I’m contemplating submitting an RFQ for a series of similar, MT3 based tooling do-dads which are kind of outside my practical capabilities. I don’t have a taper attachment on my lathe. This is orientated for my rotary table & tailstock (hobby purposes) so I’d like to throw out the intended desired end-result for input beforehand, to see if this is even reasonable approach & what I’d be getting into.
Basically I want a series of machinable, tapered plugs. The base section is kind of common geometry – the top datum is defined by a specific diameter (about 0.890”) then reducing at MT3 taper angle to about 2” length. Some would have a straight, concentric hole drilled/reamed into them to accommodate typical nominal sized ground drill blank pins, like 0.125”, 0.250”, 0.375”.. Some would have an extending, integral cylindrical shaft section say 0.750”dia x 3” long (ie to be turned at the same time so it’s concentric with the MT taper). Some would have a blank, oversize knob that that I can turn to specific shapes on my own (and so 60 deg centers on both ends so I can take it from there.).
When I look at typical commercial MT3 arbors & tooling, I’m guessing they are hardened & ground for precision & wear etc. I’m also guessing that replicating that on my small qty, specialized request would be big bucks & probably not an option. So my question is: could this be done on a cnc lathe to ‘pretty-close-to’ commercial MT3 arbor standards, meaning surface finish & concentricity/runout if I opted for the best ‘machined’ surface possible from some suitable steel? Ie, trying to mitigate hardening + grinding $$ operation. If so, what kind of material would be best to request? How would I define the equivalent, (practical) surface finish? In this application, would it be advisable to have the MT plug partially 'splined', kindof like an ER collet?
I thought long & hard about modifying 15$ offshore MT blanks, but I just can’t see how I would properly hold that in my lathe to part-off the extending diameter, whether I could drill good tolerance holes in that kind of steel etc. Any input welcome. I can provide a drawing, that’s the easy part!
Basically I want a series of machinable, tapered plugs. The base section is kind of common geometry – the top datum is defined by a specific diameter (about 0.890”) then reducing at MT3 taper angle to about 2” length. Some would have a straight, concentric hole drilled/reamed into them to accommodate typical nominal sized ground drill blank pins, like 0.125”, 0.250”, 0.375”.. Some would have an extending, integral cylindrical shaft section say 0.750”dia x 3” long (ie to be turned at the same time so it’s concentric with the MT taper). Some would have a blank, oversize knob that that I can turn to specific shapes on my own (and so 60 deg centers on both ends so I can take it from there.).
When I look at typical commercial MT3 arbors & tooling, I’m guessing they are hardened & ground for precision & wear etc. I’m also guessing that replicating that on my small qty, specialized request would be big bucks & probably not an option. So my question is: could this be done on a cnc lathe to ‘pretty-close-to’ commercial MT3 arbor standards, meaning surface finish & concentricity/runout if I opted for the best ‘machined’ surface possible from some suitable steel? Ie, trying to mitigate hardening + grinding $$ operation. If so, what kind of material would be best to request? How would I define the equivalent, (practical) surface finish? In this application, would it be advisable to have the MT plug partially 'splined', kindof like an ER collet?
I thought long & hard about modifying 15$ offshore MT blanks, but I just can’t see how I would properly hold that in my lathe to part-off the extending diameter, whether I could drill good tolerance holes in that kind of steel etc. Any input welcome. I can provide a drawing, that’s the easy part!
