Tapmatic on CNC mill?

[Muzzer]

Doesn't look too difficult actually, famous last words. You tell Fusion you have a drill, not a tap. That way you can control the feedrate by playing in the tool manager to make a new "drill" tool.

For an M4 coarse you need a 0.7mm pitch. That's the "feed per rev" in Fusion terms and it is calculated from the spindle speed and the "plunge feedrate". I entered an expression of "0.7*tool_spindleSpeed" for the plunge feedrate but you could do that in your head. Obviously if you bottle it and decide to reduce the spindle speed, you'd be glad you used the expression rather than a hard coded value

So with 300rpm and 210mm/min, you get 0.7mm per rev. Then type in double the expression ie "1.4*tool_spindleSpeed" for the retract feedrate.

No buggering about with macros after all if I'm right here.

The other clever bit would be to set the "bottom height" to be somewhat higher than the bottom of the hole. I'm afraid that human element is where the wheels might come off.

EDIT - my Tapmatic clone requires ~3.5mm of travel before it disengages and goes into reverse, so the "bottom height" needs to be at least 1/3 of 3.5mm (plus a margin) from the bottom of a blind hole. It also means there is a min hole depth of perhaps 2-3mm for blind holes. How low can you go?

[alanambrose]

>>> Main ballache will be restraining the reaction arm.

I planned on using a tall stud from a clamping kit mounted on the bed? Maybe with a bit of tube over it for lower sticktivity.

Alan

[Muzzer]

>>> Main ballache will be restraining the reaction arm.

I planned on using a tall stud from a clamping kit mounted on the bed? Maybe with a bit of tube over it for lower sticktivity.

Alan

I was up Dawn's crack this morning before the Domestic Manager got up and as a result managed to get some workshop time in.

In fact I find there's enough of the quill nose poking out in the parked / homed position to get a pinch collar on there. I bought a spindle speeder from JohnS a few years back that fitted his Beaver mill. I haven't used it yet, as it's imperial (NMTB40) rather than the metric of my power drawbar (ISO40). However, being a speeder it also has a reaction arm and came with a pinch collar thing for his machine. Turns out his quill was a couple of mm smaller than my Shizuoka quill, so I was able to bore it out on the lathe and Bob's your auntie - I have a solution. John must be smiling on us from his workshop up there.

I bodged a short length of steel strip into a reaction arm and I screwed a short pillar into the collar to pick it up. So I can remove the pillar when not in use and the tapping head is otherwise self contained. The pillar is made of loominum as it was ready to go but I may change it for steel at a later date if this works out.

Scarily, I have now got a tapping head ready for action and have come to believe that the CAM might be reasonably straightforward. That requires less talking and more machining. I'll think on that as I waste the rest of the day failing to be a plasterer and perhaps give it a go this evening on a piece of scrap.....



Oh good. The photo has rotated during upload.