I'm going to be purchasing a JMI DX3 focuser for my scope soon and was wondering if this will be a direct fit without any drilling? Also will I be needing an extension tube to reach focus with this focuser?
Thoughts on this focuser compare to the Crayford 10:1 ?
While the DX-3 is considered a premium focuser, it's medium grade IMO. Its not close to the Feathertouch, Moonlight some other premium focusers IMO. As Geoff says, I would go for the GSO 10/1 Crayford which bolts straight on and is a dayyam good unit for the money. In addition to the holes all being in the right place the focal plane will also be correct. The JMI-DX3 has a much lower profile than the GSO focusers and it's unlikely to reach focus with a lot, if not all your eyepieces, without an extension tube or repositioning of the primary mirror.
While I can not compare directly with the DX3 model, I have had a JMI DX series and a Moonlight...the Moonlight is hands down better...smoother and just "felt" higher quality.
The JMI IMO is not quite in the same league as the Moonlight...as suggessted, you might be better served with a GSO Crayford focuser or jump up to the Moonlight/Feathertouch category...
many thanks for the reply guys. I might then get the GSO 10:1 focuser as i don't want to drill holes in my tube... not yet anyway ..
another question, the GSO 10:1 should sustain the weight of a DSLR and maybe other equipment also such as flip mirror etc?
I reckon it would support that and then some. I've had several kilos extending a foot and half out of mine without problems (two heavy 2" barlows + binoviewer + two Panoptics).
The only tricky bit is the brass compression ring. Under heavy load with a lot of torque it can slip and sag a little. But you'll probably find this with the more expensive units too. Beefy locking screws w/o a compression ring would be better - would be a straightforward modification if the compression ring was not good enough.
Nice, isn't it? I had both Dobs out last night and was thinking that I'll have to get one of these 10:1s for the 8" as well. (My poor 12" gets hardly any use. By the time it was cool enough to view through last night, the good seeing was gone, so the 8" won again...)
very nice indeed. much more solid than the R&P. no shakes. Now i can properly collimate my scope. before the collimator was very shakey and was just a rough collimation. abit heavier now. The sky didn't last long at all. I was shooting through the sky fogs till 2:30am until the sky was completely covered. only then i decided to give up. argh well, just wait for another 2 months before another clear sky
a 10:1 it is!.
But figuring in postage from Sydney, it's just as good a deal from Bintel Melbourne. 
