# Making One Washer



## spike7638 (Feb 8, 2016)

I was going to post a question about making a large washer -- 2.625 OD, 1.06 ID, about .375 thick -- until I realized I could buy almost exactly what I needed from Fastenal .. problem solved. The tolerances are pretty loose in this whole problem -- 2.5" or 2.75" OD would be OK, as would a 1.125" ID, or .400 thickness, etc. 

But since I was going to ask about this sort of thing anyhow, I might as well proceed. 

My plan was to make this from some flat stock: Mark a center and a 2.625" circle, drill a 1" hole using the milling machine, cut that out roughly with the bandsaw, put the piece on a mandrel and chuck it in the lathe, and then make it a bit more properly round (which probably means doing an interrupted cut, since my bandsaw work will probably end up making something like a 16-sided polygon rather than a circle), press out the mandrel, re-chuck the piece in the 3-jaw chuck, and bore it out a tiny bit larger (or use a 1  1/16" drill, which is close enough). 

Alternatively, I could have gone back to the milling machine to drill that last hole, and that's where my question arises: 

When you've got a relatively small, relatively thin, piece of material that you want to work on using the milling machine (imaging that I want to make the center circle into an oval, say), how do you hold onto it? Or is this just a bad idea, and I'm supposed to do something entirely different? This problem, in various forms -- small pieces that I can't seem to hold well -- keeps arising, and I figure someone must have solved it. My only thought so far was to make a "sandwich" with my piece between two slabs of aluminum, with through-bolts to clamp the aluminum pieces together. Of course, that means I can't see the workpiece any more...but at least it'd be held fairly securely. 

Any suggestions for an amateur like me? (My general approach is to give up, because I'm really scared by what can happen to pieces that get loose...)


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## mmcmdl (Feb 8, 2016)

Lots of unknowns here but ....drill an undersize hole in that plate , mark your OD , cut it on the saw , either use 2 sided tape on your jaws or take light cuts with your live center acting as a pressure pad . It may spin but it won't fly out . Then you could finish your ID hole to size in your 3 jaw . As far as milling . Get yourself a piece of aluminum suitable for your millvise . Put some tapped holes in it thus you have a mini sub plate and can clamp your workpiece down . You can re-skim the plate as necessary if you need .


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## spike7638 (Feb 8, 2016)

mmcmdl said:


> Lots of unknowns here but ....drill an undersize hole in that plate , mark your OD , cut it on the saw , either use 2 sided tape on your jaws or take light cuts with your live center acting as a pressure pad . It may spin but it won't fly out . Then you could finish your ID hole to size in your 3 jaw . As far as milling . Get yourself a piece of aluminum suitable for your millvise . Put some tapped holes in it thus you have a mini sub plate and can clamp your workpiece down . You can re-skim the plate as necessary if you need .



Thanks very much for the quick answer. 

I'm not sure I entirely understand (in fact, I'm sure I don't). The hole in the middle is for the live-center to hold the rough-cut piece against the faces of the chuck jaws, with the two-sided tape providing spin-resistance. That much makes sense.  Presumably I cut the thing to something like 3" or 3 1/2". 

Now to get it to 2.625, I come in with the tool by moving the saddle towards the chuck, cutting deeper and deeper into my material. At some point, I've gone all the way through, and the disk falls into the space between the jaws, while the remaining "ring" at the outside, no longer held by the live center, is free to move (although held in place by the two-sided tape, we hope). And we hope that the tape is thick enough that my tool, making the last bit of the cut, didn't actually try to start cutting the chuck-jaws. 

I must be misunderstanding, because this sounds like a recipe for disaster...that loose piece could get wedged between the tool and the jaws (which are separated by only a small distance, or the tool, which is now cutting only the outer ring, could apply enough force to overcome the strength of the tape, making that ring get loose, and then get wedged, and ... 

As I said, I must be misunderstanding. 

For the mill: I get the idea here, I think. But when you say "clamp my piece down", do you mean "catch an edge of the piece under the lip of the screwhead", or "hold it down with a strip of aluminum or steel that's held down by some screws in those threaded holes" or something else?


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## mmcmdl (Feb 8, 2016)

Your finished part must be on the tape , on the jaws . You will be turning the OD , not trepanning it to size as I believe you mean . Use a backer to avoid cutting into your jaws . Clamping on your subplate can be up to you . Step blocks can be cheaply purchased or made .

Edit . I guarantee you won't overcome the tapes strength if done correctly !! It's an mfer to get your part back sometimes ! LMAO .


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## spike7638 (Feb 8, 2016)

Thanks. That makes total sense now that you say "turning the OD rather than trepanning" (a term I've only heard used in the context of 19th century medicine, for removing a piece of skull!). And now that I see that the piece is held throughout the process, it seems totally reasonable. (And you can surely see my concern with what I *thought* you were suggesting!)


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## mmcmdl (Feb 8, 2016)

Ahhaaa  . Sure do . I've turned many a parts into " spaceflight material " thruout my years !


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## RJSakowski (Feb 8, 2016)

I have made many washers from flat stock or plate.  I drill a suitable hole in the center and rough out  the O.D. with a band saw.  I then take a suitable bolt and cut the head off.  Next, I thread a nut on, place the blank on the bolt, followed by a second nut.  The assembled mandrel is chucked in the lathe and the O.D. turned to size.  The mandrel is removed and the disk chucked in the lathe and the I.D. finished to size with a drill or boring tool.


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## stupoty (Feb 8, 2016)

Hole saws are quite handy for roughing out a circle with a hole in the middle, very easy to over heat them on steel though so lots of coolant.

Stuart


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## David VanNorman (Feb 9, 2016)

se a hole saw and cut it to 2 3/4 then a hole saw to get your inside dia use a mandrel to hold it and turn the outside.


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## mmcmdl (Feb 9, 2016)

Here's the problem when using mandrels in a lathe or grinding situation . The L over D ratio ( length over diameter ) tends to throw your faces out of perpendicularity . You may have ..500 bore by 1/4" length and an OD of 3" just to say . It would wobble . Mandrels are better suited for longer length parts . Any mandrels I've used or made are .0005 per inch taper on the diameter .

Better option and possibly cheaper ..........turn your ID on an aluminum bar with a tapped hole . This is called a " spud " . All planes run true in this set-up . Don't ask me why it's called a spud , but it sounds good enough to eat !


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## planeflyer21 (Feb 9, 2016)

Check out myfordboy's youtube channel.  He is always cutting sheet metal on the lathe, using some of the techniques given here and using some other ideas too.


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## brino (Feb 9, 2016)

spike7638 said:


> The tolerances are pretty loose in this whole problem



That really makes things easier.

There are many ways to skin this cat. My personal choice would be all drill-press solution; hole saw the outside, clamp the ring down, hole saw the inside using the same centre hole......just because I could do it so quickly.

Do you have either a set of inside jaws for your 3-jaw chuck or reversible jaws for the 4-jaw chuck that are small enough to go into the 1" ID?

Another useful device is an expanding collets, they can be bought or made:
http://www.bealltool.com/products/turning/ix_collets.php

The shop made ones are typically a "stepped cone" with a number of stopped axial slits and a tapered internal thread (pipe thread) and plug that goes into the end. The work is placed onto an appropriate "step" then the plug is screwed in to expand the cone and grab the part. If I was at home I'd include a photo of one.

One advantage of this type is that the part can be pressed against the shoulder of the next bigger step to help overcome the problem that @mmcmdl mentions above. They are useful for turning parts like washers and rings.

also a related thread:
http://www.hobby-machinist.com/threads/how-to-do-it.33081/

-brino


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## hermetic (Feb 9, 2016)

for 1 off big washers I save old saw blades, tile cutter blades and the like. straight in the three jaw chuck, bore or trepanne the ID then measure and sharpie mark the OD, and trepanne that out, less than 5 minutes. Made one a couple of weeks ago for a 2-1/2 sink waste.
Phil


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## brino (Feb 9, 2016)

Here's some shots of the "stepped cone" expanding collet:





The shoulder of the next bigger step helps get the washer square to the lathe axis.
This one is meant to thread directly onto a small lathe spindle.
The smallest step is about 5/8" diameter, the biggest about 1-5/8".
It is about 2-1/2" overall length.
The screw has a tapered head that rides on a tapered hole above the threads for the bolt.
-brino


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## planeflyer21 (Feb 10, 2016)

That's pretty slick brino!  I'm going to have to make one of those.


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## mmcmdl (Feb 10, 2016)

Brino , that's a nice home project for everyone and and a handy little fixture . We made them quite frequently drilling the hole and tapping with a tapered pipe tap . Same results . I nice ID holder .


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## Wreck™Wreck (Feb 13, 2016)

A simple method, made several of these Friday afternoon, not actually washers as they get some mill work done to them, from the drawings they appear to be some sort of flanges used in a linear motion assembly.

This is 6061 aluminum but I would do it the same way in steel.

2 1/4" OD X 1.063" ID X .188" thick. All dimensions +- .005

Install suitable soft jaws on chuck, the jaws in the pic are the wrong diameter for the stock but this does not matter as the material is 2 3/8" they do however have the proper sized pocket to hold the finished part.
Face the stock then turn the finished OD, rough drill the bore, in this case I used a 31/32 drill.
Turned with an 80° diamond  aluminum specific insert, 1000 RPM's, .008 IPM feed and .032" DOC
Drilled at 530 RPM's from the tail stock with a 31/32" S&D drill without a center drilled or spotted hole, also no pilot hole, straight in with the .980" drill.




Finish the bore with a boring bar, used a 1/4" shank bar because I had used it on the previous job that had a .6254 +.0005 -.0000 bore and 0nly had to go from .980 to 1.063 on these parts. 1000 RPM's, .015 DOC and .004 IPM feed. I left them .010" long for finishing.



Part off, Kyocera .125" wide insert parting tool 500 RPM's .002 Feed rate, caught the part with a T-handle hex key.



Place parts in jaw pockets and face off the .010" left, this customer requires very nice surface finishes and the parting does not leave a suitable finish itself.
Done, including set up, changing jaws, adjusting the chuck, picking out the tools and programming, the first part came off in less then 45 minutes.
This is in a chucker CNC lathe, it is possible that I could have done it faster on a manual lathe for one part but the chucker is superior when making several parts.


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