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Flap motor worm drive gear

cdmiller

Well Known Member
I recently had a flap motor failure in my RV-8. I took it apart and cleaned grease from it according to suggestions make on VAF. After about 10 hours, it failed again. I bought a new motor to install on the flap drive mechanism, but can't figure out how to remove the worm drive gear from the old motor shaft and install it on the new motor shaft. Have any of you done this? There is no evidence of a set screw in the gear and the new motor does not have a splined drive shaft or a flat spot on the shaft. I would appreciate suggestions about how to go about this.

Thanks,

Dan Miller
RV-8 690 hours
 
I had the same problem as you are having, bought the same motor as you and could not get the gear off of my old motor. I talked to Usher Precison about it and was told I was not going to be able to get the gear off without damaging it. Usher will sell you a new motor with the gear attached, that is what I did no problems since. As I remember they are about 100.00 from Usher.

Bill

http://www.usherprecision.com/
 
I had the same problem as you are having, bought the same motor as you and could not get the gear off of my old motor. I talked to Usher Precison about it and was told I was not going to be able to get the gear off without damaging it. Usher will sell you a new motor with the gear attached, that is what I did no problems since. As I remember they are about 100.00 from Usher.

Bill

http://www.usherprecision.com/

I went through this with a flap motor failure on the first flight with the Lycoming conversion last January. It was the 3rd time the motor had failed since 2003.

I got in touch with http://www.motionsystem.com/ in New Jersey, the original supplier of flap motors to Vans. They told me they did not know the motors were going to be used in an airplane and the reason they failed so frequently was they were not designed for that use.

The guy offered to rebuild my motor to much better specs and it would not fail as did the old units, so I went for it. It came back looking completely different with much improved seals very apparent.

So far, so good. :)

The cost of the rebuild was $199.77 including shipping and they turned it around in a couple days.

I don't know anything about the Usher motors.
 
Hello David

Thats interesting!

Did you know the name of the guy that have done the modification?

Also, did the outside dimension of the motor looks the same and does it still fit into the center-console?

Thanks and regards,

Dominik
RV-7A
 
Hello David

Thats interesting!

Did you know the name of the guy that have done the modification?

Also, did the outside dimension of the motor looks the same and does it still fit into the center-console?

Thanks and regards,

Dominik
RV-7A

The motor has a cover over it and the entire unit fits like before. I think it is the same original drive but completely rebuilt. It just looks different because of the seals and the motor cover.

I do not have a name but you can call Motion at (732) 222-1800 and ask for the service department.
 
flap motor brushes

Had a flap motor failure at about 200 hrs.
Cleaned motor and brushes and no problems now for 1,000 hrs.
I purchased a set of brushes just in case and keep them in my tool bag.
For $16 you can get a new brush assembly (p/n 79633-004)
They are in New Jersey at
www.motionsystem.com
(732)222-1800

From Rosie: I just bought a new set of brushes on 12 Oct 2011, no change in price, part & contact info all good ;-)
 
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Flap motor INOP now

I returned from a late night flight a couple of weeks ago and my flap motor went INOP also. I've not had time to tear it down to see if it's the motor or the relay from the control switch. I've needed to fly, so I've been without flaps until I get at it, but at least it quit in the full up position. I have 480 hrs now,,

I guess I'll be calling Motion also? Any additional thoughts?

Kenny Gene
294TC RV 7a
 
I returned from a late night flight a couple of weeks ago and my flap motor went INOP also. I've not had time to tear it down to see if it's the motor or the relay from the control switch. I've needed to fly, so I've been without flaps until I get at it, but at least it quit in the full up position. I have 480 hrs now,,

I guess I'll be calling Motion also? Any additional thoughts?

Somewhere in another thread......... I mentioned that my flap motor quit because of fraying wires where they come out of the motor housing. They were bent on a 90 degree angle. By moving them around a bit, the motor worked. I'm going to pull it apart today. My motor is a late 90's version.

L.Adamson -- RV6A
 
Flap motor brushes

Somewhere in another thread......... I mentioned that my flap motor quit because of fraying wires where they come out of the motor housing. They were bent on a 90 degree angle. By moving them around a bit, the motor worked. I'm going to pull it apart today. My motor is a late 90's version.

L.Adamson -- RV6A


I had the exact same thing happen on my RV-4. I ended up breaking the brush assembly trying to fix it. Warning: it is very brittle. Now I'm looking to purchase a new brush assembly and will let you know what I find.
 
Van's never had a flap position failure untill they came out with flap motors. And that's progress?
 
... interesting!

David: can you post a couple if pics of the rebuilt motor?

Thanks.

Alf, I would love to but the hangar is very cold right now. I'd have to remove the seats and the side panels to get to it.

Let me say, it fits perfect. At least it went in just like it came out before the rebuild. The motor head is under a cover and I don't know how it is attached. The other end where the screw shaft comes out is also sealed. It just seems much better than it was.

That being said, I don't trust these things. Could be the Usher units are good from the beginning but the Motion units have been a royal pain in the butt.
 
Huh???

They told me they did not know the motors were going to be used in an airplane and the reason they failed so frequently was they were not designed for that use.

"Not designed for that use"???? Huh???

The flap motor model number supplied by Van's (ES 85615-157-1), appears to be designed to handle 100 lbs of load, per the supplier. http://www.motionsystem.com

Based on the fulcrum advantage of the flap arm (130%), I can't possibly imagine the air loads generating that much force on the motor. It can't matter if it's in an airplane, a car, or a basement toy. The only "design" issue is, what IS the actual air load on the motor.

I am puzzled though, how is it this "same" motor shown at motionsystems has a long black rod sticking out of it, but our motors don't have that? Something seems amiss?? And why do this flap motor failures seem to keep happening? Sounds like a MOTOR design problem to me...........
 
I am puzzled though, how is it this "same" motor shown at motionsystems has a long black rod sticking out of it, but our motors don't have that? Something seems amiss?? And why do this flap motor failures seem to keep happening? Sounds like a MOTOR design problem to me...........

My 1998 Motion Systems motor looks the same as in the pic. The moving part of the telescoping unit is black.

Recently, I took mine apart. There was an "exploded view" picture of all the parts on the net. Might even have been linked from here. I just googled for it.

While others had too much grease that worked it's way to the brushes, mine was a case of the wires that came out of the housing being pressed at a hard 90 degrees (from my installation). The insulation frayed, and one wire got to the point of intermittent operation.

The fix wasn't too tough. You remove the housing and end up with the wires & brush wires being pressed into a small hole with a pin. I found the pin somewhat difficult to press back in, so I just soldered them together, and re-routed the wires through the slots that hold them. There's a few tricks to keeping the spring loaded brushes in place, while you insert them around the motor armature, but it's not difficult either.

All in all, the unit is simple and fairly robust in construction. It works just fine now.

L.Adamson --- RV6A
 
I had the same problem as you are having, bought the same motor as you and could not get the gear off of my old motor. I talked to Usher Precison about it and was told I was not going to be able to get the gear off without damaging it. Usher will sell you a new motor with the gear attached, that is what I did no problems since. As I remember they are about 100.00 from Usher.

Bill

http://www.usherprecision.com/

Bill have you had any problems with you new motor? I need another one I've cleaned mine about 4 times now.
 
When I first started flying mine used to quit ever 10-20 hours. Someone told me to spray gobs of contact cleaner in, and try it again. This worked every time and became more and more effective. Last time it quit was 5 years ago.
 
Brush assembly for flap motor

I found a brush assembly from Click Automation that fits the motor.
Their part number was 862754 If I remember correctly it was about $14 and the shipping was $21 so I ordered two, one for new set and one for a spare in the tool bag. The major difference in the "brush", as they call it, is that it doesn't have wires to the brushes and little springs pushing the brushes as they are silver soldered to some leaf type tension springs. It is much easier to remove and install on the motor.
I saw one reference by Pittman industries to a SuperBrush, but I am not sure if this in fact what they are referring to.
Now we carry the correct size allen wrench (to remove the motor from the jack shaft) and a spare brush. I am hoping with that insurance, that it won't fail again ;) Their web site is http://www.clickautomation.com/ and then just search for the part number 862754.
I installed the new brush about 50 airframe hours ago with no problems yet.

Good luck.
John Myers RV8 N851JM
 
flap motor worm gear

Just had a friend show me his failed flap mechanism. The worm gear was completely wiped out. we both finished our planes at the same time his with less flying time than mine.
He ended up buying the whole flap mechanism. Any thoughts on this?
 
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