10 replies to this topic

[RonLevandoski]

Good evening and Happy New Year!

 

I have a next door neighbor kid and his parents who picked up an old vintage Meade DS-10. The young kid is really interested in astronomy and this scope is a big deal to him and his sister.

 

It's actually in remarkably good condition, the only problem is that the top of the pier that allows for polar elevation adjustments is broken. You can see the crack in the image. 

 

I looked into repairing it with aluminum welding and apparently the casting does not weld very well and would not be satisfactory. So, it appears that we need a replacement. 

 

Does anyone have any suggestions on how to proceed ?

 

Thanks in advance. 

 

ron Levandoski

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[Augustus]

Might have it in my basement. I'll look today.

[chuckyou]

you can braze cast iron

[B 26354]

you can braze cast iron

But it's cast aluminum.

[DLuders]

You could attempt to repair it using some of the techniques in this previous Cloudy Nights Forum topic.  

[clamchip]

I would use Super Glue.

Loctite brand, water thin.

Don't try cleaning the break.

As long as the oil from the threads has not migrated onto the break.

Don't touch the break with your fingers.

If the break is contaminated - game over.

Test fit the 2 parts to see if the grains of aluminum key together well.

If they don't key together don't bother trying glue.

If they do key together apply glue and push together and hold 2min, allow 24hr cure.

[Stevegeo]

Could you send me a few measurements  of the base Outside diameter that fits inside the tube , 

A drawing with measurements  of the ears ( height) and hole diameter . 

 

I may have one.. or better yet MAKE YOU ONE OF STEEL .  Cheap . I work in a fab shop. Things like this are cake to make . 

DM me if you get stuck . 

 

Stevegeo  

[Geo.]

Or make a mending plate from some 1/4-3/8" aluminum, tap and thread the cast pieces and run screws threw the plate to the cast. Bore for the pin. 

 

Take the bits to a foundry and have then cast a nice one in bronze.

[Gil V]

I would bolt up the mount and then use plate stock and some hardware to reinforce it. It doesn’t move much, so as long as it’s immobile and sturdy, you’ll be fine.

[clamchip]

This repair is mentioned before in this post but I'm thinking

how about go to the hardware store and buy a big washer.

Glue the parts together to hold them in place.

Clamp the washer over the break, drill 4 holes all the way

though the washer and casting.

Tap the holes in the casting and enlarge the 4 holes in the

washer so the screws pass through into your threaded

holes.

Robert

 

Edited by clamchip, 01 January 2021 - 06:47 PM.

[Tenacious]

If you can replace the top cap, that's probably the best option.

 

Short of replacement, I would be tempted by the mending ideas:

  1  Glue it together as Roberts says.

  2  Sister-on a mending plate, except make it the same shape and as large as the original tab.  To attach the mending plate, maybe tap the holes down low where the original casting has more "meat" and is undisturbed. 

  3  Buy a longer pivot bolt to go though the whole assembly and put a steel nut and washer on the end of that.  The nut will allow enough clamping force.  Over-torquing the pivot bolt might be what caused the crack and failure of the original casting.

 

  4  After painting it black, it should look pretty good and be as strong as the original casting.

Edited by Tenacious, 02 January 2021 - 12:39 PM.