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View Full Version here: : G11 motors keep falling out of gearbox


icytailmark
29-12-2011, 09:52 PM
everytime i setup my mount i have problems with the maxxon motors coming out of the gearbox. Ive tried replacing the screws, gluing the motors to the gearbox nothing works. Does anyone else have this problem?

midnight
29-12-2011, 10:02 PM
Mark,

To me, the G11 seems to have a weakness in this area as the standard motor is only held in by two screws and even then into plastic I think. I have a G11 with Gemini 2 and I resorted to using a cable tie to bind the motor and gearbox better to provide a smoother slew (guide speed and move were no problem). I don't have any experience with the Maxxon motors.

However, on saying that, I had noticed since then that my root cause for poor slew performance was improper balancing. I now take more time to balance the system better and I now no longer need to put any additional re-inforcing to the RA motor (ie factory mounted)

Check your balance Mark ;)

Darrin...

TrevorW
30-12-2011, 04:34 PM
I have the latest Losmandy G11 with G2 and Maxxon motors and they fit snug as a bug in a rug, so I can't understand your issue, each motor is held on by two metal Allen head screws, the motor housings are aluminum.

??

[1ponders]
30-12-2011, 05:06 PM
Yes Mark, biggest let down of the G11 (and G8) are the plastic threaded slots into the gearbox. So easy to strip. For something that is a precision instrument I don't understand why they haven't been changed years ago.

My suggestion ...... araldite down the screw holes and screw the motors back on and hope you don't have to separate them at some later stage. Or maybe even some Locktite


about the limit of my engineering skills I'm afraid

Omaroo
30-12-2011, 05:14 PM
Easiest thing to do, if already stripped and over-loose, is to create a pseudo rawl plug by cutting a common dressmaker's pin down with a pair of wire cutters. Stick this, pointy end out, into the threaded hole and re-insert the allen-headded bolt. The added thickness of the pin forces the bolt to cut deeper into the plastic opposite. It's just like sticking a wooden match or two into a masonry hole before inserting the bolt. In fact, if you're more comfortable, do that instead - use a wooden match split in half or thirds inserted into the treaded hole and cut off to length. Certainly good in an emergency rather than using sticky and permanent epoxies that make undoing the whole thing a pain.

mithrandir
30-12-2011, 05:43 PM
Is this one of the places where you could put the case in a drill press, drill through the hole and replace the screw with a nut and bolt?

icytailmark
31-12-2011, 12:13 AM
thanks for your suggestion guys. I drilled a couple of holes where the plastic pins hold the motors to the gearbox and replaced them with larger screws. I then glued the motor to the gearbox around the edge. Its very stable now. What im gunna do is leave the Motor cables in so i dont even need to touch the motors. I agree with you paul they really need to fix those plastic pins i mean come on who designed this mount?

bojan
31-12-2011, 07:47 AM
The accountant contractor (cost reduction exercise)

multiweb
31-12-2011, 09:31 AM
I've never had problems with the motors on my mount. I am well aware that the motor holders are threaded into plastic. They're just meant to hold the motors. They don't need to be tight. The meshing on the cog is wide enough to transmit the torque. There is no axial push that would cause the motor to pull out. I don't think balance is an issue either. Over tightening steel screws in plastic thread is.