Orion Accufocus

[barees63]

I've been looking at the Orion AccuFocus electronic focuser adapter for R&P focusers has anyone here got one of these? They are advertised in AS&T (by sirius-optics) at AUD95 and in the US they are about USD49, I've read a few reviews of them and they sound quite good, looks like they'd fit a GSO focuser without modification (or with minor modification to the bracket at most)..

I'm real interested to hear if anyone has tried one with a GSO scope?

But I think I going to go for it, I just need to find out the cheapest (eg best shipping) place to import one from..

[janoskiss]

You won't do much better than $AU95, with postage and US-AU$ conversion, so why not just get it from SO?

[barees63]

I might in the end if they ship to NZ, but postage from Australia to New Zealand can be more expensive than from the US (I don't know why), AUD95 is fairly high considering the real price is under USD50 (AUD65)..

[barees63]

well, I bought one off AstroMart, around AUD80 including shipping for "New in Box". If it works out I'll post a mini-review with installation pics if anyone's interested..

[janoskiss]

That would be great. Thanks!

[netwolf]

ya Bruce, pls post some details. Will this work only with the R&P Focuser or can it be adapted for a Crayford also. I have an R&P And was thinking of upgrading but the reviews of this on Cloudynights forums are very promising on a R&P focuser. Also does one need to get the helical 2" to 1.25" adapter also for this, does it add any benfits.

Regards
Netwolf

[anthony2302749]

Have you looked at Rigel Systems nFocus plus motor http://www.rigelsys.com/.
It avaliable in Australia. I use one on my ED80

[barees63]

What advantages would a motorised Crayford have over a motorised R&P focuser?

[janoskiss]

That Rigel one is pretty expensive compared to the Orion one. I imagine you would still get image shift with an R&P, motorised or not. I can't see why the Orion one couldn't be made to work with the Crayfords.

On the subject of Rigelsys, anyone know who sells their products (I'd like to get a quickfinder).

[davidpretorius]

i am having huge problems working out what the motorized crayford is sooooo expensive!!!

I am about to build a hand controller for focussing (my computer linked one is ok, but i think a hand controller would be better) , and thought i could adapt the r&P rigel one instead for a crayford. It is a 4mm shaft on the crayford, which throw in a coupler, and some stabilizing legs, then i can't see why they try and charge so much

[netwolf]

The rigel one says it will work with GSO crayford focusers, like the ones on the Meade Lightbridge (specifcally mentioned). I am guessing it maybe better to buy a GSO Crayford and then add the Nfocus from Rigel. But a cheaper upgrade for my current system would be to just get the Orion AccuFocus + helical adapter and upgrade to a crayford later.

Regards

[davidpretorius]

i assume the basic versions attach to the actual wheel of the R&P focusser, if they can be attached to the shaft and still have enough range for fine tuning, it might be worth adapting it?

has anyone got a better picture of it or some specs. The 1.8 degree stepper motors i ripped out of a 5 1/4" disk drive and then directly coupled 1:1 with the shaft of the focusser gave me 10 steps where it was very hard to notice any change in focus. It was very precise!!

I think i will still investigate building a stepper driver and a few push buttons to try and run the 1.8 degree stepper via battery

[barees63]

David - Were you asking about the AccuFocus? My understanding is you remove one of the knobs then couple the motor to the shaft via an included coupler. The actual motor mounts to the focuser via an L-Shaped bracket that attaches via two of the bolts that hold the little plate underneath the (R&P) focuser.

NetWolf.. I don't believe you require the helical adapter but I could be wrong, anyway - all should be revealed in a couple of weeks when I actually get my grubby little hands on it.

[davidpretorius]

that sounds more promising. if it is geared to attach to the shaft then it should n't matter whether it is r&P or a crayford. Some mods may be needed to get the focusser to get a solid base on a crayford, but that should be easy.

I would love to check out some photos when she arrives Bruce

[barees63]

In the meantime: http://www.cityastronomy.com/accufocus.htm

[[1ponders]]

Try BATSC/Bintel Steve.

[janoskiss]

BATSC don't exist no more and Bintel only sell the Telrad (which I've got already), but for an 8" scope or smaller, the Rigel quickfinder would be more suitable.

Come to think of it maybe Andrews has them. I've seen them on a couple of their Dobs members here posted pics of.

[lost_in_space]

Andrews does have them, I got one with my new scope.

[[1ponders]]

I'm pretty sure they still sell the focusers with motor Steve.

[netwolf]

Paul,
please confirm does Bintel sell Orion Accufocus?

FYI cloudynights thread on Helical vs Accufocus.. It seems some people are very happy with what the accufocus can do for your average R&P focuser.
http://www.cloudynights.com/ubbthreads/showflat.php?Cat=&Board=telescopes&Number=790953&Forum=All_Forums&Words=accufocus&Searchpage=0&Limit=25&Main=771786&Search=true&where=bodysub&Name=&daterange=1&newerval=1&newertype=y&olderval=&oldertype=&bodyprev=#Post790953
and the Helical review at Astromart..

http://www.astromart.com/articles/article.asp?article_id=347

Would it not be better to use both, best of both worlds. Motor focus and helical for fine adjustments.. all for USD $100 pretty cheap.. for those of us on a budget.

Regards
Netwolf.

[[1ponders]]

Netwolf, I was talking about the Rigel systems nfocus with motor , not the Orion Accufocus.

[Thiink]

barees63: has it turned up yet? Im keen to hear how you go with it.

[barees63]

Hi Simon, no should be here any day..

[barees63]

Hi Guys,

Well, the kit arrived today.. here's what you get (plus instructions):

http://www.zitafarm.com/astro/afocus1.jpg

The installation on my GSO 10" Dob was a breeze taking about 5 minutes, the procedure is to remove one of the focuser knobs and slide the flexible shaft coupler onto the focuser shaft, tighten two set screws, then attach the bracket under the focuser using the existing screws that hold the focuser backplate on, then attach the bracket to the motor unit with two thumbscrews and finally velcro the control unit somewhere convenient for storage.

http://www.zitafarm.com/astro/afocus3.jpg

Here's a close up:

http://www.zitafarm.com/astro/afocus4.jpg

To use the Accufocus you simply pull it off the velcro, set the desired focus speed via the rotary control then use the forward and back buttons.. slowest speed looks very slow indeed and should be ideal for high magnifications. I'll post a "first light" report when I get a chance to use it for real.

btw, in the two US reviews I read of this unit both reviewers complained about the difficulty installing the battery, one person claiming it took him 15 minutes and required tools.. I found you simply need to put the battery in the right way round (wires at top) and it just snaps right in - got to wonder about Americans sometimes ;)

[davidpretorius]

greatstuff, i have a crayford with a 4mm shaft, would in your opinion it fit. that shaft on the rack and pinion looks wider?

thanks for posting

[barees63]

The shaft on the R&P is 8.5mm, the coupler is held by two short grubscrews so I guess worst case you'd need to find longer screws, don't know about the bracket though?

[davidpretorius]

thanks, are the grub screws at 180 degrees to each other?
re the bracket, i will have a look at the crayford and i might have to use up some scrap aluminium i have.
what was your final landed cost again if you don't mind me asking?

[barees63]

the grub screws are 90 degrees apart



Bearing in mind I bought it privately off AstroMart (as "New in Box") and I live in NZ, the landed cost was approx AUD85. Retail is USD$49.95.

[davidpretorius]

bugga , i would have to build the 4mm shaft up otherwise i will get the wobbles

thanks for your great help, it looks like i will have to make it.

[janoskiss]

Thanks for filling us in Bruce.
I wont wan! :tasdevil:

[Thiink]

Woo, it turned up! Thanks for the write up and pictures Bruce, looking forward to the first light report. It sure looks the goods!

..and now to get some money together to buy one (so many money sucking things going on at the moment :().

[[1ponders]]

Swank looking unit Bruce. :cool2:


DP, I wonder if you could simply find a sleeve of the same external diameter as needed but with an inner diameter similar to yours. I know it's probably a big ask, but you never know. The flexible shaft coupler doesn't seem to go all the way on, so you could put a couple of grub screws or small bolts at the inner end to tighten the sleeve to your existing 4mm focuser shaft. Something to think about.

Or....maybe the manufacturers already have a different flexible shaft coupler for your size???

[barees63]

Well, I took it out tonight and it gets the big thumbs up! It worked perfectly.. focusing was smooth and totally vibration free, so much easier to focus when the image is rock steady..not much more to say really except that I highly recommend it.. one thing that surpised me was how finely balanced the GSO Dobs are, with the focuser attached the springs were not providing sufficient tension at some angles so I'll need to sort out a counter weight. a bit OT but I also had my first opportunity to use the Vixen LV 25mm and 6mm EPs I bought from H0ughy.. wow! the difference between the 25mm LV and the GSO 25mm was quite amazing, I especially noticed it with clusters.. just seemed to be many more stars.. with the 6mm EP I was able to see the Cassini Division for the first time ever :cool: and I saw 7 stars in the trapezium in M42 (had seen 5 once previously).. a good night.

[janoskiss]

Sounds fantastic, Bruce. I've just sent an email off to Sirius Optics. Even with the Crayford (cheap one), focusing at high power is difficult.