New Counterweight Shaft and Flange Advice :)

[KonusKing]

Hello, thank you in advance for your assistance!

I recently received a Konus Super Polar System equatorial mount as a gift, which I will use with my 114mm/900mm reflector scope. The mount is in great shape, but it is missing the counterweight shaft, nut, and flange. I would really appreciate your advice on replacing these!

You can see a lot of pictures of the exact type of mount I have here. I believe that this mount is similar to an EQ3.2, or the same as a Celestron CG4 or CG5. The hole in the mount where the counterweight shaft screws into is 15mm across, and the interior holes in the two counterweights that came with the mount are 25mm across. Here is a picture of my mount:

Here is a picture of the manual, showing the pieces I am missing:

And here are a few pictures from the internet of the same mount, but showing what I am missing: the counterweight shaft, "toe-saver" nut, and the flange (the reverse cone shaped connector):

I have found a 25mm diameter counterweight shaft that I could order online, at this link. But, will this be able to screw into the 15mm hole in my mount? Additionally, the flange on this looks entirely different, but to be honest I am not sure how necessary the flange really is. I would appreciate your input on if I should even worry about finding a similar flange. I did find a replacement counterweight shaft that I could order that has a similar looking flange, but this is only 20mm in diameter, linked here, but I assume that would not work with my counterweights that have a 25mm hole. Please be aware that I am located in Italy, so I am intending to order from a European site to make shipping easier.

I have also seen some people with the same mount who have done a DIY counterweight shaft, and this is why I am posting on this forum. If the options above won't work, how would you recommend that I make a new shaft and flange myself? In this image, I see someone using two large nuts where the flange goes, but does this give the necessary stability?

TLDR: What do you recommend I do for a mount with a 15mm hole for the counterweight shaft, and two weights that have 25mm holes in them?

[Elp]

Hi, you can save a lot of money if you try using an all threaded steel bar, you can clamp the weights with large steel washers and flanged nuts to suit the bar. At least this way you can chose how long the bar will be and can use less weight on a longer bar if needs be.

[KonusKing]

1 hour ago, Elp said:

Hi, you can save a lot of money if you try using an all threaded steel bar, you can clamp the weights with large steel washers and flanged nuts to suit the bar. At least this way you can chose how long the bar will be and can use less weight on a longer bar if needs be.

Thanks Elp, I appreciate your advice! Do you think the threaded steel bar needs to be the same diameter as the holes in my counterweights? These are my two weights, and both have a 25mm hole, and a screw on the side to tighten them to the rod, but I'm concerned that if the rod is thinner than 25mm, they won't be stable. 

[Elp]

All I can suggest is try it. You'll be using an M16 bar I presume (it's always best to try with a bolt first to confirm the diameter and thread pitch of a hole, it could be Imperial though I doubt it).

My setup was for a Star Adventurer and AZgti, two smaller threaded bars, but the weights used were weightlifting ones 1.25kg much lighter than yours with 28mm holes, the washers were 50mm diameter so larger than the weight holes, with the flanged nuts top and bottom of each weight they clamp pretty tight, because it's on a thread highly unlikely they'll slip.

You could probably get a thinner threaded bar to put into the side holes, cut to length so they can physically tighten onto the main threaded bar.

Edited December 2, 2021 by Elp