Trim
Allan Farr
Hi Peter. I'm not quite sure what you mean by "LH throttle cable". Do you mean a vernier throttle control?
toggle quoted messageShow quoted text
Regards Allan
----- Original Message -----
From: Peter Harris To: Q-LIST@... Sent: Tuesday, March 11, 2008 5:26 PM Subject: RE: [Q-LIST] Differential brake pictures Mike, I have the LS1 canard and the sparrow strainers are OK. Using the LH throttle cable control for my trim I can leave it free during take off and climb ie there is no issue with stick forces. I set the trim (for nose down) after leveling out and final trim with the reflexer which is electric. I release it for descent and set it again (for nose up) turning base. The issue that I had with the plans trim is because mine was stiff ie it did not free wheel and by design it is always engaged. Having set up for cruise, if the fan stops it was not easy to reset the trim and if it was not reset you then have to hold against the springs and when speed drops off that gets increasingly heavy. Then reaching with the left hand to hold the stick against an increasing load from the springs and unwind the trim with the RH my head was below the sill and no view of the horizon. That was ugly with a silent engine. Similarly the starter key ignition was central and also needed the RH. Now I have a LH starter button just like a Bentley Continental I particularly like the LH throttle cable control for trim because it can be easily locked or unlocked at any setting, and as you say there is not much force on the stick when it is unlocked. The plans trim cannot be unlocked it is always engaged and therefore it needs to be adjusted to the correct setting or otherwise freewheel when not clamped. Some of the guys find that it will freewheel which sort of solves the problem, but by design I think it is not meant to free wheel because of the ratio. Mine did not. You could test for freewheeling by moving the stick fore and aft on the ground while the plans trim is not clamped. The wheel would move like a little buzz saw. . I agree the left side is getting crowded. I have aileron trim, pitch trim, a single finger brake, a toggle for the reflexor, a restart button, throttle and choke, but they all feel different. If I was starting over I would make two side sticks and centralize all the other controls and that would leave the RH available for writing also. Pat has a schematic from the Dragonfly. Peter . _____ From: Q-LIST@... [mailto:Q-LIST@...] On Behalf Of Mike Perry Sent: Tuesday, 11 March 2008 11:33 AM To: Q-LIST@... Subject: RE: [Q-LIST] Differential brake pictures Peter, several thoughts: 1) If I remember right, you have a GU canard, guys with LS-1 and the sparrow strainers set right don't have much force on the trim (anyone with a flying LS-1 agree or disagree?) 2) In a Cessna 172 or Piper Cherokee I can set the trim for best glide without looking -- just trim full nose up, you will be within 1-2 knots of best glide. It seems to me that you should set trim limits the same way in your experimental. (Some instructors don't like full nose up trim, "you can get an accelerated stall . . ." Rubbish. It's in the certification standards, at least for these light planes, that you can't get a stall at any trim setting without further control input. It sure makes it easy to run the "engine out" protocol if you don't have to worry about setting/holding best glide speed.) 3) I've thought about putting trim to the left, but the left side is getting real crowded with engine controls, reflexor and finger brakes all on the left side. Some days I think it would be better to fly out of the right seat with the stick in my left hand and my right hand free for all these other things -- then I think, "nah, just finish the thing and go fly." Thanks for the insights, I'm still thinking about it. Mike Perry Q-2xx in progress, Canard repair and engine next At 01:56 PM 3/10/2008 +1000, you wrote: >Mike if you are thinking about ergonomics, consider making a pitch trim to >be operated with the left hand. I had some anxious moments when the fan >stopped due to the Norton rotary engine. My plans built trim was stiff ie it >did not freewheel and so it had to be manually adjusted up or down. For me >that meant changing hands on the stick leaning forward to use my RH on the >trim wheel so I could not see the horizon momentarily. When the fan stops >you need to be able to hold the stick with the RH and trim the nose up and >you need to be able to hold the nose up easily while you adjust the trim. >You need the left hand ready to operate the throttle in a re start and you >need a start button near the LH. I fitted a starter button near the throttle >for LH operation. You should be able to see the horizon throughout the >procedure. > >I made a LH trim control using a throttle cable which I use disengaged until >required I mounted the supplied trim springs vertically and the free end of >the Throttle cable pushes or pulls at the centre of the springs. The outer >end of the cable is secured to the mount that was used before for the >original cord pulley attachment. > >Peter > >(PS Sam is right, spam cans are not for friends) > >_____ > >From: <mailto:Q-LIST%40yahoogroups.com>Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com >[mailto:Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com] On Behalf Of >Mike Perry >Sent: Monday, 10 March 2008 1:26 PM >To: <mailto:Q-LIST%40yahoogroups.com>Q-LIST@yahoogroups. <mailto:Q-LIST%40yahoogroups.com> com >Subject: Re: [Q-LIST] Differential brake pictures > >Well I'm not making any snide comments, Sam. I appreciate Paul's help with >the pictures of cockpit layout and fingerbrakes -- and your's too. I'm >still trying to figure out ergonomics, maintainability and buildability >(whatever those last few words might mean!). > >Mike Perry >Q-2xx in progress
|
|