Re: [CAD_CAM_EDM_DRO] Tapping success!

hi vince-

great to see a manual tapping head work under cnc. did this with a
tapmatic 30x using #6 taps and broke more a handful within minutes on the
cnc'd minimill. but then again, the holes were more more than 1/2" deep :)

haven't yet tried the 50x on a full sized mill (it's too big for
mini-mills) but glad to see that'll work.

thanks!
david



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On Mon, 11 Dec 2006, Vince Endter wrote:

> I decided to try tapping with Mach 3 today using a tapping head.
> Several months ago I purchased a Procunier size 3 tapping head on
> eBay for $90. At the time I had no idea how big a size 3 was. It
> turned out to be huge. I just put it in a drawer and forgot about
> it. Fast forward to this weekend. I decided to make a welding table
> out of a 35"x15"x1" piece of aluminum with holes drilled and tapped
> on 2" centers. I had made a similar plate for my mill while I was
> taking a CNC class and had use of a Haas CNC mill. This time I would
> use my converted Bridgeport. Due to the size of the plate I had to
> drill and tap it in 4 quadrants (after tig welding 20 holes closed
> that came in the plate and surfacing it).
>
> I used a G73 peck drilling cycle for the holes and then just G1 and
> G0 moves for the tapping. The Procunier tapping head reversed at
> twice the RPM as the feed. I was running it at 210 RPM to it would
> reverse at 420. I have read that I should feed it at 95% of the
> calculated feed rate to account for any possible slippage or slop in
> the system. I used a forward feed rate of 15.2 IPM and a reverse at
> 30.4 IPM. The size 3 is so large that it took all but the last 1" of
> my knee travel to clear the table. I am always nervous any time I
> try some new program but everything went perfectly. The holes were
> drilled at a rate of 1 every 36 seconds and the tapping took 12
> seconds per hole. There are 112 holes in the plate. I posted a
> video here:
>
> http://www.flyingcritters.com/video/Tap.wmv
>
> I know some people will cringe at using WD-40 for tapping fluid, but
> it works for me. The ½" tap I am using has tapped over 250 holes 1"
> deep and it still looks sharp.
>
> Vince
>
>
>