Electric gear issues

[mgan]

I have a 1965 M20E with the electric gear (dukes actuator)

The actuator motor has always been really slow bringing the gear up.  We got the plane on jacks to do gear swing and the motor struggles very hard when swinging the gear up.

While we had the actuator off to inspect the gears, we tried moving everything by hand and there doesn't seem to be any binding.

worm gears look ok.  cleaned and packed with all new grease and it still struggles to bring the gear up (takes about 12 seconds)

has anyone seen this issue? It feels like it must be the motor itself that is the issue since it is struggling during the entire stroke.

Another issue we have is sometimes when the gear goes down, the light turns green and the motor gets de-energized and relaxes just enough to allow the limit switch to trip then it will turn on until it turns on green light.... then turn off and relax and repeat.  So the green light flashes on and off and the relay/motor keep turning on and off.

has anyone experiences either of these issues and have the ability to offer insight?

[ShuRugal]

Do the bungee springs have the correct tension?

Sent from my Pixel 3a using Tapatalk

[Andy95W]

That sounds a lot like the motor is ready for an overhaul of the internals.  Yours might have some internal binding or friction that is showing itself when it’s trying to retract the gear.

As to the “relaxing” issue and relays turning off and on, I had that exact same issue on my first Mooney, a 67 M20C.  There are 2 internal springs in the motor housing that hold tension on the shaft when the motor is de-energized.  Those springs lose tension over the years and allow the shaft to relax due to the bungee spring force at the landing gear legs.

I took my landing gear motor to a knowledgeable old-school Mooney guy (at Dugosh) and he installed 2 standard washers to shim those springs and make them tighter.  It worked for a few years until I sent it out for overhaul.  Again, this would be solved with an overhaul along with the other issue.

And like ShuRugal said, the actual gear rigging should be checked, to ensure the springs bungees at the mains and nose gear are tensioned correctly when the gear is down and locked.

[mgan]

we checked the tension and it appears correct.

I was suspecting the motor was the issue as we basically eliminated all other variables, so I am glad you are able to confirm this suspicion.

Where did you send it for overhaul and how much does it cost? (at least 10x what it should, I'm sure.... kinda like a $20 worm gear set selling for $1850)

[FlySafe]

mgan, I just recently had my done by Lasar, they first inspected the internal gears and if they pass that inspection, they will then send on to another individual (semi-retired) who overhauls the motor; otherwise they will first replace your worn gear set with a new 40:1 set (~$1,800) and then send it on to the gentleman to deal with the electrical motor overhaul. My gears were in good shape and the overhaul alone cost was ~$1,600 plus labor and shipping. took about 6 weeks from start to end. good luck.

[Andy95W]

Like Freemasm said, I sent mine to George’s Electrical, but that was more than 20 years ago.  I would go with Kurt’s suggestion and call LASAR first.

As my first airplane owner mentor told me about 30 years ago, “It’s an airplane.  It costs a lot of money.”  Just think, it could be a Bonanza ($$$).

[tmo]

Just for kicks, see if you can measure a significant voltage drop somewhere close to the motor - maybe you just have tired wiring / connectors / relays?

[A64Pilot]

Worn brushes will act like your describing,and are usually easily replaced. Ther isn’t much to an electric motor, brushes, holders and springs, commutator and bearings and not much more.

I’m not saying you should fix it, just it ought to be fixable.

Edited August 17, 2021 by A64Pilot

[mgan]

Well I opened the motor up and it is definetely the problem.

Unfortunately, it is not going to be an easy repair.  the commutator is completely worn down (to nothing in areas).

Does anyone have any leads on who might have an armature or who might have a commutator and be able to rebuild the armature?

Or does anyone have a salvage motor I can buy and rebuild?

thanks

[Bob R]

On 8/17/2021 at 9:12 AM, Freemasm said:

Georges Electrical in Sacramento for motor OH, if they're still around.

I just spoke with Don Maxwell and this is who he used to use. I am in Sacramento but unfortunately, George’s is closed I am told. The shop does pull up in a google search but I have not called to verify they have closed.

[carusoam]

For pre-flown Mooney parts…

Check in with…

@Alan Fox

@Jerry Pressley

@SheryLoewen

 

Good luck in the hunt…

Best regards,

-a-

[MikeOH]

4 hours ago, mgan said:

Well I opened the motor up and it is definetely the problem.

Unfortunately, it is not going to be an easy repair.  the commutator is completely worn down (to nothing in areas).

Does anyone have any leads on who might have an armature or who might have a commutator and be able to rebuild the armature?

Or does anyone have a salvage motor I can buy and rebuild?

thanks

Damn, that's what we call BER!

(Beyond Economic Repair)

[Culver LFA]

4 hours ago, mgan said:

Well I opened the motor up and it is definetely the problem.

Unfortunately, it is not going to be an easy repair.  the commutator is completely worn down (to nothing in areas).

Does anyone have any leads on who might have an armature or who might have a commutator and be able to rebuild the armature?

Or does anyone have a salvage motor I can buy and rebuild?

thanks

I still have all the electric gear components that were removed from my F when I converted it back to johnson bar, $2500 for everything and you'll have all the spare parts you could ever need!

[ShuRugal]

Holy shit, what was that motor using for brushes, tungsten carbide???

Sent from my Pixel 3a using Tapatalk

[mgan]

8 hours ago, ShuRugal said:

Holy shit, what was that motor using for brushes, tungsten carbide???

Sent from my Pixel 3a using Tapatalk
 

I think the brushes were wore down to the wire (no carbon left)

I'm just amazed it was able to retract the gear at all

Edited August 19, 2021 by mgan

[mgan]

18 hours ago, carusoam said:

For pre-flown Mooney parts…

Check in with…

@Alan Fox

@Jerry Pressley

@SheryLoewen

 

Good luck in the hunt…

Best regards,

-a-

Thanks!

I'm reaching out to them now (although I'm hitting a 3 msg per day snag on mooneyspace)