Long Perng Newtonian Focuser quality?

[Garyh]

Hi,
Have been doing some research on Newtonian crayford focusers and have come across Long Perng focusers. They look rather nicely made and have noticed Andrews sell them.
Just wondering has anyone seen one in the flesh and compared them to a GSO one? Would they rate better in build quality, slop, smoothness?
Can`t seem to see much info on the net about them..

The manufacturer has little info on there site about there specs...
http://www.longperng.com.tw/product_in1.asp?id=133

cheers Gary

[skygawker]

Hi Gary
I just took delivery of a LP crayford (11:1) from Andrews ($149) but haven't installed it yet since it involves redrilling and I want to do the mod at the same time as flocking (on order). Can't vouch for the GSO units but the quality seems very good - smooth operation, graduated drawtube, excellent quality finish. The standard one that came with my SW 10" dob was pretty basic. Feel free to PM if you need any other info.
Allan

[Mark]

I have the SNT-30A version. They are nicely made units. I cannot directly compare it with a GSO at this time (no GSO's within fondling distance). I can compare it with an old JMI focuser however.

Mine came with no instructions.
This one weighs in at a tad over 1kg (1004g). It has a non-rotating base, though there are four grub screws in the base (2 each side) which may allow this (haven't tried). It is of quite solid construction with an excellent finish. The coarse focus control is ..er..um..coarse. It is a little 'lumpy' with substantial stiction. Definitely NOT silky smooth. A bit of torque is required to operate it. The fine focus is smooth and has much better 'feel'. The coarse knobs have knurled rubber grips, the fine knob is solid plastic. There is a tension control grub screw that works but requires an Allen key. I tweaked mine a little when I first got it. It supports my heaviest eyepiece (22mm T4 Nagler) and my Canon 40D with adapters easily and does not slip. There is no noticeable slop in the drawtube. The drawtube lock and compression ring thumb screws are nice and big and work well. The 2" compression ring on mine is very snug and actually needed a little attention when new. I had to remove it and carefully bend it by trial-and-error until all my 2" kit was easily inserted. The 1.25" ring was fine.

In comparison to my JMI unit: The JMI has a much smoother focus but it is only single speed and no compression rings. The LP also supports more weight. The LP also cost 50% of a new JMI. :)

Some specs:

Weight: 1004g
Travel: 30mm (has graduations in mm)
drawtube outer diameter: 58mm
Baseplate mounting holes: 6mm dia at 54mm x 91mm

Hope this helps!

Cheers,
Mark

[Garyh]

Thanks Allan and Mark for that info, very much appreciated! :) they sound very solidly made. They seem to be very heavy in weight as well as the GSO ones weigh in at 750g.
Is your one the full height one Allan? The lower profile one would suit my needs much better. Anyone seen one of these?
cheers Gary

[CoombellKid]

I have a new GSO low profile 1:10 and it comes in at 640gms including
rotatable baseplate. Yet to fit it so I really cant give you a run down on it
but it does appear a little stiff on the 1 to 1 knob but alot smoother on
the 1 to 10 knob. It has to be fairly tight just to keep the drawtube
lock at where ever one leaves it... I'm a lil suspicous of how it's going to
perform once it has XW's and low FL Naglers in it. But like most things if you
spend the money you will get pleasure... and if not you just have to
go with what you can get kinks an all.

regards,CS

[Garyh]

Thanks Rob, yeah I have heard similar stories about the GSO low profile focuser, not the best for anything heavy, just wondering if the Long Perngs are any better..
This focuser is going on that tube I got from you!
Done some minor panel beating on it today!..LOL
cheers Gary

[skygawker]

Mine's a SNT-30A like Mark's unit Gary.
Allan