Was in Sydney last week and had a chat with Lee at Andrews and told him about my very stiff focuser. He told me to send it to him and he would sent it to his guy in Brisbane. IT MAY TAKE 2-3 WEEKS TO GET IT BACK. I don't want to go without viewing for that long. Any ideas how to loosen it up a bit? I have unscrewed (a little)the four screws holding the focuser arm, but that hasn't helped at all. I'm on holidays for 2 weeks starting Friday and dont want to go the entire holidays without looking up. Any help in this area would be very much appreciated. If push comes to shove I could always use the time to heavily modify my scope (Frankie, If you have seen my due shield you would understand why I called it Frankie) and add an eyepeice or 2 to my collection.
There's a plastic screw on the back of the focuser (not the 4 in front) that determines how tight or loose it can be..
Tighter, you get less slop in the barrel but harder to focus up and down. Looser, it's easier to focus up and down, but you get slop in the barrel.
Try that one.
If it's still bad, you can do what John Bambury does occassionally with his R&P (same as yours), and that's pull it apart and re-grease it with better lubricant. Apparently that can make a reasonable difference.
The other option, is to spend $100 and get a crayford from Andrews. It will bolt straight into your existing focuser holes in the OTA, and it is a 300% improvement on the R&P. Anthony (frogman) has the crayford on his 12" dob - did you get the chance to try it up at Kulnura?
The last option, is to spend $300 and get a moonlite CR2. It's the top of the range, obviously. You'll need to drill 4 new holes into your OTA to mount it though.
Before you go spending too much of the hard earned or even worse, breaking something, have a look at this page on tuning a GS rack and pinion focuser. It made a world of difference to my scope:
Great page Rob, it looks like I might be pulling apart my focuser this weekend if it is cloudy. What did you use to relubricate everything? I have a can of silicon spray sitting at home I might give a try (the stuff is great!).
I pulled mine apart and degreased it (just the gear part). I have silicon spray too, I think its a bit too light... but the stuff they have in there is more like glue :/
The silicone spray is OK with the usual care.....KEEP IT AWAY FROM THE OPTICS
I used some light lithium grease I found in the back of the shed and that worked OK. After saying that I think I may be upgrading to the Crayford soon or, should I buy the new 6mm eyepiece I want? Always too may things to do and buy and not enough time or money.
Your not wrong Rob
I loosened the screw at the back a little and that freed it up a lot. I will have a go at taking it apart and hitting it with some silicon or whatever I have hidden in the shed.
My wish list
Argo Navis or skycommander
Frankenstein stickers and iceinspace sticker
crayford focuser
and an Indian curry for dinner
The silicone spray is OK with the usual care.....KEEP IT AWAY FROM THE OPTICS
I used some light lithium grease I found in the back of the shed and that worked OK. After saying that I think I may be upgrading to the Crayford soon or, should I buy the new 6mm eyepiece I want? Always too may things to do and buy and not enough time or money.
Keep looking up.
I'd be applying the silicon by spraying it onto a cloth and then onto what ever parts needed lubricating, wouldn't spray it directly onto the parts. That should be enough to keep it away from my optics.
I second that Simon, don't spray any stuff near your optics, it could cost you a lot of work, or money getting it off.
Fingers are best.
I'm not sure about the Lithium grease either, You need to know if it is acidic or alkaline, alkaline stuff eats aluminium.
The glue grease that comes as standard is horrible sticky stuff that gets thicker in the cold weather. I couldnt disolve it with metho or turps and ended up using paint thinner as a solvent.
I used a standard automotive grease to regrease . After regreasing with a lighter grease it becomes apparent that they used such thick sticky grease to hide the machining imperfections in the rack and pinion. Even with the rough spots in the movement, I found the exercise well worth the effort.
The GS crayford focuser is certainly a worthwhile upgrade, especially if they still sell for $100 ! I paid $170 to get one from the states before they were available here and still see it as good value for money.
Hi guys. I did the same thing for my R&P on my refractor (same glue grease). I rang Bintel and asked what they used for regreasing. Super Lube synthetic grease from Wagners Electronic Services, in Ashfield Sydney. Great stuff. While it didn't turn my R&P into a crayford, the improvement was substantial. Also used it for regreasing the entire mount head. Unfortunately I found I had the same problem Starkeler getting the old glue out. I'm not sure I did a good enough job on the mount head, but the focuser was great.
Hiya all, When I O/Hauled my r&p, I pulled all the old teflon tape out & started from scratch. Luckily a friend had a supply of various thicknesses, so I was able to get it juuuussstt right, no image shift & with NO grease/silicon spray of any kind. It only attracts dust & dirt imho. L.
Worth putting an EP purchase to the side temporarily. You can have an extra EP that won't focus easily like all the others, or a smooth easy focus for all the EP's you already have. Your choice!
Yes Ken I am seriously thinking about giving Lee a call and seeing if he will take back my bodgy focuser and give me a discount on a crayford one...because of the hassle I have had with this one...the worst that can happen is he'll laugh and hang up on me lol
Gazz/Irish
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L.
