How to balance an 80ED

[MattJenko]

I have an Evostar 80ED, but when mounted with a flattener and a DSLR, there is no way I can get the balance right when in focus, as the draw tube is out enough that I cannot push the tube any further through the rings, nor move the dovetail any further along the mount. I know that the HEQ5 can easily carry this load, but wondering how I could go about getting everything perfectly balanced anyway?

[swag72]

How are you mounting it? You could try a longer dovetail - That would give you more movement. 

[MattJenko]

Hi Sara - I could indeed get a longer dovetail, and think I probably will as you suggest, as the one I have on there is the one it came with and is less than the distance of the middle section of the tube - ie no extension either side of the rings, so not much to play with.

I wondered if anyone added more weight to ends of OTAs to get balance. Also, how much does it really matter when you are over-mounted to start with?

[swag72]

I used to add weights to the front of one of my scopes as it was impossible to balance any other way. Worked well, a flower pot filled with concrete and a piece of tubing through it for the very long scew attached. There are prettier solutions out there!!

[wxsatuser]

I added a counter balance that was added to the front of the dovetail.

It was made from an old cheap dovetail and I had a lump of lead attached.

The weight ended up just under the dewshield.

[Scott]

I now use a duel mounting bar with an altir astro 60mm and st80 and can now achieve balance but when I had a finder guider, I had to add a 2kg wrist weight to the front of the 60mm. As Sara says, not so pretty but a working solution is better than a pretty one

[MattJenko]

I'll get a range of flower pot sizes and some concrete in then 

Seems like balance is generally taken more seriously than I had originally taken it. I assumed that being well under mount capacity limits would reduce the impact enough to not have to care, but I shall look into my options - thanks.

[swag72]

I'll get a range of flower pot sizes and some concrete in then 

Don't forget to put a plastic tube right though the middle so you can easily bolt it to your dovetail!

[Alien 13]

I did see a rather neat way of balancing a scope in a thread about the AZ3 that should work, cant find it at the moment but im sure a search will find it.

Edit found it.http://stargazerslounge.com/topic/222894-az3-saddle-and-counterweight-mod/?hl=%2Baz3#entry2398016

Alan

[Leveye]

In the field I've had to use old Batteries and duct tape. You do what you must! haha...Seriously though like the others I suggest a real counterweight and or a longer dovetail bar. My particular iOptron mount has a counterweight extension bar accessory that was offered and i went with that. It was much cheaper than the extra counterweight.

[MattJenko]

I do have a spare counterweight which could be pressed into service, although velcro weighted wristbands might be an option - but soaking up that lovely dew might cause problems thinking about it...

[IanL]

I don't have a balance problem with my 80ED (though I know what you mean about the short dovetail that comes with it); I have the ST80 and QHY5 piggy-backed on top, and it gives sufficient extra weight at the front to counterbalance everything.  You'll just need to get creative - here's something I put together for counterbalancing my SCT:

It's a washing-machine shipping bolt (nice and long) which I put new threads on using a cheap tap and die kit, plus a bunch of heavy metal corner brackets that I got from B&Q and bolted together.  Works like a charm when needed.

I guess the main problem with your setup is finding somewhere to attach the extra weight.  One idea might be to use the camera mounting hole on the top of the front tube ring.  You just need a bit weight with a hole in it and a short bolt to fix it in place - see above for creative thinking.  I don't reckon you will need that much extra to be honest, and a small bit of imbalance is not a problem (and can be helpful when guiding).