Jump to content

Banner.jpg.b89429c566825f6ab32bcafbada449c9.jpg

What weights for rear heavy refractors?


Recommended Posts

Due to the convoluted focusing setup I have on my TMP 105/650 it is very rear heavy and as things stand I cannot get the DEC balanced as I cannot get the scope far enough forward.  I do have an ADM saddle mount on the way which will help but are there any solutions for adding some weight around the dew shield say?

Link to comment
Share on other sites

Any thoughts of adding a longer dovetail bar under the existing one?
Preferably one with the slot for the mounting screws [assuming the existing dovetail has some threaded holes in it] then you could 'slide' the rig up and down accordingly. I do this with my 're-modded' ETX105 when it is rear-end heavy.
Apologies... I don't have an image of it to show at the present time.

Link to comment
Share on other sites

2 minutes ago, Philip R said:

Any thoughts of adding a longer dovetail bar under the existing one?
Preferably one with the slot for the mounting screws [assuming the existing dovetail has some threaded holes in it] then you could 'slide' the rig up and down accordingly. I do this with my 're-modded' ETX105 when it is rear-end heavy.
Apologies... I don't have an image of it to show at the present time.

Yes - funny you should say this as it just occurred to me after I posted I could look at a longer dove tail.  That said some form of weights would likely be cheaper!.  Good quality Losmandy bars are pricey :).  It is probably the correct solution though...

  • Thanks 1
Link to comment
Share on other sites

I had similar problem and longer dovetail with rings at the end and in the middle solved it:

DSC06694.thumb.JPG.7dfcaf101788cd891e71a9885cdc0a28.JPG

Dovetail (yellow) is mounted in the saddle at the rear part, and rings (green arrows) in the front part of the dovetail. 

Edited by drjolo
Link to comment
Share on other sites

The StellaMira Losmandy dovetails are a real bargain and great quality.

https://www.firstlightoptics.com/dovetails-saddles-clamps/stellamira-universal-losmandy-style-dovetail-bar.html

Replaced the stock dovetail on my Technosky with the 15” one and no problems balancing now. 👍🏻

E82B487E-0501-4E3E-9D1F-80D7EF21C789.jpeg

Edited by johninderby
  • Like 1
Link to comment
Share on other sites

I use a cheap skywatcher tube ring with  weight suspended from it, and just move the ring up and down as needed. The weight in this case is a very strong taxi magnet that I picked up on Ebay, to which I can add more weight if needed....:smiley:

IMG_2374.JPG

  • Like 1
Link to comment
Share on other sites

I have an 8" dovetail on my 72ED and a 14" dovetail on my 90mm APO triplet to get the CG far enough back to use heavy 2" eyepieces and binoviewers with both.  I do have to be careful with the focuser knob's orientation, or it will either touch the dovetail or be behind it, depending on the scope.  I suppose dovetail flex would be an issue for imaging, but it's not an issue for visual observing.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.