DEC Balance & My Nerves

[Mav359]

Hi Guys

I have balanced my mount in DEC however it required the removal of the rear saftey screw. This concearns me slightly, granted the OTA would have to be facing the floor and the dovetail would have to let go but does anyone else have this problem.

My nerves are getting the better of me....

[hemihaggis]

you should not have to remove safty screw to balance in dec , just move the weights ??

[swag72]

Or can you move the scope in the rings? Or buy a longer dovetail.

[Mav359]

you should not have to remove safty screw to balance in dec , just move the weights ??

I thought moving the wieghts only affected RA balance?

Celestron instructions for balancing in DEC say that state that you lock the RA clutch in place have the OTA paralel to the ground then you unlock the DEC clutch and the scope will roll one way or the other, you counter the imbalance by moving the scope along the dovetail. If the RA clutch is locked how can the wieghts effect the OTA?

Am i doing this wrong?

[A McEwan]

Yes, weights on counterweight shaft is RA, tube position in rings or dovetail position is DEC.

Ant

[hemihaggis]

Sorry my mistake , to balance scope other way you move the tube in the rings ...??? What's all this safety screw stuff ??

[Mav359]

If the OTA was pointing directly at the sky (for instance) & the dovetail wasn't tightened up the scope could simply slide out of the dovetail onto the floor (reaches for gun ), the retaining screw screws to the OTA and extends beyond the dovetail meaning if it did slip the screw would keep it in the dovetail & my OTA wouldn't make a mess of the floor (Puts gun down ).

My OTA has a screw either end of the dovetail but in order to get my scope balanced in DEC i have to remove the rear safety screw to slide the scope back far enough where its balanced.

This would only cause an issue while the scope faces the floor so during use it wouldn't be an issue but once i park my scope it faces down to the ground to make enough room for my obs roof to close.

If i come down to the obs one day and my scope was lying on the floor........

What i wanted to know was do other people have the issue and what have they done to get round it

[A McEwan]

It sounds like quite an odd problem. I presume the dovetail is attached directly to the OTA, and you're not using rings?

Ant

[m.tweedy]

Can you not add a little weight to the front end of the tube. something like an adm mini top rail and counterweights

First Light Optics - ADM Mini Dovetail Counterweight Kit

and slide the counterweight along the bar

[Mav359]

Can you not add a little weight to the front end of the tube. something like an adm mini top rail and counterweights

First Light Optics - ADM Mini Dovetail Counterweight Kit

and slide the counterweight along the bar

That's so logical & obvious i'm quite annoyed at myself

Cheers Michael

[Mav359]

At that price though i can feel a DIY project on the horizon

[m.tweedy]

:pThat is the power of the collective.

It is only obvious if you know it. The reason I suggested that solution is that on my C11 by the time I have the crayford, diagonal and the 21 Ethos I had the same problem. In the end as I have a top adm mini bar I mount my Megrez 90 and slide it along to counteract the problem.

[E621Keith]

A cheaper alternative is this baader counter weight. It should attach to the CGEM dovetail in front of the clamps

Baader 1 kg tube balance weight for 3' prism rails

If your scope uses Vixen type dovetail there is this

Baader Edelstahl Laufgewicht 1kg - mit 1/4' Anschlussgewinde

Also, a dew shield at the front can move the balance forward.

[Mav359]

Ive the dew shield on but its not nearly heavy enough, whats put me over the edge is that 27mm Hyperion coupled with the DSLR causes the camera to be suspended quite far back from the scope.

I reckon i only need half the weight of the camera to bring it back far enough in the dovetail to replace the safety screw.

I think i might be able to cable tie something to the front of the dovetail underneath the OTA, as long as there is no movement in it it should work, no pretty but effective.

[Starlight 1]

can you add some car wheel weights to something to put round the tube.

[Mav359]

I don't know yet i'm not home so i cant check but i'm thinking replace the safety screw at the front of the scope with a longer version that i could run through a weight essentially a weighted safety screw.

See when i get in

[m.tweedy]

something like this

Metric Threaded Rod

cut down and screwed where your safety bolt sits. two nuts one on each side of an appropriately drilled piece of metal.

I used a different approach on the clubs 12 inch dob.

I attached a length of heavy duty velcro to the tube then cut some squares off some metal bar like this

16mm x 3mm Mild steel flat, Mild Steel Flat Bar, Mild Steel | Metal & Plastic online Metals4u

hammorited them then used the other side of the heavy duty velcro on them. The advantage of this method is you attach as many of the squares to get balance. change the eyepiece and either add or remove some of the squares the regain balance.