Grease Options

[Shelster1973]

Well...tonight was not a good night for imaging.

Went to slew mount for initial alignment and half way through the slew heard very funny noise from the Dec motor followed by a stall in the slew.  Released the clutch and was very stiff to turn by hand and also had funky smell coming from motor area.

Decided it was best not to keep on going, so packed all away and stripped the mount down, removing saddle, motor housing and then the whole Dec rotator from the mount and then stripped that down further to remove the motor and worm gear.

When the motor was attached, could freely turn in one direction, but turning back hit a stop at one point and the inside appeared to jump upwards....which was very disconcerting.  I thought then that the worm gear or the gearing inside had become worn, but when inspecting on strip down, there were no metal shavings and the Dec rotator could be freely turned by hand.  The worm gear also does not appear to be worn or missing anything, so am hoping all is good.

Am now planning on going a complete de-grease and clean on what is there and then re-greasing, but am wondering what peoples opinions are on a suitable replacement.  Am thinking a very light Teflon grease, not light enough that it gets runny and vanishes out of the mount in warm weather.

For those of a nervous disposition, look away now as here are some pictures of the insides........

 

 

[Davey-T]

Done mine recently with white lithium grease, mainly because it was all I could get, I think Baader recommend the teflon grease.

Keep those tissues handy, you may need them 

Dave

[Dave In Vermont]

The Teflon-containing SuperLube grease is excellent stuff. I've seen it last for over 20 years on high-stress components in bicycles, like bottom-brackets.

Dave

[cdh79]

i just read an article about a strip-down of an Eq6 mount and they recommend to use TF2 white lithium grease with teflon..

 

good luck, i hope it all is good again, once put back together!

[Shelster1973]

Cheers all

Going to nip into Evans Cycles in town later and see what they have

Does anyone know how you get the geared bearing out of the housing? Don't want to force it out but feel it will be easier to clean and regrease if out

[Shelster1973]

It's all OK. ...managed to get it out with my thumb nail. Was being held in with tension of the current grease

Time to get cleaning....

[Shelster1973]

Well.....good news and bad. The good is the reason grease went great. Used Teflon red and is very smooth

The bad is it appears the actual Dec axis is seized. With clutch off you cannot turn it one bit. Is now stripped down and soaking in wd40. Hopefully that may free it

Any idea how much a new dec head will set me back?

[Shelster1973]

Yep..Dec axis is properly seized.

Am looking at trying to get the bearing / sleeve out of the casting part now, but not having any luck.

Have written to Celestron to see if they have any tech drawings showing the construction and can then see how it will come apart.

This is very annoying, really do not need to buy a new mount at the present time......may look for a second hand AVX and see if I can rip the parts i need from it

[Shelster1973]

Some news...and it is good  / bad.

The good is I have managed to free the axis and remove the casting.

The bad is that some cack had made it's way in there and that was what was causing the seize.  It also caused a rather large amount of scoring in the removal.  Have cleaned it up and will be re-greasing and re-fitting later on today.

Wil put some pics of the mess that I removed and how it is now (pre-grease) later on when I get onto a computer that lets me do it.

Am feeling very relieved that I have sorted it out as really did not want to face the expense of either a new mount or a replacement casting.

[Shelster1973]

As promised..here are the images.

As you can see...it was a right old state.

All is now re-greased and re-fitted.

Ran the mount through 2 x 360 spins with only counter weight bar on 1st...the 1st revolution sounded a bit rough and was as if the motor was labouring, but when taking it back it sounded as per normal.  Then loaded it up fully with the OTA on and ran through another 2 x 360 (each way round) and all was good.  Clutch releases and axis spins freely, so all in all it was a very good fix

[cdh79]

glad to read that it moves freely now.. 

the images do look pretty rough

[newbie alert]

So did it need a new DEC head? 

The second pic down the thread looks a bit rough..

[Shelster1973]

No managed to get away with it. The thread does indeed look rough, but it has no impact on it going back together....thankfully