Rebuilding HEQ5Pro - what grease do you use?

[Jasp05]

Decided i would strip the mount down, replace the bearings, regrease everything and adjust the worm gear mesh on my mount.

All is going well. Except once the mount is together my grease has turned out to be too sticky.

Dec axis still spins even though the clutch is not engaged when i turn the worm drive.

Im using inox mx6 with ptfe (teflon). I put a thin coating on the bearings and the brass ring gear. But after finding it was sticky i dismantled and wiped off some of the grease away and left a very thin layer. Still too sticky.

So i stripped again cleaned grease off completely and tried a sewing machine oil. Very light coat on the ring gear. And its better. But still too sticky.

Any ideas as to why? The lubricant that was in the mount upon first dissambly reminded me of like vaseline or silicon grease. Very slippery. Very little tackiness.

Any recommendations for a grease to use?

[Jasp05]

Not sure if this will make sense without a picture. But the brass ring gear has 2 main bearings in it. and on the top of one the mount had a washer (compressed fibre) on top. Whilst that washer is installed between the ring gear and the bearing in the mount housing my dec axis will spin with the worm drive even though the clutch is disengaged.

as part of my process of trial and error in trying to figure out why the dec axis is engaging without the clutch, I tryed playing with the taper bearing and all other bearings on the dec axis. (regreased, degreased, reseated) nothing worked. Until i removed that washer mentioned above and now the mount is moving as it should. free spinning without the clutch and once clutch is engaged I get movement.

I'm going to assume this washer is definately a neccessary item. (I think it has something to do with spacing the ring gear to the worm drive so they engage at the right height?? ). If so I might go and try and replace that washer and see if things still work.

[RobF]

Superlube white lithium grease is what most have used:
http://www.iceinspace.com.au/forum/showthread.php?t=76222

The spacers in the EQ6 are critical - I've never done a HEQ5 but would expect you'll definitely need any spacers back in position.

Have you seen Astrobaby's great strip-down guide?
http://www.astro-baby.com/heq5-rebuild/heq5-d1.htm

[Jasp05]

Hi Rob,

Yeah astrobaby's guide is what I used to strip it down.

I cannot for the life of me get the mount to move properly with that washer in place. I have tried no grease/ lubricant at all in the dec axis to remove stiction and put that washer in there and its still sticking with dec clutch disengaged.

I still need to thin the grease out on the brass ring gear in the dec head (creates suction which is causing the stickiness) but I can get it to move properly in this config with no washer.

Are the washers meant to be compressed fibre or just a plastic of some sort?

and I've seen everyone talk about that superlube. it must be like water or WD40 to be thin enough to not cause any issues. Or there is that little used.. not sure. (at the moment I put a dab the size of 2-3 grains of rice. and spread that right around the ring gear. Then wiped off with rag and spread the little bit that remained after wiping around the gear again. thats how thin it is right now).

Going to buy a plastic washer tomorrow to see if that can fix my problem. but super frustrating right now. and Rob you mentioned "spacers" in the EQ6. Is this one for the RA and Dec axis each? or multiples per axis?

Only one came off my dec axis. (haven't started the RA yet). The guy who owned it previously had done a rowan belt mod on it so not sure if my washer is even original.. or what was in the mount originally.

[astro_nutt]

I was looking for a fine lube for a reduction gearbox/motor set up and found a silicone paste made by Herschell and found in Repco stores.
Hope this helps.
Cheers!

[Jasp05]

Is silicon paste/ grease ok to use in a mount? I thought silicon dries out and goes powdery after a while??

If anyone else can confirm, my only other thought for an alternative lubricant is a silicon based one.

[Jasp05]

I ended up leaving the thinnest coating of grease on the ring gear and have put the washer in place.

The Dec axis stills spin with the clutch disengaged, but it requires the smallest of forces to stop it spinning. Just enough to overcome the stickiness of the grease. I thought about it and it shouldn't affect my ability to balance a scope on it greatly.

Not sure what effect that stickiness will have on guiding but maybe it will loosen up with use..?

Still looking for options or alternatives to use as grease/ lubricant. I still have to dismantle the RA Axis. (putting it off until I resolve this issue with the dec axis).

[RobF]

Just looking at the HEQ5 guide, there don't seem to be as many delrin spacers in there.

Sorry can't help more - haven't had mine apart....

[Jasp05]

No worries Rob. I think :shrug: I have got it figured. Dec axis does not spin when clutch is not engaged which was one problem solved. Just had to really thin the coating in the housing down. like a film more so than anything.

And I seem to have eliminated that knock and not have any point bind on the worm drive. :thumbsup:

So at this point everything is at it should be I believe. One last test is take it out and do some calibrating with PHD2 and see if I fixed my dec backlash issue for certain...

[RobF]

Getting the mount to turn without binding while minimising backlash seems to be a tricky balance - glad to hear you're getting there.

[ZeroID]

Lithium ( spray can) works for me. Goes on very wet and foamy but almost frictionless when the propellant evaporates off and it stays in place. Electronics shops ( Jaycar eg ) have it. Great on bike chains as well, water repellent.

[Jasp05]

So it can be a very thin film or spray on lube in that housing. I wasn't sure as no guides anywhere specified grease or spray. Ive got the grease down to a thin film now so should be right. If i have any dramas will definately try a lithium spray as lubricant.