I don't mean Barbara, either...
How do you put a workpiece on an expanding mandrel? Specifically, the ones with a sleeve on them. After mounting the workpiece on, it's simply turning between centers, no big.
I have never personally done this but the books I have say that you use and arbor press to press the workpiece on and off the mandrel
Carl Boyd
With force. :-)
The ones I have seen also do have a nut that pushes the sleeve "up the ramp".
Nick
The mandrel is also known as an arbor, hence arbor press.
Pete Keillor
I've only used the one-piece tapered type, and I rest the work on open vise jaws and tap the mandrel in with a soft hammer which doesn't damage the center. For -light- finishing I just hold the work in one hand while tapping in the arbor and thus avoid scratches. As long as cuts apply force only toward the big end that is usually enough.
If I have to cut deeper or on both sides I oil it and push it in harder with an arbor press. The center hole may be slightly distorted so I start one size smaller, such as 7/16 if the finished hole will be
0.500.Deep sockets make good supports for pressing arbors.
jw
Pete Keillor wrote in article ...
The OP is talking about "expanding mandrels" - which do NOT require an arbor press.
Do you have the one with the three anvils that slide in the grooves on the central shaft?
If so, you put the workpiece on the anvils, but NOT in contact with the stops (lugs at the end of the anvils), slide the shaft in until it has contact, then "bump" the end of the shaft with a babbit mallet to snug things up in proper fit. NOT too hard, as you will distort something, maybe.
In the shop where I worked, , these were for inspection and gaging purposes, not for machining. Highly polished, superbly finished, cleaned and lubricated only with a Hoppes silicone gun cleaning cloth. They were () expensive. Manufacturer's name eludes me, now. (What the heck, so does a lot of other stuff)
Flash
Expanding mandrels are not as accurate as the tapered type. I've got 2 sets of "machineable" expanding mandrels - one has straight shanks and the other has 5-C shanks.. To use them you machine the head to a thousandth or so under-size of the diameter of the intended workpiece. Then place the workpiece over the mandrel and screw in a cone shaped SHCS to cause the mandrel to expand into a tight fit.
Pete Keillor wrote in article ...
The OP is talking about "expanding mandrels" - which do NOT require an arbor press.
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