Regreasing a PMX mount

[gregbradley]

I regreased my PMX mount this afternoon. It took several hours.
Its the first time I have regreased it since I got it and its about 3 years old.
The mount was making some groaning sounds when slewing so that was one thing that made me think it needed regreasing. Also I am trying to get it to handle the extra weight of the AP RHA scope and it was sometimes and not others.

The result has been very good. The mount sounds a lot better. The PEC curve I got afterwards seemed smoother. The T-point model got lower errors. Autoguiding is more accurate and more reliable now.

Overall its been very successful and probably prolongs the life of the mount.

The old grease was semi hard and dark grey and a bit clumpy. The new grease is white and quite liquid.

One tip. Unless you have magnetic tipped Allen keys place a bit of blue masking tape on the end of the allen key you use to remove the 2 lower bolts of the worm. Otherwise it is almost impossible to get them back into their recessed holes without them falling off into the mount or outside. Same with removing them. The tape makes them jam onto the allen key a bit so they stick out straight from the end of the allen key.

Greg.

[SpaceNoob (Chris)]

Originally Posted by gregbradley

I regreased my PMX mount this afternoon. It took several hours.
Its the first time I have regreased it since I got it and its about 3 years old.
The mount was making some groaning sounds when slewing so that was one thing that made me think it needed regreasing. Also I am trying to get it to handle the extra weight of the AP RHA scope and it was sometimes and not others.

The result has been very good. The mount sounds a lot better. The PEC curve I got afterwards seemed smoother. The T-point model got lower errors. Autoguiding is more accurate and more reliable now.

Overall its been very successful and probably prolongs the life of the mount.

The old grease was semi hard and dark grey and a bit clumpy. The new grease is white and quite liquid.

One tip. Unless you have magnetic tipped Allen keys place a bit of blue masking tape on the end of the allen key you use to remove the 2 lower bolts of the worm. Otherwise it is almost impossible to get them back into their recessed holes without them falling off into the mount or outside. Same with removing them. The tape makes them jam onto the allen key a bit so they stick out straight from the end of the allen key.

Greg.

Awesome work, they need this routinely and you'll have less issues hopefully.

[roughy (Mark)]

Is there a particular grease that should be used? Also is it inadvisable to use a degreaser and preferable to simply wipe off the old grease?

[gregbradley]

Originally Posted by SpaceNoob

Awesome work, they need this routinely and you'll have less issues hopefully.

Thanks Chris. It was your advice on this that was most helpful. The old grease goes a bit stiff and I am sure that starts to make accurate guiding a bit harder.

Greg.

[gregbradley]

Originally Posted by roughy

Is there a particular grease that should be used? Also is it inadvisable to use a degreaser and preferable to simply wipe off the old grease?

Here is the video showing how to do it from Software Bisque and they mention the brand:

There is a link for the PMEII/MX/MX+:

https://youtu.be/qe11z6sQzz4

I don't know that the grease is anything special. Its reasonably flowy and liquid. It looks very similar to some Nulon Teflon grease additive I use on Tak adapters.


As far as degreasing goes it may be messy if you start using liqiuids. I don't think you want liquids flowing inside the mount. She mentions not putting on too much grease in the video so as to not get on the homing sensor in the video.

They recommend a toothbrush for the main gear and a non shedding cloth for the worm and simply rotate the worm with a cloth engaged on it.

I also used the tootbrush to clean the worm.

There were tiny specks of metal wearings on the main gear I could see so that could affect PE.
Greg.

[roughy (Mark)]

Excellent, thanks Greg

[Paul Haese]

Yep time I did my PME again. PMX does not need doing yet. Tape over the holes will stop screws falling into the mount too. I use a broad paint brush (artist type) to remove the grease and then regrease on both mounts. I don't remove the worm gear.

[gregbradley]

Originally Posted by Paul Haese

Yep time I did my PME again. PMX does not need doing yet. Tape over the holes will stop screws falling into the mount too. I use a broad paint brush (artist type) to remove the grease and then regrease on both mounts. I don't remove the worm gear.

I should do my PME also.
Is the worm exposed in the PME? Its not accessible in the PMX and you have to remove it.
Greg

[Paul Haese]

Yes Greg the PME worm gear is exposed by the removal of the bottom cover plate (black) on the drives.

[gregbradley]

Originally Posted by Paul Haese

Yes Greg the PME worm gear is exposed by the removal of the bottom cover plate (black) on the drives.

Thanks for that.

Greg.