Comments on AccuFocus?

[DaveO]

Has anybody got any experience with the Orion AccuFocus? I am thinking of getting one to attach to my R&P focuser that comes with the SkyWatcher 10" newt.

Once attached, do you still have manual focus capability, or is it only via the remote?

Longer term I want to replace the R&P with a motorised crayford from JMI or the like, but that requires approval from the Chairman of Capital Appropriations! :rofl:

[janoskiss]

I have one. It works well and it's inexpensive. You lose manual focus unfortunately, but you can loosen where it locks onto the shaft with an allen key if the battery goes flat and then you can still use manual focus.

I used a well made R&P the other w/e at Little Desert that was better than any Crayford I've seen.

[DaveO]

Thanks Steve. Always better to hear from somebody who has used one. And I always keep lots of batteries!!

[iceman]

Would it be better to get a 10:1 crayford in the short term? You can probably still put accufocus on it and it's tonnes better than most generic R&P's.

They only cost $120 or so.

[janoskiss]

You cannot as easily put the accufocus unit on a Crayford (it uses the pinion shaft cover screws to attach to the focuser which are absent on a crayford). The 10:1 Crayford is good because it uses no power, can handle a lot more weight and has zero image shift, but the 'hands off' motorised focuser can be better if you have a bit of a wobbly mount.

[rogerg]

I bought one recently for my WO Megrez 80. I find it great. I think you could mount it on a Skywatcher newtonian, if you are handy with a hacksaw and trill... and can get a little sleve made up to adapt between the diameter of the skywatcher's focus knob shaft and the accufocus coupler diameter.

See my thoughts on it here (with pictures of how I adapted it to my Megrez)...

http://www.rogergroom.com/rogergroom/esh_rog_item.jsp?Item=424

Roger.

[DaveO]

The comments are very useful guys.

I had thought about going to a crayford with 10:1, but you can't motorise them easily, unless you are paying big bucks. I am interested in the JMI, but it'll cost me $640, and I won't get away with that sort of expenditure at the moment!

The main reason was to make focusing easier when using the web cam. Not really at the point where autofocus is a requirement yet, but playing with the focus manually is a pain. I have an EQ6 mount, but avoiding manual touching has to improve things all-round.

[Astroman]

Another way to motorise the 10:1 using the accufocus is to mount the accufocus away from the focuser somehow and run a belt between the focusing knob and the output shaft of the accufocus.

I have an Accufocus attached to my JMI NGF-DX3 which is a crayford, I had to make up a little sleve to make it fit though. The Accufocus' flexable shaft will fit directly onto any focuser shaft that is 8mm in Diameter, might be worth checking that out first.

I have found although the Accufocus is a brilliant and fairly inexpensive way to get pretty good motorisation, I wish it were a little slower on the slow setting. Just my personal preference.

[janoskiss]

Since you are going to be using it for imaging, I say get the standard Crayford (not 10:1) for stability *and* the accufocus for fine control, and do a little bit of work to fit the AF. Ken (ballaratdragons) fitted an AF to his GSO crayford. Ken, if you're reading this, how about some piccies? If not then DaveO, you could PM Ken and ask for some pics of his setup.

[rogerg]

Brilliant! Why didn't I think of a belt. That would mean if I got a second Accufocus I could motorise the focus on my SLR lenses by putting a belt around them.... hmmmmm..

Roger.

[Astroman]

Good idea Roger :)

[iceman]

Motorising the crayford can be done easily with the belt idea, as I've done with my Moonlite CR2.

RAJAH235 (Laurie - where is Laurie btw?) made the unit for me and my dad and I made a bracket to fit it to the scope. I use an O-ring to drive the fine focus knob.

Here's the thread when it was first done, 18 months ago! Wow how time flies.

http://www.iceinspace.com.au/forum/showthread.php?t=2116&highlight=motorised+CR2

[DaveO]

Boy some of you guys are very inventive aren't you!

Sounds like it is worth the investment on the AF then. The Crayford will have to wait though - SWMBO would freak if she catches my buying more bits!

[ballaratdragons]

Yep, that's right. I fitted an Orion Accufocus to my Crayford Focuser. Was an easy fix.

ALSO, using the method I used, you can also turn the remaining focuser knob manually!!!

I posted pics and instructions in here when I did it. I will go look for them. Back soon.

[ballaratdragons]

I'm back!

Here is the link to the adaptor I made.
http://www.iceinspace.com.au/forum/showthread.php?t=10782&highlight=orion+accufocus

It is tight enough to not slip but still allows manual focus :thumbsup:

And this is the bracket I made for it to match height with the Crayford.
http://www.iceinspace.com.au/forum/showthread.php?t=10850&highlight=orion+accufocus

You could use any material (aluminium, plastic etc) for the bracket.

I also went to an electronics shop and had the correct plugs put on the ends of a 10m telephone cable so I can focus from inside my control room :)

Good luck with it davo, it's a simple custom job.

[ballaratdragons]

Oh, by the way, I have also made another bracket on my ED80 so the Accufocus fits it too!

The ED80 Crayford has the same shaft as my 12" scopes Crayford, so the adaptor works on both.

It takes me about 1 minute to undo the 2 thumbscrews, swap the Accufocus over to the other scope, do up the thumbscrews, and I'm in business again.

[[1ponders]]

Ken, can you post a pic of the Accufocus attached to the Orion. I'm thinking of going that line, but I'd like to get some ideas on how others have attached it.

[DaveO]

Thanks guys, especially Ken - I remember those threads now.

Well the Board of Astronomical Appropriations conceded to my request as my Christmas present, so once 25 Dec gets around, I'll have the AccuFocus! Shame - I could have really used one last night, and here it was sitting in a box at home waiting for wrapping! :screwy:

Probably won't get approval for any form of Crayford for some time, so will just have to cope until then. May take a Lotto win to justify the EV1nm from JMI, but after trying one of their focusers last night on a friend's scope, I am now more eager than ever. :sadeyes:

[Harb]

Old photcopiers are a great source of belts pulleys and various other bits and pieces for this kind of work......
Hit the local tip or scrap yard...

You could motorise the 10:1 shaft if you really need slow speeds

cheers
John

[ballaratdragons]

Yep Paul, here ya go :thumbsup:

The Bracket I made is just the corner cut off a busted printer case. You could just make an angle bracket.

The Bracket mounts to the scope by using 2 of the 4 screws that hold the focuser tensioner underneath the focuser and the 2 original Accufocus screws hold the Accufocus to the bracket.

By using plastic, I didn't have to tap the threads out for the thumbscrews. I just drilled the holes slightly smaller and screwed the thumbscrews in, making it's own thread.

And the Crayford focuser shaft adaptor is explained in the link above.

It works excellent Paul :thumbsup:

[[1ponders]]

Thanks Ken :thumbsup:

[ballaratdragons]

Show us the pics of your finished product when done please Paul.