Autohelm Linear Drive

[sabray]

Again lasted about 5 miles. Been doing the aft cabin boogie 30 seconds off helm jump down snip pull pins etc... Having the thing out front cover off back cover won't budge.. Any replaced the drive motor on a linear drive. How to take off the back cover. Undid 4 bolts at corners but it won't budge.

[S/V Antares]

Hmmm.
Did it work before?
Was this a new install? (looks new)
If new do you have rudder stops that limit the rudder travel before it hits the end of the linear drive travel?

[sabray]

Should have continued old. Stopped working and screen says drive stopped.I went through found bad ground wire. and it worked briefly. Guess is the brushed burned from bad electrical contact I'm underway. I have a spare motor. But the back case will not come off. I also have a spare hydraulic drive. That might go on but not while underway.. If I could get the case open I could pop the new motor in

[jcapo]

I seem to recall that the brass studs have to be removed.
Pix of the internals.

[sabray]

Yes it's worked for years and is calibrated well nit hitting stops. Raymarine suggest this is likely brushed. The motor has a hot burnt smell.

[sabray]

Originally Posted by jcapo

I seem to recall that the brass studs have to be removed.
Pix of the internals.

Thanks I was about to but it seemed not intuitive. Give it a try

[sabray]

Originally Posted by jcapo

I seem to recall that the brass studs have to be removed.
Pix of the internals.

That did it thanks bang head smiley face

[bazzer]

My guess this drive unit is just to small for your boat. I say that because you mention you have a hydraulic unit as well, so why did you fit a all electric drive? What model is it and did you change the settings on your AutoPilot from hydraulic to electric. I don't think a bad ground wire would cause a overheating problem.

[donradcliffe]

Overheating could mean the motor bearings are seizing up.

Steps to fix Raymarine linear drive:

1. disassemble
2. verify gears are plastic
3. toss overboard
4. install hydraulic drive

[sabray]

It has run for years on the boat when I bought it. There was a ground wire main feed making poor and intermittent contact. Fixed that. A poor ground would be the same as undersized wire I think that the brushed and motor would not like this. Could be another problem. Gears belt all looked good motor had hot electric smell. Hopefully it's not the head. The hrdraulic is a spare I picked up from the hopper rebuilt and tested. We shall see late today when the hook goes down

[bazzer]

Originally Posted by sabray

It has run for years on the boat when I bought it. There was a ground wire main feed making poor and intermittent contact. Fixed that. A poor ground would be the same as undersized wire I think that the brushed and motor would not like this. Could be another problem. Gears belt all looked good motor had hot electric smell. Hopefully it's not the head. The hrdraulic is a spare I picked up from the hopper rebuilt and tested. We shall see late today when the hook goes down

Whats a hopper? Is this a tiller boat or wheel? Does the steering need more force than before? Hot motor could be to much load, or a short in the windings. Either is fixable. If the ground was the problem because it is undersized the problem would have always been there. Besides, its really the size of the -ve and +ve that is important to the motor, but a bad connection would unlikely cause a overheating motor.

[DeepFrz]

bazzer, hopper is the British term for garbage bin, dumpster, etc.

If the motor is all gunked up with dust from the brushes it could certainly give you the same symptoms. There was a thread about 5 years ago and the OP ended up cleaning all the carbon dust out of the motor and his drive worked well after that.

[bazzer]

Originally Posted by DeepFrz

bazzer, hopper is the British term for garbage bin, dumpster, etc.

Don't think so, Im a Brit, working class from the South and I've never heard that before, I'm guessing it's a Auzzie expression .
But I think your right!!

[DeepFrz]

Sorry, I thought it sounded British to my Canadian ear. I remember a post a while back where he snagged the drive from a bin.

[donradcliffe]

Motors usually overheat when they can't turn freely. It could be the drive has too much friction, brush gunk in the motor, bearings, or the rudder system itself. First step is to take things apart and see what is seizing.