radion control & retracts

jaymak · Oct 24, 2009, 05:36 AM

Radio control systems and retracts ????
Newbe questions. Have a Lexor nova 6 plus. Instructions say channel 1 -4 are controls, speed, ailerons etc. But only say 5 and 6 button. Assume 5 and 6 are one function buttons I.E. on- off used for retracts. Correct or not?

This lead’s to question two. Am building a Guillow B-17, and installing retracts. On the B-17 the gear does not go all the way up. Wheels retract into wheel wells but remain over half way out. Have worked out all the details save one. The retracts will not lock in the up position because they don’t travel the full 90d distance, so will the servo hold them up or will it burn up the servo?

Andrew McGregor · Oct 24, 2009, 06:10 AM

Well, retracts is one of many things you can use a switch-only channel for.

As for retracts not locking up... that's bad. It might fry the servo, or it might damage the BECs in the speed controllers, or it might run the battery flat, but whatever, it's likely to lead to a loss of control. You need that gear to lock. Probably the best way is to rotate the retract units a little so they lock up, and accept that the gear won't be quite vertical down, or move them down a little.

If you search the site, that plane must have been converted before, and someone will have done a retracts install, I'm sure.

Also look up about multi-engine planes and BECs: you can't assume that just plugging in two or more ESCs will work correctly.

Which brings me to another point: if this is your first plane, by all means finish the build, but learn to fly on something else first, because it would be a shame to waste all that effort on beginner pilot mistakes.

eflightray · Oct 24, 2009, 07:11 AM

Jaymak

Have a look at this thread - Scratch-built Guillow's B-17 I think it may be the only one I have come across that mentions retracts in the Guillows B-17.

I'm not sure the project ever got finished, the thread just runs out.

You have a major project on your hands that few experienced modelers would like to take on. Good luck.

flypaper 2 · Oct 24, 2009, 07:53 AM

A normal retract servo shuts off when it gets to the end of its travel, also they rotate 180 degrees, but I don't think they make one small enough for your plane. A longer arm on your servo will give you more travel as long as it has enough power to lift the gear. I've used over centre springs to help carry some of the weight.

Gord.

Oct 24, 2009, 05:36 AM	#1
jaymak Registered User wisconsin Joined Jan 2009 72 Posts	radion control & retracts Radio control systems and retracts ???? Newbe questions. Have a Lexor nova 6 plus. Instructions say channel 1 -4 are controls, speed, ailerons etc. But only say 5 and 6 button. Assume 5 and 6 are one function buttons I.E. on- off used for retracts. Correct or not? This lead’s to question two. Am building a Guillow B-17, and installing retracts. On the B-17 the gear does not go all the way up. Wheels retract into wheel wells but remain over half way out. Have worked out all the details save one. The retracts will not lock in the up position because they don’t travel the full 90d distance, so will the servo hold them up or will it burn up the servo?

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Oct 24, 2009, 06:10 AM	#2
Andrew McGregor Registered User Christchurch, New Zealand Joined Jun 2006 6,794 Posts	Well, retracts is one of many things you can use a switch-only channel for. As for retracts not locking up... that's bad. It might fry the servo, or it might damage the BECs in the speed controllers, or it might run the battery flat, but whatever, it's likely to lead to a loss of control. You need that gear to lock. Probably the best way is to rotate the retract units a little so they lock up, and accept that the gear won't be quite vertical down, or move them down a little. If you search the site, that plane must have been converted before, and someone will have done a retracts install, I'm sure. Also look up about multi-engine planes and BECs: you can't assume that just plugging in two or more ESCs will work correctly. Which brings me to another point: if this is your first plane, by all means finish the build, but learn to fly on something else first, because it would be a shame to waste all that effort on beginner pilot mistakes.

Oct 24, 2009, 07:11 AM	#3
eflightray An itch?. Scratch build. South Wales U.K. Joined Mar 2003 10,366 Posts	Jaymak Have a look at this thread - Scratch-built Guillow's B-17 I think it may be the only one I have come across that mentions retracts in the Guillows B-17. I'm not sure the project ever got finished, the thread just runs out. You have a major project on your hands that few experienced modelers would like to take on. Good luck.

Oct 24, 2009, 07:53 AM	#4
flypaper 2 Canadian Bacon Kingston, Canada Joined Jun 2004 10,426 Posts	A normal retract servo shuts off when it gets to the end of its travel, also they rotate 180 degrees, but I don't think they make one small enough for your plane. A longer arm on your servo will give you more travel as long as it has enough power to lift the gear. I've used over centre springs to help carry some of the weight. Gord.