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Author Topic: First time making shims-Advice please  (Read 3410 times)

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First time making shims-Advice please
« on: February 03, 2010, 02:27:23 PM »

Hi, For the first time I need to make some steel shims for a couple of bearings on a project.

The dimentions are approx 50mm x 0.2mm with a 45mm bore, I have shim stock and thought the best way to do this
without making a "Tool for the job" would be to secure shim stock on a piece of flat wood to the mill table and use
a fly cutter to cut inside and then the outer cut.

Anyone have a suggestion whether this will work or perhaps there is a better method.

Cheers
John

Offline Dan13

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Re: First time making shims-Advice please
« Reply #1 on: February 03, 2010, 03:09:48 PM »
HI John,

I am guessing you intend to cut the shim rings from a sheet metal. I would assume the diameters don't have to be accurate. There are many ways to do this, and I think you should go with the one you can handle best using your tooling and equipment.

The way you're suggesting is very good if you can adjust the fly cutter for the required diameters. On a CNC mill it would be much easier - just using an end mill to orbit the circles.

If you don't have a CNC mill, I'd prefer making it on a manual lathe. The way I did it was to attach the material to the lathe face plate using double sided type and cut the circles using specially ground tool, but with 0.2mm I think you can use almost any sharp tipped tool. You could mount a piece of sacrificial plate on the face plate, even MDF would be good for this. Worked well for me in cutting 150mm diameter circle from 10mm thick stock.

Hope it helps.

Daniel
Re: First time making shims-Advice please
« Reply #2 on: February 03, 2010, 06:38:58 PM »
Hi Daniel, Thanks for your response, I do have a cnc mill although the max spindle speed is 850rpm so using small cutters makes progress real slow.

The sheet is about 100mm x 300mm so I thought it best to use a fly cutter on the mill and do a few, what I dont want is to tear the material up as it does the final cuts.

Double sided tape sounds good though, I'll give that a try.

Thanks

John

Offline Graham Waterworth

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Re: First time making shims-Advice please
« Reply #3 on: February 05, 2010, 10:59:17 AM »
Scissors seem like a good idea to me, I cant see the shim staying put when you touch it with a tool.

Graham
 
Without engineers the world stops
Re: First time making shims-Advice please
« Reply #4 on: February 05, 2010, 07:40:15 PM »
Ha, Did I have fun with those shims.

All methods I tried had showed other problems, I found the head on the mill isn't perfectly trammed so the fly-cutter as it broke through ripped the material to shreads.

I expect that most people a mile around heard my frustration at that point because it took me an hour before, trying to get the backing off the carpet tape I used to secure the material.

In the end I nailed the shim material to a flat piece of wood and used a hole saw in the pillar drill to delicately cut out the inner hole making sure as it breaks through only very light cuts. I cleaned the edges of the hole with a drum sander on a dremel and then used a marker pen to draw round the bearing placed over as a template. Using scissors I cut out the rest to produce a near perfect shim.

A few shims later, all smiles and satisfaction.

Thanks again for all the advice.

Cheers
John

Offline Dan13

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Re: First time making shims-Advice please
« Reply #5 on: February 06, 2010, 12:54:27 AM »
Glad you got them done in the end, John :)

Daniel

Offline Graham Waterworth

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Re: First time making shims-Advice please
« Reply #6 on: February 06, 2010, 05:41:27 AM »
I hope you used the wifes best scissors, that way you will never forget how you made the shims  >:D :D ;D
Without engineers the world stops