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Elevator trim

The question is...what do you want? If you really feel its necessary then it is worth it. I for one prefer manual trim as I am used to using that type, plus its one less electrical thing to fail. Do a forum search on manual vs. electric trim. You'll see both sides of the argument.
 
My electric elevator & aileron trim is on the joystick hat switch. I wouldn't have it any other way. My 6's aileron trim is of the hinge tab system that mounts to the aileron with a servo mounted inside the aileron. Not as simple as the bias spring method, but I prefer it. Van's still sells them, though.
 
Neither electric trim system is worth the money nor the extra time it takes to install it.
IMHO
 
Future RV 9 Flyer said:
is it worth the extra cost?
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Wrong question I think. Compared to the total cost of a build, it's a fraction of 1%. So instead, think which method you want to fly with. As you can see you'll get die-hard adherents to either method.

Me, I went with electric 'cause I've never flown a certificated airplane that had a good manual trim system. In other words, they always had a bit of slack and hysteresis which was annoying. And I like the idea of a hat switch on top of the stick to activate the trims. I intend to use a trim speed controller (reduces trim motor speed above a certain airspeed) for better control.
 
Two points in favor of electric roll trim: it won't creep with vibration, and you don't have to cram your hand between the seats to grope for the handle. Electric pitch eliminates the big knob and cable loop that eat up leg wiggle room. Otherwise electric has no improved functionality for $550 more.

John Siebold
 
POUNDS vs. ounces

RV7ator said:
.....Electric pitch eliminates the big knob and cable loop that eat up leg wiggle room.....
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For the weight conscious aircraft builder seeking accurate data, this perennial topic is a very good place to make a direct comparison devoid of personal bias. Die-hard fans of the manual system may be unquestioningly fond of their preferred choice of trim system but such ardor cannot lessen manual trim's one truly significant drawback....weight. The heavy steel cable assembly that is the very heart of the manual trim system tips the scales at a hefty 2.5 pounds. That substantial amount of weight does not include the required turning knob, mounting bracket and associated installation hardware. Are the sum of those parts effectively reducing leg wiggle room some builders report?

By way of direct comparison, the total installed weight of an electric trim system is approximately 7-8 ounces. Do the math and then decide if you comfortable with a manual trim system that is at least 5X heavier than electric. VAF members have reported that Van's chooses to install electric trim in its own factory built airplanes. Why is this so? If actions speak louder than words, Van's clear preference for electric does not exactly shout a ringing endorsement for the virtues of its manual trim system.
 
I like the fine tuning of manual

I like being able to turn the knob in very tiny increments to get the manual trim just right. Having said this I have never flown with electric but visualize it being like my car window, where I can not finely adjust it. I am sure you can slow electric down but do you have a two position switch in order to have fine and course trim?
 
RV7AV8R said:
I like being able to turn the knob in very tiny increments to get the manual trim just right. Having said this I have never flown with electric but visualize it being like my car window, where I can not finely adjust it. I am sure you can slow electric down but do you have a two position switch in order to have fine and course trim?
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It's been said by others..........that my aircraft was one of the finest trimming RV's out there. It would fly in perfect balance. I was proud, considering it was a 6, I built on a jig for straightness, as the fuse isn't prepunched. It used electric servo trim for both elevator and aileron, with no speed control. Hat switch on the joystick.

L.Adamson
 
better yet, auto electric trim. put a gizmo in the system and never trim again when using the auto pilot. wonder if you could get it to work without the AP? might as well use some of those electrons.
 
Rick6a said:
By way of direct comparison, the total installed weight of an electric trim system is approximately 7-8 ounces. Do the math and then decide if you comfortable with a manual trim system that is at least 5X heavier than electric. ...
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Thanks, Rick. I was having trouble with Van's claim of "Weight comparable to standard manual installation." as stated in the RV-7/7A order form. When I received the emp kit a couple of weeks ago, I was really surprised to find that the contents of the electric trim kit "feels" lighter that the box it comes in. That is as it should be, seeing as how it is installed IN the elevator.

Having flown a 1955 C-170B for the last 29 years, I'm very comfortable with manual systems, but I opted for electric trim for my 7, as the installation seems much more straightforward, and installation of a speed control or an autopilot with auto trim should handle the speed issue. Even though I'm an EE I've always harbored a distrust in the reliabiliy of things electrical, but it seems the Ray Allen trim system has been giving folks statisfactory service.

I'm still on the fence with the electric vs. manual flaps because with manual, you can put them WHERE you want them WHEN you want them. I'll probably go with electric in the end as that appears to be the only option for the 7 without rolling my own system.:eek:.

OT Warning!
Rick6a said:
VAF members have reported that Van's chooses to install electric trim in its own factory built airplanes. Why is this so? If actions speak louder than words, Van's clear preference for electric does not exactly shout a ringing endorsement for the virtues of its manual trim system. ...
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By the same token, Van's seems to have a preference for tip up canopies.:p
 
longranger said:
I'm still on the fence with the electric vs. manual flaps because with manual, you can put them WHERE you want them WHEN you want them. I'll probably go with electric in the end as that appears to be the only option for the 7 without rolling my own system.:eek:.
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All depends on how fat the passenger is, and how chummy you want to be... In some cases, that flap handle could be awful hard to reach! :D

Besides, that's where I kept my bottled water.
 
longranger said:
......I'm still on the fence with the electric vs. manual flaps because with manual, you can put them WHERE you want them WHEN you want them.....
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WARNING. THREAD DRIFT ALERT!

Miles,

Before you jump off that fence and finally make a flap system purchasing decision, make it a truly informed purchasing decision. I sense you may not be fully aware of the possibilities available to you. In that spirit, I feel that I must comment on your WHERE and WHEN assumptions regarding the real or imagined operational advantages of a manual flap system compared against a popular alternative...electric flaps.

By design, manual flaps only offer a few fixed settings, commonly established by the builder to be 10º, 20º, 30º and 40º and a big honking space wasting flap handle to accomodate manual flap operation. A tried and true manual flap system, there is no denying that it works well enough to satisfy the needs and desires of many, many pilots. I sometimes wonder how many old school RV8 pilots would opt for manual flaps if they had the choice. Alternatively, by sporting electric flap operation, I effortlessly manipulate the momentary flap toggle switch positioned atop the Infinity stick grip and enjoy the satisfaction of knowing that unlike manual operation, I can deploy a truly infinite range of flap settings from 0º thru 40º. If I so choose to deploy 13¾º of flaps, I can do just that. Does manual flap operation give the pilot any ability to crank in 27½º or 34¼º of flap deployment? The answer to that is not just no but heck no.

It has been commented before....yet I have no first hand knowledge that the occasional formation pilot has been known to take advantage of that infinite flap setting capability to make slight adjustments (1º or 2º) to more easily maintain formation flight. Whether that is true or not, what I do know for sure is that I have found when practicing touch and gos or doing an unexpected go-around, it is very convenient without removing my hand from the joystick grip to retract the flaps to any degree I want, WHEN I want. By keeping a firm grip on the joystick at all times, specifically NOT having to reach for a panel mounted electric flap switch or a floor located manual flap handle, my full attention to the task at hand need not be even slightly diverted. I feel my preference (electric flaps with grip mounted momentary toggle) is a good and safe arrangement all around but of course mine is a highly personal choice, the type of decision each builder has to decide for himself. :)
 
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Back on the trim topic :D

I like manual trim and think of it as a backup control for the elevator. I had planned from the outset to have manual trim in my 6A. Now that I have most of it built and have been working to best fit my 6'4" frame, I need all the knee room I can spare. I recently made the decision to go with electric trim. The only other option I saw was to buy a longer (and heavier) cable I could route all the way up to the panel and put next to the throttle, mixture.

I have the spring bias aileron trim, but I will likely put in a servo to operate that as well. If you are going to go, go all the way..haha
 
Electric trim can run away. Manual trim will not.

Most modern airplanes have electric trim because is is convenient and cheaper to install. Most modern airplanes have run away protection of some sort. Be aware, with the RV's there is no run away protection except hit the switch in the opposite direction.
 
David-aviator said:
Electric trim can run away. Manual trim will not.

Most modern airplanes have electric trim because is is convenient and cheaper to install. Most modern airplanes have run away protection of some sort. Be aware, with the RV's there is no run away protection except hit the switch in the opposite direction.
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Or have a little switch right above the throttle that kills the trim power. I did. It had a red enclosure around it. Supposeable purpose, is if the passenger/pilot gets carried away with trim. Besides, RV's have been tested with full trim, and not too tough to overcome. Cable trim also get's slop.
 
runaway protection...

David-aviator said:
Electric trim can run away. Manual trim will not.

Most modern airplanes have electric trim because is is convenient and cheaper to install. Most modern airplanes have run away protection of some sort. Be aware, with the RV's there is no run away protection except hit the switch in the opposite direction.
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The Vertical Power electrical management solutions all have trim control and runaway protection built in... hard to conceive of a better system than trim on the stick.
 
After originally building my elevators for electric trim, I changed to manual while building the fuselage. I did so just because I like simple and because I like the idea of not needing electricity to have trim. Having just completed transition training with Mike Seager in his RV-7 with manual trim, I know I made the right decision for me.

The trim knob is located in the perfect spot, is very intuitive, it is super responsive and easy to fine trim but nearly impossible to over trim, and can be reset on a stop and go merely by turning the knob 360 degrees (two quick 180s). Don't even need to look at an indicator.

Just another opinion.
 
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