brucen

This is the one I have. I have bought quite a few things from them and they have all been good quality and arrive quickly.

http://www.ebay.co.uk/itm/6-4m-Coiled-Telephone-Handset-RJ10-Cable-Lead-Black-/200553785416?pt=UK_Phones_PhoneLeads_RL&hash=item2eb1efe848#ht_1724wt_993

I think RJ10 might also work as I see I bought a 6.4 metre RJ10 coiled lead off ebay for £2.49 earlier this year when I extended mine. Works fine and cheap as chips!

Good luck. I still haven't done mine as I bought a Skyliner 200p around the time of the post and was not sure how much I would use the 130p afterwards. As the Dob is no good for webcam use I am pretty certain I will be ordering the auto focuser when I start using the webcam again in the autumn.

Actually, it does, because the standard 2" focuser has insufficient outward travel to get most of 2" eyepieces into focus, so in this case, the 2" adapter is more of an extender.

You learn something new every day!

I don't have any 2" eyepieces to check but both my scopes have 2" focusers fitted with 1.25" adapters. No other parts came with them so I have always assumed I could just remove the adapter and fit a 2" eyepiece directly into the focuser?? It doesn't seem logical to need an adapter to use a 2" eyepiece in a 2" focuser!

If it's like mine the scope has a 2" focuser that is fitted with an adapter to reduce it to 1.25". To use a 2" eyepiece you just remove the adapter that is already there.

Thanks brucen. Haven't taken it off yet so will check if only one end is bent once it is off and make a decision then. Thanks again to you and assasincz for putting your experiences with this mod on the forum.

You should be able to see before you take it off. Turn the focuser with one knob and see if the other just turns on its axis or whether it does a bit of an orbit. Then do the same with the other knob. If there is any movement I don't think the motor, which will be clamped to the focuser, will like it and will almost certainly shorten its life even if it works at all.

Thanks for your efforts Brucen; I was just about to embark on this mod myself and was wondering how to get the knobs off the Skywatcher 2" focus rod. The rod on my telescope appears to be bent too (from new!); does everything still work OK after you had managed to straighten it? If it is supposed to be bent, it seems to be a strange design feature!

Mine was only bent at one end and a few gentle taps with a small hammer put it straight. Worked fine before and works fine now - just looks better as the knob stays in one place when it's turned!

If yours is only affected at one end it could either be straightened or you can just use the end that is straight already as it can be reversed. Good luck with the mod.

Great summary of the pain you go through when you realise it's not quite as easy as you thought! If I know what time I will be going out I use the handset with Stellarium earlier in the day and decide which stars I will use. Still not knowing my way about the sky that well I draw a little diagram of the areas of the sky I will need for setup which I find easier to use in the dark than a sky chart. What used to take me an age now only takes a couple of minutes - unless there are clouds in the wrong places! I also have a small bag of sand (about 2.5 kg) that I put on the eyepiece tray to add further stability to the tripod.

Excellent Job Bruce, I'm surprised that you had to use a vice to remove the knob though, I now wonder if a little bit of heat might've done the trick and loosened the red stuff?

I padded the vice so that it would not cause any damage so it was not that risky. I also managed to straighten the rod as one end was bent a little so it was a worthwhile exercise. It would not be that easy to heat the thread due to the shape of the knob but might be possible.

Should anyone else have the 2" focuser I can confirm that the knobs do unscrew although I had to hold the rod in a vice to do so as they were so firmly tightened. There was also a red powdery residue left on the thread so I assume some form of adhesive was involved as well.

Those pictures look very much like a celestron 80ed R&P focuser, http://www.celestron.com/media/catalog/product/cache/2/image/9df78eab33525d08d6e5fb8d27136e95/5/2/52280_80edrefractor_large.jpg

In the centre of the focuser knob, you can just about make out some little celestron stickers , those stickers are on a round nub, which the focuser shaft screws into, check if you focuser has that nub, if so you can be fairly certain that it's a screw on and you probably just need to be a bit braver twisting it to free it, I remember mine was quite stiff, obviously holding one knob whilst turning the other one will help (just in case you're tempted to just rack the focuser in and use that to hold the shaft whilst you twist the knob).

If it's not screwed on or screw on, then it's push fit, which means that twisting it will not be an issue as it will still come free, mine is 2 different metals for the shaft and the knob, the knob is ali, the shaft looks chrome plated.

Certainly looks and sounds similar. I can't twist any harder with it on the scope so I will need to take it off and put it in the vice to see if I can shift it. Just need to pluck up the courage now!

I suspect it is a 2" rack and pinion focuser rather than 1.25" one - an I close to the mark?

If so, it is indeed a different focuser entirely. That said, I doubt that the focusing rod and the knobs are all machined from one piece of metal, as it would be indeed too pricey. In fact, I have seen in a review of the very same scope here at SGL that the knobs seem to be made from aluminium, which is unlikely to be the same material the focusing rod is made from, so they have to be seperate. Perhaps somebody with the very same focuser will enter this thread and give you an advice on how to get the focusing knobs off, but I would say, do not give up - it is unlikely that it is all one piece.

If the knobs are not screwed on, then, they ought to be held in place either by locking screws, glue or they might be pressed to the focusing rod.

Furthermore, if the focusing rod is bent, presumably on one side, then just remove it from the focuser and flip it around.

Good point, yes, it's a 2" focuser. The knobs are definitely separate but are either glued or are a very tight fit as there are no screws. I had not thought about turning it around but this would solve the problem as it is only one end - the one I need - that has the elliptical orbit. Perhaps I will whip it off and give the knob a few taps with a hammer to see if it shifts.

Hi Brucen,

That setup is very different to mine, and this is standard from new? With the knobs, they haven't got a hidden screw holding them in place? Have you taken a look under the rubber grips?

Sean.

This is how it was from new - July last year. The knobs are hollow and there are no screws to be seen. I have twisted pretty firmly and there is no movement. I don't really want to take it apart unless I am sure they will come off as I don't want to have to saw it. The fixing plate on this one is also secured by 4 screws rather than 2 so it is obviously a completely different focuser.

I have been looking to do this for a while but have 2 problems.

First, I seem to have a different focusing rod and I have tried unscrewing the knobs but they don't seem to want to come off. Secondly, the rod is not straight (was like it from new) which does not affect manual focusing but would not work with the motor. I could probably straighten the rod if I took it off but won't bother if the knobs are not removable. Has anyone removed this type before?