lubing focuser

[mister brot]

just a question...I read somewhere (not sure where) but someone said he uses bee wax for his focuser.you know the stuff that you are suppose to rub on untreated wood Is this a good idea ?or is this guy just bonkers,,,,

ps

just happened to have a half can of the stuff left over from when I put new shelving in for my kitchen....been sitting on my workshop shelf for years.....

[Herbig]

You don't say what sort of focuser you want to lube?

[JamesF]

I don't think I'd use pure beeswax. It's quite solid at the temperatures you'd be likely to experience whilst observing. If it's mixed with something to soften it then I don't see why it wouldn't work. I know divers sometimes use a beeswax-based lubricant for the zips on drysuits.

James

[mister brot]

ahhh not sure what kind (what it's called) here is a pic

[JamesF]

That's a rack and pinion focuser (sometimes just called R&P).

James

[Chris]

I know you've got to be very careful what lubricant you use if you anywhere near optics, I remember my father in law surprised me by saying that KY jelly was the best thing to use on focuser mechanisms, I think his scope must be about 40 years old so I guess he's had to oil the focuser a few times, god this all sounds a bit wrong doesn't it, my apologies:D

[mister brot]

I don't think I'd use pure beeswax. It's quite solid at the temperatures you'd be likely to experience whilst observing. If it's mixed with something to soften it then I don't see why it wouldn't work. I know divers sometimes use a beeswax-based lubricant for the zips on drysuits.

James

hey! that's fantastic ahhh??? what do you think I could mix with it oil? or maybe hand cream?

[mister brot]

I know you've got to be very careful what lubricant you use if you anywhere near optics, I remember my father in law surprised me by saying that KY jelly was the best thing to use on focuser mechanisms, I think his scope must be about 40 years old so I guess he's had to oil the focuser a few times, god this all sounds a bit wrong doesn't it, my apologies:D

[Herbig]

Rack and pinion! You could use Bees wax thinned down but I suspect it would get too thick and sticky when the temp drops.

Some old focusers rely on thick grease to take up some of the slack in the mechanism but a modern one should not need much lubrication at all. A drop of light oil should be all that's needed and applied very sparingly at that.

[mister brot]

That's a rack and pinion focuser (sometimes just called R&P).

James

r&p duh I knew that!! thanks for helping an old man remember

[DaveGarland]

Actually, is there a good lubricant I can use for my T-ring thread? It squeaks like a good in in the dead of night.

[mister brot]

Rack and pinion! You could use Bees wax thinned down but I suspect it would get too thick and sticky when the temp drops.

Some old focusers rely on thick grease to take up some of the slack in the mechanism but a modern one should not need much lubrication at all. A drop of light oil should be all that's needed and applied very sparingly at that.

thanks herbig....i am going to plead gilty...I have never had scope out in winter only in spring-fall and to tell you the truth......I hate the cold(winter)so that never came to mind but thanks for the info

[alexog]

White Lithium grease is a popular choice. Usually available from bike shops.

Alex

[LukeSkywatcher]

I have a refrac with a R&P focuser and the lube used on it is stupidly thick and sludgy. I dont use the scope now but i often thought about taking out the focuser and cleaning it and using something else. The lube on it is nothing short of crude oil.

[LukeSkywatcher]

Sorry crude oil isnt even the correct viscosity................its more like petrolium jelly.

[JamesF]

I wonder if the Chinese words for "lubricant" and "adhesive" are unusually similar?

James

[LukeSkywatcher]

I wonder if the Chinese words for "lubricant" and "adhesive" are unusually similar?

James

LOL.....................

It does seem so.

[sam mayo]

roses a nice meal followed by a few compliments usually makes it easier!

there is a lubricant my dad uses a lubricant on his saxophone no pun intended but i imagine it would be good and the right viscosity the link is here http://www.dawkes.co.uk/accessories-saxophone-lubrication.html sorry if im wrong and wasted your time thanks sam

[LukeSkywatcher]

The focuser on my Celestron 8se is even very slow. I dont know if that is mechanical design or the grease used. I'm not about to try to remove it to find out, but it could be better.

Me being a complete numpty with scopes, do you think i could remove the focuser from my 8SE and clean it off and use a different lube to make the focus mechanism more smooth and faster?

[JamesF]

If it's anything like the SW Mak focusers you may need to take the entire scope apart to do that. In the Mak, the mirror is carried on a bearing that slides up and

down the outside of the baffle tube. Fixed to the bearing is a plate that reaches the back of the focuser mechanism where a threaded rod passes through it. As you turn the focuser knob the threaded rod turns and the plate moves up and down the thread, pulling or pushing the mirror bearing along the baffle tube at the same time. If you remove the threaded rod, the mirror bearing is free to spin around inside the OTA and you'd have a nightmare of a job getting it back in place without removing the corrector and probably needing to recollimate.

I've not taken my SCT apart, but I wouldn't be that surprised if they were similar given that they suffer from the same problems with mirror shift.

James

[LukeSkywatcher]

If it's anything like the SW Mak focusers you may need to take the entire scope apart to do that. In the Mak, the mirror is carried on a bearing that slides up and

down the outside of the baffle tube. Fixed to the bearing is a plate that reaches the back of the focuser mechanism where a threaded rod passes through it. As you turn the focuser knob the threaded rod turns and the plate moves up and down the thread, pulling or pushing the mirror bearing along the baffle tube at the same time. If you remove the threaded rod, the mirror bearing is free to spin around inside the OTA and you'd have a nightmare of a job getting it back in place without removing the corrector and probably needing to recollimate.

I've not taken my SCT apart, but I wouldn't be that surprised if they were similar given that they suffer from the same problems with mirror shift.

James

Just looking at my SCT, the removal of the focuser is a 3 screw operation. However it is not a simple case of in or out as with a Refrac. Its a left to right situation, so at a glance i think i would be removing the whole back from the scope to do a job on the focuser and i really am not qualified to do that.

[LukeSkywatcher]

I'd have to remove the whole back section to deal with the focuser because it is internal on the SCT

[mister brot]

I wonder if the Chinese words for "lubricant" and "adhesive" are unusually similar?

James

[glowjet]

R&P focusers can be cleaned with an old tooth brush and lint free cloths using a little white spirit, then a light smear of Lithium grease is the most popular way to lubricate

John.