Rigid tapping toolholder

[gunmaker]

Bilz #1 System...easy to change Taps or the Tap Collet's no tools needed. each size Tap Collet has a square drive...

Does that system have a little float in and out? Or is the tap locked solid to the holder with zero movement in and out?

I was looking at this. Seems like a pretty good price.
https://allindustrial.com/techniks-2...holder-size-1/

[machinehop5]

This Cat40 would float
https://allindustrial.com/techniks-3...on-tap-holder/
The Collet's are the same for both Types (Ridge or Compress/Tension Cat 40) and many different Mfg's.
https://www.ebay.com/itm/Bilz-QC-Tap...ox!67213!US!-1

[gunmaker]

I saw that one too. They make a holder for rigid tapping as well that has very little compression and tension. quite spendy.

Still curious if the Bilz system has clearance that allows the tap to move in and out .010" or so.

[Brian L]

I use the Bilz system on my machine, with the Tension and Compression holder, but it doesn't have rigid tapping. A machine that has rigid tapping has the Z axis slaved to the spindle with the encoder, so you don't need float, slop or any other such nonsense. You put you tap in anything that will hold it, ER collets, DA200 collets, whatever... Larger taps, I'd say over 1/4" would be better with a specific "tap Collet" that has the square drive in the back of it to prevent rotation. Smaller sizes you rarely get enough torque on the tap to worry about it.

The "fudge factor" spoken of is from what I understand, the inevitable over run that comes from the spindle not being able to reverse instantaneously. Depending upon rpm, VFD settings and even voltage, the amount of over run you get will change, so if blind tapping to the bottom of a hole, you need to know what Z depth to call out so you don't slam the tap into the bottom of the hole.

Newer machines with better instant reverse can do a more precise job of hitting exact Z depths without any over run, but that's a fairly recent improvement.

[machinehop5]

maybe you're looking to buy New but, I saw this Used one at a good price
https://www.ebay.com/itm/Collis-6722...n/293089168205
and I saw these ....which are Torque control
https://www.ebay.com/itm/Bilz-Tap-ho...s/143260191531

[Brian L]

Be careful if you are looking at the Bilz style holders, they come in different size ranges, #1, #2, #3 and even a #4 if I remember correctly. Each tap holder will cost you a fair amount of money and the clutch option is nice, but doesn't do any good with a rigid tap holder... if the clutch lets the tap spin, but it's still trying to go Z minus, you are going to break a tap.

[npolanosky]

I've had luck tapping with standard ER collets up to 1/2" with no problems.
I like the Bilz system- My Flexarm tapping machine uses the clutched version, and I haven't broken a tap in...maybe a year? But those are designed for manual tapping heads and such, they won't do you much good in a CNC. You'd want the rigid ones. #1 will do up to 5/8" IIRC. They are very fast and easy to change out, I am thinking of getting a couple cat40>bilz holders to leave in my machines since then I can just quick-change the tap and have it touch off the tool, instead of having to go disassemble an ER collet assembly on the bench.

I guess you could use a drill chuck but I wouldn't. Too easy to have the tap slip, and some drill chuck types (keyless ones in particular) may let go when you reverse the spindle.

A tension/compression holder is a good idea if you suspect sync issues, Maritool has some (both integral cat40 and shank type) for a fair price. And with regard to blind holes, you should always give yourself a little extra room just in case. Usually 2-3 thread pitches at least.

Finally, it might be a good idea to have some pin gauges to properly measure your minor diameter and some thread plug gauges so you can tell if you've got sync issues. If you're a tiny bit out of sync it may not break the tap, but instead introduce pitch errors, tearing, or other artifacts- Especially when backing out of the hole.

Best of luck!

[gunmaker]

was the Z axis Backlash checked?

I've found the directions for addressing backlash in X Y, but not Z.

Any good tips on how to double check the Z backlash comp on my machine?

[rl49]

Was it this document?

[Brian L]

I don't think there is any realistic way to check Z backlash. You have what, 500 pounds or more of head stock bearing down on the lead screw, essentially creating a zero backlash situation. Now, if your machine has counterweights that balance out the weight of the head, maybe you could see/check backlash on the Z... but even machines with counterweights, I suspect the weight of the head is still considerably more than the counterweights.

[gunmaker]

It does have a counterweight. I just got an er20 tap collet this morning for my standard cat40 er20 tool holder. As soon as I finish checkering this rifle, I'll squirrel my checkering cradle away and give it another shot. Then I'll try and check blacklash and try it again. My shop is 20x20 and I've got 3 mills(Milltronics, Bridgeport clone & Hardinge TMUM), 13X40 Kent TRLlathe, 6x18" Mitsui surface grinder, 6' stock duplicator, 8" Shape Rite shaper, 18" Grob vert bandsaw, 80 gal air compressor, 5HP dust cyclone, standing SouthBend drill press, Tig welder, 18"x24" surface plate, 2 tool box rollaways, 6x48" belt sander, 2" beltsander 6" wheel grinder, Baldor polishing lathe, reloading bench and work bench. I've got to run the Milltronics table off to one side to make room to checker and then play Jenga until I can turn on the CNC and home it again. Shop's a little tight. Had to cut a "skylight" hole in the ceiling so the head of the RH19 would go all the way up. Had 1/2" clearance after taking the Z axis motor off shoehorning it into the shop.

[Brian L]

I hope you are skinny.... As for the rigid tapping, you shouldn't have any issues. One thing my son noticed with his machine, if he tapped something and then shut down and came back the next day, and tried to re-tap, he messed up the threads. So for whatever that is worth, you might not want to try to come back to a hole after the machine has been shut down and re-homed.

[positiverake]

This is what I use, it uses quick change tap holders and does have a little movement but is Rigid, works great

[machinehop5]

timing is everything...control of

[gunmaker]

This is what I use, it uses quick change tap holders and does have a little movement but is Rigid, works great

Any more info on that?
Thanks

[ToolHIT]

You will want a Tension/Compression Tap Holder with the Axial Compensation like the picture above. The collets have the square drive for the tap and holder itself has .290" Tension and Compression to compensate in the Z. They are offered in either Series 1 that goes from #6 to 9/16 tap sizes or Series 2 which goes from 5/16" to 7/8" Tap Sizes. Here are links to each to help you out:
CAT40 TC Series 1 Holder
CAT40 TC Series 1 Tap Collets
CAT40 TC Series 2 Holder
CAT40 TC Series 2 Tap Collet

Or you can get Axial Compensating ER Tap Collets that is a much more economical option if you already have ER Collet Chucks. These will fit into your existing ER Collet Chuck (from ER16 to ER40) and they have the square drive along with the axial compensation you need. Here is a link to them:
ER Axial Compensation Tap Collets

Hopefully this helps you out!

Mike