Making shim washers

[kiwi2]

Hi,
I've made a new 2mm pitch topslide and nut to replace the old imperial set on my boxford lathe. There is a bit of backlash in the operation which I would like to take out with some 3/8"ID x 5/8"OD shim washers. I've made one 0.5mm thick but I need to take out a bit more play using brass shim plate down to 0.05mm thick. Can anyone tell me the best way of drilling the 3/8" hole into such thin shim plate? I've tried a step drill without too much luck - I 'm left with a raised rim on the outlet side.
I've made the shoulder on the screw a bit oversize, so if I have to I can add another 0.5mm washer and skim the shoulder but I'd prefer to shim it if I can.
Regards,
Alan C.

 

[bazmak]

Make a simple punch and die

 

[Wizard69]

The best way to put holes in shim stock is with a punch set designed for that need. Most of the sets I’ve seen are expensive and you still get a tiny burr. Expect to need to deburr with any approach you take.

You could make your own punch and die. For one off this wouldn’t even need to be hard. Long term though a DIY built set, properly hardened, isn’t a bad idea.

For smaller round shims a leather punch ( the type with a rotating head ) has been known to work. Works better in plastic rather than brass.

Super glue and sacrificial material can often do the job. One way would be to face a piece of aluminum in the lathe and then glue a rough cut blank to that face. Carefully remove material from the inside out. A little heat will then free the washer.

I guess the bigger question here is why the need for washers in the first place? A lot of lathes have an adjustable nut on the lead screw for this issue.

 

[XD351]

Simple - clamp the shim between two pieces of wood or metal and drill the hole then cut the outside diameter to size with snips .

 

[ALEX1952]

Use of wood is tried and tested and works great I would only add to make it hard wood and screw together as close to the material as tight as possible and use light cuts if more than one is needed do it as a stack, if you have to drill go one lower and then finish drill. If you use glue etc you are only complicating matters and punches will distort.

 

[ALEX1952]

Forgot to add to turn O/D clamp your bored shims on a bolt with appropriately sized support washers either side and finish turn again light cuts, if your support washers are bigger than finished O/D all the better as you will only produce a light burr maybe none.

 

[werowance]

what a great idea, sandwiching the shim stock between 2 sacrificial pieces of wood or other material. I have also had the problem of drilling thin washers or copper head gaskets. thank you all for this very usefull tip.

 

[Scott_M]

Here you go



If you have not watched any of Joe Pie's videos before, he is very talented and has some great ideas. Get a cup of coffee and have a seat.

Scott

 

[Neil Lickfold]

I make shims often. I made a simple fixture. It has a block that goes into the lathe, with a counter bored hole of 12mm that is about 3mm deep. Then there is a M6 tapped hole that goes as deep as the tap can go, about 25mm. There is 4 tapped M6 holes spaced at +-13mm or 26mm square pattern. This allows up to 30mm squares of shim to be placed in between the screws. I buy 30X3 ali strip and cut that into squares . One goes top and bottom of the shim stock. The top steel support plate has a 23mm hole through it. When making shims, I make the inner mandrel 1st, and it's length is the thickness of the top ali plate,(3mm) plus the thickness of the shim stack plus 1mm. It is drilled with a 6mm drill so is not too loose on the m6 capscrew.
Drill a 10mm hole through the entire stack and the bottom support plate. Then I bore out the inside to suite the inner mandrel. Bore deeper than the mandrel by 1mm, leaves 1 mm thickness or so left on the bottom plate. Place the inner mandrel in and then remove the outer steel top cap. The OD of the shim stack can now be turned to size. While leaving the stack on the assembly, this can now be put on the mill and slots or drilled holes can also be put into the shim stack. I have a small setup for shims from 30mm squares that finish at 28mm od, and a larger version that allows me to make shims up to 50mm od. Ill take some picks of my fixtures and post latter. When cutting 1 thou shims, the tools need to be very sharp and you want a very slow feedrate, I try to feed at around 2 um per rev. I work this out by running the spindle at around 600 rpm and feed it at around 0.02mm per second. The Myford lathe lead screw handle is graduated in 0.02mm increments. I use a time base and part mm per second for guessing feedrates for a lot of things.
This way, when you take it all apart, the shims seperate nicely and have nice crisp sharp edges.

 

[XD351]

+1 for the joe’s videos ! His last one about drilling freehand on the drill press and the simple tool he described to make it safe was brilliant!

 

[bazmak]

For drilling shim steel I fix the large piecc of shimstock to timber with clouts
then drill using a woodworking drill with a butterfly end then cut out the od with snips

 

[Neil Lickfold]

Here are the fixtures I use for shims.

 

[kiwi2]

Thanks for the tips. I made a crude punch from mild steel and used a piece of aluminium as the anvil. It worked well enough for my purposes, but using Joe Pie's method would have given a superior result.
The backlash in the screw is where the shoulder is held, not where the screw engages with the nut. I've got it down to about .05mm which I think should be OK.
Regards,
Alan

 

[kadora]

I use these simple punches for shims up to 0.25 mm

 

[fcheslop]

Made a set of these before you could buy them and they have done a good job
https://www.rdgtools.co.uk/acatalog/9PC-PUNCH-AND-DIE-SET-1-8----3-4--982.html

 

[nel2lar]

There is things we can learn from almost everyone we meet either in person of through a video. I have been doing metal work for many years and as mentioned earlier about Joe Pie in Austin Texas is one of the sharpest cookies around. Some of his ideas are what textbooks are made of what make us better at what we do. There is nothing that he can not do and like it was said sit down and enjoy. Here is his: site https://www.youtube.com/channel/UCpp6lgdc_XO_FZYJppaFa5w/videos

making washers:


There is a wealth of info, enjoy

 

[Harry.]

Great video with lots of information. Has anyone tried to blacken their washers?

 

[werowance]

ferric chloride available at electronics stores for etching circuit boards will darken to almost a black color regular steel. here is a photo of a spring that was nice and shiney steel before I did it. the copper deposits are from where my ferric chloride was heavily used and has a lot of dissolved copper in it from etching ciruit boards thus it deposited some back on the steel had it been new or not as heavily used it would not have done that. this color came from about 30 seconds in the solution

 

[kiwi2]

Hi,
What was the concentration of the ferric chloride solution?
Thanks,
Alan

 

[werowance]

normally I just use it right out of the bottle it comes in however this was a very very used batch that I had and often times when doing circuit boards I cut it with a little hydrogen peroxide to speed up etching the copper, ive had this used batch for a few years so id say it wasn't full strength by any means but you only dip it for a few seconds then rinse off with regular water.