Simple Adaptor for Orion Accufocus and Crayford

ballaratdragons (Ken) · #1 13-06-2006, 05:36 PM

As you may already know, I am a junkie for using junk when it comes to making things.

Well, here's another tip using junk (or a new bit if you ain't got one)

I needed to make an Adaptor to marry the Orion Accufocus to the Crayford Focuser shaft.

My solution from the shed was an old Plastic Fuel Filter from a car (I don't throw much out) and I hacked the end of. Both ends are a perfect fit!!!!!

If you are worried about slippage, just put a very small hose clamp on the focuser shaft end.

You may pinch my idea if you want to.

See diagram below

ballaratdragons (Ken) · #2 13-06-2006, 05:55 PM

Not a great photo, but it shows the Adaptor on the Accufocus!

and there is a shoulder to stop the adaptor going in too far!!! or the fexi-drive won't flex. These filter people certainly know how to make adaptors

Wombat_In_Space (Darren) · #3 13-06-2006, 05:56 PM

I love the way you make stuff out of nothing Ken.

ballaratdragons (Ken) · #4 13-06-2006, 06:01 PM

It ain't outta nothing Darren. That was a perfectly good 'used' clogged up Fuel Filter I hacked up to make this adaptor!

janoskiss (Steve H) · #5 13-06-2006, 06:15 PM

Glad that it's being put to good use Ken, instead of sitting in its box like it was doing over at my place. How are you going to attach the motor housing to the scope?

ballaratdragons (Ken) · #6 13-06-2006, 06:19 PM

Steve,

I am going to make a bracket just like the original, but the right fit.

davidpretorius · #7 16-01-2007, 04:42 PM

do we have a diameter of the accufocus shaft?

ballaratdragons (Ken) · #8 16-01-2007, 04:54 PM

Davo, the Accufocus doesn't have a shaft, it has a Flexi-drive. The Focuser shaft goes inside the Flexi-drive. Or in the case of a Crayford, the adaptor goes inside the Flexi-Drive.

davidpretorius · #9 16-01-2007, 04:59 PM

thanks Ken

Bintel were getting it in the post this arvo from Sydney. I can't wait to see it!

ballaratdragons (Ken) · #10 16-01-2007, 05:09 PM

The adaptor goes into the black flexi-drive section and is held in with a grub screw. The small hole in the adaptor slides onto the Crayford focuser shaft.

erick (Eric) · #11 09-06-2007, 06:54 PM

OK, I did the job today - and am happy with the result!

Here's the story:- Orion Accufocus (thanks Fahim), designed for an Orion rack & pinion focuser, but destined for my GSO Crayford focuser.

I've already turned my focuser by 45 deg from parallel with the OTA, so I left it there. I decided to put the motor on the left hand side of the focuser.

Not having a used fuel filter

, I had to go and spend a whole $3.99 at Supercheap Auto! Took a pair of calipers and the items that needed to fit. Good idea since different fuel filters have different size pipes.

Photo one shows left hand knob removed and "fuel filter" plastic sleeve in place. It was a tightish fit over the shaft, but just the way I wanted it. Big thanks to Ken for this tip!

Photo two shows the motor hanging off the flexible coupling and shaft while I worked out how to design and fit a bracket to support the motor. Everything was fairly well lined up above one of the screws that hold the focuser on the OTA, so I used that. I retained the black nut inside the OTA, found that the thread is M4. I cut out and fitted a bracket, from moderate gauge aluminium. A spray of matt black paint to finish it off (hide my scratches and vice marks

).

Photo three shows the bracket in place. For the time being, I've left the whole Orion rack & pinion mounting bracket in place - in case I decide I don't want the electric focuser any more and put it back on the market. However first impressions are great, and I expect to be sawing off the excess of the bracket after a few nights of testing, leaving just the plate that the two screws fit into.

Now, what I didn't like the prospect of was the loss of my manual focusing, so I designed a way to swap easily between electric and manual. I had seen a suggestion to carry the allan key and loosen the grub screws - nope, I'll lose it, drop it!! So I replaced one grub screw with a finger operated screw. See photo four. Guess what, it's M4 again, so I cut down a screw, fitted a large washer under its head and filed some flutes in the washer so I could get a good grip on it - and hit it with some paint as well (yep scratches again!). Now I leave the second grub screw on the plastic sleeve loose. If I want to use the motor, I finger tighten the screw and it works a treat. If I want manual, I loosen off the screw and use the right hand knob. When I do that, the plastic sleeve turns smoothly inside the flexible coupling (but I did have to debur the grub screw holes on the inside of the flexible coupling). I checked that the screw head clears everything as it rotates around the shaft axis.

I checked collimation - I was a bit worried since I had loosened one screw on the focuser - but no problem.

OK, I set up on Venus - max magnification (2x barlowed 6mm = 400x). Seeing not great (swimming a fair amount), but the electric focuser was super. On slowest speed I could easily go in and out of focus in both directions. No vibration observed. Easy to stop at best focus. No backlash, or whatever there was did not worry me at all. I'm happy! I've put buying a 10:1 focuser out of my mind now.

Hand control fits neatly in my bits&pieces case. Motor doesn't seem to be in the way as I store and carry the scope.

One test is going to be operation of the screw with gloves - we'll see. Also the little speed control knob on the handset, but with my manual focus ability, I can probably always leave that on the slowest setting.

ps. It looks like it's going to be a glorious observing night in Melbourne. However, family dinner tonight takes precedence - I have to hold out hope for tomorrow night before Monday's predicted showers. Thank you, your Majesty, for the public holiday Monday so that Sunday evening becomes an option!

JethroB76 (Jeff) · #12 18-09-2007, 10:24 PM

Ok, I've dug this thread up rather than start another.
I'm thinking of fitting one of these to the lightbridge rather than going for a 10:1 focuser.

Are those who have one of these setups still happy with them? Is there anything you might change in the mods required to fit it?

Anybody?.......Eric?

ballaratdragons (Ken) · #13 18-09-2007, 10:34 PM

Nope, I wouldn't change a thing!

I use mine every time I image (which is every clear night) and it still works perfectly. It sits outside on my ED80 and I control it from inside my control room.

2 thumb screws and I fit it to my dob in about 1 minute.

Terry B · #14 18-09-2007, 11:18 PM

Quote:

Originally Posted by ballaratdragons

Nope, I wouldn't change a thing!

I use mine every time I image (which is every clear night) and it still works perfectly. It sits outside on my ED80 and I control it from inside my control room.

2 thumb screws and I fit it to my dob in about 1 minute.

How do you control it remotely? Have you created a cable other than the hand controller?

ballaratdragons (Ken) · #15 18-09-2007, 11:22 PM

Quote:

Originally Posted by Terry B

How do you control it remotely? Have you created a cable other than the hand controller?

Same controller, Terry, just a lot longer cable.

I use a 10m telephone cable (not the coily ones), and the electronics store near here (Wiltronics) where I bought it attached the correct plugs on the ends for me. Full price was $8 if I remember correctly.

I still use the little coily one when I view thru my Dob though.

erick (Eric) · #16 19-09-2007, 11:43 AM

Mine is permanently on and gets lots of use. I struck a problem with the screw catching when I thought I had loosened it enough - so when I wound manually, it would catch against the motor.

Took the screw out and filed the end again to a nice flat surface, checked the plastic spacer wasn't all "butchered" - it wasn't - put the screw back and it's been fine since - I just ensure I've screwed the screw out far enough, but no so far it comes out and falls into the grass

I've developed the practice of keeping the screw head right in front - no good having it rotated behind where you cannot undo it. So all rough focussing is done manually, then tighten up the screw for the motor-driven fine adjustment which is never more that a few degrees of rotation back and forward so the screw head stays accessible, in front.

Now, I mush get a longer lead - that has become a problem. I've been hanging it off the motor, but if I leave it swinging, I get seasick looking through the eyepiece

So I place it against the finderscope bracket - but it's inclined to fall down occasionally or gets in the way when I want to use my laser to align the scope.

Looks like I need a metre uncoiled lead. Ken, I think they are standard telephone handset connectors - is that RJ12 whereas the telephone cable connection is RJ11 - help anyone?

Terry B · #17 19-09-2007, 12:21 PM

Quote:

Originally Posted by erick

Mine is permanently on and gets lots of use. I struck a problem with the screw catching when I thought I had loosened it enough - so when I wound manually, it would catch against the motor.

Took the screw out and filed the end again to a nice flat surface, checked the plastic spacer wasn't all "butchered" - it wasn't - put the screw back and it's been fine since - I just ensure I've screwed the screw out far enough, but no so far it comes out and falls into the grass

I've developed the practice of keeping the screw head right in front - no good having it rotated behind where you cannot undo it. So all rough focussing is done manually, then tighten up the screw for the motor-driven fine adjustment which is never more that a few degrees of rotation back and forward so the screw head stays accessible, in front.

Now, I mush get a longer lead - that has become a problem. I've been hanging it off the motor, but if I leave it swinging, I get seasick looking through the eyepiece

So I place it against the finderscope bracket - but it's inclined to fall down occasionally or gets in the way when I want to use my laser to align the scope.

Looks like I need a metre uncoiled lead. Ken, I think they are standard telephone handset connectors - is that RJ12 whereas the telephone cable connection is RJ11 - help anyone?

No they are not the RJ12. They are little narrow 4 pin plugs. The RJ12 can have 6 pins although most telephone ones only have 4 in them.

erick (Eric) · #18 19-09-2007, 01:37 PM

Thanks Terry. Yes, they are the ones used for the telephone handpiece. Narrower than RJ11, but I cannot remember its number. I think I have a handpiece extn lead amongst my telephone bits and pieces at home. I'll check and meter the wiring to check the plugs are wired the same.

ballaratdragons (Ken) · #19 19-09-2007, 06:15 PM

Eric, yes they are 4 pin, but they are even narrower than a phone plug

erick (Eric) · #20 19-09-2007, 08:18 PM

Yes, I just found I have a packet of the connectors in my telephone junk box. I've sent my son to cut the bigger ones off a phone cable and put these on - without the right crimp tool - should be fun. We'll see how he goes. (and check the wiring connections first on the original coiled cable so he gets them the same!) ps. the connector packet is marked "RJ11 4/4"