SLT goto mount / pier advice

[sbj]

My scope collection is about to double as bought a Celestron Nextsar 127 to go with my Dob. I've read good things about the scope, but lots of comments about the wobbly mount. I don't need my scopes to be portable at all as have wide open dark skies from my garden (very lucky), and Mrs SBJ has given permission for me to build an "unobstructive easily disguisable structure"! So, has anyone build a pier for their celestron / skywatcher mak ? Are there decent improvements in stability to be gained? Is this type of mount head easy to attach to a pier structure? Thanks for any input.

[E621Keith]

I don't know the answer to you question, but this should be a interesting thread. I have never heard anyone making a pier for any mount smaller than a EQ5/CG5. Usually people who build permanent pier built it for their imaging rig to get rid of any last bit of vibration and flex.

If you want a more stable mount for your 127. It may be cheaper to buy a Celestron 6/8 SE mount. I think a permanent pier will be overkill for the SLT and still won't solve the issue coming from the mount head.

[sxinias]

Hi,

I have a SW SynScan AZ GOTO mount which is pretty much the same as the SLT mount and has the identical tripod. While I have not had the mount on a pier, I do put it on my CG5 tripod occassionally. The mount undergoes a transformation on the CG5 tripod and should behave similar on a rigid pier. Vibration is not existant and gotos are very accurate. I can even put my 8 inch SCT LX200 OTA on it and obtain accurate gotos. The rigid mount greatly facilitates focusing, needless to say.

As far as the tripod goes, there are some simple things that improve it. Tighten up all the nuts and bolts, especially the bolts that attach the tripod leg sockets to the tripod head. Inject superglue or epoxy in the paper thin crack between the upper tripod leg and its upper and lower sockets beiing careful not to get glue on any moving parts. Always have the accessory tray installed and locked in place. Do not extend the extension legs any more than need be. 30 % at the most. You can remove the extendable legs and wrap them to increase their diameter and reduce wobble.

The above will not eliminate vibration but does dampen it and reduce decay times.

[sbj]

Thanks for the input.

I know it is probably overkill but the idea of being able to stick the 127 onto something that doesn't wobble like my tummy is very good indeed. I'm only ever going to stick a webcam on it at most in terms of imaging so penned a design based on the old concrete filled tube. Bought the bits and had a friend of the family do a bit of machining for me, and would love to show some pics if I could work out how !?

[Demonperformer]

Hanging some form of weight from the centre of the tripod should help. Bag filled with a couple of pounds of sand or similar can work wonders.

[sbj]

Here it is - pretty solid and a lot more convenient.

[StarryEyed]

Four walls and a roof and your a made man!

[rowan46]

that is absolutely bonkers, but in such a good way

[jambouk]

That is great. And looks much cheaper than a second hand HEQ5 or NEQ6 and probably more stable.

Great thread.

James

[sbj]

A pic of the actual plates for anyone who is interested:
 
 

[perfrej]

That looks like a job very nicely done! Why the long threaded bars? I use a total of 70mm of M12 on mine for stability. They are headed bolts welded to the underside as to enable a totally flat surface. Note the distance between the pier base plate and the top plate in the image.

Now, given the size of your scope, that is not going to be a problem, but you may want to consider shorter bolts for future upgrades. And you will get upgrades, and it will drain your wallet and you will enjoy every second of it

All the best,

Per

[sbj]

Thanks Per, I love the look of your mount! Maybe upgrades should happen soon!.........

The bolts are so long basically as I haven't got round to trimming them off yet.  I'm limited to how close I can have the plates due to the central mount bolt that I decided to use (in retrospect this would have been different), but all in all I'm fairly happy with it for now.  Looking forward to the return of the dark nights.

[perfrej]

[Eclectic_Mixer]

Hi,

Any chance of a close-up on how you attach the goto to the top of the pier. I was going to use the top of the tripod with the legs removed . Looks good though , such good scopes' spoiled by a bobbins tripod.

[sbj]

Have drawn a little schematic which will show it all better - bur left it at work. durr.

Will scan it and post again tomorrow.

[sbj]

Here you go, hope that helps.  Happy to email the scan if needed.

SBJ

[Eclectic_Mixer]

Thanks very much SBJ, I have downloaded piccy. Neat design there I have the Skywatcher 127 but the are much the same scope I believe. Do you align the horizontal axis N-S? when setting up?

[sbj]

I never have.  Just made sure the plate is level and do two star alignment.

Meant to say that the threaded rod that goes up into the goto mount is not a metric thread.

will check the thread size and post again.