[How do I?] Prevent the MT2 taper from slipping

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Robert
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So I would like to use this hole saw in the tailstock to rough out a 2-3/4" hole.

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I am certain that my MT2 taper will slip and possibly score the taper. How can I prevent this? I could put a spanner on the drill chuck? I don't have a proper trepanning tool. Any other ideas? I am drilling through 1-1/2" aluminum so I plan to attack from both sides.
Alternatively, I could just drill the pilot hole on the lathe and then move to the DP (although that has a MT2 taper also now that I think about it.)
Robert
 
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It would be nice if you had another, "less nice" chuck for this job. But you work with what you have. Generally, if you take some fairly coarse AO cloth and "rough up" the taper on the shank by stroking the shank lengthwise a few times with fresh grit, it will greatly increase the resistance to spinning. Won't hurt to give it a couple of firm whacks with a dead blow to seat it in the quill either.

Those saw arbors usually are hex, so they cannot slip, so that isn't in your favor. Keyless chucks can get a death grip on something if a lot of torque is applied, so getting the arbor out might be difficult as well. It will help if you use minimal force in -Z- as you go and keep your chips clear.

As an alternative, if your application allows, can you just do this with a hefty hand drill?
 
If you insist on using hole saw ??? then use arbor with tang. I would just bore the 1 1/2". By the time you cut halfway thru with the holesaw and the flip the part and dial it in, then cut the other half you could have bored it 3 times.
 
I think you are correct that it is likely to slip. Also be aware of the surface feet per minute (SFPM) of the hole saw, and of the number of teeth it has. It is extremely easy to over speed a hole saw, and is also extremely easy to fill up the gullets between the small teeth with chips, all of which can produce galling and locking up, which breaks the Morse taper free from the headstock. If you must do it with that setup, keep the SFPM well below 400, and peck very often to let the chips out. It is much slower but much safer and reliable to drill the largest hole you feel comfortable with using a drill bit, and then follow with boring bars, taking the deepest cuts you can safely manage, and then take lighter finishing cuts. Drama and pucker are not words I like to use in my shop, and I find enough of both without trying stuff that I know is dicey from the start...
 
I wouldn't do it. If the MT doesn't slip you'll be using a pipe wrench to open the chuck to remove the hole saw arbour. Keyless chucks shouldn't be used above they're rated capacity.

Greg
 
Thanks guys. I have a large Jacobs Superchuck that I could use also rather than keyless. A tang would be useless since the tailstock has no slot. My drill press has a slot! Heck I think I will go that route.
Robert
 
Do you have a mill , that is what I would use , or a tanged arbor in dp. Wouldn’t want to ruin tailstock ram.
 
If you can drill say a 1/4 inch hole where the saw runs it will help evacuate the cuttings. Lots of WD40 or kerosine helps flush the cuttings as well.

Greg
 
Do you have a quick change tool holder on the compound? if so you could hold the hole saw in it instead of the tailstock, also as Mikey says, you could indeed bore it out.
 
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