Postmortem of a vise clamp

[chris.trotter]

In the spirit of this sub-forum "learn how to machine", I present my latest failure.

The goal was to create a vise clamp for the small 'toolmaker' vise (don't know the correct name) that came with my mill. It has a series of holes in the side (which, in retrospect, I assumed, were) for clamping. It did not, however, come with any clamps, so I've either not been using this, or clamping it very poorly.

Start to "finish" this took about 3 hours, although I had lots of fiddling on the lathe getting the new QCTP stuff set correctly.

What went well?

• Flycutting! I can now get pretty smooth uniform surfaces (Note: starting with irregular surfaces definitely make flycutting take longer and 'catch' more often - a definite reason to do very straight hacksaw cuts)
• Learned how to use a wiggler set for locating holes, yay garagePuter for YouTube instructions
• Press fitting recycled stainless rod in the vise, starting to get a feel for what a press fit is
• Taking the plunge away from slathering everything with motor oil - stuff still cuts! Less mess!
• My filing technique is improving, can get a more consistent edge when deburring (I suppose I should get a deburring tool)

What didn't go well?

• Flycutting is very tedious on a mini-mill with no power feed
• I am apparently really bad (or, perhaps more kindly, very inexperienced) at measuring and laying things out
  • The hole spacing was off by half a diameter (but pretty much exactly half! so that's a win for layout)
  • The hole height was just arbitrarily scribed to the middle of the face (hole height was actually crucial, lol)
    • This was, honestly, probably me rushing plus inexperience. Pretty dumb mistake.
• Drilling one of the holes didn't work out, very loose fit
  • Probably because the drill bit got stuck - need to ensure drill chuck is super tight
  • Need to understand proper speeds/feeds for drilling
• I don't have any way of milling a 10mm blind hole w. square shoulders
• Using my new parting tool on the lathe was a spectacular failure (most likely a speeds/feeds + tool height thing)

What will I do differently now?

• Having drawings figured out ahead of time (and checked/verified!) is crucial - measuring on the fly is probably a bit advanced for me
• The square design looks kinda silly, need to investigate ways of cutting large chamfers (get angled parallels?)
• Really gotta get an x-axis power feed going
• X&Y table locks for drilling...is that what the little socket head bolts are for?? (one of them was stripped)
• A DRO would seriously make things go faster for layout/accurately milling pockets
• Boring head for expanding 3/8 holes? Or just bigger end mills? (or both!)

 

[2volts]

Learning by doing.
Can’t beat it.

pete

 

[Dave Paine]

Looks like a good project for gaining knowledge. Sometimes projects teach us what to do, sometimes what not to do, sometimes both.

I would have transferred the centre of hole to the side of the clamp. This video by Little Machine Shop shows their design of nuts to use the holes in the vise for hold down. Their design has vertical adjustment so the nut is parallel.

Little Machine Shop video mounting vise

You can salvage your clamp by milling a spacer / washer to fit under the mounting bolt.

 

[chris.trotter]

@Dave Paine That is exactly what I was doing, sorry if the pictures were not clear. Or maybe I misunderstand what you mean by 'transferred the centre of hole to the side of the clamp'. You mean, like, transfer punch kinda thing? That did not cross my mind (obviously) during this effort.

Also, the clamp can't be salvaged without me getting creative with the 2nd hole - the 2nd hole's current center line meets the outer diameter of the next hole. I'd have to bore it out, press in a bigger stud, and then turn that on the lathe or something on the correct centre point. It's probably worth keeping this as a memento and starting again.

 

[Dave Paine]

I meant transfer punch style. Poor-mans version, machine a taper on a piece of rod which fits the hole, then use this to mark on the work.

Another thought would be using the piece of rod in the hole, measure to the top of the rod when in the hole, measure dia of the rod then subtract the radius of the rod. Now you have the distance from the table.

 

[Silverbullet]

Lots of ways to get the spacing of holes , could clamp the block to the vise and used a drill bit to mark the block. Quick and easy. Using a mini mill consumes much more time do to the limitations . But if you take the time there's almost nothing that can't be done within the sizes it can hold.

 

[chris.trotter]

Ya this was purely me not thinking ahead, lack of experience. You guys (experience) make it clear that some kind of transfer method was the best way. Good suggestions, thanks!

 

[royesses]

I used the print from Little machine shop for clamps on a 3" screwless vise.