so i fitted a 10:1 focuser on my ED80...

[troypiggo]

... and now I ask the questions. :screwy:

I bought the Bintel 10:1 focuser (https://www.bintelshop.com.au/Product.aspx?ID=7467) and it went pretty easily onto my SW ED80 (the gold one) (http://piggo.com/%7Etroy/images/potn/troys_rig.jpg). One small oddity was that the way the 3 holes are in the refractor tube are 180 degrees from the ones on the new focuser, so now the labels on the refractor will be upside down if the focuser is up the right way.

Question 1: There's no fine adjustment mechanism in the fitting of them, so assume there's no collimation required now?

Question 2: The new focuser has no socket for a finder scope attachment like the original one, so how do I connect a finder to it? I actually bought a new finder scope as well, this Antares illum right angle one (https://www.optcorp.com/product.aspx?pid=105-166-280-4213). It just didn't fit in the original scope finder bracket, just by a smidgen. So guess I'll need a new bracket anyway. Recommendations?

Question 3: When moving it in and out, the new focuser is not silky smooth - I guess that'll smooth out after a bit of use?

[[1ponders]]

I don't know about the bintel on Troy, but the WO one has a couple of grub screws (one on either side of the focuser) that can be removed and a finderscope bracket foot can be attached. I'd contact bintel to see what bracket and foot they recommend.

Strange that the focuser will only go one way. From memory my WO will go into any of the three holes. I thought they were all 120deg apart??

I find that the coarse focus is quite firm but the 10:1 is a dream. It might need a slight adjustment or it might need the crayford lapping job done to it. There used to be a webpage that showed how to lap the flat section of the focuser tube of crayford focuser to improve their movement. I'll see if I can find it somewhere

[casstony]

Focuser tune-up: I keep this in my favourites in case I buy a GSO focuser some day:
http://www.backyardvoyager.com/gsofocuser.html

[[1ponders]]

Ah an updated one, thanks Tony. The one I was looking for was for the old single speed GSO

[Waxing_Gibbous]

I thought the Bintel focuser units (as opposed to the mounting base) rotated thru 360*? Would that not solve the problem?

[mithrandir]

I think you'll find backing off the screw closest to the mounting ring allows the body of the focuser to rotate 360 degrees.

[troypiggo]

Cool. Thanks very much for the tips. Must admit I had my breath held while swapping the focusers already, let alone pulling apart the actual unit. But I'll see how I go.

Will contact Bintel about what they recommend for finder attachment.

And the collimation question - nothing required?

@Ponders - I didn't mean that the focuser will only go one way. The holes are 120deg apart. But if you can imagine that on the OTA the holes are at 12, 4 and 8 o'clock, yet on the focuser they're at 2, 6, and 10 o'clock.

[peter_4059]

The picture of the Bintel focuser looks like it has a screw near the OTA flange to allow the focuser to rotate. The text also says:

"Has two mounting holes to attach finderscope bracket on right or left hand side of the focuser.
Tensioning screws allow you to adjust the drawtube tension to suit heavy loads or provide easy movement with light accessories."

[troypiggo]

Who reads the text? :) I'm on it, dude.

[troypiggo]

Just spoke to Bintel and have ordered finder dovetail base and bracket. Apparently I need to countersink the base, but I'll look into that when it arrives. Great service, those guys.

[dpastern]

Thanks for that link, much appreciated.

Troy - fingers crossed you get it all working!

I also agree about Bintel and great service (Orion starshoot autoguider arrived today!).

Dave

[telecasterguru]

I also did the 10:1 mod on my ED80 and couldn't be happier. Mine is also offset due to the screw holes but hey I only use it to guide so I don't mind.
I don't have a finder on mine but I use a green laser and it fits the same as a finder.
Michael at Bintel in Sydney actually countersunk the holder while I was in the shop.
Fabulous work and service.
Frank

[troypiggo]

Not sure who it was I spoke with, but now that I think back he may have offered to countersink mine too. Will know when they turn up.

[troypiggo]

Amazing. Yesterday morning I spoke with them. It arrived today in the mail, Sydney to Brisbane. Good on ya Bintel!