Can anyone machine this for me?

[yesyes]

I hope I can ask this here. Or should this better go in the "Wanted" section?

I need my EOS 1000D to be closer to the OTA to achieve focus and at the same time be able to use 2" filters. I also don't want to be limited by the 1.25" adapter with T thread that came with the scope.

So I think the adapter below should do the trick. Would anyone be able to make one of these for me and how much would that cost?

I can imagine that more people would be interested who have a Skywatcher/Celestron Newtonian with that weird focuser and want to attach a DSLR.

Chris

[blinky]

You know you can replace the standard focuser with a low profile one and it will allow a DSLR to come to focus?

[yesyes]

Yes I do. But they are rather expensive. I was hoping the adapter would be cheaper, especially if more people wanted one.

Also, most of these focusers have the mounting holes in different places. I'm not sure I'm ready to drill into my OTA.

So I was wondering if an adapter would be a viable option.

[Glider]

Hi, search this DIY forum for my effort at exactly this item. If you get a SW focuser to 2" EP holder and a Canon T mount I know a man who will machine one for you at a nominal cost if you supply the parts.

The parts cost me about £30.

[yesyes]

Ah, yes, I knew I had seen something similar here...

This one here:

http://stargazerslounge.com/diy-astronomer/107657-skywatcher-focuser-adaptor-canon-eos.html

You're going directly to the EOS mount without T thread. That should be fine. I don't plan on getting any other DSLR any time soon. Using the barrel of a 2" EP is a good idea. I guess I didn't really realise when I read your thread at the time.

So you'd need me to post you an EOS T-Ring and a 2" Skywatcher adapter?

[Glider]

Yep, that's the one.

NOTE, the 2" EP barrel was the component that that let me use 2" filters with the arrangement. You'll need one of those aswell. Sorry It's been a while since I made mine. I use it all the time.

Astroboot was a good source for all of the parts.

[yesyes]

Yeah, I was thinking AstroBoot as well. But it's been a bit slow recently.

I can put in the 2" barrel here myself I think. I'm doing a lot of DIY myself but I'm not well equipped for round things. ;-)

I'll have a look if I can find this Skywatcher 2" adaptor somewhere...

I'm still interested if someone can make the whole thing in one piece though ...

[Glider]

Ok, just let me know. The concept is sound though. It's a lot cheaper than a low profile focuser and I too felt faint at the idea of cutting/drilling my OTA to take one. As soon as you do that I felt the OTA lost resale value.

I looked at machining the whole thing in one piece but the cost of the stock plus the ability to cut the threads killed it for me.

Hope you have better luck. As you say, you're not the only one.

[yesyes]

I have decided to buy a replacement focuser anyway. RVO are selling a direct replacement dual speed 2" crayford for £99 that is supposed to fit my scope exactly.

I've always liked the idea of having a finer focusing but was always put off by the price. Now that I found one below £100 (just...) I took the plunge...

It's not low profile but RVO assured me that it's optically shorter than the original.

[yesyes]

I might as well post a link to the focuser I ordered.

Skywatcher Dual Speed 2” Crayford Focuser | Telescope Accessories | Rother Valley Optics

[haitch]

YesYes,

Can you tell me if the round collimatable section is exactly the same dimensions on the base as the original focuser? (I.e. is it possible to change it out from there and leave the square base on the tube attaching the rest of the new one?

hope I'm making sense - my reason for asking is that to fasten the base of an original Skywatcher "crayford style" focuser to the tube of my 14" dob I had to fasten it in a fairly permanent way.

[Glider]

That looks great, let me know how it goes.

[yesyes]

YesYes,

Can you tell me if the round collimatable section is exactly the same dimensions on the base as the original focuser? (I.e. is it possible to change it out from there and leave the square base on the tube attaching the rest of the new one?

Will post back here once I have the focuser and have tried to mount it to the scope. RVO said they will post it today, so hopefully I'll have it tomorrow.

I'll keep this thread updated, although it's no longer a DIY project, strictly speaking... ;-)

[simon84]

Just had a quick read through this and I found a 1mm thick EOS T ring available at Modern Astronomy, the normal one is nearly 11mm so this might help.

[yesyes]

Just had a quick read through this and I found a 1mm thick EOS T ring available at Modern Astronomy, the normal one is nearly 11mm so this might help.

I saw that too. You mean the 3rd item from the bottom on this page?

Accessories @ Modern Astronomy

I'm keeping that as an option in case I need the extra 10mm. But should be OK with the new focuser.

[haitch]

Will post back here once I have the focuser and have tried to mount it to the scope. RVO said they will post it today, so hopefully I'll have it tomorrow.

I'll keep this thread updated, although it's no longer a DIY project, strictly speaking... ;-)

Thanks for that - I'll keep watching the thread.

[simon84]

I saw that too. You mean the 3rd item from the bottom on this page?

Accessories @ Modern Astronomy

I'm keeping that as an option in case I need the extra 10mm. But should be OK with the new focuser.

Yes thats the one. Looks rather nice. When I had my Newt I moved the mirror as far up (I think) the tube as I could and the collimated it, gave a few extra mm's to help get that focus.

[yesyes]

Quick update on the focuser. It has arrived today with a bit missing. The EP end of it has a slightly bigger than 2" thread and that's it. The adapter that holds the 2" EP is missing.

I called RVO and after they called around a bit it turned out that the whole batch has the adapters missing. ;-)

They are now being shipped to the distributors from China. So there's going to be some delay in reporting back whether it works/fits. RVO reckon about 10 days...

[yesyes]

Hm... I held it next to my focuser on the scope and it turns out it's too big. It seems OK in one direction (around the tube) but is too long lengthwise.

So much for retro-fit direct replacement. :-/

now I'm wondering should I drill or send it back? RVO said they'd give me a full refund if it didn't fit.

[haitch]

How about where I was saying about the circular centre part? Could it be detached there and the new cicular section attached like I want to do with mine?

Does that make sense? Can you post a piccy with both focusers side by side?

[yesyes]

I remembered to check that but it turns out the original focuser doesn't have the round detachable bit. It's all in one piece including the mounting plate.

I'll see if I can take a few pics later today...

[haitch]

I remembered to check that but it turns out the original focuser doesn't have the round detachable bit. It's all in one piece including the mounting plate.

I'll see if I can take a few pics later today...

Aaah, I think yours might be an earlier focuser then - not sure of that but I think all the later ones can seperate at the circular bit.

[yesyes]

OK, I have made a few pictures of the 2 focusers. First, here is the original one:

Someone said that the original should also have the collimatable ring at the bottom but it doesn't. Does that mean I got an old model? I bought the scope new just under a year ago.

Here is the new focuser held next to the original. In this direction the mounting holes seem to line up:

Here is where the problems start. In the other directions the mounting holes on the new focuser are further apart:

Luckily I don't need to worry about the size of the hole the focuser barrel needs to go through. The barrel of the new focuser actually fits inside the old focuser as seen here.

Now I'm a bit at a loss what to do. RVO have agreed that I can return the focuser for a refund. But it looks like there's no focuser available that would fit directly. So if I ever wanted a dual speed crayford (and I do already), it looks like there's no getting away from some DIY to make a focuser fit.

I was thinking that I might be able to drill new holes in the new focuser mounting plate instead of the OTA. Or maybe I could think up some sort of adapter. But it would have to be very slim.

Or should I just send it back, get a refund and go back to the adaptor idea in my first post in this thread?

Any advise welcome .. ;-)

[haitch]

The tube might fit but what about the lump of metal that sits around it under the curve of the monting plate? That looks much bigger.

I was making assumptions before about it being an older model - I could be wrong. Is your original focuser a crayfordesque one or a rack & pinion? I was thinking it was a Crayford. I can't see the mechanism on the photo but the drawtube locking screw is usually the same side as the knobs on a Crayford which isn't the case on yours. That said I thought the single speed Crayford was supposed to be a direct replacement for the rack & pinion so there's still a mismatch appeared from nowhere/somewhere I don't know.

Another thought... Does the EP holder off your existing focuser tube fit onto the new focuser drawtube where the holder is missing? If so then the lower profile holder off the new one (when it arrives) should fit your old focuser. That solves the height but you are still single speed. You can then sell on the new focuser but with the higher EP holder to recoup some of your costs.

[yesyes]

Not quite sure what you mean by lump of metal. Do you mean inside the OTA? I haven't actually looked there how this is mounted from the inside.

The original focuser is a standard R&P type. I have asked RVO if they have, by any chance, sold me an old model just a bit less than a year ago. Let's see what they say.

The EP holder from the old focuser does not fit. It is in fact not an EP holder but the holder for the Skywatcher-style adapter which is the EP holder. The ring on the old focuser is quite a bit bigger than the on the new one. In fact, the outside of the draw tube of the new one fits inside the draw tube of the old focuser. (See last picture above)

If I keep the new focuser, I'll check if I can drill new holes in the base of the focuser, rather than in the OTA, if possible. I want to avoid pressing too much onto the OTA when drilling, making it oval. It would also mean I don't have to strip down the whole OTA and clean all the metal dust out of it.