FLT Cancelled - Flap Motor TU

David-aviator · #1 12-04-2007, 08:09 PM

I was ready to taxi this afternoon when the flap motor wouldn't raise the flaps. Total bummer. This is a replacement motor for a grease filled one of 2 years ago. These motors are unreliable, a source of aggrivation and besides that, no darn good.

The side panels were removed to get at the motor but before removing it, the switch was activated one more time - the motor ran! Double bummer, I couldn't get it to NOT run, so now what? A search of the forum on this subject revealed there are dozens of messages on the problem. No solutions, just lots of temporary fixes, like clean the brushes, replace the brushes, replace the motor etc, etc. I remember flying around with the first motor not using flaps out of concern they would not come up - sometimes they worked, sometimes they didn't. What a total pain in the patusch!

Why did Vans ever depart from the simple manual flap system? I would ten times rather have a handle to move the flaps than an unreliable motor that won't when I need it. The flap system should be as reliable as the ailerons, elevators and rudder - it is not. We need a manual kit or a better motor.

Build9A · #2 12-04-2007, 09:35 PM

I have had no trouble with my flap motor for 3 years. That said, I have also heard stories of motor failures and agree that there have been numerous problems.

I am no electrician, far from it, but could your problem be in the switch?

L.Adamson · #3 12-04-2007, 10:09 PM

Quote:

Originally Posted by Build9A

I am no electrician, far from it, but could your problem be in the switch?

Or how about a wire connection behind the side panels?

L.Adamson

Ironflight · #4 12-04-2007, 10:25 PM

Take a deep breath Daivid.....

OK, isn't that better? (Yeah, I know....it doesn't do much but slow you down for a minute, and doesn't take away the frustration...)

I had this happen after a few hundred hours. Took the motor apart and cleaned the brushes, and it has worked ever since. I could probably do it again in 10 minutes now that I am practiced. I think the only "special" tool I needed was some fine safety wire to hold the brushes for re-assembly, and I just make sure I have that in my fly-away tool kit.

Then I don't let it bother me. Or haven't, but maybe I will when it does it again....

(P.S. - I found the exact same motors - except marked for 24 volts - at a surplus electronics place here in town for $5.00 each. Bought a couple, tested them, and they work fine. I figure I have emergency spares for quite awhile!

asav8tor · #5 12-04-2007, 10:32 PM

Quote:

Originally Posted by David-aviator

Why did Vans ever depart from the simple manual flap system?

Because people kept clamoring for electric.

lrfrey · #6 12-05-2007, 06:52 AM

David I'm sure it's frustrating, but the probability is it was/is a dirty, stuck or worn brush. There is a write up on disassembly/reassembly in either a Service letter or one of the RVaitor's, can't recall which. Don't have them here now but I can research if you can't find it.

Paul, how are you going to convert the 24V motors to 12V?

Larry

David-aviator · #7 12-05-2007, 07:44 AM

Quote:

Originally Posted by lrfrey

David I'm sure it's frustrating, but the probability is it was/is a dirty, stuck or worn brush. There is a write up on disassembly/reassembly in either a Service letter or one of the RVaitor's, can't recall which. Don't have them here now but I can research if you can't find it.

Paul, how are you going to convert the 24V motors to 12V?

Larry

The wires are all soldier sealed at connections, there are no quick disconnects. Could be the switch, but I don't think so. The wires going into the unit were moved and I believe that's what got it working again.

I have the motor service bulletin, having been through this once before with the grease. It was cleaned but never did work right and was replaced with a new unit from Vans.

I know there are guys flying around for years without a problem but this is second failure for me which indicates a quality control problem. If you get a good one, you're lucky, if you get a bad one or two, you're unlucky.

I have two 4" DC actuaters that were intended for cowl flaps but the idea was shelved in favor of keeping things simple. They look like the present motor but are much better built. A quick measurement revealed the Vans units are about 5.5" of movement. A bracket 1.5" below the present bracket would work but it would limit flaps to about 30 degrees instead of 40. I am thinking about it.

The source of this motor is http://www.dcactuators.com/

Maybe one of you could check out this product and see if there is a good reason not to continue thinking about it. The 30 degrees flap limitation is really no big deal, just have to adjust an approach speed to whatever the stall speed difference is and it won't be much. I've flown commercial airplanes where flaps were limited to something less than certified full flaps, we simply adjusted the numbers and pressed on.

lrfrey · #8 12-05-2007, 09:58 AM

That actuator looks really good. The only questions I would have are how does the speed (.5"/sec X 4"= 8 seconds to 30 degrees of flap) and load (110 lbs) compare to the Van's unit?

The speed sounds close but since I'm not quite flying I haven't timed it under load. I have no idea what the load rating on the Van's unit is, don't ever recall seeing it published (I haven't really looked for it). I see it has an internal limit switch too, that's nice.

I agree, 30 degrees should be sufficient flaps. Seems to me that you could get back to the full 40 degrees if you chose to shorten the arm on the flap weldment, tho that would probably increase the load on the actuator. Still, if the actuator is strong enough....maybe.

Larry

mark manda · #9 12-05-2007, 02:24 PM

i had a problem a year ago and I got the motor to run also, so I ran them up(pulled the breaker) and flew for a couple mos without flaps.

I feel for you.

What's up with these RA relays?

cjensen · #10 12-05-2007, 02:36 PM

Quote:

Originally Posted by David-aviator

Why did Vans ever depart from the simple manual flap system? I would ten times rather have a handle to move the flaps than an unreliable motor that won't when I need it. The flap system should be as reliable as the ailerons, elevators and rudder - it is not. We need a manual kit or a better motor.

Totally agree with ya David! That's why I threw out the electrics (well, I sold them), and made my own manual flaps with a manual weldment out of an RV-6. I have another one in my garage if you (or anyone) wants to give it a go...not difficult at all, other than making a new cover for the center tunnel.

No electrics for me!