Diy Sct mirror stability collet locks

[yobbo89]

I havnt used my 12" meade sct In a while, I actually hate it and kind of regret not buying a Ritchey Chretien astrograph instead, I've pulled the scope appart and added thicker grease and it has reduced the mirror flop a fair bit and also modified the focuser lock to grab a little tighter, the collet ring was a little oversised so I made it a little smaller but the scope still needs to be colimated on each meridian flip

Any how I will be making a new alluminium mirror plate that has 3 contact points, I'm just woundering if anyone knows where to find these collet locking rods or if anyone knows what exactly they are called, I can make cheap ones with grub screws but I rather a collet lock with a knob.

Pulled some example images of the collet lock from users over at cn


Edit:

[yobbo89]

I found these, not really what I want but getting close


https://m.aliexpress.com/item/400004488 ... t=Pc2Msite

[yobbo89]

Some micro ones of these would be good, I can machine up some knobs, too bad all these are large 100-150mm dia

[Graeme1858]

Any how I will be making a new alluminium mirror plate that has 3 contact points, I'm just woundering if anyone knows where to find these collet locking rods or if anyone knows what exactly they are called, I can make cheap ones with grub screws but I rather a collet lock with a knob.

That's very inventive Rob!

Graeme

[yobbo89]

I finally got around to pulling the scope apart, had a few other projects to do, it seems this model also has the thread for the lx200 spring mirror stablizer add on.

Any how I'm planing on what to do before I touch anything , might machine up a inner tube to thread in the current plate to prevent it warping the thread and then tig weld two flat bar for the two collet bolts to thread into. Also glad there is No glue, the mirror is held in with cork and a o-ring with a lock ring. Very easy to get grease on the mirror, use two sets of gloves..

[yobbo89]

I have one rod guide machined up, it took me 2 hrs
...

Wish I had a bigger parting tool xd, it will be awhile until this sct mod is completed, I also got some flocking comming in the mail aswell .

[Graeme1858]

Looking good Rob.

I had a mirror protector sheet that came with a heated dew ring that I didn't use when I flocked my SCT. There's only a slight touch of glue on the mirror!

Your Meade will be solid as a rock when you're done!

Graeme

[yobbo89]

Looking good Rob.

I had a mirror protector sheet that came with a heated dew ring that I didn't use when I flocked my SCT. There's only a slight touch of glue on the mirror!

Your Meade will be solid as a rock when you're done!

Graeme

ohh,what did you use to flock your tube? you added the glue on the velvet aswell? i got these stick on stuff https://www.ebay.com.au/itm/36348505092 ... 2705482828

[Graeme1858]

Ebay has it all!

I used this:

https://www.firstlightoptics.com/telesc ... erial.html

Graeme

[yobbo89]

Another updated, welded the extra support lugs into the current focuser plate, welding cast alluminium is a pain, full of crud and voids which requires alot of heat and cleaning to get out,i just left a few pinholes as I didn't want to warp it with to much heat..

I just need to order 150mm long half thread hex bolts, bit of a pain to find cheap atm and machine up some locking knobs.

[yobbo89]

The clearance is perfect and it threads onto the mirror shaft with ease, very happy

[yobbo89]

Just Waiting for brass billet to come in the mail.

[yobbo89]

I got a big hunk of expensive brass xd, the collet lock I'm using is called 3/16" brass brake line union inverted female Fitting , obviously the nut will be replaced with a nice machined brass knob.

I will list all the parts when I'm done if anyone wants to mod there own sct scope.

I'm wondering if it's worth while making kits to sell, the only pain is knowing the spec of the thread on the mirror tube as there will be variable sizes due fluctuations of quality control, it can be a pain designing something from one product to work on someone else's part, I've done this before on other projects and the part did not fit on another item.

[yobbo89]

Some more progress on the knobs , scope should be back on the mount in the next few days.

[Gordon]

That's a work of art Rob!

Wish you were a bit closer, I could have used your expertise earlier this week!

[JayTee]

It is so much fun watching you craft these improvements/accessories. You my friend, are a master machinist.

Cheers,

[Ylem]

You have the patience of a saint Rob, amazing work, that thing should be nice and tight.

[yobbo89]

Works very well, holds tight with very eas twisting the knobs, I might make another surface pass next weekend to make the knobs a little more shiny, I think I need scotchbrite, I'm going to work on my scope flocking in the mean time.

[yobbo89]

It is so much fun watching you craft these improvements/accessories. You my friend, are a master machinist.

Cheers,

Thanks, I just watch youtube videos, never really knew how to use a lathe before hand

[yobbo89]

That's a work of art Rob!

Wish you were a bit closer, I could have used your expertise earlier this week!

Happy to machine you something up xd