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coop85(at)verizon.net
Guest

Posted: Wed Sep 22, 2010 4:25 am Post subject: performance (pitch trim)

Since we have drifted into a pitch trim discussion, here's a basic problem I

recently encountered with a probable solution.  My pitch works great pushing

for nose down trim, but the up portion has become intermittent.  Certainly

not good and in trouble shooting I thought the motor in the trim servo had a

bad spot that would keep it from moving but would start if I could get it

repositioned by moving the other way (old school electric motor thinking I

suspect).  I spoke to Andy at Ray Allen and apparently they had a number of

their REL-1 relays go bad and this was the symptom  (works one way, but not

the other due to the relay failing internally).  The new REL-2 relay is more

robust and fixes this.  I will trouble shoot some more (get the system to

fail and tap on the relay was the guidance) and if confirmed Andy offered to

sell me a REL-2 at half price (makes it $23 from what I can tell).



Marcus

40286

dlm46007(at)cox.net
Guest

Posted: Wed Sep 22, 2010 5:14 am Post subject: performance (pitch trim)

in addition, Ray Allen told me that the speed controller ($45) would also 

slow the trim servo response to allow finer tuning. My "safety trim" is 2 

pullable breakers that remove power to the trim and/or AP. I don't fly 

substantially above Va.

---

kdbelue(at)charter.net
Guest

Posted: Wed Sep 22, 2010 5:46 am Post subject: performance (pitch trim)

Why use relays if the trim switches can handle the trim motor current? Relays are just another part to fail. I wired my trim switches directly and they've worked great for several years....



Sent from my iPhone



On Sep 22, 2010, at 7:19 AM, "Marcus Cooper" <coop85(at)verizon.net> wrote:



 	  Quote: 	
		   

 

 Since we have drifted into a pitch trim discussion, here's a basic problem I

 recently encountered with a probable solution.  My pitch works great pushing

 for nose down trim, but the up portion has become intermittent.  Certainly

 not good and in trouble shooting I thought the motor in the trim servo had a

 bad spot that would keep it from moving but would start if I could get it

 repositioned by moving the other way (old school electric motor thinking I

 suspect).  I spoke to Andy at Ray Allen and apparently they had a number of

 their REL-1 relays go bad and this was the symptom  (works one way, but not

 the other due to the relay failing internally).  The new REL-2 relay is more

 robust and fixes this.  I will trouble shoot some more (get the system to

 fail and tap on the relay was the guidance) and if confirmed Andy offered to

 sell me a REL-2 at half price (makes it $23 from what I can tell).

 

 Marcus

 40286

Tim Olson

Joined: 25 Jan 2007
Posts: 2872

Posted: Wed Sep 22, 2010 5:46 am Post subject: performance (pitch trim)

Marcus,



You bring up a very old issue.  Those Ray Allen REL-1 relays

are a long-standing known big issue.  They've bitten many

people already.  I had the same sticky relay issues, as did

other builders who were flying about the same amount of time

as I was at the time, back in 2007.  Here's my write-up from

that time.



http://www.myrv10.com/N104CD/maintenance/20070729/index.html



It was exactly this sticky relay issue that pushed me over

the edge and made me investigate better options to those

relays for the trim. Those REL-1's are an accident waiting

to happen.  The REL-2's may be better, but they're still a

lot lot tougher to wire up than the job needs to be.

That's what made me go to Safety-Trim, and I think it's one

of the more important safety things I've added to the plane.

Here was my write-up again from 2007.



http://www.myrv10.com/N104CD/upgrades/20071027/index.html



That's why on this thread, when the worry came up about

having Auto-Trim get in the way of safety trim, I was spooked.

Safety-Trim I think is something that every RV-10 owner

should have, at least for those who don't have the Vertical

Power stuff.



Anyway, sounds like with Bob's reply that I can at least

go ahead with auto-trim if I want to, and it won't cause me

issues with safety trim.



If you're still flying those relays though, I'd tell you to just

cut your losses now. A retrofit with Safety trim will give you

some good benefits, and considering all those little wires to

solder, it's actually a lot simpler to wire in.

Tim Olson - RV-10 N104CD

do not archive

On 9/22/2010 7:19 AM, Marcus Cooper wrote:

 	  Quote: 	
		   



 Since we have drifted into a pitch trim discussion, here's a basic problem I

 recently encountered with a probable solution.  My pitch works great pushing

 for nose down trim, but the up portion has become intermittent.  Certainly

 not good and in trouble shooting I thought the motor in the trim servo had a

 bad spot that would keep it from moving but would start if I could get it

 repositioned by moving the other way (old school electric motor thinking I

 suspect).  I spoke to Andy at Ray Allen and apparently they had a number of

 their REL-1 relays go bad and this was the symptom  (works one way, but not

 the other due to the relay failing internally).  The new REL-2 relay is more

 robust and fixes this.  I will trouble shoot some more (get the system to

 fail and tap on the relay was the guidance) and if confirmed Andy offered to

 sell me a REL-2 at half price (makes it $23 from what I can tell).



 Marcus

 40286

Tim Olson

Joined: 25 Jan 2007
Posts: 2872

Posted: Wed Sep 22, 2010 6:52 am Post subject: performance (pitch trim)

You pretty much need to if you're going to have multiple sticks

controlling the trim.  You're right though that if you're only

going to have one trim switch, you could just use switches.

It's the dual-stick, or panel/stick multiple switches that

make you need a relay.



Tim Olson - RV-10 N104CD

do not archive

On 9/22/2010 8:34 AM, Kevin Belue wrote:

 	  Quote: 	
		   



 Why use relays if the trim switches can handle the trim motor

 current? Relays are just another part to fail. I wired my trim

 switches directly and they've worked great for several years....



 Sent from my iPhone



 On Sep 22, 2010, at 7:19 AM, "Marcus Cooper"<coop85(at)verizon.net>

 wrote:



> 

> Cooper"<coop85(at)verizon.net>

>

> Since we have drifted into a pitch trim discussion, here's a basic

> problem I recently encountered with a probable solution.  My pitch

> works great pushing for nose down trim, but the up portion has

> become intermittent.  Certainly not good and in trouble shooting I

> thought the motor in the trim servo had a bad spot that would keep

> it from moving but would start if I could get it repositioned by

> moving the other way (old school electric motor thinking I

> suspect).  I spoke to Andy at Ray Allen and apparently they had a

> number of their REL-1 relays go bad and this was the symptom

> (works one way, but not the other due to the relay failing

> internally).  The new REL-2 relay is more robust and fixes this.  I

> will trouble shoot some more (get the system to fail and tap on the

> relay was the guidance) and if confirmed Andy offered to sell me a

> REL-2 at half price (makes it $23 from what I can tell).

>

> Marcus 40286

>

kdbelue(at)charter.net
Guest

Posted: Wed Sep 22, 2010 7:40 am Post subject: performance (pitch trim)

No, I have trim switches on both sticks.   If it's wired right, no relays are needed and either set of trim switches can control without shorting.



Sent from my iPhone



On Sep 22, 2010, at 9:48 AM, Tim Olson <Tim(at)myrv10.com> wrote:



 	  Quote: 	
		   

 

 You pretty much need to if you're going to have multiple sticks

 controlling the trim.  You're right though that if you're only

 going to have one trim switch, you could just use switches.

 It's the dual-stick, or panel/stick multiple switches that

 make you need a relay.

 

 Tim Olson - RV-10 N104CD

 do not archive

 

 

 On 9/22/2010 8:34 AM, Kevin Belue wrote:

> 

> 

> Why use relays if the trim switches can handle the trim motor

> current? Relays are just another part to fail. I wired my trim

> switches directly and they've worked great for several years....

> 

> Sent from my iPhone

> 

> On Sep 22, 2010, at 7:19 AM, "Marcus Cooper"<coop85(at)verizon.net>

> wrote:

> 

>> 

>> Cooper"<coop85(at)verizon.net>

>> 

>> Since we have drifted into a pitch trim discussion, here's a basic

>> problem I recently encountered with a probable solution.  My pitch

>> works great pushing for nose down trim, but the up portion has

>> become intermittent.  Certainly not good and in trouble shooting I

>> thought the motor in the trim servo had a bad spot that would keep

>> it from moving but would start if I could get it repositioned by

>> moving the other way (old school electric motor thinking I

>> suspect).  I spoke to Andy at Ray Allen and apparently they had a

>> number of their REL-1 relays go bad and this was the symptom

>> (works one way, but not the other due to the relay failing

>> internally).  The new REL-2 relay is more robust and fixes this.  I

>> will trouble shoot some more (get the system to fail and tap on the

>> relay was the guidance) and if confirmed Andy offered to sell me a

>> REL-2 at half price (makes it $23 from what I can tell).

>> 

>> Marcus 40286

>> 

>> 

>> 

>> 

>> 

> 

> 

> 

> 

>

jdriggs49(at)msn.com
Guest

Posted: Wed Sep 22, 2010 7:50 am Post subject: performance (pitch trim)

Make sure that the (usually tiny) switches can handle the trim motor current. That's the only other thing you need a relay for besides multiple switch array. 



 	  Quote: 	
		   Date: Wed, 22 Sep 2010 09:48:51 -0500

 From: Tim(at)myrv10.com

 To: rv10-list(at)matronics.com

 Subject: Re: Re: performance (pitch trim)

 

 --> RV10-List message posted by: Tim Olson <Tim(at)myrv10.com>

 

 You pretty much need to if you're going to have multiple sticks

 controlling the trim.  You're right though that if you're only

 going to have one trim switch, you could just use switches.

 It's the dual-stick, or panel/stick multiple switches that

 make you need a relay.

 

 Tim Olson - RV-10 N104CD

 do not archive

 

 

 On 9/22/2010 8:34 AM, Kevin Belue wrote:

 > -->  RV10-List message posted by: Kevin Belue<kdbelue(at)charter.net>

 >

 > Why use relays if the trim switches can handle the trim motor

 > current? Relays are just another part to fail. I wired my trim

 > switches directly and they've worked great for several years....

 >

 > Sent from my iPhone

 >

 > On Sep 22, 2010, at 7:19 AM, "Marcus Cooper"<coop85(at)verizon.net>

 > wrote:

 >

 >> -->  RV10-List message posted by: "Marcus

 >> Cooper"<coop85(at)verizon.net>

 >>

 >> Since we have drifted into a pitch trim discussion, here's a basic

 >> problem I recently encountered with a probable solution.  My pitch

 >> works great pushing for nose down trim, but the up portion has

 >> become intermittent.  Certainly not good and in trouble shooting I

 >> thought the motor in the trim servo had a bad spot that would keep

 >> it from moving but would start if I could get it repositioned by

 >> moving the other way (old school electric motor thinking I

 >> suspect).  I spoke to Andy at Ray Allen and apparently they had a

 >> number of their REL-1 relays go bad and this was the symptom

 >> (works one way, but not the other due to the relay failing

 >> internally).  The new REL-2 relay is more robust and fixes this.  I

 >> will trouble shoot some more (get the system to fail and tap on the

 >> relay was the guidance) and if confirmed Andy offered to sell me a

 >> REL-2 at half price (makes it $23 from what I can tell).

 >>

 >> Marcus 40286

 >>

 >>

 >>

 >>

 >>

 >

 >

 >

 >

 >

 <br======================

&gt=======
	


 	  Quote:

dave.saylor.aircrafters(a
Guest

Posted: Wed Sep 22, 2010 8:14 am Post subject: performance (pitch trim)

 	  Quote: 	
		  >no relays are needed and either set of trim switches can control without shorting<<


	


I'd be interested in seeing a schematic for two trim switches without a relay.Â  Are you using a selector switch for one stick or the other?

  

The installations I've seen without a relay or a selector switch would always pop the breaker if both tried to trim at the same time.

Dave Saylor

AirCrafters

140 Aviation Way

Watsonville, CA 95076

  831-722-9141 Shop

831-750-0284 Cell

 



[quote]

 [b]

pitts_pilot(at)bellsouth.
Guest

Posted: Wed Sep 22, 2010 8:25 am Post subject: performance (pitch trim)

The problem isn't dual sticks ..... it won't matter if the switches 

are wired in parallel to control the servo or to control the relay.  

What matters is the switch itself.  Some grip switches will handle the 

current of the servo, and some won't .... for long.

Linn

On 9/22/2010 11:11 AM, Kevin Belue wrote:

 	  Quote: 	
		   



 No, I have trim switches on both sticks.   If it's wired right, no relays are needed and either set of trim switches can control without shorting.



 Sent from my iPhone



 On Sep 22, 2010, at 9:48 AM, Tim Olson<Tim(at)myrv10.com>  wrote:



> 

>

> You pretty much need to if you're going to have multiple sticks

> controlling the trim.  You're right though that if you're only

> going to have one trim switch, you could just use switches.

> It's the dual-stick, or panel/stick multiple switches that

> make you need a relay.

>

> Tim Olson - RV-10 N104CD

> do not archive

> On 9/22/2010 8:34 AM, Kevin Belue wrote:

>> 

>>

>> Why use relays if the trim switches can handle the trim motor

>> current? Relays are just another part to fail. I wired my trim

>> switches directly and they've worked great for several years....

>>

>> Sent from my iPhone

>>

>> On Sep 22, 2010, at 7:19 AM, "Marcus Cooper"<coop85(at)verizon.net>

>> wrote:

>>

>>> 

>>> Cooper"<coop85(at)verizon.net>

>>>

>>> Since we have drifted into a pitch trim discussion, here's a basic

>>> problem I recently encountered with a probable solution.  My pitch

>>> works great pushing for nose down trim, but the up portion has

>>> become intermittent.  Certainly not good and in trouble shooting I

>>> thought the motor in the trim servo had a bad spot that would keep

>>> it from moving but would start if I could get it repositioned by

>>> moving the other way (old school electric motor thinking I

>>> suspect).  I spoke to Andy at Ray Allen and apparently they had a

>>> number of their REL-1 relays go bad and this was the symptom

>>> (works one way, but not the other due to the relay failing

>>> internally).  The new REL-2 relay is more robust and fixes this.  I

>>> will trouble shoot some more (get the system to fail and tap on the

>>> relay was the guidance) and if confirmed Andy offered to sell me a

>>> REL-2 at half price (makes it $23 from what I can tell).

>>>

>>> Marcus 40286

>>>

>>>

>>>

>>>

>>>

>>

>>

>>

>>

>

kdbelue(at)charter.net
Guest

Posted: Wed Sep 22, 2010 9:14 am Post subject: performance (pitch trim)

It does matter if the switches are wired in parallel because if up is selected on one stick and down is selected on the other then 12v is shorted to ground. But it can be wired so that doesn't happen. As we both said, the switches

must have a current rating to handle the trim motor.



Sent from my iPhone



On Sep 22, 2010, at 10:45 AM, Linn Walters <pitts_pilot(at)bellsouth.net> wrote:



 	  Quote: 	
		   

 

 The problem isn't dual sticks ..... it won't matter if the switches are wired in parallel to control the servo or to control the relay.  What matters is the switch itself.  Some grip switches will handle the current of the servo, and some won't .... for long.

 Linn

 On 9/22/2010 11:11 AM, Kevin Belue wrote:

> 

> 

> No, I have trim switches on both sticks.   If it's wired right, no relays are needed and either set of trim switches can control without shorting.

> 

> Sent from my iPhone

> 

> On Sep 22, 2010, at 9:48 AM, Tim Olson<Tim(at)myrv10.com>  wrote:

> 

>> 

>> 

>> You pretty much need to if you're going to have multiple sticks

>> controlling the trim.  You're right though that if you're only

>> going to have one trim switch, you could just use switches.

>> It's the dual-stick, or panel/stick multiple switches that

>> make you need a relay.

>> 

>> Tim Olson - RV-10 N104CD

>> do not archive

>> 

>> 

>> On 9/22/2010 8:34 AM, Kevin Belue wrote:

>>> 

>>> 

>>> Why use relays if the trim switches can handle the trim motor

>>> current? Relays are just another part to fail. I wired my trim

>>> switches directly and they've worked great for several years....

>>> 

>>> Sent from my iPhone

>>> 

>>> On Sep 22, 2010, at 7:19 AM, "Marcus Cooper"<coop85(at)verizon.net>

>>> wrote:

>>> 

>>>> 

>>>> Cooper"<coop85(at)verizon.net>

>>>> 

>>>> Since we have drifted into a pitch trim discussion, here's a basic

>>>> problem I recently encountered with a probable solution.  My pitch

>>>> works great pushing for nose down trim, but the up portion has

>>>> become intermittent.  Certainly not good and in trouble shooting I

>>>> thought the motor in the trim servo had a bad spot that would keep

>>>> it from moving but would start if I could get it repositioned by

>>>> moving the other way (old school electric motor thinking I

>>>> suspect).  I spoke to Andy at Ray Allen and apparently they had a

>>>> number of their REL-1 relays go bad and this was the symptom

>>>> (works one way, but not the other due to the relay failing

>>>> internally).  The new REL-2 relay is more robust and fixes this.  I

>>>> will trouble shoot some more (get the system to fail and tap on the

>>>> relay was the guidance) and if confirmed Andy offered to sell me a

>>>> REL-2 at half price (makes it $23 from what I can tell).

>>>> 

>>>> Marcus 40286

>>>> 

>>>> 

>>>> 

>>>> 

>>>> 

>>> 

>>> 

>>> 

>>> 

>> 

>> 

>> 

> 

> 

> 

> 

>

jump2(at)sbcglobal.net
Guest

Posted: Wed Sep 22, 2010 4:28 pm Post subject: performance (pitch trim)

I too have the TW safety system and the auto trim, two sticks with trim control. Not a problem. I put the auto trim in last winter when I redid my panel and once we got it tweaked up at Trutrak it has worked beautifuly. Thats been about 140 hrs now. You do not have trim control as long as AP in on, but once you kick it off your back in business.

Patrick Thyssen

231 hrs on 15pt

New paint 

--- On Wed, 9/22/10, Linn Walters <pitts_pilot(at)bellsouth.net> wrote:

 	  Quote: 	
		  

From: Linn Walters <pitts_pilot(at)bellsouth.net>

Subject: Re: Re: performance (pitch trim)

To: rv10-list(at)matronics.com

Date: Wednesday, September 22, 2010, 10:45 AM



--> RV10-List message posted by: Linn Walters  <[url=/mc/compose?to=pitts_pilot(at)bellsouth.net]pitts_pilot(at)bellsouth.net[/url]>



  The problem isn't dual sticks ..... it won't matter if the switches 

are wired in parallel to control the servo or to control the relay.  

What matters is the switch itself.  Some grip switches will handle the 

current of the servo, and some won't .... for long.

Linn

On 9/22/2010 11:11 AM, Kevin Belue wrote:

 	  Quote: 	
		   -->  RV10-List message posted by: Kevin Belue<[url=/mc/compose?to=kdbelue(at)charter.net]kdbelue(at)charter.net[/url]>



 No, I have trim switches on both sticks.   If it's wired right, no relays are needed and either set of trim switches can control without shorting.



 Sent from my iPhone



 On Sep 22, 2010, at 9:48 AM, Tim Olson<[url=/mc/compose?to=Tim(at)myrv10.com]Tim(at)myrv10.com[/url]>  wrote:



> -->  RV10-List message posted by: Tim Olson<[url=/mc/compose?to=Tim(at)myrv10.com]Tim(at)myrv10.com[/url]>

>

> You pretty much need to if you're going to have multiple sticks

> controlling the trim.  You're right though that if you're only

> going to have one trim switch, you could just use switches.

> It's the dual-stick, or panel/stick multiple switches that

> make you need a relay.

>

> Tim Olson - RV-10 N104CD

> do not archive

> On 9/22/2010 8:34 AM, Kevin Belue wrote:

>> -->   RV10-List message posted by: Kevin Belue<[url=/mc/compose?to=kdbelue(at)charter.net]kdbelue(at)charter.net[/url]>

>>

>>  Why use relays if the trim switches can handle the trim motor

>> current? Relays are just another part to fail. I wired my trim

>> switches directly and they've worked great for several years....

>>

>> Sent from my iPhone

>>

>> On Sep 22, 2010, at 7:19 AM, "Marcus Cooper"<[url=/mc/compose?to=coop85(at)verizon.net]coop85(at)verizon.net[/url]>

>> wrote:

>>

>>> -->   RV10-List message posted by: "Marcus

>>> Cooper"<[url=/mc/compose?to=coop85(at)verizon.net]coop85(at)verizon.net[/url]>

>>>

>>> Since we have drifted into a pitch trim discussion, here's a basic

>>> problem I recently encountered with a probable solution.  My pitch

>>> works great pushing for nose  down trim, but the up portion has

>>> become intermittent.  Certainly not good and in trouble shooting I

>>> thought the motor in the trim servo had a bad spot that would keep

>>> it from moving but would start if I could get it repositioned by

>>> moving the other way (old school electric motor thinking I

>>> suspect).  I spoke to Andy at Ray Allen and apparently they had a

>>> number of their REL-1 relays go bad and this was the symptom

>>> (works one way, but not the other due to the relay failing

>>> internally).  The new REL-2 relay is more robust and fixes this.  I

>>> will trouble shoot some more (get the system to fail and tap on the

>>> relay was the guidance) and if confirmed Andy offered to sell me a

>>> REL-2 at half price (makes it $23 from what I  can tell).

>>>

>>> Marcus 40286

>>>

>>>

>>>

>>>

>>>

>>

>>

>>

>>

>





  --> http://forums.matr            - List Contribution Web Site;                     &nb; http:========================
	






	
 [quote][b]

Strasnuts

Joined: 10 Feb 2009
Posts: 502
Location: Salt Lake City, UT

Posted: Wed Sep 22, 2010 6:25 pm Post subject: Re: performance (pitch trim)

Hey Tim,



I was thinking about all this about the trim and thought about the Citation.

The Citation has had a history of runaway trims that has prompted previous AD's and flight manual changes.

Here is what they came up with per Flight Safety Manual:



1. Autopilot/Trim Disengage Switch........................PRESS

2. Pitch Trim Circuit Breaker (LH Panel).................PULL



Pull the PITCH TRIM circuit breaker to permenantly remove power from the trim motor before releasing the autopilot/trim disengage switch.



3. Manual Elevator Trim.........................................AS REQUIRED



                                NOTE



Do not attempt to use the autopilot if the electric trim is 

inoperative.  The autopilot is not able to trim-out servo 

torque, and disengaging the autopilot with light servo torque

could result in a significant pitch upset.





The problem with this scenario is now I can't return to home base single pilot if I land somewhere else with a inop Autopilot.

I also remember four down and three over by memory for the CB position.



Maybe we can have a TRIM Disconnect on one of the many switches on the infinity grip??

_________________
40936
RV-10 SB N801VR Flying
780 Hours
SuperSTOL 60 hours

Tim Olson

Joined: 25 Jan 2007
Posts: 2872

Posted: Wed Sep 22, 2010 7:10 pm Post subject: performance (pitch trim)

That's true, that would be an option. I see what you mean,

they have you push the button which disengages, then pull

the breaker since you now have time to do that.  That's

not a bad way to go either.  I do think that I'm pretty

happy with what I have now in that even if it ran away

with a broken switch, it can't get too out of whack.

Also, Bob incorporates an OFF switch that I have located

by my quadrant, and that same switch does REVERSE if you

really want, as a momentary switch.  That way you can

reverse what was done, unlike when I had the relay failure

at OSH and had no choice but to strong arm the plane down

final.



I don't know, I think that's not a bad option, but,

I also would miss ANY of my infinity switches that

I now have used.  If I had a couple more switches,

maybe.  I just think that with what I have in the

plane right now, I don't have the worries.  With the

way it was before that, I had worries.  I had a

sudden pitch-up experience when doing my flyoff while

calibrating my AP.  Was looking at the manual, laid

the binder a little to low and it hit the trim switch.

Suddenly I was rocketing for the sky, trying to figure

out what the heck just happened.  It takes you a second

to figure out if it's your AP going nuts, or the trim.

I was playing with the AP, so I thought it was the AP,

and hit the AP disconnect.  Nope, that wasn't it.

So it took a couple seconds to figure it out.  I

pulled a couple G's in that mess.  But in testing I've

seen worse.



After finding a good solution that is really working well,

I don't intend to re-invent the wheel and go down another

path...but that option doesn't sound bad to me.



Tim Olson - RV-10 N104CD

do not archive

On 9/22/2010 9:25 PM, Strasnuts wrote:

 	  Quote: 	
		   


	




<snip>

 	  Quote: 	
		   Maybe we can have a TRIM Disconnect on one of the many switches on the infinity grip??

lbender(at)neb.rr.com
Guest

Posted: Wed Sep 22, 2010 8:36 pm Post subject: performance (pitch trim)

Tim:



You probably know this already but a feature of the auto trim system is that the manual trim system is DISABLED  anytime the autopilot is engaged.  Makes it impossible to inadvertently, or intentionally, manually trim the airplane without first disengaging the AP.  Absent a system failure of some sort of course.  I like the safety trim idea and am considering installing one. Sounds like its compatible with the auto trim system I currently have installed.



Lyle Bender  N159LB

---- Tim Olson <Tim(at)myrv10.com> wrote: 



=============




That's true, that would be an option. I see what you mean,

they have you push the button which disengages, then pull

the breaker since you now have time to do that.  That's

not a bad way to go either.  I do think that I'm pretty

happy with what I have now in that even if it ran away

with a broken switch, it can't get too out of whack.

Also, Bob incorporates an OFF switch that I have located

by my quadrant, and that same switch does REVERSE if you

really want, as a momentary switch.  That way you can

reverse what was done, unlike when I had the relay failure

at OSH and had no choice but to strong arm the plane down

final.



I don't know, I think that's not a bad option, but,

I also would miss ANY of my infinity switches that

I now have used.  If I had a couple more switches,

maybe.  I just think that with what I have in the

plane right now, I don't have the worries.  With the

way it was before that, I had worries.  I had a

sudden pitch-up experience when doing my flyoff while

calibrating my AP.  Was looking at the manual, laid

the binder a little to low and it hit the trim switch.

Suddenly I was rocketing for the sky, trying to figure

out what the heck just happened.  It takes you a second

to figure out if it's your AP going nuts, or the trim.

I was playing with the AP, so I thought it was the AP,

and hit the AP disconnect.  Nope, that wasn't it.

So it took a couple seconds to figure it out.  I

pulled a couple G's in that mess.  But in testing I've

seen worse.



After finding a good solution that is really working well,

I don't intend to re-invent the wheel and go down another

path...but that option doesn't sound bad to me.



Tim Olson - RV-10 N104CD

do not archive

On 9/22/2010 9:25 PM, Strasnuts wrote:

 	  Quote: 	
		   


	




<snip>

 	  Quote: 	
		   Maybe we can have a TRIM Disconnect on one of the many switches on the infinity grip??

bcondrey

Joined: 03 Apr 2006
Posts: 580

Posted: Thu Sep 23, 2010 6:35 am Post subject: Re: performance (pitch trim)

Lyle,



There are two ways to wire in the AP auto-trim system from TT.  First way is as you describe - when the AP is enabled the auto-trim system takes over and manual trim is disabled.  Second way has a switch to disable autotrim completely at any time and revert to manual trim.



Bob

Lenny Iszak

Joined: 23 Mar 2008
Posts: 270

Posted: Thu Sep 23, 2010 9:39 am Post subject: Re: performance (pitch trim)

Here's how Trio Avionics suggests to wire in their autotrim.



The autopilot has trim all the time, except when you activate the manual trim, the power going down the trim wires, will activate a relay which removes control from the autopilot's autotrim and gives control to the manual one.



This works out pretty good as long as that relay doesn't fail. I have yet to figure out what are the failure modes of the Omron relay.

I was thinking of hooking up a relay to a microcontroller and let it switch on and off a gazillion times until it fails.



The cool feature i like about this is that when the autopilot is not engaged, the knob on the autopilot can be used to run the trim, which provides for a nice backup to the manual trim system.



See attached image for wiring (Option 2)



Lenny

Lenny Iszak

Joined: 23 Mar 2008
Posts: 270

Posted: Thu Sep 23, 2010 10:06 am Post subject: Re: performance (pitch trim)

Oops, forgot the picture. Here it is:

trio_autotrim.jpg

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_________________
Lenny Iszak
Palm City, FL
2014 RV-10, N311LZ - 500 hrs

rv10flyer

Joined: 25 Aug 2009
Posts: 364

Posted: Thu Sep 23, 2010 11:50 am Post subject: Re: performance (pitch trim)

I think I will install a "pitch trim enable" push button switch just above my rocker switch on the panel. Switch will have deep bezel. Both next to throttle control. Then no worries about motor speed, stuck relays, kids or something resting on the stick. Also less weight/money/build time.

_________________
Wayne G.

Bob Turner

Joined: 03 Jan 2009
Posts: 885
Location: Castro Valley, CA

Posted: Sat Sep 25, 2010 12:17 pm Post subject: Re: performance (pitch trim)

I've put pullable CB's for the trim and autopilot right next to each other, just right of center in front of the pilot, easily reached by the right hand. I'll put a red box around them. My plan is that if the pitch goes nuts, I'll pull both breakers, then sort out the problem.

_________________
Bob Turner
RV-10 QB

rv10flyer

Joined: 25 Aug 2009
Posts: 364

Posted: Sat Sep 25, 2010 7:35 pm Post subject: Re: performance (pitch trim)

Bob, 



That was originally the way I was going to do it, but as fast as things could happen I thought I might be safer going this route. As long as we do something that is the main thing. Those are some huge trim tabs.

_________________
Wayne G.

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