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View Full Version here: : Unmounted 50mm Filters in a qhy Wheel.


Tandum
31-08-2012, 10:31 PM
Has any one else tried putting unmounted filters in a qhy wheel? I have the bag of nylon screws/washers explicitly for the job but they seem to have 3 screw holes for these instead of the usual two. One is on the far inside edge of the filter hole. This obstucts the carousel from seating on the central drive wheel,the washers get in the way.

Do these guys even test the stuff they make or look at how others do it? Sure, I can get a pair of cutters and snip a bit off the washer to make it fit but that is not the point. Obviously they didn't even test it or they would have fixed it. I wanna see one screw/washer holding down 2 filters, isn't that the way it's normally done?

Grrrrrr ... Both Paul Keating and Forest Gump's mum were right ..... :rolleyes:

pmrid
01-09-2012, 02:06 AM
Had the same experience and moved away from QHY FW also avoiding the motor sticking out in the wrong places. Went SX instead.
Peter

Tandum
01-09-2012, 02:20 AM
Sorry Pete, they only do 50mm and 50.8mm unmounted carouels. These baader filters are 50.4mm and going by the sx wheels I have owned, tolerances are really close in the filter size department.

Besides, I want QHY to fix it not for me to buy another wheel :)

Squeek Squeek ....

pmrid
01-09-2012, 03:23 AM
Another quirk I've found with unmounted filters is that some - Astronomic Ha 12nm for example are onlt 1mm thick glass substrate and the well in the SX filter wheel is 2mm deep so you have to either fake an O-ring somehow or find some other way to pad the filter out so the retaiing screws will hold it. I imagine this is a problem with many FWs - not just SX.
Peter

RickS
01-09-2012, 11:33 PM
Peter,

I found that rolling up a little bit of teflon tape (used for plumbing) makes a good spacer!

Cheers,
Rick.

Tandum
04-09-2012, 05:37 PM
I ended up tapping new holes, 4mm with blade heads instead of 2mm with phillips heads.
Luckily I had some big washers from a different carousel.