Nuts

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ctwo
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Nuts

Post by ctwo » Mon Aug 13, 2012 12:25 pm

Any tips on machining nuts?

I wanted to make 1/2" adapter "nuts" out of plastic. I have a sheet of 1/2" plastic, so I cut off a strip wide enough so I could machine it into an octagon.

First I "squared" it up (0.500 x 0.5774). I thought I could vise it longways, sitting on a 123 block, rotated 30*, and take a surface cut at depth of 0.125". I used another large nut to gauge the rotation, and referenced the cutter by a skim cut off the point. Then just flip it over and set it flat on the 123 block to cut the other side to the same depth. I repeated this for the remaining two cuts.

So I ended up with a few inches of plastic octagon bar of proper size to each opposing flat, but not all of the flats are symmetrical to the center. It was kind of hard anyway, so there must be a better way.

Note, my mill's head does not rotate.
Attachments
nut.png
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sjames
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Re: Nuts

Post by sjames » Mon Aug 13, 2012 1:45 pm

ive always started with round stock in a dividing head for the few nuts ive made. starting from 1/2 sheet defiantly sounds like it would be finicky.

Harold_V
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Re: Nuts

Post by Harold_V » Mon Aug 13, 2012 2:13 pm

ctwo wrote:Any tips on machining nuts?

I wanted to make 1/2" adapter "nuts" out of plastic. I have a sheet of 1/2" plastic, so I cut off a strip wide enough so I could machine it into an octagon.

First I "squared" it up (0.500 x 0.5774). I thought I could vise it longways, sitting on a 123 block, rotated 30*, and take a surface cut at depth of 0.125". I used another large nut to gauge the rotation, and referenced the cutter by a skim cut off the point. Then just flip it over and set it flat on the 123 block to cut the other side to the same depth. I repeated this for the remaining two cuts.

So I ended up with a few inches of plastic octagon bar of proper size to each opposing flat, but not all of the flats are symmetrical to the center. It was kind of hard anyway, so there must be a better way.

Note, my mill's head does not rotate.
Your problem is most likely related to the fact that you are using 30° for an octagon. If that's (octagon) not a typo, the angle should be 45° instead of 30°. Is your objective a hex nut or an octagonal nut?

Harold
Wise people talk because they have something to say. Fools talk because they have to say something.

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ctwo
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Re: Nuts

Post by ctwo » Mon Aug 13, 2012 2:28 pm

I don't know why I wrote octagon - it's not a typo as much as it is a short circuit.

The part came out and would work, but is not ideal as it is supposed to be a drive nut and its present shape leaves some corners unloaded. I ended up with a shape more like the pic below...

That is also not pointing out that when I clamped the stock, it bows up slightly in the middle, so it's also not uniform.
Attachments
nut2.png
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Richard_W
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Re: Nuts

Post by Richard_W » Mon Aug 13, 2012 2:32 pm

I would have made the material round after sawing it from a sheet. Then use a spindex in the mill to machine a portion of it hex. Then went to the lathe faced the end of the hex stock and drilled and tapped it and parted it off.

Richard W.

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GlennW
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Re: Nuts

Post by GlennW » Mon Aug 13, 2012 2:34 pm

Here's a quick way using a collet block.

Hexing the round stock. (ETD150)
P3040050.JPG
Over to the lathe to drill, tap, chamfer, and part off.
P3040049.JPG
P3040052.JPG
A sharp end mill, face mill, or fly cutter may have been a better choice, but the end mill was already in the spindle,, the vise was set up. and it was a quick job.

Looks like Richard was typing while I was loading pics... :D

And, Nope, I couldn't just buy them. 7/32-28 BSF thread with 10mm hex.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

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ctwo
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Re: Nuts

Post by ctwo » Mon Aug 13, 2012 2:54 pm

OK, I don't know what a spindex is, but suspect it is some sort of indexing part holder...

I can't quite turn the material to get a circle because it is not thick enough (see attached pic).

I thought of ways to hold the material in my rotab, but could not come up with anything (I just have RT and a few table clamps), and the material is a bit flimsy so would probably need to cut maybe two parts worth at a time (I needed to make 8).
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nut3.png
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Standards are so important that everyone must have their own...
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tornitore45
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Re: Nuts

Post by tornitore45 » Mon Aug 13, 2012 3:11 pm

The way I see it is your main problem is flex in the middle to start with.
Since this is plastic, clamp down on the table and place at least one support on the side pushed by the cutter.

Not moving the head/knee the flats are guarantee to hold the same dimension.

Second is difficult to set a square down on edge at 30degree to start the 2nd and 3rd cut.
Some kind of 30 Dgrees wedge with a lip to hold the part against the cutter push is required.

Clamp on ends and waste the ends under the clamps that can not be machined.
Mauro Gaetano
in Austin TX

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Richard_W
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Re: Nuts

Post by Richard_W » Mon Aug 13, 2012 3:19 pm

ctwo wrote:OK, I don't know what a spindex is, but suspect it is some sort of indexing part holder...
Here is one and it takes 5C collets.

http://www.use-enco.com/CGI/INSRIT?PMAK ... TPG=INLMK3

They do make 3 and 4 jaw chucks with a 5C mount that will fit the spin-dex. Bottom right of the page.

http://www.use-enco.com/CGI/INPDFF?PMPA ... M=890-8833

Richard W.

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ctwo
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Re: Nuts

Post by ctwo » Mon Aug 13, 2012 3:30 pm

Now I had a thought - I might try it again...

Thread the ends to accept a larger size nut than I'm trying to make. I'll screw and lock the nuts on each end to provide for clamping and indexing.

I'll also think about picking up a collet block set, since that will likely come in very useful. Shars has a kit for $40, then I'll need some 5C collets...
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

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ctwo
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Re: Nuts

Post by ctwo » Mon Aug 13, 2012 3:33 pm

Richard_W wrote:
ctwo wrote:OK, I don't know what a spindex is, but suspect it is some sort of indexing part holder...
Here is one and it takes 5C collets.

http://www.use-enco.com/CGI/INSRIT?PMAK ... TPG=INLMK3

They do make 3 and 4 jaw chucks with a 5C mount that will fit the spin-dex. Bottom right of the page.

http://www.use-enco.com/CGI/INPDFF?PMPA ... M=890-8833

Richard W.

That spindex is even cheaper than the collet blocks they sell...with the chuck, that seems like a nice way to go...thanks!
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

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Richard_W
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Re: Nuts

Post by Richard_W » Mon Aug 13, 2012 3:54 pm

Actually the collet block set and the spin-dex are both nice to have, along with a collet vise.

Richard W.

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