Worm gear for EQ6

[weathermon]

Hi everyone,

Do you know where I can source a replacement worm gear for the EQ6? My RA one is chewed pretty badly from incorrect meshing so needs to be replaced.

Cheers, Mike

[Atmos]

Not cheap but it may be worth while to do.

https://www.deepspaceproducts.com/hypertune-do-it-yourself-kit-for-the-atlas-eq-6-mount_8_4227_8642.html

[weathermon]

Yeah I'm replacing all the bearings with SKF ones today and found the damaged worm gear. All the shims are in good condition still so they'll stay.

[weathermon]

Or if anyone has a spare worm they're willing to sell that's in good condition then I'll buy it. Here's the wear on the RA one, you can see it's quite uneven wear:

https://www.youtube.com/watch?v=tU9urNuk1gg

The RA gears were starting to squeak which is why I took it all apart for a service. It's gonna get a good clean up and then superlubed with new bearings.

[bojan]

I think the wear as visible on the video is not that bad.

Perhaps you should consider lapping with diamond paste (discussed couple of times on this forum).
It will save you quite a lot, plus you will end up with lower PE.

[Shiraz]

Not sure that it looks so bad Mike - I would have thought that normal wear would take off the polished surface where the gears mate - they don't touch over the whole surface

It would have squeaked if the lubricant dried out, but does it track badly if you lubricate it?

edit: sorry Bojan - snap

[weathermon]

Thanks guys, I wasn't sure if it needed replacing or not as some of the marks on the gears are quite deep on the teeth - I'll have a look at how to lap the gear teeth - and yeah it was pretty horrid tracking with PHD2, with it spiking from a -3 to +3 arcseconds every few minutes which bloated the stars..

[AndrewJ]

Gday Mike
This mob do new worms and wormwheels, but not cheap.
http://www.aeroquest-machining.com/photos.php

Andrew

[bojan]

If you really need to replace the worm gear, you can try this mob as an alternative:
http://www.teleskop-express.de/shop/product_info.php/language/en/info/p7322_Skywatcher-Ersatzteil---Schneckenrad-fuer-EQ6-SynScan--Syntrek-----Montierungen.html

EDIT:
And, the most practical alternative - simply swap RA worm gear with DEC, they are identical.

[weathermon]

Thanks guys,

I'm gonna try lapping the gears - is aluminium polish considered ok to use? I've been doing a bit of research and apparently you need to be careful of using some lapping compounds as they embed into the material - toothpaste is another good alternative as well?

[bojan]

A friend of mine used diamond lapping paste, 0.5 um
http://www.ebay.com.au/sch/sis.html?_nkw=12+pcs+5gram+Diamond+ polishing+lapping+paste+compound&_itemId=350411795346&_trksid=p2047675.m4099

Yes, you have to wash the gears properly after lapping. And be careful not to allow the paste end up in bearings.

[weathermon]

No worries, thanks for your help! Glad that it's able to be fixed.

[codemonkey]

You can get a replacement from Tasco, the Australian distributor for Skywatcher. I was quoted $36.30 including freight to QLD for one back in March.