Tapping with Sheetcam - what do I need?

[hlombard]

I would like to do tapping on my X2 - cnc mill using the rigid tapping procedure in Sheetcam, but what do I need?

1. Can I measure my spindle speed (laser tacho) and just enter the speed?

2. How will sheetcam reverse my spindle? Do I need spindle control?

3. Do I need a special tapping holder (compression/ extention)

Any help appreciated!

[locost_cam]

1. Can I measure my spindle speed (laser tacho) and just enter the speed?

If your spindle speed is very stable you may get away with this for rigid tapping. It also needs to stop and start quickly. You will have to experiment a bit and it is likely that you will break a few taps before you get everything right. If you use an automatic tapping head there is a lot more leeway. With an automatic head you just need to make sure you feed slightly slower than the theoretically correct speed.

2. How will sheetcam reverse my spindle? Do I need spindle control?

If you want to use rigid tapping then yes, you need spindle control.

3. Do I need a special tapping holder (compression/ extention)

There are three ways of doing this.
1 Solid tap holder or collet chuck. The tap is rigidly held and you need very accurate spindle/feed synchronization. This is not really a practical solution for an X3 retrofit.

2) Rigid tapping head. These have some Z travel and are spring loaded. With care and some experimentation you should be able to get one of these to work. You do need fairly accurate synchronization between the spindle and feed.

3) Automatic tapping head (aka tapmatic). These have built in clutches and a gearbox. The spindle keeps running in the same direction. When you stop feeding down the tap stops rotating. When you feed up, the head automatically reverses. These heads are the easiest to use but they are quite long so you need a fair amount of Z travel.

Go to the Tapmatic website and have a look at their technical information. There is a lot of useful information in there.

[hlombard]

Thanks for the info.

I'll see if I can get the plans for a compression/tension tapping shaft - like the one Hoss made.

Anybody has plans for this?

Thanks