Van's Air Force
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RV-8 trim: manual or electric?
- Thread starter gengrumpy
- Start date
ronschreck
Well Known Member
Yet another opinion. Imagine that!
If you fly a lot of formation you may find that taking your hand off the throttle to twist manual trim can be tricky. Having said that, I have a few formation buddies that say it isn't a problem. Some of them just set the trim and accept a bit of out-of-trim on occasion while in formation. Personally, I want to be able to trim while in formation. My airspeed range in formation varies between 80 KTAS and 220 KTAS, so accepting a trim condition somewhere between those extremes would mean accepting a very heavy stick a lot of the time. It's difficult to maneuver with precision when you are dealing with heavy stick forces.
But, you are building an airplane that suits you, so weigh the pro's and con's and make your own decision. I decided on electric trim.
Well, no, there is also electric.
Well, no, not me.Turns out electric trim was just a fad. Everybody is going manual now
If you fly a lot of formation you may find that taking your hand off the throttle to twist manual trim can be tricky. Having said that, I have a few formation buddies that say it isn't a problem. Some of them just set the trim and accept a bit of out-of-trim on occasion while in formation. Personally, I want to be able to trim while in formation. My airspeed range in formation varies between 80 KTAS and 220 KTAS, so accepting a trim condition somewhere between those extremes would mean accepting a very heavy stick a lot of the time. It's difficult to maneuver with precision when you are dealing with heavy stick forces.
But, you are building an airplane that suits you, so weigh the pro's and con's and make your own decision. I decided on electric trim.
ronschreck
Well Known Member
And another thing...
If you have an autopilot with vertical hold, you cannot have auto-trim unless you have electric trim.
Did I mention that I like auto-trim!
If you have an autopilot with vertical hold, you cannot have auto-trim unless you have electric trim.
Did I mention that I like auto-trim!
humptybump
Well Known Member
Some reasons for each option ...
Electric trim eliminates the big stiff cable from the build. In general, this is a one time issue. However, it does make removal of the elevator more challenging if you paint after phase one rather than paint before assembly.
With electric trim, you may want to insure easy access in the empenage for future maintenance.
With the manual trim knob on the left, just above and forward of the throttle, it is easy to reach without even looking.
Person opinion here - I found electric trim to be hard to judge but with manual trim, I quickly got the feel for very minor adjustments (eg turning 1/12th is often the amount if the the plane has a small climb/descend in hands off). With manual elevator and aileron trim, I found it much easier to get the plane in perfect trim.
Person opinion here - my plane is KISS for as many things as possible. carb, mags, fixed prop, manual trims, etc.
As is often said on this forum, "build the plane you want, not the plane others want you to build" - and - "build for your mission".
Electric trim eliminates the big stiff cable from the build. In general, this is a one time issue. However, it does make removal of the elevator more challenging if you paint after phase one rather than paint before assembly.
With electric trim, you may want to insure easy access in the empenage for future maintenance.
With the manual trim knob on the left, just above and forward of the throttle, it is easy to reach without even looking.
Person opinion here - I found electric trim to be hard to judge but with manual trim, I quickly got the feel for very minor adjustments (eg turning 1/12th is often the amount if the the plane has a small climb/descend in hands off). With manual elevator and aileron trim, I found it much easier to get the plane in perfect trim.
Person opinion here - my plane is KISS for as many things as possible. carb, mags, fixed prop, manual trims, etc.
As is often said on this forum, "build the plane you want, not the plane others want you to build" - and - "build for your mission".
ronschreck
Well Known Member
It's more like 10-20 pounds. The Blues do keep down-trim in, but they trim during the maneuvers to maintain a reasonable down-trim force. And....they have electric trim, just like me!
GeneL
Well Known Member
Blue angels
Smokey, Sorry if I am misinformed, my info came from Rob Kurrle, my friend and neighbor (Blue Angel #3 2010, #4 2011). His dad won a Broonze Lindy at AirVenture 2012 for an RV7 he built. Are you or the team going to Tripple Tree this weekend? Gene "Whiskey 3" in Van's 2012 calander Nov.
Smokey, Sorry if I am misinformed, my info came from Rob Kurrle, my friend and neighbor (Blue Angel #3 2010, #4 2011). His dad won a Broonze Lindy at AirVenture 2012 for an RV7 he built. Are you or the team going to Tripple Tree this weekend? Gene "Whiskey 3" in Van's 2012 calander Nov.
ronschreck
Well Known Member
Maybe it's a personal preference among the Blues. My info from conversation with Greg McWherter.
The Team is not going to Triple Tree, but a few may go on their own. I'm thinking about it.
Silver Fox
Member
Electric Elevator trim
One data point; we have the electric trim on our RV-8. It is VERY sensitive in flight - once in cruise a tiny blip on the motor makes all the change one needs. With only one aboard, we cannot trim to approach speed; we always have a little nose down force to overcome to maintain our 65 Knot approach speed even with full nose-up trim. And if we want to do stop and goes, we need a short time on the runway to get the trim back to neutral and the flaps up. One of my partners checked out in a RV-7 with the manual trim and I believe that given the choice, we would select that. Not to change the subject (says he changing the subject) be we also have electric aileron trim. It is glacially slow and a real contrast to the elevator trim which is lightening fast.
One data point; we have the electric trim on our RV-8. It is VERY sensitive in flight - once in cruise a tiny blip on the motor makes all the change one needs. With only one aboard, we cannot trim to approach speed; we always have a little nose down force to overcome to maintain our 65 Knot approach speed even with full nose-up trim. And if we want to do stop and goes, we need a short time on the runway to get the trim back to neutral and the flaps up. One of my partners checked out in a RV-7 with the manual trim and I believe that given the choice, we would select that. Not to change the subject (says he changing the subject) be we also have electric aileron trim. It is glacially slow and a real contrast to the elevator trim which is lightening fast.
panhandler1956
Well Known Member
Etrim on coolie hat
e-trim on the stick - works good, lasts a long time...
e-trim on the stick - works good, lasts a long time...
JonJay
Well Known Member
Check the "never ending debates" section. I think it runs about 50/50.
I am a manual trim guy under the KISS principle. I fly a lot of formation and do not find it an issue but I am not flying to the extremes of TEAM RV, not even close. Standard FFI stuff for me.
If you find a compelling reason to go one way or another, you then will be elected to do the same for tip-up vs slider and FP vs CS..... good luck! ha!
I am a manual trim guy under the KISS principle. I fly a lot of formation and do not find it an issue but I am not flying to the extremes of TEAM RV, not even close. Standard FFI stuff for me.
If you find a compelling reason to go one way or another, you then will be elected to do the same for tip-up vs slider and FP vs CS..... good luck! ha!
cdmiller
Well Known Member
I like my electric elevator trim
I have electric trim on my RV-8 with trim buttons on the top of the stick. I love it because I like to keep the plane in trim all the time. Without moving my hand from the stick, I can constantly trim off any control pressures. That way, I am always controlling the stick with thumb and index finger and it is always in trim.
Finally, I know of nothing that you would give up by installing electric trim. I think that it is well worth the cost.
Good luck with your project. The RV-8 is a wonderful plane; you are going to love it!
Dan Miller
RV-8 IO-360 M1 with WW 200RV prop. 1190 hours of fun.
I have electric trim on my RV-8 with trim buttons on the top of the stick. I love it because I like to keep the plane in trim all the time. Without moving my hand from the stick, I can constantly trim off any control pressures. That way, I am always controlling the stick with thumb and index finger and it is always in trim.
Finally, I know of nothing that you would give up by installing electric trim. I think that it is well worth the cost.
Good luck with your project. The RV-8 is a wonderful plane; you are going to love it!
Dan Miller
RV-8 IO-360 M1 with WW 200RV prop. 1190 hours of fun.
Rick6a
Well Known Member
Is that really the whole story? For instance, electric trim pitch change most certainly need not be "lightening fast" if a speed controller such as the MK111 is installed. With the device and the pot on it adjusted to suit, the trim button can take considerably more than a very quick blip to effect a pitch change, even in high speed cruise. If your electric trim is as fast as you say, you can easily slow it down with a speed controller to satisy any personal preference or comfort zone.
Neal@F14
Well Known Member
I've put about 25 hours on an RV-4 with manual elevator trim, about 100 hours on an RV-8 with electric trim, and now have about 30 hours on my RV-6 with electric trim. I prefer the electric trim much more now. Both the 8 and the 6 have the Ray Allen adjustable speed controllers on the trim too.
