Jump to content

Radial Brushing Attempt Without A Lapping Machine


Recommended Posts

I’ve got a case that I’d like to do some radial brushing on.   A lapping machine is far out of my budget, so I tried to improvise this evening. 

I secured the case between a nylon washer and one of my plastic crystal dies.  I chucked it into a drill, and then used that to align it at the proper angle against a brushing wheel.   

It’s clearly not perfect, but I think the concept is sound.   I’ll probably need something different other than a thick brushing wheel to get the desired effect, so I’ll play around with it a bit more. I am encouraged that this may be a workaround to a very expensive tool.  

Obviously a lapping machine can do many other things, but I’m just trying to accomplish this radial brushing for now.  

About two weeks ago I came up with a very crude way of holding a case back centered and allowing it to spin, so I can apply radial brushing to that part. It seemed to work pretty well.

The first two pictures are before my brushing attempt on the case. 


  • Like 7
Link to comment
Share on other sites

17 hours ago, mikepilk said:

What kind of wheel did you use for the brushing?

As it turns out, not a correct wheel to accomplish what I was wanting, but it worked moderately.  It was a Bergeon 6085-E2 wheel.  I aligned the case to the corner edge of that wheel in an attempt to minimize the amount of contact (width wise) with the case at any given time. 

Just messing around with an idea, but it got me thinking immediately about ways to improve it.

Link to comment
Share on other sites

  • 1 month later...

Well I happen to score a Horotec polishing vice for a song on eBay.  I was able to call up a friend with a lathe and got an adapter machined so I could mount it to my motor arbor. Horotec sells a reduction die, but the size wasn't compatible with the arbor on my motor. I got this little part made, then drilled and tapped a few set screw holes for the arbor side. I can't wait to destroy a few junk case backs & bezels while I learn how to use it properly!




  • Like 2
Link to comment
Share on other sites

I usually use 400 grit wet and dry (used dry). 

For straight grain, this is my cheapo set up. It works really well. I stick the case back to the bracket with some Rodico. Running along the wood means I can run it up and down and keep the grain straight. 
If the case back is not absolutely flat, I put a very thin layer of something spongy under the paper (I use some thin packing foam).

For circular grain, I use 400 grit on a stick, and pull it from the centre out.

I don't have space for a bench polisher so have to use a Dremel type tool. With practice I can get a good finish.


  • Like 5
Link to comment
Share on other sites

5 minutes ago, mikepilk said:

For straight grain, this is my cheapo set up. It works really well. I stick the case back to the bracket with some Rodico. Running along the wood means I can run it up and down and keep the grain straight. 

Sometimes the simplest solutions are the best - consider this copied 🙂


  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • These are the places where I oiled with HP 1300...  These are the places where I oiled with HP 1300...  I can see that the cannon pinion is moving as it should once I installed the pallet fork. I created a small video but was not able to upload it. It is a mov file type. I need now to source a GR4014X mainspring, a stop ever #9433 and both calendar disc as the days/dates are peeling out... This is the mido watch which holds the ETA Movement.... I just want to thanks all of you guys for your help, specially @eccentric59 who nailed it! So, I would consider this case as closed unless of course any question from any of you... Best regards Fernando     I could not download the file... I will tray to located. Many thanks. 
    • Thanks a lot everyone!  I'll update you as soon as a final decision has been made by my friend (and depending on her decision, what I may find inside). 
    • Thanks Marc, clearly I have a lot to learn about metallurgy. I’d expect the cutting of tool or spring steel to be a lot harder to cut into a precise shape- I expect I’d have to anneal it first? 
    • Unfortunately if you have used mild steel you will have little hope of hardening and tempering it, it simply doesn't contain enough carbon. You need to use a steel with a higher carbon content like tool steel or spring steel. One good source for this is engineers feeler gauges which can be picked up relatively inexpensively and provide a range of thicknesses of material. this will then harden and temper in pretty much the way you have described.
    • Thanks for this excellent tutorial and very fine illustrations @Jon! Really first class! 👍 I noticed that your image was a bit too small to read with ease, so here's a larger copy of it. I summarized @nickelsilver's method for adjusting beat errors to the following, but you can find all the info in the thread I linked to: “For everyday work, from the smallest ladies’ movements to marine chronometer, I set the balance with the cock on a bench block so the roller table is in a hole, balance on the block. Lift up the cock and move it over- not flipping it, just moving laterally, until I can see the slot in the hairspring collet, get in there and adjust (for tiny watches this is usually with an oiler, larger, a small screwdriver). Go back in the watch and check on the machine. I hold a balance arm of the rim with tweezers while moving the collet.”    
  • Create New...