Broken Skytech pinion tooth (Q200)


britmcman99
 

Hello All:

There is a lot of available science out there regarding failure analysis.
The broken gears that so many of you seem to have produced should be looked at
by a metallurgical analytical lab. In order to solve this problem there
ought to be someone at Skytec doing all of this anyway. When something isn't
right, there is a reason. Consider defective metals, castings, forgings, heat
treatments, case hardenings, etc. A look at the fracture with an electron
microscope may reveal the real reason that gear tooth broke off.

I would insist that the manufacturer conduct a thorough root cause and
corrective action investigation. They should insist on doing it if they want to
stay in business. The starter's design and materials should be robust enough
to survive routine occurrences such as kickback.

Phil Lankford
N870BM
B&C Starter


Kevin Fortin <kfortin@...>
 

Brad Olsen and guys,



First off, my apologies to Brad Olsen for not responding to an offline email
he sent me regarding the following subject. My email was filtering emails
without attachments and I didn't realize it.



I am responding to his email on list because I think it is of interest to
many regarding Skytech starters.



Background: I ordered a Skytech starter on the basis of what Skytech
told me and after discussing what seemed to be the problem with Jim
Patillo's starter aka. "electronic ignition induced kickback". Upon
receiving the new starter I installed it and it seemed to work well, but had
more of a "grinding" sound in operation than I would have liked. After a 10
MAXIMUM total starts, in a hurry to get the airplane to an avionics shop
(onfield), I forgot to turn on the fuel, and, after a very short taxi, the
obvious happened, I ran out of gas. Duh!!! I turned the gas valve on,
waited about a minute, then tried starting again. The prop turned for
somewhere between 6 to 10 seconds before the engine caught and I taxied on
my merry way. A couple of days later, I picked the airplane up, jumped in to
start it, and was met with what seemed to be the grinding sound of gears
with missing teeth (the engine did start, however).



The following weekend I pulled the engine and the starter only to find a
tooth missing from the Skytech starters drive pinion gear. That was the bad
news. The good news, I was able to find the tooth. (I thank the Q god's for
that one.)



On the following Monday, I called Skytech and explained the problem and they
did all they could to help. I can't complain about their customer service.



At this point, I have received a replacement starter (new) from Skytech, but
as of yet, I have not installed it. All my mental alarms are going off
related to something that can throw of a piece off big enough that it could
gum up my engine (read off field landing and/or a damaged engine) or at the
least break off a tooth on the crankshaft gear, which at the least, is going
to be damn expensive.



Relevant info 1. As far as I know I did not have a kickback.

2. I was starting on left mag only

3. I believe the real problem is Skytech's control of the
centerline distance of the pinion/crankshaft gear set. In an effort to
loosen the tolerances in the manufacture of the starter, Skytech has allowed
the pinion to get too far away from the main gear on the crankshaft. This
results in an incredible force trying to separate the gears. This force than
further deflects the shaft that holds the pinion, which leads to even higher
forces on the gears, then ultimately to a broken tooth.

4. I am going to try to get some measurements on the
centerline distances this weekend and I will let you guys know what I find.

5. Item 3 is only conjecture at this point. Please take it
as so.

6. I have high compression pistons, but I don't know the
ratio.

7. I usually don't write well and tonight is even worse.





If anyone has a better starting system idea, let me know. I am not feeling
to good with this right now.



Kevin Fortin

N275CH

Except for the starter, damn close to flyin'


Brad Olson <n1tm@...>
 

--- In Q-LIST@..., "Kevin Fortin" <kfortin@p...> wrote:
Kevin,

Thanks for the info and glad you found that tooth! I talked to Rich
at Sky Tec the day after you called, and he relayed your story. I
started asking general questions about a Sky Tec with a high
compression O-200, but then cut to the concern with Jim Patillo's
three failures. Rich was very upfront about the whole matter and told
me not to buy a Sky Tec for a high compression O-200. He said they
need to go to work and find the problem, and he assured me he would.

After searching the Internet and not finding any real issues with Sky
Tecs and O-200s, I was prepared to buy one as I thought Jim's
problems may have been partially related to the dual electronic
ignition. Instead, my pull starter comes off this weekend for an
overhaul. Maybe a B&C will go in next winter.

Brad Olson
N321TM, Livermore

Brad Olsen and guys,



First off, my apologies to Brad Olsen for not responding to an
offline email
he sent me regarding the following subject. My email was filtering
emails
without attachments and I didn't realize it.



I am responding to his email on list because I think it is of
interest to
many regarding Skytech starters.



Background: I ordered a Skytech starter on the basis of what
Skytech
told me and after discussing what seemed to be the problem with Jim
Patillo's starter aka. "electronic ignition induced kickback". Upon
receiving the new starter I installed it and it seemed to work well,
but had
more of a "grinding" sound in operation than I would have liked.


Jim Patillo
 

Kevin,

1. Thank Rich for all his help, send it back and try to get a refund.
Don't waste your time trying to make another Skytec work. I tried
that three times.
2. Buy a B&C, have Bruce Bainbridge upgrade the motor to a 320, no
charge(better for high compression)and install it.
3. Go fly!

The B&C starter has worked perfectly since the install. The
modification to the mag box was simple and the motor mount only
needed to have one corner cut off the pad. About 10 hours work, start
to stop.

As I've said before the B&C starter takes much less power to run it.
Hopefully I've put the starter issue behind me. You can do the same.

Sorry to hear of your troubles. I do understand!


Regards,
Jim P

--- In Q-LIST@..., "Kevin Fortin" <kfortin@p...> wrote:
Brad Olsen and guys,



First off, my apologies to Brad Olsen for not responding to an
offline email
he sent me regarding the following subject. My email was filtering
emails
without attachments and I didn't realize it.



I am responding to his email on list because I think it is of
interest to
many regarding Skytech starters.



Background: I ordered a Skytech starter on the basis of what
Skytech
told me and after discussing what seemed to be the problem with Jim
Patillo's starter aka. "electronic ignition induced kickback". Upon
receiving the new starter I installed it and it seemed to work
well, but had
more of a "grinding" sound in operation than I would have liked.
After a 10
MAXIMUM total starts, in a hurry to get the airplane to an avionics
shop
(onfield), I forgot to turn on the fuel, and, after a very short
taxi, the
obvious happened, I ran out of gas. Duh!!! I turned the gas valve
on,
waited about a minute, then tried starting again. The prop turned
for
somewhere between 6 to 10 seconds before the engine caught and I
taxied on
my merry way. A couple of days later, I picked the airplane up,
jumped in to
start it, and was met with what seemed to be the grinding sound of
gears
with missing teeth (the engine did start, however).



The following weekend I pulled the engine and the starter only to
find a
tooth missing from the Skytech starters drive pinion gear. That was
the bad
news. The good news, I was able to find the tooth. (I thank the Q
god's for
that one.)



On the following Monday, I called Skytech and explained the problem
and they
did all they could to help. I can't complain about their customer
service.



At this point, I have received a replacement starter (new) from
Skytech, but
as of yet, I have not installed it. All my mental alarms are going
off
related to something that can throw of a piece off big enough that
it could
gum up my engine (read off field landing and/or a damaged engine)
or at the
least break off a tooth on the crankshaft gear, which at the least,
is going
to be damn expensive.



Relevant info 1. As far as I know I did not have a
kickback.

2. I was starting on left mag only

3. I believe the real problem is Skytech's
control of the
centerline distance of the pinion/crankshaft gear set. In an effort
to
loosen the tolerances in the manufacture of the starter, Skytech
has allowed
the pinion to get too far away from the main gear on the
crankshaft. This
results in an incredible force trying to separate the gears. This
force than
further deflects the shaft that holds the pinion, which leads to
even higher
forces on the gears, then ultimately to a broken tooth.

4. I am going to try to get some measurements on
the
centerline distances this weekend and I will let you guys know what
I find.

5. Item 3 is only conjecture at this point.
Please take it
as so.

6. I have high compression pistons, but I don't
know the
ratio.

7. I usually don't write well and tonight is even
worse.





If anyone has a better starting system idea, let me know. I am not
feeling
to good with this right now.



Kevin Fortin

N275CH

Except for the starter, damn close to flyin'












Kevin Fortin <kfortin@...>
 

Brad,

If my Q had a pull starter, from what I know, I would stick with that.

Kevin

-----Original Message-----
From: Brad Olson [mailto:n1tm@...]
Sent: Tuesday, February 22, 2005 8:56 PM
To: Q-LIST@...
Subject: [Q-LIST] Re: Broken Skytech pinion tooth (Q200)



--- In Q-LIST@..., "Kevin Fortin" <kfortin@p...> wrote:
Kevin,

Thanks for the info and glad you found that tooth! I talked to Rich
at Sky Tec the day after you called, and he relayed your story. I
started asking general questions about a Sky Tec with a high
compression O-200, but then cut to the concern with Jim Patillo's
three failures. Rich was very upfront about the whole matter and told
me not to buy a Sky Tec for a high compression O-200. He said they
need to go to work and find the problem, and he assured me he would.

After searching the Internet and not finding any real issues with Sky
Tecs and O-200s, I was prepared to buy one as I thought Jim's
problems may have been partially related to the dual electronic
ignition. Instead, my pull starter comes off this weekend for an
overhaul. Maybe a B&C will go in next winter.

Brad Olson
N321TM, Livermore

Brad Olsen and guys,



First off, my apologies to Brad Olsen for not responding to an
offline email
he sent me regarding the following subject. My email was filtering
emails
without attachments and I didn't realize it.



I am responding to his email on list because I think it is of
interest to
many regarding Skytech starters.



Background: I ordered a Skytech starter on the basis of what
Skytech
told me and after discussing what seemed to be the problem with Jim
Patillo's starter aka. "electronic ignition induced kickback". Upon
receiving the new starter I installed it and it seemed to work well,
but had
more of a "grinding" sound in operation than I would have liked.





Quickie Builders Association WEB site
http://www.quickiebuilders.org


Yahoo! Groups Links


Kevin Fortin <kfortin@...>
 

Guys,

I forgot to include in my previous email that a major deflection of the
pinion shaft was detectable because the pinion was pushed far enough off
center to put a gouge in an aluminum "shroud" that wraps around the "open"
side of the pinion (the shroud is part of the starter casting). Skytech knew
immediately what I was talking about when I mentioned this. This deflection
is what made me believe that the gears are off center to begin with. I know
from experience that improper centerline distances, on the plus side,
increase gear separation forces dramatically.

I don't think there is anything intrinsically wrong with the pinion itself.
Apparently it is supplied by Hitachi and is used for other starters in the
aircraft industry.


Kevin

-----Original Message-----
From: britmcman@... [mailto:britmcman@...]
Sent: Tuesday, February 22, 2005 9:02 PM
To: Q-LIST@...
Subject: Re: [Q-LIST] Broken Skytech pinion tooth (Q200)


Hello All:

There is a lot of available science out there regarding failure analysis.
The broken gears that so many of you seem to have produced should be looked
at
by a metallurgical analytical lab. In order to solve this problem there
ought to be someone at Skytec doing all of this anyway. When something
isn't
right, there is a reason. Consider defective metals, castings, forgings,
heat
treatments, case hardenings, etc. A look at the fracture with an electron
microscope may reveal the real reason that gear tooth broke off.

I would insist that the manufacturer conduct a thorough root cause and
corrective action investigation. They should insist on doing it if they
want to
stay in business. The starter's design and materials should be robust
enough
to survive routine occurrences such as kickback.

Phil Lankford
N870BM
B&C Starter


[Non-text portions of this message have been removed]




Quickie Builders Association WEB site
http://www.quickiebuilders.org


Yahoo! Groups Links


Kevin Fortin <kfortin@...>
 

Jim,

I know about the motor mount mods that need to be done but haven't heard
about the "magbox" mods you mentioned. What's happening there?

Thanks for you time and I wish I had listened to you earlier (oops).

"Experience is what you get when you don't get what you want".



Kevin

-----Original Message-----
From: Jim Patillo [mailto:logistics_engineering@...]
Sent: Tuesday, February 22, 2005 9:24 PM
To: Q-LIST@...
Subject: [Q-LIST] Re: Broken Skytech pinion tooth (Q200)




Kevin,

1. Thank Rich for all his help, send it back and try to get a refund.
Don't waste your time trying to make another Skytec work. I tried
that three times.
2. Buy a B&C, have Bruce Bainbridge upgrade the motor to a 320, no
charge(better for high compression)and install it.
3. Go fly!

The B&C starter has worked perfectly since the install. The
modification to the mag box was simple and the motor mount only
needed to have one corner cut off the pad. About 10 hours work, start
to stop.

As I've said before the B&C starter takes much less power to run it.
Hopefully I've put the starter issue behind me. You can do the same.

Sorry to hear of your troubles. I do understand!


Regards,
Jim P

--- In Q-LIST@..., "Kevin Fortin" <kfortin@p...> wrote:
Brad Olsen and guys,



First off, my apologies to Brad Olsen for not responding to an
offline email
he sent me regarding the following subject. My email was filtering
emails
without attachments and I didn't realize it.



I am responding to his email on list because I think it is of
interest to
many regarding Skytech starters.



Background: I ordered a Skytech starter on the basis of what
Skytech
told me and after discussing what seemed to be the problem with Jim
Patillo's starter aka. "electronic ignition induced kickback". Upon
receiving the new starter I installed it and it seemed to work
well, but had
more of a "grinding" sound in operation than I would have liked.
After a 10
MAXIMUM total starts, in a hurry to get the airplane to an avionics
shop
(onfield), I forgot to turn on the fuel, and, after a very short
taxi, the
obvious happened, I ran out of gas. Duh!!! I turned the gas valve
on,
waited about a minute, then tried starting again. The prop turned
for
somewhere between 6 to 10 seconds before the engine caught and I
taxied on
my merry way. A couple of days later, I picked the airplane up,
jumped in to
start it, and was met with what seemed to be the grinding sound of
gears
with missing teeth (the engine did start, however).



The following weekend I pulled the engine and the starter only to
find a
tooth missing from the Skytech starters drive pinion gear. That was
the bad
news. The good news, I was able to find the tooth. (I thank the Q
god's for
that one.)



On the following Monday, I called Skytech and explained the problem
and they
did all they could to help. I can't complain about their customer
service.



At this point, I have received a replacement starter (new) from
Skytech, but
as of yet, I have not installed it. All my mental alarms are going
off
related to something that can throw of a piece off big enough that
it could
gum up my engine (read off field landing and/or a damaged engine)
or at the
least break off a tooth on the crankshaft gear, which at the least,
is going
to be damn expensive.



Relevant info 1. As far as I know I did not have a
kickback.

2. I was starting on left mag only

3. I believe the real problem is Skytech's
control of the
centerline distance of the pinion/crankshaft gear set. In an effort
to
loosen the tolerances in the manufacture of the starter, Skytech
has allowed
the pinion to get too far away from the main gear on the
crankshaft. This
results in an incredible force trying to separate the gears. This
force than
further deflects the shaft that holds the pinion, which leads to
even higher
forces on the gears, then ultimately to a broken tooth.

4. I am going to try to get some measurements on
the
centerline distances this weekend and I will let you guys know what
I find.

5. Item 3 is only conjecture at this point.
Please take it
as so.

6. I have high compression pistons, but I don't
know the
ratio.

7. I usually don't write well and tonight is even
worse.





If anyone has a better starting system idea, let me know. I am not
feeling
to good with this right now.



Kevin Fortin

N275CH

Except for the starter, damn close to flyin'
















Quickie Builders Association WEB site
http://www.quickiebuilders.org


Yahoo! Groups Links


Jim Patillo
 

Kevin,

The shiny spot (scrape) you saw on the side of the housing is
indicative of the pinion gear being side loaded when fully engaged
into the starter gear on the engine. Rich Chappee would immediately
diagnose that as a kickback.

I'm of the opinion that you either had an electrical kickback or a
hydraulic kickback. Given the fact that you use a mag to start
indicates a hydraulic kickback. That happens when the battery you
are using doesn't have enough amperage to get over the top (high
compression). The result is a damaged housing, shaft, seals, etc.

As I've said before, the inrush amperage required to run a permanent
magnet starter is much greater than that of a B&C starter and
requires a larger battery. I still use a 25RG even though the B&C
will start an IO540 with an 18AH battery.

The reason we initially started using the Skytec was because it was
a direct replacement for the stock unit, no modifications.

The B&C requires modification to the mag box because the solenoid is
mounted at 45 degrees or so as opposed to vertical for the Skytec.

Simply mount the B&C and determine the area to be cut out of the mag
box. Use the piece you cut out, reverse it and flox back into place.
Reglass to restore rigidity to the mag box. Cut the interfering
corner of the motor mount pad so that the starter clears on
installation. You will need about a quarter of an inch clearance
around the new starter to prevent rubbing.

Hope this helps you. I really think you're wasting your time putting
on another reworked Skytec. Rich is a really nice guy but there is
an issue that needs to be solved here.

Good luck,

Jim P.
"Kevin Fortin" <kfortin@p...> wrote:
Jim,

I know about the motor mount mods that need to be done but haven't
heard
about the "magbox" mods you mentioned. What's happening there?

Thanks for you time and I wish I had listened to you earlier
(oops).

"Experience is what you get when you don't get what you want".



Kevin

-----Original Message-----
From: Jim Patillo [mailto:logistics_engineering@m...]
Sent: Tuesday, February 22, 2005 9:24 PM
To: Q-LIST@...
Subject: [Q-LIST] Re: Broken Skytech pinion tooth (Q200)




Kevin,

1. Thank Rich for all his help, send it back and try to get a
refund.
Don't waste your time trying to make another Skytec work. I tried
that three times.
2. Buy a B&C, have Bruce Bainbridge upgrade the motor to a 320, no
charge(better for high compression)and install it.
3. Go fly!

The B&C starter has worked perfectly since the install. The
modification to the mag box was simple and the motor mount only
needed to have one corner cut off the pad. About 10 hours work,
start
to stop.

As I've said before the B&C starter takes much less power to run
it.
Hopefully I've put the starter issue behind me. You can do the
same.

Sorry to hear of your troubles. I do understand!


Regards,
Jim P

--- In Q-LIST@..., "Kevin Fortin" <kfortin@p...> wrote:
Brad Olsen and guys,



First off, my apologies to Brad Olsen for not responding to an
offline email
he sent me regarding the following subject. My email was
filtering
emails
without attachments and I didn't realize it.



I am responding to his email on list because I think it is of
interest to
many regarding Skytech starters.



Background: I ordered a Skytech starter on the basis of
what
Skytech
told me and after discussing what seemed to be the problem with
Jim
Patillo's starter aka. "electronic ignition induced kickback".
Upon
receiving the new starter I installed it and it seemed to work
well, but had
more of a "grinding" sound in operation than I would have
liked.
After a 10
MAXIMUM total starts, in a hurry to get the airplane to an
avionics
shop
(onfield), I forgot to turn on the fuel, and, after a very short
taxi, the
obvious happened, I ran out of gas. Duh!!! I turned the gas
valve
on,
waited about a minute, then tried starting again. The prop
turned
for
somewhere between 6 to 10 seconds before the engine caught and I
taxied on
my merry way. A couple of days later, I picked the airplane up,
jumped in to
start it, and was met with what seemed to be the grinding sound
of
gears
with missing teeth (the engine did start, however).



The following weekend I pulled the engine and the starter only
to
find a
tooth missing from the Skytech starters drive pinion gear. That
was
the bad
news. The good news, I was able to find the tooth. (I thank the
Q
god's for
that one.)



On the following Monday, I called Skytech and explained the
problem
and they
did all they could to help. I can't complain about their
customer
service.



At this point, I have received a replacement starter (new) from
Skytech, but
as of yet, I have not installed it. All my mental alarms are
going
off
related to something that can throw of a piece off big enough
that
it could
gum up my engine (read off field landing and/or a damaged
engine)
or at the
least break off a tooth on the crankshaft gear, which at the
least,
is going
to be damn expensive.



Relevant info 1. As far as I know I did not have a
kickback.

2. I was starting on left mag only

3. I believe the real problem is Skytech's
control of the
centerline distance of the pinion/crankshaft gear set. In an
effort
to
loosen the tolerances in the manufacture of the starter, Skytech
has allowed
the pinion to get too far away from the main gear on the
crankshaft. This
results in an incredible force trying to separate the gears.
This
force than
further deflects the shaft that holds the pinion, which leads to
even higher
forces on the gears, then ultimately to a broken tooth.

4. I am going to try to get some measurements
on
the
centerline distances this weekend and I will let you guys know
what
I find.

5. Item 3 is only conjecture at this point.
Please take it
as so.

6. I have high compression pistons, but I
don't
know the
ratio.

7. I usually don't write well and tonight is
even
worse.





If anyone has a better starting system idea, let me know. I am
not
feeling
to good with this right now.



Kevin Fortin

N275CH

Except for the starter, damn close to flyin'
















Quickie Builders Association WEB site
http://www.quickiebuilders.org


Yahoo! Groups Links