miyu1975

miyu1975

Well Known Member
If I choose to have manual trim vs electric where would the trim switch/trim roller be located in the cockpit? Between the sits??
 
In a homebuilt, you could put it where ever you wanted to. But, the plans put it on the floor below the throttle. Kind of sticks up between the pilot and passenger's knees.

I really like manual trim, btw!
 
Quick question about manual vs electric.

I've got a handful of hours in a DA-20 some time ago and found that the electric trim was NOT accurate enough for liking.

How accurate is Van's trim for getting the aircraft trimmed perfectly. Manual trim, I found so far on most aircraft, you can't go wrong.
 
miyu1975 said:
If I choose to have manual trim vs electric where would the trim switch/trim roller be located in the cockpit? Between the sits??
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Which RV are you building?

On the side-by-side RV's the manual trim knob goes just in front of the main spar, between the two seats, down by the floor, just forward of the fuel valve. See this picture.

I think on the -3, -4, -8's it goes down low on the left side, below the throttle.

Is manual trim even an option on the -10?
 
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Adam Oke said:
Quick question about manual vs electric.

I've got a handful of hours in a DA-20 some time ago and found that the electric trim was NOT accurate enough for liking.

How accurate is Van's trim for getting the aircraft trimmed perfectly. Manual trim, I found so far on most aircraft, you can't go wrong.
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I'll let you know in about 3 weeks or so...:D

In "non-RV" aircraft I've found that I like the manual trim a lot better because there's good feedback. There's a feel to moving a wheel or turning a crank that just pushing a button doesn't give. When I fly aircraft with both - Piper Arrow, Bonanza, SE Cesssna - I usually use the manual wheel and not the electirc yoke trim button.
 
FWIW------------ I absolutely "love" the electric pitch and roll trim in my RV6A. And I don't have speed controllers either.

In fact, a 9A driver commented on how well my trim works! It just seems to settle right in, without that too little or too much scenario.

Just last weekend, as my wife and I flew a 7.6 hr cross-country......... I asked how'd she'd like it, if I had to reach down between the seats everytime to twist a trim knob instead of merely tapping the 4-way trim switch on my joystick. And it would be even worse, if it was attached to a center post which steals knee room. Needless to say, we both much prefer the little trim button on the stick!

I can't even imagine grabbing between the seats for a "flap handle"! :D Yes, mine is certainly electric too! :)

L.Adamson --- RV6A
 
JDRhodes said:
In "non-RV" aircraft I've found that I like the manual trim a lot better because there's good feedback. There's a feel to moving a wheel or turning a crank that just pushing a button doesn't give. When I fly aircraft with both - Piper Arrow, Bonanza, SE Cesssna - I usually use the manual wheel and not the electirc yoke trim button.
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If they had electric, I used it! Same with my RV.

L.Adamson --- RV6A
 
Does the 9 need a trim speed controller?

Does anyone know if the 9(A) electric trim is as sensitive or touchy as the 6 & 7's are supposed to be? I've built for either but will have to decide soon and I'm leaning toward electic so I can have the autopilot manage it if I want to.

dave
 
IowaRV9Dreamer said:
Does anyone know if the 9(A) electric trim is as sensitive or touchy as the 6 & 7's are supposed to be? I've built for either but will have to decide soon and I'm leaning toward electic so I can have the autopilot manage it if I want to.
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I don't think they're touchy at all. I just "blip" the button. You can always add a speed controller if you want. The majority of my RV time, before my 6, was with two different 9A's with elec. trim.

L.Adamson
 
Thoughts on Manual vs. Electric Trim

Well, I have very little RV time, like maybe 4 hours, but when I first used manual trim I instantly fell in love with it. Completely intuitive, you feel the air pressure right through the knob, I am now a huge manual trim fan. I'm sure I'll figure out the electric trim that my (yet to fly) ship has.

The electric trim is good for its fingertip use, ease of installation and low weight.

The manual trim is more precise and easier to set exactly you want it, less expensive but it is harder to install and much harder to replace whenever that needs doing. Strangely I think it is simpler.

Hans
 
They are different...

You can argue both ways. One nice thing about manual trim is that the user adjusts the rate of change at any airspeed. It is very intuitive, feedback is exacting, and you can easily trim perfectly at any airspeed. Despite what some have said, you dont have to "reach" anywhere. The trim is right by your hand and very easy to "reach". To each his own. I have flown both and like both of them but they are different and I prefer the tactile feedback that only the manual trim provides.
 
My RV-6 has been flying with manual trim and manual flaps since early 1993. If I built another one today, I would built it the same.
I've flown many RVs with electric trim also, and it's fine if that's what you want. It's a personal thing. I like manual "stuff".
 
JonJay said:
I have flown both and like both of them but they are different and I prefer the tactile feedback that only the manual trim provides.
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I can actually get "tactile feedback" from a desktop flight simulator with only a centering spring for the joystick. Other than that bit of spring resistance, it's only what you see on the screen..........and what your mind adapts too.

I'd even get feedback from an R/C airplane that has no mechanical linkage to my fingers. Once again, it was a combination of sight, and the "feel" of that bit of spring pressure thats required to override the out of trim situation.

Personally, I once again find little difference in feedback from elec. or manual trim. This time the mind is picking up clues from stick pressures and sight. It's what you get use too, I suppose. But it's really the forces on the stick, versus the flight attitude we want to see --------that is really the "feedback".

L.Adamson
 
I have the Manual System

I have a very densly packed center console in my RV-6Aand I route the trim cable through that so that it curves back and falls naturally to hand. Its function and performance are outstanding. Once I get through the speed mods that are still ahead of me I am going to develop a manual rudder trim.

Bob Axsom
 
Love the Manual Trim

Didn't love it that much when installing it, but now that we've figured out how to locate it for take-off, I wouldn't have it any other way, and I've many thousands of hours with electric trim in other aircraft.
Sometimes in flight you just want to move it half a degree, and that's easy with the manual trim.
Here's a photo of the trim in take-off position. (please pardon the cleaning rag in background). You can see the dab of paint on the inner shaft up against the outer nut. Yellow arrow is up.

By USCANAM
Takes about 1/2 turn down for level flight, and I find that I've turned it about 2 turns eventually for landing.
Gives a very positive feedback.
Jack
 
USCANAM said:
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Your pic, proves my point perfectly. At least in reference to side by sides. With the trim located just above the fuel selector.............you're always reaching down. It's fine if flying by yourself, but not so great when there are two sets of legs. If the trim is in a center console of any kind, you're removing some comfortable knee room. RV's are tight as it is! :)

With my trim on the joystick hat switch; one hand is on the stick, while the other is on throttle and flap switch for landing. I can make any necessary trim changes while keeping each hand on the main controls. I don't have to remove a hand from the throttle, and reach down between two legs to change a setting. :D

And the same applies to flaps. Flying by yourself is one thing, but always reaching between two people is quite different. In my setup, I can do everything, while keeping my hands on the stick and throttle. I just think that's the "better" setup!

L.Adamson
 
Here' s what I did. The mounting bracket was already set up to be removable for working under the panel. I mounted it to the bottom of the panel so that I could adjust the trim easier during formation flying.

Bonus is that it no longer cuts into my leg on long x-c.

Vern

img002.jpg
 
Please explain

L.Adamson said:
Your pic, proves my point perfectly. At least in reference to side by sides. With the trim located just above the fuel selector.............you're always reaching down. It's fine if flying by yourself, but not so great when there are two sets of legs. If the trim is in a center console of any kind, you're removing some comfortable knee room. RV's are tight as it is! :)


L.Adamson
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Mr. Adamson
I don't understand what you're saying here. With the trim knob in the center of the console, just about below the throttle, what are a set of legs doing there to get in the way??
It only takes about a second to reach down and move the trim in the direction it needs to be rotated..
As for the flaps, my flap switch is just to the left of the throttle, so I move the flaps with my thumb without taking my hand off the throttle.

By USCANAM

The only switch I have on my stick is the PTT one, and even then, I know sometime in the future that will fail usually because of the wire below the stick. That's why I like the mechanical trim and flap switch where it is.
I even located the A/P disconnect on the lower panel within each reach of my right hand. Same for squawk switch, just reach over and press the button on the transponder. Lot less chance of wire failure.
Also, some dark and stormy night, it will save me from disconnecting the A/P when all I wanted to do was squawk!!! It's not always that easy to re-engage the Blue Mountain auto pilot!!

I'm always interested in hearing why people select the methods of construction that they've picked. That's why we build our own planes, and we share our ideas with others.
Best regards
Jack
 
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USCANAM said:
I'm always interested in hearing why people select the methods of construction that they've picked. That's why we build our own planes, and we share our ideas with others.
Best regards
Jack
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In addition to my trim switch on the left handed joystick, the trims and PTT switch are repeated on the lower right hand panel, for right side pilot use and redundency. As to the flaps, good to see your using electric... :D

L.Adamson
 
L.Adamson said:
As to the flaps, good to see your using electric... :D

L.Adamson
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Didn't have a choice !! They we the only option.
I'm happy so far with the electric flaps, that is until I have the problems with them as reported on this forum.
So, as suggested by others, use very little flaps most of the time, especially at take-off.
Jack
 
USCANAM said:
Didn't have a choice !! They we the only option.
I'm happy so far with the electric flaps, that is until I have the problems with them as reported on this forum.
So, as suggested by others, use very little flaps most of the time, especially at take-off.
Jack
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I only go half flaps usually for landing. My approaches are still steep.. thanks to the C/S prop. I don't use flaps for takeoff either; and my airport is 4603' msl. The RV6A in the hangar next door is 12 years old, and his flap motor still works. He also has near 1300 hrs on the plane. Come to think of it, my flap motor is about 12 years old too. Just not much time on it.....

L.Adamson ---- RV6A
 
Personal taste!

L.Adamson said:
Oh........but I have lived! :D

It's just that I'm closing in on 60 years now... :)

L.Adamson
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I'm coming up on 66 and wouldn't trade my manual flaps or manual trim for all the electrics in the world.
 
what about the autopilot trim?

What I'm struggling with is the interaction between autopilot and pitch trim. I'm planning the Trio Pro Pilot autopilot, and for only a bit $$ more I can get it to control the electric trim. The idea is that it will manage the trim when the A/P is engaged, so the plane will be in trim when it's disengaged. Another cool feature is that you can control the trim from the control head when the autopilot is off - I think in really small increments.

I've heard from people with TT autopilots that it is tricky to keep the plane trimmed enough to make the autopilot happy - that's why I'm thinking of electric trim.

If I knew for sure that the Trio Pro Pilot would not be annoying with lots of trim requests, then I might go for manual trim. Like Mel, I like manual stuff.

Anyone have any experience with Trio autopilots with or without pitch trim? How often are you re-trimming at the autopilot's request, and how annoying / difficult is it?

dave
 
IowaRV9Dreamer said:
What I'm struggling with is the interaction between autopilot and pitch trim. I'm planning the Trio Pro Pilot autopilot, and for only a bit $$ more I can get it to control the electric trim. The idea is that it will manage the trim when the A/P is engaged, so the plane will be in trim when it's disengaged. Another cool feature is that you can control the trim from the control head when the autopilot is off - I think in really small increments.

I've heard from people with TT autopilots that it is tricky to keep the plane trimmed enough to make the autopilot happy - that's why I'm thinking of electric trim.

If I knew for sure that the Trio Pro Pilot would not be annoying with lots of trim requests, then I might go for manual trim. Like Mel, I like manual stuff.

Anyone have any experience with Trio autopilots with or without pitch trim? How often are you re-trimming at the autopilot's request, and how annoying / difficult is it?

dave
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I have many hours with the Trio autopilots and manual trim in my RV-6. I assume the auto-trim feature of the EZ-Hold works as advertised, but I have never felt the need for it in my plane. The manual elevator trim is precise, easy to adjust in fine increments, and has nearly zero failure modes.

If you have the plane anywhere close to trimmed properly, the EZ-Hold servo will have no problems with maintaining altitude without slipping. You would have to burn off a lot of fuel for the plane to be out of trim very much when the system is disengaged.
 
good info Sam... got any more?

Thanks Sam - BTW your posts (combined with their servo design and astonishing customer service) are why I'm going with Trio.

So are you saying that you don't get trim change requests from the A/P at all, or very infrequently in cruise?

If I win the lottery and can afford a GNS430 I'd like someday to be able to fly coupled approaches with the autopilot (GPSS/GPSV). I know this is a planned feature for the Pro Pilot. Given your experience, would you think there would need to be big trim changes during those operations (I think maybe so). If so, do you think you could do it manually at the A/Ps request while leaving it engaged?

Thanks for any words of wisdom.

dave
 
IowaRV9Dreamer said:
Thanks Sam - BTW your posts (combined with their servo design and astonishing customer service) are why I'm going with Trio.

So are you saying that you don't get trim change requests from the A/P at all, or very infrequently in cruise?

If I win the lottery and can afford a GNS430 I'd like someday to be able to fly coupled approaches with the autopilot (GPSS/GPSV). I know this is a planned feature for the Pro Pilot. Given your experience, would you think there would need to be big trim changes during those operations (I think maybe so). If so, do you think you could do it manually at the A/Ps request while leaving it engaged?

Thanks for any words of wisdom.

dave
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Dave, the only time I have seen a trim request (actually it was the "clutch slip" message--I have the clutch set up pretty light so the plane can be easily hand flown even with the servo engaged) was during a high speed descent with the trim still set for cruise speed. A slight twist of the trim knob was all that was necessary to get everything squared away. You might be interested to know that during a similar scenario in turbulence I saw the system disengage when a particularly sharp jolt triggered the over-G safety release. It was nice to watch this valuable feature working as designed.

You have raised a valid question about large speed/trim changes during an approach. If your plane was trimmed for cruise and you transitioned to 90-100 kts for an approach, you might see a trim needed indication (the location of the CG on your plane will be a major factor). However, the times I played around with approaches with the Trio system, it seems I've spent a few moments hand flying while setting things up and reflexive manual retrimming occurred due to habit. If you want your plane to have a wide speed envelope without the need to touch the trim, then the auto-trim would probably be a worthwhile feature. You could easily retrim manually but the auto-trim would allow you to transition from cruise to approach without having to touch the controls.
 
The autopilots (either TruTrak or Trio) really don't care too much if the airplane is a little out of trim either way. Manual or Electric trim doesn't really change that fact. I guess from my standpoint - either TT or Trio, once you use the auto pitch trim you really get very spoiled....it is pretty darned slick. If/when your AP is 2 axis and coupled up to follow a flight plan throught the climb, enroute, descent and approach, the auto trim is really nice. Same in really bumpy turbulence. For the relative cost of the auto pitch trim (in either of the companies cases), I'd encourage you to do it, especially if flying IFR.

Either way with either company you'll be happy. Both TT and Trio are RV guys who own and fly their own RV's - their experience with AP's is proven, and both companies are very nice people.

Anyway, nothing wrong with manual trim (I have manual Aileron trim in my plane, but electric elevator) so I won't get into that argument. I'll just say one last time that the Auto Pitch Trim from either company is REALLY slick when you've got everything coupled up - let's not start that debate either! :)

My 2 cents as usual!

Cheers,
Stein
 
SteinAir said:
Either way with either company you'll be happy. Both TT and Trio are RV guys who own and fly their own RV's - their experience with AP's is proven, and both companies are very nice people.
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The Trio guys fly those backwards plastic airplanes but as stated, they know what they are doing and are very nice people! :D
 
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