First time using super glue chuck

[John Hasler]

When I use superglue I try to find a way to hedge the part in with clamped down blocking.

[whateg0]

I'd guess that full coverage would have made a significant difference, but that's just an educated guess based on how hard it was to get my part off the fixture. It's been my experience that superglue does not do well under tension. When drilling holes like that, as the sheet flexes ever so slightly when the drill starts, it's under compression, but as soon as the drill starts to dig, it's pulling up on the sheet. From there, it's peeling the sheet away from the fixture surface. I wonder if it would have held with painters tape applied as had been suggested to me. The tape would do the flexing, allowing the glue to maintain contact with it maybe?

[whateg0]

When I use superglue I try to find a way to hedge the part in with clamped down blocking.

My part was located on a register, so it couldn't move laterally. Aside from turning the OD of my part, the rest of the cutting was facing cuts. I started out with a live center as well, but soon removed it to see if it was really needed. When I did that, I reduced my spindle speed "a lot" until I was comfortable with how secure it seemed. I don't recall if I mentioned it, but I did watch a guy on Youtube in the UK, I think, who glued a part to the ends of the jaws of his 3 jaw chuck and then used a live center to keep it pressed against the jaws. He was turning the OD down.

[Mr Ron]

If I use a 3 or 4 flute end mill, will that put less stress on the glue bond than a 2 flute end mill? Since crazy glue is stronger in shear than in tension, using end mill cuts should not compromise the glue bond; right?
P.S. Sorry for hi-jacking this thread.

[whateg0]

If I use a 3 or 4 flute end mill, will that put less stress on the glue bond than a 2 flute end mill? Since crazy glue is stronger in shear than in tension, using end mill cuts should not compromise the glue bond; right?
P.S. Sorry for hi-jacking this thread.

It's fine. Plus, it seems it's your first time using superglue, too, right? So it's still applicable, right?

I don't know how the math works out on the use of different numbers of flutes. Might be that the issue is in the material. Even on a small drill like that, maybe it should be ground to near zero rake?

Dave

[Mr Ron]

I've tried carpet tape to hold aluminum stock for milling with success. I want to use either a glue or tape that will hold the work without failure. Here is a sample part I am making. It is laid out on a 3/8x3/8 brass bar attached to an aluminum waster. After machining, I have to separate each piece along the brass bar and then separate them from the waster piece.

[whateg0]

That looks like a lot of material to remove. I can't imagine it being a problem, though if you glue the whole thing down and take reasonably light cuts. Don't take my advice, though. I've only used it once!

[Harold_V]

I question the need for any type of holding aside from the vise on your mill. I've held smaller parts with success, and that's how I'd hold these if the task was mine. What is required is the proper height parallel, and you can make a temporary from a piece of aluminum that will perform perfectly well. Also, note that the entire piece could be held below the top of the vise jaws for the slotting. It need not stick above the jaws.

Note that when you do small work, it's easy to crush the parts with the vise. You can limit the crushing by using one side of he vice to hold the work piece, with a like piece set at the opposite end. That distributes clamping pressure evenly, and keeps the vise jaws parallel. A light touch on the vise handle is required. Be careful to not over tighten the vise.

H

[Mr Ron]

Trying to clarify what I'm trying to do: As the picture shows, is a piece of brass bar, 1/4"x5/8"x2.875" long attached to the aluminum waster piece by tape or super glue. After all the slots and holes are made, I want to use an 1/8" end mill to separate each piece from the brass bar leaving 8 identical parts which will then be separated from the aluminum waster. I think this is the right way to do it. I have other similar pieces to make. The parts will be soft soldered to brass wire to make a pantograph for a model electric locomotive. If there is a better way of doing this, please let me know.

[John Hasler]

Soft jaws of aluminum angle?

[Harold_V]

I now understand your approach.
I wouldn't make them that way. I'm not suggesting you shouldn't, however.
You may be mistaken with your idea of separating the pieces by using an end mill. It will drift, so it won't cut where you want it to. If that was going to be my choice, I'd make sure the spacing was such that I could make a pass, leaving the part too wide, then taking a finish cut on each one, so the cut would be straight, eliminating any deflection you'd get from the slender end mill.

I specialized in small work when I was active in my shop commercially. I would have made those parts as individual pieces, starting with squaring, each face getting machined. I can see no reason why they need be made in a strip, although I also can see no reason why they shouldn't be. You could slot each one individually, so little time, if any, would be wasted doing them that way, and you'll have eliminated the risk of the piece releasing from the base piece.

When I made similar items, I used the factory jaws----and would work on one end of the vise. I'd place a like piece at the opposite end, which limits crushing, and keeps the vise jaws dead parallel. If you try holding a small piece on the end of your vise, you'll come to understand that the jaws don't stay parallel, which results in the work piece being able to pivot on the inside end. Any end mill work on the outside end offers the risk of the part rotating up in the vise (due to the helix angle of he end mill). Holding a part on each end eliminates that risk.

H

[Mr Ron]

If I made them individually, I would be cutting 8 pieces, chucking each one up in the vise. It seems it would be a lot more work doing it that way. Making it from a strip minimizes setup. The super glue failed on another setup I was machining, so I need to rethink it. I can do all the machining, but when it comes to separating the pieces, that's where I have adhesive failure. Here are a few more parts I am making. Thank you Harold. I have several ideas to work with.