Author Topic: Short QC Biltz type tapping chuck (Read 14626 times)

PekkaNF · « **on:** February 04, 2019, 12:26:00 PM »

I have some 19 mm arbor size tapping adapters and chuck. The chuck has some spring load float out. Problem is that the tap hangs out pretty far.

The quick connect does not appear too complicated. I disassembled MT2 (in picture) chuck and the quick connect coupling looks pretty simple to make.

I checked ebay...looks like Britons have it pretty easy, but many shops have jacked up P&P to Finland to over 30€.

1: Any good DIY pointers? I'm thinking a simple standard ball coupling - linear or twist lock.

2: Maybe I have missed a proper search word for chuck only...I find only very expensive ones.

Pekka

awemawson · « **Reply #1 on:** February 04, 2019, 12:55:35 PM »

Pekka,

I have only ever bought them second hand on eBay where often sellers hope for a fortune but bargains CAN be had. New ones demand a Kings ransom !

There are two styles (straight and torque limiting) the later being adjustable with a pin spanner. and come in a range of sizes besides your 19 mm from very small to quite large, and of course each range comes in a variety of tap shank and square sizes.

I see no reason why a spring loaded ball attachment wouldn't work well so long as you incorporate the side float.

They are brilliant devices, and I use them all the time on my CNC mill except when space limitations preclude them as they are bulky. In those circumstances I use a standard holder (with end float) as although I'm set up for rigid tapping, I never entirely trust it !

PekkaNF · « **Reply #2 on:** February 04, 2019, 01:51:09 PM »

Kings ransom

Still - quite right.

I also saw a QC collet with drill chuck taper. Seems usefull, but pretty expensive for what it is. Maybe another project. I happen to have two extra chucks that has thread mount.

Pekka

chipenter · « **Reply #3 on:** February 04, 2019, 02:04:07 PM »

Are these any good the postage is right https://www.banggood.com/Tapping-Chuck-ISO-Standard-GT12-M4-M8-Overload-Protection-Pneumatic-Tapping-Collet-Chuck-p-1401903.html?rmmds=search&ID=514217&cur_warehouse=CN .

PekkaNF · « **Reply #4 on:** February 05, 2019, 02:13:27 AM »

I have bought some chinese here

Adapters:
https://toolsmach.com/en/82-tapping-adapters

But their chuck is pretty long, as you see:
https://toolsmach.com/en/tapping-head-sets/651-tapping-head-set-thread-range-m3-m12-morse-3-ggz.html

Therefore my plan is make one shorter (without that much axial float) - if I can't buy one at reasonable price.

I would resorts paying Kings Ransom (still funny

) if I had really expensive CNC machine or expensive parts, but I got neither.

I remember in history that during crusades least one kings ransom was paid, but dictionaries don't support that...this may be totally unrelated:
https://en.wikipedia.org/wiki/Richard_I_of_England#Captivity,_ransom_and_return

Pekka

PekkaNF · « **Reply #5 on:** February 05, 2019, 04:25:59 PM »

I checked some products, could not find what I needed...then checked my stock and tools. Looks like only tool I need is an 5 mm (r 2,5 mm) profiling tool or grooving tool. Apparently not the most usual insert/holder dimenssion - not exremely rare, but not the most common either.

I have ONE 5 mm solid carbide cutter I could chop and braze on a shank. Is this a idea?

Pekka

awemawson · « **Reply #6 on:** February 05, 2019, 04:48:51 PM »

Seems a shame to sacrifice a carbide mill.

Have you no bits of silver steel that you could turn a 5 mm end on, mill off half and then harden ?

PekkaNF · « **Reply #7 on:** February 06, 2019, 02:37:10 AM »

Could try that, but that means swapping the material softer (like 42CrMo, I probably have one rusty bar marked with blue tape - my way of marking known materials).

Maybe I could plunge mill 5 mm hole (pocket) 10 mm deep to end of flat steel, mill extras of and braze silver steel plug there. Sort of make pocket for cuting bit - I have to draw it into scale....if I put that "rod" upright, it would have perfectly round projection (cutting face)....should be long enough to allow clearances 20 mm OD turn piece to plunge cut....Might even work good enough if tilted forward few degrees - projection error probably still would good enough. Can't take too agressive cut with this sort of form tool.

Today I'm trying to find some ready made parts and if it does not work I'll start this build.

Pekka

PekkaNF · « **Reply #8 on:** February 10, 2019, 07:27:51 AM »

Took few shotrcuts with this tool and so far good progress (very litle time innvested).

But weird thing happened: I was cutting off 10 mm long piece of the 5 mm dia carbide and it just snapped.

I had the round tngsten carbide mill shank rotating on the lathe few hundred rpm and decided to cut it with cout out blade. 3M 1 mm wide cubtron ussually cuts anything clean, but it was a little hesitant on this one. Suddenly the TC rod just snapped.

Last picture is mock up where the TC rod is form tool, but need to decide how to grind it. I was thinkking of using diamond hone manually, but that rounded edge set the idea back a little.

Pekka

awemawson · « **Reply #9 on:** February 10, 2019, 08:11:14 AM »

Thermal stress probably.

We used to make containers out of milk bottles that way. Fill with oil to the level you need the break, then plunge a red hot poker in the oil. The hot surface layer of the oil snapped the glass bottle at the right place as it was much hotter than the body of the bottle.

PekkaNF · « **Reply #10 on:** February 10, 2019, 09:29:39 AM »

Quote from: awemawson on February 10, 2019, 08:11:14 AM

Thermal stress probably.

You are probably right.

Quote from: awemawson on February 10, 2019, 08:11:14 AM

We used to make containers out of milk bottles that way. Fill with oil to the level you need the break, then plunge a red hot poker in the oil. The hot surface layer of the oil snapped the glass bottle at the right place as it was much hotter than the body of the bottle.

That's faster than scoring, heating and plunging into cold water....success rate was not spectacular. How about your method?

awemawson · « **Reply #11 on:** February 10, 2019, 10:08:17 AM »

Worked very well so long as the bottle was reasonably even walled. I doubt it would work so well on the modern titanised glass bottles.

PekkaNF · « **Reply #12 on:** February 10, 2019, 12:29:10 PM »

form tool and test

PekkaNF · « **Reply #13 on:** February 10, 2019, 12:39:59 PM »

And some results. QC drill chuck mounts and releases.

First step.

PekkaNF · « **Reply #14 on:** February 12, 2019, 03:39:04 AM »

Next thing would be to make a short QC holder for these adapters.

I think I have figured out how this ball-lock works - appears that the balls are used to pretension the adapter "out" to keep adapter seated.

The original holder has some extensive travel in/out. Shorter holder has less space for it and when used manually on mill/drill pinole on drilling mode (against the spring pressure).

I think that a little provision for spring cushioned travel inwards would be a good thing. Or maybe a thick O-ring?

Any pointers here?

Pekka

awemawson · « **Reply #15 on:** February 12, 2019, 03:56:44 AM »

The 'in out' spring loaded travel makes up for the difference between the pitch of your thread and the pitch of your down feed, particularly when accelerating and decelerating.

More is better than less

PekkaNF · « **Reply #16 on:** February 12, 2019, 11:24:41 AM »

Yes, but I am not making here rigid tapping.

More like limp tapping with manual quil feed

I was just thinkking that slight cushion might save a tap if I bump it down too fast.

Pekka

PekkaNF · « **Reply #17 on:** February 22, 2019, 05:25:15 PM »

Bussy at work and some seasonal work at home.

Got few hours on this one. I'm having trouble locating a fitting spring for ball lock. I need a spring that fits over 25 mm tube. I don't need too much force, just to press 5 mm balls into contact. Stroke is about 5 mm and there is 15-20 mm of lengt available.

Thinking of making a spring, because I can't locate this size compression spring locally.

Found this video:

Will piano wire work?

I have always thought that spring needs heat threating after winding.

Pekka

WeldingRod · « **Reply #18 on:** February 22, 2019, 05:43:01 PM »

You dont need heat treatment for your service.

Sent from my SAMSUNG-SM-G891A using Tapatalk

PekkaNF · « **Reply #19 on:** February 24, 2019, 04:35:39 AM »

It did not go "As seen on TV" at all.

1: Only "musical wire" I found was 6m of 0,5 mm piano wire. Way too thin for this one.

2: Mandrel calculator or table (could not find metric) is good, found this one:
https://www.daycounter.com/Calculators/Springs/

Anyway decided to try this and produced four "springs", none of the succesfull on any application. But good learning experince.

Now I attacked to one pull string to make it larger and transform it to compression spring. Nearly correct size.....just OD should be ID and it is of wrong sex.

Pekka

PekkaNF · « **Reply #20 on:** February 24, 2019, 05:21:42 PM »

All starts with a wrong type spring that has right wire size, but is bit too small: OD25 mm, ID21 mm over a 28 mm OD pipe. Whole set into 290C oven for an hour.

After taking it off OD grew to 29,5 mm and ID 25,4 mm. Interesting.

Little deburring and parts start to look ready to assemble.

PekkaNF · « **Reply #21 on:** February 26, 2019, 04:41:22 AM »

Turned a simple bushing to keep the spring from doing springy stuff and to locate the sliding /locking outer bushing in check. Simple job made out of acetal (POM) and then it was time pres the locking bushing into MT arbor.

It works better than I expected, spring forces are good and ejection of the QC-holder is positive but not with terminal velocity.

Nice excercise and learned bit more about the springs.

Pekka

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Author Topic: Short QC Biltz type tapping chuck (Read 14626 times)