Lapping setup

[Narcissus]

I’ve always been really impressed by the lapping machines that are used to achieve flat faces and crisp on cases. Although I don’t do enough case refinishing to warrant the price of a machine, I though maybe I could achieve a similar result with something home built. The impetus to try came when I bought an Omega Chronostop. The case came with a sunburst case finish that was long gone and would require precise brushing.

 

 

I figured I could replicate the multi-axis adjustment by using a telescope head. Found one on eBay for $125. Then added a 3 jaw Chuck for $50. My only issue was that I needed to adapt the two together. Because the stress won’t be so high I figured I could just 3D print some adapters and it worked perfectly! The great thing about the resin printer is that the resolution allowed me to actually print the threading!

 

 

 

Because the case is a top loader, there was no good way to hold it properly so I printed an adapter to screw on the back.

 

 

 

All ready to go:

 

 

I am really happy with the results! The case has some dings that I wish I could laser weld but alas I can’t built one of those on the cheap. Lol.

 

My next step is to find a way to fasten everything down so I get more consistent engagement with the sander and recreate the angles consistently between checking my work.

 

 

 

 

 

- Craig

[HSL]

Must say this looks like a cool project, seems to do the business as well. Good work!

[oldhippy]

Wow that looks incredible.  

[tobich]

I’ve always been really impressed by the lapping machines that are used to achieve flat faces and crisp on cases. Although I don’t do enough case refinishing to warrant the price of a machine, I though maybe I could achieve a similar result with something home built. The impetus to try came when I bought an Omega Chronostop. The case came with a sunburst case finish that was long gone and would require precise brushing.
 

 
I figured I could replicate the multi-axis adjustment by using a telescope head. Found one on eBay for $125. Then added a 3 jaw Chuck for $50. My only issue was that I needed to adapt the two together. Because the stress won’t be so high I figured I could just 3D print some adapters and it worked perfectly! The great thing about the resin printer is that the resolution allowed me to actually print the threading!
 

 

 
Because the case is a top loader, there was no good way to hold it properly so I printed an adapter to screw on the back.
 

 
 
All ready to go:
 

 
I am really happy with the results! The case has some dings that I wish I could laser weld but alas I can’t built one of those on the cheap. Lol.
 
My next step is to find a way to fasten everything down so I get more consistent engagement with the sander and recreate the angles consistently between checking my work.
 

 
 

 
 
- Craig

Nice Idea, can you please post the ebay link to the telescope head.

[Narcissus]

Nice Idea, can you please post the ebay link to the telescope head.

My exact listing is gone but the parts are:

- Celestron Astromaster CG-3
- CME 2”/50mm 3 jaw Chuck

[jdm]

On 5/21/2020 at 2:57 AM, Narcissus said:

Then added a 3 jaw Chuck for $50. 

Nitpick, the market price for that type of chuck is a little more than $30 shipped. Alos interesting the below for $22, from the jaws casting marks it appears they are of a softer alloy, which is good to preserve the finishing of the work.

https://www.aliexpress.com/item/4000276565113.html

 

[Stevelp]

Very cool! What grit of sandpaper are you using to get that finish?

[Narcissus]

mostly 600 but I did a skim pass at 800 just to knock the roughest bits down. gives a nice varied grain.

[swiss2k]

Greetings @Narcissus,

Great results indeed! Can you tell more about your setup and maybe were one could find tooling like that? 

Thank you and all the best.