Precise Flight Speed Brakes, not fully retracted.

[Mooneymuscle56m]

Any one have experience with the electric Precise Flight Speed Brakes?  I have the right wing not fully retracted.  It’s roughly up 1/4”.  The aircraft is a 2007 M20TN 31-046.  I can press it down a little and it doesn’t move much,  I’ve tried lube, and taking it apart then chickened out part way on the dissembling. 

[amillet]

They’re supposed to be sent back to the factory every 1000 hours.  I had exactly the same symptoms a few years ago. MSC returned them to Precise flight.  Problem solved

[LANCECASPER]

Most of the time the worm and worm gear have not been lubricated yearly with Aeroshell 22. Do not use spray lubricant and do not push it down. I was told that lifting it or pushing it down manually was not good for the clutch in there. Mine were slow in extending and retracting. I pulled out the cartridges and lubricated with Aeroshell 22 and exercised them quite a few times and they are much better now.

[Mooneymuscle56m]

Do you remember what the cost was to send them in? When I go through the logs, they seem to be sent in muiltple times.  The aircraft has 1350TT and the last time they were sent in was at 500 hours.  
 

Seems like it may have skipped a gear on the worm drive, still goes in and out, just not all the way.  
 

Any way to disassemble and move it a tooth on the worm drive? 

[LANCECASPER]

I would be surprised if you took the cartridges out and they weren't dry. The Aeroshell 22 is the only approved lubricant and needs to be done every year. About one Mooney out of 100 gets the speed brakes lubricated every year. Everyone seems to wait until they fail and then send them in for $1000 each to be serviced.

[Duane Baker]

In my case the gears inside the motor were the problem. Any AP/IA should be able to disassemble and repair. The geared motor is available. Search MS, I listed the motor number and a source for the 24 volt. Duane 

[StevenL757]

Another issue is whether you’ve had the airplane exposed to rain recently...whether it be inflight or outside.  It’s a known issue for the brakes to behave like this if water that gets down inside the motors and clutches doesn’t completely dry after an exposure.

Steve

[Duane Baker]

I was told by PF it would be $1700/2500 for a repair.

[carusoam]

Worn clutches are the usual send it back to the factory for service...

Mine went back after about 1500 hours in flight...?

Skipping a tooth on a worm drive sounds ‘interesting’...

Since your mechanic will be taking it out to send it in... he can always look to see if anything is broken or can be reset...?

The service is quite quick...

Service during Corona Time May have some ill effect...

Best regards,

-a-

[milotron]

I don't think it is an issue with a gear drive. All of the electric speedbrakes use either limit switches ( 1000 series ) or position sensors ( 2000 series ) for controlling the motor and clutch for up or down.

I have one that sticks halfway down and releases ( drops ) when the breaker is pulled. I think it is an issue with one of the microswitches with high resistance on the contacts. It has been back to Precise flight several times according to the log books, all for the same issue that seems to keep returning. 

 

iain

[Mooneymuscle56m]

13 minutes ago, milotron said:

I don't think it is an issue with a gear drive. All of the electric speedbrakes use either limit switches ( 1000 series ) or position sensors ( 2000 series ) for controlling the motor and clutch for up or down.

I have one that sticks halfway down and releases ( drops ) when the breaker is pulled. I think it is an issue with one of the microswitches with high resistance on the contacts. It has been back to Precise flight several times according to the log books, all for the same issue that seems to keep returning. 

 

iain

I’ll try the breaker, but even with the master off it shouldn’t It fall down? 

[milotron]

It should. In the 100 series the clutch is always powered when power is available at the breaker. I think the 200 series is the same, but that constantly powered circuit runs through the controller first.

My understanding of these is that pulling the breaker should cause them to retract in case of emergency or erratic operation.

Sounds like you might have some other mechanical issue with them then, maybe a foreign object causing it to not fully seat?

[Dustin Kurath]

On 3/22/2020 at 8:20 PM, Mooneymuscle56m said:

Any one have experience with the electric Precise Flight Speed Brakes?  I have the right wing not fully retracted.  It’s roughly up 1/4”.  The aircraft is a 2007 M20TN 31-046.  I can press it down a little and it doesn’t move much,  I’ve tried lube, and taking it apart then chickened out part way on the dissembling. 

Just curious, what ended up being the solution to this problem? My ovation has developed the exact same issue, left wing it sticks up about 1/4 inch when retracted. I'm torn between sending the speed brakes in to get looked at or try to have my mechanic. It has to be something simple. I have the 2000 speed brakes. 775 TTAF.

[PT20J]

Since you have to remove it to send it for overhaul it doesn't hurt to remove it and take a look and see if it is something simple. If they've never been removed before, use a paint cutter around the screws to minimize damage to paint.

Skip

[DonMuncy]

Be careful if you decide to lubricate things to get it working. As I understand it, getting lubricant in the clutch is bad news.

[carusoam]

It is hard to measure how much use is on the clutches…

There isn’t an hour meter or cycle counter for them….

But, if you have a couple thousand hours on the plane, and use them often… it may be time for an OH…

 

If your mechanic is knowledgable on these devices… it might be a low cost part keeping it from doing its job…

 

Either way…

expect that your mechanic is going to take them out…

If he sends them off to Precise Flight… they come back pretty quickly… like new in the way they operate…

 

Best regards,

-a-

 

[N201MKTurbo]

The clutches are not used for normal operation. The motor drives them up and down through the clutch. The clutch is just there for emergency retraction. If you pull the circuit breaker it opens the clutch and the spring pulls them down. The asymmetric detector will also open the clutch if it senses they aren’t even. The big failure potential lies with the motor, not the clutch.

[carusoam]

1 hour ago, N201MKTurbo said:

The clutches are not used for normal operation. The motor drives them up and down through the clutch. The clutch is just there for emergency retraction. If you pull the circuit breaker it opens the clutch and the spring pulls them down. The asymmetric detector will also open the clutch if it senses they aren’t even. The big failure potential lies with the motor, not the clutch.

Rich,

Is there something that opens/closes the clutch mechanism?

With the electric version… it might be a low cost solenoid or something… that looks similar to a worn clutch in the way it fails…

PP thinking out loud only…

-a-

[N201MKTurbo]

1 hour ago, carusoam said:

Rich,

Is there something that opens/closes the clutch mechanism?

With the electric version… it might be a low cost solenoid or something… that looks similar to a worn clutch in the way it fails…

PP thinking out loud only…

-a-

The electric version has an electric clutch. It has an electromagnet that pulls the clutch plates together. 
 

I haven’t been inside the vacuum or cable versions, but I don’t think they have a clutch.