V

vasrv7a

Well Known Member
I will soon be upgrading/converting my RV-7A from VFR to IFR. I currently have MANUAL elevator and aileron trims which I like and I'm very comfortable using (they work well and I have had little to no maintenance issues). It was suggested (for IFR) that I upgrade both trims to ELECTRIC. I am concerned about not having the precise trim control (using ELECTRIC TRIM) that I now have with MANUAL, and I am concerned about ongoing maintenance (trim servo) issues that may become problematic. I would appreciate comments, suggestions and recommendations regarding whether to keep the trims manual or upgrade to electric. Also, which electric trim servos are people using that have given good performance with little or no maintenance issues.

Thanx very much.

Victor
 
Victor,

My two cents (but as a non-IFR pilot) would be that if you are comfortable with the manual trim, just leave it that way. The only reason (in my mind) to have the electric would be having the switches on the stick.

greg
 
vasrv7a said:
I currently have MANUAL elevator and aileron trims which I like and I'm very comfortable using (they work well and I have had little to no maintenance issues).

Thanx very much.

Victor
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So.....tell us again why you would want to make a change...? :)
 
Electric from the beginning.................and it's been a pleasure of perfection. What else can I say... :D

My Ray Allen joystick has a four way hat switch.

L.Adamson -- RV6A
 
Sam,

It was suggested that due to the heavier workload flying in an IFR environment, Electric trim would be an advantage...

I am asking for comments from others with IFR experience in IMC.

Thanx.

Victor
 
vasrv7a said:
Sam,

It was suggested that due to the heavier workload flying in an IFR environment, Electric trim would be an advantage...

I am asking for comments from others with IFR experience in IMC.

Thanx.

Victor
Click to expand...

I would prefer to fly the systems I am familiar with and trust. There will plenty of new stuff to learn while getting the rating. :)
 
Sam Buchanan said:
I would prefer to fly the systems I am familiar with and trust. There will plenty of new stuff to learn while getting the rating. :)
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FWIW, there are plenty of RV owners around here, who have electric trim. It's simple, and doesn't require the hand to be moved from the stick. In fact, you'll probably keep the aircraft in trim more often, just because of the convience. It's just a simple blip of the button or hat switch. Very simple. My 6A trims extremely well. It uses the hinged tab method on the aileron, with no bias spring. I'd even do it that way on a 7, 8, or 9. Even if it meant building in a tab for looks.

L.Adamson --- RV6A
 
vasrv7a said:
..... I would appreciate comments, suggestions and recommendations regarding whether to keep the trims manual or upgrade to electric.
Click to expand...
You might as well be asking who was the superior fighting force,....the Hittites versus the Egyptians at Kadesh or the Carthaginians versus the Romans during the first Punic War. History is always written by the winner and at present, ELECTRIC trim fans are still engaged in pitched battle with the slaves of manual labor, er trim....over who really does possess the superior system....manual or electric? Times change, but people never do. So the best advice I can offer you is to pick your battles carefully because in the end, no matter what you may believe or think, there will always be those who strongly believe HIS system is superior...and will not hesitate to quickly inform you so. :D
 
L.Adamson said:
FWIW, there are plenty of RV owners around here, who have electric trim. It's simple, and doesn't require the hand to be moved from the stick.

L.Adamson --- RV6A
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The standard manual trim on all side by side RV's doesn't require you to move your hand from the stick to adjust either axis. You use the same hand you use for throttle, mixture, prop RPM, to write notes, change altimiter setting, change avionics settings/freq. ,etc.
I like my manual trims, and I don't think the work load would be any different flying IFR (though I do not do that).
 
Rick6a said:
You might as well be asking who was the superior fighting force,....the Hittites versus the Egyptians at Kadesh or the Carthaginians versus the Romans during the first Punic War. History is always written by the winner and at present, ELECTRIC trim fans are still engaged in pitched battle with the slaves of manual labor, er trim....over who really does possess the superior system....manual or electric? Times change, but people never do. So the best advice I can offer you is to pick your battles carefully because in the end, no matter what you may believe or think, there will always be those who strongly believe HIS system is superior...and will not hesitate to quickly inform you so. :D
Click to expand...

Yes, Rick even put a constant speed prop on his new RV8.........'cause I
I told him so.... :D His prior plane has fixed pitch.

But other than that, the opinions expressed on this forum, are always just from those who are most vocal, and may or may not present the majority.

In fact, at the end of the day......You might be so confused, that you'll wonder why you even asked.. :)

L.Adamson --- RV6A
 
rvbuilder2002 said:
The standard manual trim on all side by side RV's doesn't require you to move your hand from the stick to adjust either axis. You use the same hand you use for throttle, mixture, prop RPM, to write notes, change altimiter setting, change avionics settings/freq. ,etc.
I like my manual trims, and I don't think the work load would be any different flying IFR (though I do not do that).
Click to expand...

You're right.....

I got ahead of myself.
 
If it's not broke...

vasrv7a said:
Sam,
It was suggested that due to the heavier workload flying in an IFR environment, Electric trim would be an advantage...
I am asking for comments from others with IFR experience in IMC.
Thanx.
Victor
Click to expand...
As a CFII, if using trim (either manual or electric) is a workload issue, you are way way behind the airplane :eek: (I have a fair amount of IFR experience in IMC :cool:)
The Cessnas I teach in have both manual and electric trim and invariably each student gets comfortable using one or the other and rarely switches. Neither one is a workload issue. I suspect (predict) that if you switch to electric trim now, your workload will increase for a while (likely longer than your IFR training) Until you get used to the 'new' system you will initially reach for the trim wheel, especially in a high work load situation, and then remember to use the stick switch. Not a big deal, but definitely a change.
If you want to switch, it should be for other reasons - like you just want to :rolleyes:
 
The builders I talk with who want to use manual trim usually want to do so because they believe the manual trim is more finely adjustable. Electric trim can be quite sensitive (hard to set precisely) in cruise unless you use something like a Vertical Power system to reduce the sensitivity and then it becomes quite easy to set it exactly where you want it.

Another thing to consider is the weight of the long trim cable vs the weight of the trim servo and the wire.

Of course, if you have one type already and like it, why change? :)
 
I flew IFR with manual trim for decades in the sensitive Yankee. I put electric trim in my RV-8 (and am installing it in the -3) because I like it. But personally, I wouldn't tear apart a working airplane with trim that I liked because I was starting instrument training. If you decided to change, do it because you want to, not because you have to.

That's from an electric trim fan! ;)
 
Huh!

I just don't get this at all.

As a devoted manual trim guy, I won't try to sell you on or dissuade you from the electric. I will suggest that if you're wondering about changing, then go fly the electric first. That way you'll know whether or not YOU like instead of what someone else likes. :D

PS. best line in this thread is that if trimming is a workload issue then you're way behind the airplane. Can't argue with that!


vasrv7a said:
I will soon be upgrading/converting my RV-7A from VFR to IFR. I currently have MANUAL elevator and aileron trims which I like and I'm very comfortable using (they work well and I have had little to no maintenance issues). It was suggested (for IFR) that I upgrade both trims to ELECTRIC. I am concerned about not having the precise trim control (using ELECTRIC TRIM) that I now have with MANUAL, and I am concerned about ongoing maintenance (trim servo) issues that may become problematic. I would appreciate comments, suggestions and recommendations regarding whether to keep the trims manual or upgrade to electric. Also, which electric trim servos are people using that have given good performance with little or no maintenance issues.

Thanx very much.

Victor
Click to expand...
 
Do you have a wing leveler autopilot? Pitch autopilot? I would surmise that those are far more important than whether trim is manual or electric, especially if they can be coupled to the instrument procedure in your avionics.
 
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Manual vs Electric

While either manual or electric trim is suitable for instrument work, the electric trim can be incorporated into the autopilot system thru the optional autotrim. It is nice to change flight configurations or speeds and have the autopilot hand back a trimmed plane when the autopilot is disengaged (especially at 200' AGL). Some of the autopilots utilize idiot lights to indicated a need for trim if manual trim is utilized. A good autopilot is an invaluable tool for serious instrument work.

I am not very familiar with the autopilots being used the the RV's. Do they utilize lights to indicated a need for trim? Do they provide the option for autotrim?
 
DaAV8R said:
I am not very familiar with the autopilots being used the the RV's. Do they utilize lights to indicated a need for trim? Do they provide the option for autotrim?
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There are options for autotrim with the lower cost "experimental" auto-pilots that we often use.

L.Adamson --- RV6A
 
Thank you everyone for your contributions to my information search. As always, I received a good cross section of information which is very helpful and is very much appreciated.

Thanx.

Victor
:)
 
One of the bad things about electric pitch is that the sensitivity goes up with speed so that at higher speeds you musy give just little blips to the switch for pitch trim. It' really bad when you go over 200 mph IAS.
For lateral trim it is much better to have a spring-loaded trim in the aileron activation vs an aileron trim tab for the same reason. If you have to trim out a lateral unbalance then an aileron trim tab set at high speed will have to keep getting set higher and higher as the speed is decreased, whereas a spring-loaded trim on the aileron actuating mechanism automatically sets a given force which keeps the aileron load constant and deflects the aileron farther at lower speeds. I designed a trim-speed compensating mechanism based on IAS to have the trim operate at 6 sec. end-to-end at low speed and 18 sec. at high speed and it was much better to use.
 
elippse said:
One of the bad things about electric pitch is that the sensitivity goes up with speed so that at higher speeds you musy give just little blips to the switch for pitch trim. It' really bad when you go over 200 mph IAS.
For lateral trim it is much better to have a spring-loaded trim in the aileron activation vs an aileron trim tab for the same reason. If you have to trim out a lateral unbalance then an aileron trim tab set at high speed will have to keep getting set higher and higher as the speed is decreased, whereas a spring-loaded trim on the aileron actuating mechanism automatically sets a given force which keeps the aileron load constant and deflects the aileron farther at lower speeds. I designed a trim-speed compensating mechanism based on IAS to have the trim operate at 6 sec. end-to-end at low speed and 18 sec. at high speed and it was much better to use.
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There is another thread, within the last few days, where some with bias spring aileron trim systems have been experiencing out of trim conditions laterally from the opposite side, during various speed changes. The thought, is the load changing on the spring. Some were going to disconnect the spring.............to check it out. I have not heard of results yet.

Since my 6A doesn't hit 200 IAS (often), I've had good results with my 1" * 6" tab mounted on the right aileron. I just do quick blips, and haven't required the need for a speed controller.

L.Adamson --- RV6A
 
Manual Trim Quality?

I am going to be ordering my empennage kit in early September. I am curious about what the manual trim is like to use. I have flown with a few different types of manual trim, (and one airplane with electric) and a well designed manual trim system is really nice to use. Is the manual trim in RVs better than the old 1960s or 1970s Cessna trim?
 
WHY BUY TROUBLE?

I called VAN's to order the electric trim upgrade about a decade ago. Whoever I talked to at the time talked me out of it. He said the VAN's plane recently flown to SUN-N-FUN had an electric trim failure and flying with stuck trim is a bummer, why subject yourself to that? So I continued on with the original manual trim and quit worrying about it.
 
Haptic Feedback is the Best

I LOVE the manual trim on an RV. You can feel exactly where you need to set the knob. I speak of elevator trim. I have electric trim on my bird, but flying other RV's with manual trim made me see the light. The downside? Manual trim is heavier, and occupies more space. Electric trim on the stick is nice, but you are sort of trying to time your stabs, rather than being able to set the trim exactly by touch.

Hans
 
nucleus said:
I LOVE the manual trim on an RV. You can feel exactly where you need to set the knob. I speak of elevator trim. I have electric trim on my bird, but flying other RV's with manual trim made me see the light. The downside? Manual trim is heavier, and occupies more space. Electric trim on the stick is nice, but you are sort of trying to time your stabs, rather than being able to set the trim exactly by touch.
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But manual cables get slop..............or so I hear. Other than that, don't stab it..........just blip it.
 
L.Adamson said:
Since my 6A doesn't hit 200 IAS (often), I've had good results with my 1" * 6" tab mounted on the right aileron. I just do quick blips, and haven't required the need for a speed controller.

L.Adamson --- RV6A
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Sorry! That controller was meant for the pitch trim, not the lateral trim.
 
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