Rings for 50mm finder???

[Merlin66 (Ken)]

Any ideas on obtaining a set of rings suitable for a 50mm finder?
I have the ring mount with a curved base for an SCT, but now want to mount the finder onto the CNC rings (flat) on the ED80.
Can't see anything suitable on the Bintel site......

[bojan]

3-D print?
I recently made it for guider.. rock solid.

[OffGrid (Steve)]

I got on of these light and sound stage clamps for my vintage 50mm refractor so I could mount to a camera tripod. Worked a treat.
I think they also come in plastic.
The bolt and wing nut at base is removable so it may be adaptive for your needs.
http://www.jdsound.com.au/products/1...0mm-truss.aspx

[Merlin66 (Ken)]

Steve,
Looks like a good solution....
I've just measured the OTA of the finder - it's 54.1mm diameter.
Do you think that would fit it these clamps???
Ken

[OffGrid (Steve)]

G'day Ken,
54.1 mm may be a stretch.
I will have a look a mine over the weekend and let you know.

[bojan]

Found this on thingverse, very similar to my design (I have hex holes for m5 nuts instead of thread into plastic):
http://www.thingiverse.com/thing:461148
http://www.thingiverse.com/thing:1246269

It is quite easy to design something like this using (free) 123d or similar.

[Merlin66 (Ken)]

Bojan,
OK, what's the likely cost of getting say a 55mm pair of rings 3D printed??

[bojan]

No idea about others...

I can do it for you gratis, by end next week (I am away this weekend)
It would help if you provide me with design.. or drawing at least.

I will post the photo of my ring later today.

[OffGrid (Steve)]

Ken,
Unless JDSound has the size you need then 50mm won't do it.
It measured a shy over 50mm between the jaws of the lower part of the clamp.
Happy hunting mate
Steve

[ausastronomer (John Bambury)]

Originally Posted by Merlin66

Any ideas on obtaining a set of rings suitable for a 50mm finder?
I have the ring mount with a curved base for an SCT, but now want to mount the finder onto the CNC rings (flat) on the ED80.
Can't see anything suitable on the Bintel site......

Hi Ken,

The Williams Optics finder bracket should work for you.

http://www.williamoptics.com/accesso...t_features.php

I have one of these I bought several years ago and I dont think the design has changed in the past 7 years, or so. The post is fixed to the finder bracket with a couple of machine screws which you can undo, remove the post and then mount it flat. Just double check the widest OD of your finder as this bracket has an inside diameter clearance of only 55mm. It is designed for the WO 7 x 50 finder. Unlike some cheaper options this bracket has the finder alignment screws which you need to properly align the finder with the telescope. You might also like to check with Williams Optics, or one of the US dealers whether the recent manufacture units still allow the post to be separated from the bracket.

You can buy them from Agena Astro. Most other US dealers only sell them with the finderscope.

http://agenaastro.com/william-optics...mm-finder.html

Cheers,
John B

[Merlin66 (Ken)]

Bojan/ Steve/ John,
Thanks guys.
Revisiting the problem, I think I'll just cast an epoxy insert to "flatten" the base plate and fit that to the ED80 CNC rings.

[ausastronomer (John Bambury)]

Devcon Aluminium Putty would work really well for this but if you don't have some on hand, a tin of this will cost as much, or more than the WO finder bracket.

This is 2 part epoxy putty / filler and a truly excellent product which can be machined, drilled, sanded, filed and screwed etc. It is a commercial grade product and it is very strong and durable, but it aint cheap. I used to use it for floating and bedding the barrels on my target rifles and found 100 other uses for it.

https://www.blackwoods.com.au/part/0...FQwmvQodnSwEyQ

Cheers,
John B