knife edge has no longeron to support its inboard edge (page 7-9) and you've carved away the foam below the main wing but ABOVE the level where that knife edge line would continue aft of the seatback bulkhead. The dashed lines in the plans on page 7-9 behind station 78.0 extend too high up the inside wall of the fuselage side, causing the foam to be carved completely away or a compromise carving modification that results in an awkward bulge just aft of the canopy. My advice, since you're already carved the inside of the fuselage sides, is to modify the page 7-12 station 70.0 and station 89.0 carving profiles to leave more foam outboard of the longerons so that a smooth external shape can be achieved aft of the seatback bulkhead. (Too many words!)

Wing foam: make sure your wing foam has large enough surface pores for a good mechanical bond of the wing skins to the foam.

Epoxy: I am told that MGS-335 is NOT adequately fuel proof for fuel tanks. Be sure to use EZ-Poxy or Derakane 204 (or newer variant) for the inside of your fuel tank.


Eugen Pilarski
 

David,

thank you very much vor your email and the valuable information.

Please find in the attachment a cross section view from the fuselage that show which angle I choice for conturing. The angle in the Q1 drawings show up a 30°, as it also be captured, so I did it in the same way. The pictures from my past email deceive a bit, after some of the experts asked me about it, I did made a test piece and measured that unit again, it fits. But the countering area need some additional sanding to fit the requirements. 

Thanks for the tip with the main wing and the fuselage. I think before I will shape the fuselage, to build at first the main wing.  When these are available, then to form the fuselage. Or I will make a matching molded piece of the main wing from this area, we'll see. If necessary, it would be possible to insert a further struts in this area to support the fuselage wall? Sufficient space would be available in the segment. 

In the case of resin, I do not use MGS-335. My choice is HEXION MGS L385 and H 386 (aero approved), but that need a subsequent tempering of all parts, what is already schedule. Please find in the attachment a data sheet. My buddy has a paint booth with integrated heating that allows a temperature of 65°. Do you have a source I can refer to that does not confirm fuel resistance of the resin mentioned? I would be very interested in such a source. Thank you very much.

The wing foam that I chose is come from the the same supplier like the LongEz and Cozy guys here in Europe use, so it should be work for the Quickie too. But I will double check it too.

Best regards from Germany

Eugen  



Am 06.04.2021 um 09:51 schrieb David J. Gall <David@...>:

Eugen,

It appears that you machined a 45 degree bevel on the inside contouring of your fuselage sides and bottom. The section A-A you refer to shows a much more shallow bevel. You MAY encounter problems of break-through when contouring the outside of your fuselage. You WILL encounter an awkwardness when contouring the outside of the fuselage at the seatback bulkhead/main wing saddle area. The plans show the fuselage sides contoured to a "knife-edge" thickness of foam at the longerons (page 7-12, Station 70.0 and station 89.0) but immediately aft of the seatback bulkhead that knife edge has no longeron to support its inboard edge (page 7-9) and you've carved away the foam below the main wing but ABOVE the level where that knife edge line would continue aft of the seatback bulkhead. The dashed lines in the plans on page 7-9 behind station 78.0 extend too high up the inside wall of the fuselage side, causing the foam to be carved completely away or a compromise carving modification that results in an awkward bulge just aft of the canopy. My advice, since you're already carved the inside of the fuselage sides, is to modify the page 7-12 station 70.0 and station 89.0 carving profiles to leave more foam outboard of the longerons so that a smooth external shape can be achieved aft of the seatback bulkhead. (Too many words!)

Wing foam: make sure your wing foam has large enough surface pores for a good mechanical bond of the wing skins to the foam.

Epoxy: I am told that MGS-335 is NOT adequately fuel proof for fuel tanks. Be sure to use EZ-Poxy or Derakane 204 (or newer variant) for the inside of your fuel tank.


Niklas Bostelmann
 

Hi there, hi Eugen, I worked on German Certified Aircrafts and there we used a special resin for the Fuel Tank, it's not very great for laminating but it's the best resin for chemical/fuel resistants. We first did the entire Layup with the resin but later switched to only coating the finished fuel tank with a thick layer of the resin because it has a high viscosity it's not the best for laminating.


That's where you can get the resin

I have some other projects going but hope to get time to start building my Q1 soon... 

Greetings from Germany
Niklas 

Eugen Pilarski <interbus@...> schrieb am Di., 6. Apr. 2021, 11:42:

David,

thank you very much vor your email and the valuable information.

Please find in the attachment a cross section view from the fuselage that show which angle I choice for conturing. The angle in the Q1 drawings show up a 30°, as it also be captured, so I did it in the same way. The pictures from my past email deceive a bit, after some of the experts asked me about it, I did made a test piece and measured that unit again, it fits. But the countering area need some additional sanding to fit the requirements. 

Thanks for the tip with the main wing and the fuselage. I think before I will shape the fuselage, to build at first the main wing.  When these are available, then to form the fuselage. Or I will make a matching molded piece of the main wing from this area, we'll see. If necessary, it would be possible to insert a further struts in this area to support the fuselage wall? Sufficient space would be available in the segment. 

In the case of resin, I do not use MGS-335. My choice is HEXION MGS L385 and H 386 (aero approved), but that need a subsequent tempering of all parts, what is already schedule. Please find in the attachment a data sheet. My buddy has a paint booth with integrated heating that allows a temperature of 65°. Do you have a source I can refer to that does not confirm fuel resistance of the resin mentioned? I would be very interested in such a source. Thank you very much.

The wing foam that I chose is come from the the same supplier like the LongEz and Cozy guys here in Europe use, so it should be work for the Quickie too. But I will double check it too.

Best regards from Germany

Eugen  



Am 06.04.2021 um 09:51 schrieb David J. Gall <David@...>:

Eugen,

It appears that you machined a 45 degree bevel on the inside contouring of your fuselage sides and bottom. The section A-A you refer to shows a much more shallow bevel. You MAY encounter problems of break-through when contouring the outside of your fuselage. You WILL encounter an awkwardness when contouring the outside of the fuselage at the seatback bulkhead/main wing saddle area. The plans show the fuselage sides contoured to a "knife-edge" thickness of foam at the longerons (page 7-12, Station 70.0 and station 89.0) but immediately aft of the seatback bulkhead that knife edge has no longeron to support its inboard edge (page 7-9) and you've carved away the foam below the main wing but ABOVE the level where that knife edge line would continue aft of the seatback bulkhead. The dashed lines in the plans on page 7-9 behind station 78.0 extend too high up the inside wall of the fuselage side, causing the foam to be carved completely away or a compromise carving modification that results in an awkward bulge just aft of the canopy. My advice, since you're already carved the inside of the fuselage sides, is to modify the page 7-12 station 70.0 and station 89.0 carving profiles to leave more foam outboard of the longerons so that a smooth external shape can be achieved aft of the seatback bulkhead. (Too many words!)

Wing foam: make sure your wing foam has large enough surface pores for a good mechanical bond of the wing skins to the foam.

Epoxy: I am told that MGS-335 is NOT adequately fuel proof for fuel tanks. Be sure to use EZ-Poxy or Derakane 204 (or newer variant) for the inside of your fuel tank.


Rob de Bie
 

Eugen, I think it's great that you will postcure your epoxy. I would do the same, since room temperature cured epoxy has a way too low glass transition temperature (Tg). Also, generally speaking, epoxy does not develop its full strength at room temperature. I've seen stress-strain curves of RT-cured and post-cured epoxy, and the difference is huge.

However, be sure to ramp your paint booth temperature carefully, so that you do not exceed the then-current Tg.

Another comment is that it is quite difficult to post-cure everything on your aircraft. As soon as you make a small repair, or add something, you have a non-postcured part on a postcured airframe. The same goes for epoxy glue joints by the way. You can solve that by building a local post-curing 'tent' and heat that. But it takes some discipline and thinking to keep the whole airframe postcured.

Rob

On 06 Apr 2021 11:41, Eugen Pilarski wrote:
David,
thank you very much vor your email and the valuable information.
Please find in the attachment a cross section view from the fuselage that show which angle I choice for conturing. The angle in the Q1 drawings show up a 30°, as it also be captured, so I did it in the same way. The pictures from my past email deceive a bit, after some of the experts asked me about it, I did made a test piece and measured that unit again, it fits. But the countering area need some additional sanding to fit the requirements.
Thanks for the tip with the main wing and the fuselage. I think before I will shape the fuselage, to build at first the main wing.  When these are available, then to form the fuselage. Or I will make a matching molded piece of the main wing from this area, we'll see. If necessary, it would be possible to insert a further struts in this area to support the fuselage wall? Sufficient space would be available in the segment.
In the case of resin, I do not use MGS-335. My choice is HEXION MGS L385 and H 386 (aero approved), but that need a subsequent tempering of all parts, what is already schedule. Please find in the attachment a data sheet. My buddy has a paint booth with integrated heating that allows a temperature of 65°. Do you have a source I can refer to that does not confirm fuel resistance of the resin mentioned? I would be very interested in such a source. Thank you very much.
The wing foam that I chose is come from the the same supplier like the LongEz and Cozy guys here in Europe use, so it should be work for the Quickie too. But I will double check it too.
Best regards from Germany
Eugen

Am 06.04.2021 um 09:51 schrieb David J. Gall <David@Gall.com <mailto:David@Gall.com>>:

Eugen,

It appears that you machined a 45 degree bevel on the inside contouring of your fuselage sides and bottom. The section A-A you refer to shows a much more shallow bevel. You MAY encounter problems of break-through when contouring the outside of your fuselage. You WILL encounter an awkwardness when contouring the outside of the fuselage at the seatback bulkhead/main wing saddle area. The plans show the fuselage sides contoured to a "knife-edge" thickness of foam at the longerons (page 7-12, Station 70.0 and station 89.0) but immediately aft of the seatback bulkhead that knife edge has no longeron to support its inboard edge (page 7-9) and you've carved away the foam below the main wing but ABOVE the level where that knife edge line would continue aft of the seatback bulkhead. The dashed lines in the plans on page 7-9 behind station 78.0 extend too high up the inside wall of the fuselage side, causing the foam to be carved completely away or a compromise carving modification that results in an awkward bulge just aft of the canopy. My advice, since you're already carved the inside of the fuselage sides, is to modify the page 7-12 station 70.0 and station 89.0 carving profiles to leave more foam outboard of the longerons so that a smooth external shape can be achieved aft of the seatback bulkhead. (Too many words!)

Wing foam: make sure your wing foam has large enough surface pores for a good mechanical bond of the wing skins to the foam.

Epoxy: I am told that MGS-335 is NOT adequately fuel proof for fuel tanks. Be sure to use EZ-Poxy or Derakane 204 (or newer variant) for the inside of your fuel tank.