No-cost part alignment setup for mill

[homebrewed]

I'm making an enclosure for a headphone amplifier I designed/built and as part of that I needed to drill/tap some centered 6-32 holes on the ends of some .25" square stock. Setting up each piece would have been pretty tedious so I used some items I had on hand to come up with a simple alignment setup.

This is what I came up with:



The flat piece on the right side of the vise is bolted to the side of the vise so it's a fixed reference. It actually is one of the slide plates for my 7x12 lathe I replaced with some custom-made slide plates made from MoS2-filled nylon. I frequently use it for the purpose shown.

The parallel offsets my workpiece so it's near the center point of the vise & therefore is evenly held by the vise. The 1-2-3 block shown on the left side of the vice jaws is used as a 90 degree reference so my .25" x .25" workpiece can be aligned vertically. Tolerance requirements aren't all that high so it's all good. It's just an aluminum box to keep the electrons inside .

I started out using a machinist's square but it was a little fiddly compared to the 1-2-3 block.

 

[Flyinfool]

For odd ball parts what you have is great.
Your vice has a V notch on center. V notches are almost always at exactly 90°, perfect for the corner of square stock. You could have just used that to both locate and square the post for drilling and tapping and not bother with all of the setup every time.

 

[homebrewed]

For odd ball parts what you have is great.
Your vice has a V notch on center. V notches are almost always at exactly 90°, perfect for the corner of square stock. You could have just used that to both locate and square the post for drilling and tapping and not bother with all of the setup every time.

I contemplated that but worried about the fixed jaw -- it's flat and could have mashed the corners of the pieces when clamped. I probably was over-thinking it.....

 

[ChazzC]

I contemplated that but worried about the fixed jaw -- it's flat and could have mashed the corners of the pieces when clamped. I probably was over-thinking it.....

Aluminum Vee Block on the fixed jaw side: new mini-project!

 

[Chris Hamel]

I have found that by some weird coincidence, the 5/16 er32 collet I sometimes use on my lathe holds 1/4 square stock perfectly.

 

[homebrewed]

I have found that by some weird coincidence, the 5/16 er32 collet I sometimes use on my lathe holds 1/4 square stock perfectly.

The diagonal length of .25" square stock is .354" (.25 * sqrt(2) ) and 5/16 is .3125. So 1/4" stock would be a snug fit to a 5/16 collet. But then there are the slots cut in the collet -- if all corners of the stock match up with a slot you're good (and the stock would be easier to slide into the collet). Otherwise the stock would be slightly off-center.

Not an issue if the only purpose of using the collet is to get the stock perfectly vertical. Nice tip!

 

[ChazzC]

The diagonal length of .25" square stock is .354" (.25 * sqrt(2) ) and 5/16 is .3125. So 1/4" stock would be a snug fit to a 5/16 collet. But then there are the slots cut in the collet -- if all corners of the stock match up with a slot you're good (and the stock would be easier to slide into the collet). Otherwise the stock would be slightly off-center.

Not an issue if the only purpose of using the collet is to get the stock perfectly vertical. Nice tip!

Somewhere I have info (from someone else on one of the forums not that long ago) for a source of ER square & hex collets (not cheap, but not too expensive IIRC). I’ll try to find and post a link.

 

[WobblyHand]

Maritool.com has hex and square ER collets.

 

[Chris Hamel]

Turns out that the square stock was sold as 1/4 " but it was actually 6 mm. At any rate the 5/16 collet held it surprisingly well centered.

 

[ChazzC]

Maritool.com has hex and square ER collets.

Yes; finally got to my Mac and searched the bookmarks:

https://www.maritool.com/Collets-And-Sleeves-ER-Extended-Nose-/-Shaped-Collets/c21_613/index.html

Only 1/2" & 5/8" square, but a nice range of hex.

I can't use 5C in my Mini-Lathe or Spin Indexer (I got an ER32 version when I bought mine a few tears ago to suit my collets), but if I had storage space and came across a deal on a used set 5C Collets I guess it would make sense to get them and if nothing else use them in collect blocks on the Mini-Mill and could also chuck the collet blocks in the Mini-Lathe or modify a 5C collet chuck to fit the M-L (but that would be a lot of stick-out & weight).