jhovel 10th July 2012, 11:11 PM I intend to make one of these one day, but I have get a round tuit first....:D
Anyway, instead of showing off a finished project "one day", I thought someone might actually 'need' to build one now and had not seen this instructional page before.
Here it is. (http://mikesworkshop.weebly.com/improved-chuck-for-taps.html) (mikesworkshop.weebly.com has lots of other good projects) (http://mikesworkshop.weebly.com/improved-chuck-for-taps.html)
Cheers,
Joe
Dave J 10th July 2012, 11:18 PM Hi Joe,
Thanks for that,:2tsup: It has been on my to do list for a while now also.
With posting it up before it's done, thats how I felt with the under drive for the Douglas shaper, as I know it will be a while before I get around to finishing it. As you said, if someone you has time to do it now, why hold them up until you have finished.
Dave
Bryan 12th July 2012, 06:36 PM Joe, I saw that a while back and thought it was a neat solution to the problem of holding taps. Another is the 2 jaw chuck, but the one I'm liking most is this one on a German tapping head I acquired. Each of the little clamps floats in one axis and secures the tap centrally in the other. Once both screws are tight there's no float, except from the little bit of play in those bores, but that doesn't seem to be a problem. It may allow the tap to self-align. I think it's simple and clever and shouldn't be too hard to make.
Anorak Bob 12th July 2012, 07:56 PM That's got me wondering what Piper used to hold the square shank. I'm not sure if I can pull the "jaws" apart.
BT
ps. Looking further at Bryan's photos, it appears pretty much the same.
http://www.woodworkforums.com/attachments/f65/167403d1303034429-piper-tapping-chuck-piper-001-large-.jpg
Bryan 12th July 2012, 08:59 PM Bob, yes that looks the same. If you prise out the roll pin uppermost in your pic the barrels will fall out. I used small side cutters.
Anorak Bob 12th July 2012, 10:28 PM What's with the knurled calibrated collar on the German, Bryan, can you adjust the torque?
Bryan 12th July 2012, 10:39 PM Yes a clutch, like a cordless drill. I've only used the lowest setting. I hope it would let go if I bottomed.
Oldneweng 14th July 2012, 09:42 AM I have seen that design on MikesWorkshop and intended to make one. The new idea from Bryan and Bob looks much easier. One of the benefits of a long list of projects is that you have more time to refine your design and sometimes even realize that you don't need something after all. This happens when you you buy a new and better lathe.
Dean
jhovel 15th July 2012, 12:03 AM The one issue I see with the design of the tapping head (which is pretty much the same design as the chuck in one of my tapping heads), is that it can only properly grip taps with a long enough square end to go at least halfway into the second layer.
Several of my tap sets are not long enough to be held securely....
Maybe that's easily solved by grinding the square a bit longer...
Cheers,
Joe
Michael G 15th July 2012, 08:11 AM Joe, I originally thought that too, but when you think about it the square only has to be clamped by one of the two jaws. Because both jaws have a V, the other jaw will clamp on the round shank without any problems. In this situation the second jaw (on the round shaft) will just act to secure the tap so that it can not move in the 2 degrees of freedom that the first jaw would still allow.
Michael
Oldneweng 15th July 2012, 09:25 AM A neat answer Michael. I read Joe's post and looked back to Bryans pictures to see the problem actually shown in them. I did not realize that the pics were really showing the answer.
I was actually just lying in bed thinking about how I would manage some of the machining to make this before I swung my notebook around on its wall bracket and checked the forum.
Anyway it appears to me that it would be important to have the holes through the chuck and jaws drilled square to the face/outer diameter. I thought of starting with square stock for the chuck, drill and bore, rotate 90 deg adjust jaws with DI and drill and bore again. These holes have to be centred or the tap will have runout. The holes in the jaws need to be centred and square.
I am sure there are different and maybe better ideas out there. I will make this sometime as I have a tapping stand on my to do list. Lets have some other ideas.
Dean
Bryan 15th July 2012, 09:58 AM Michael that's how I read it too - the top screw clamps the square for centring and drive, the bottom one is just for centring.
Dean I was thinking likewise about starting with square stock. :)
Oldneweng 15th July 2012, 11:12 AM Yes but you don't have to.:no: Do You?:o Thanks for the confirmation.:2tsup:
Dean
jhovel 16th July 2012, 12:13 AM Thanks guys - that is the answer that had not occurred to me: I haven't pushed the taps in far enough, not realised that only the uppermost clamp really has to grab the square section.....
Cheers,
Joe
jhovel 17th July 2012, 12:15 AM By the way, here is a pic of my 'GEM' tapping head (made by Archer at one time I think). It looks very similar to Bryan's. It's chuck might be easier to replicate though. The end plate is countersunk bolted on.
Joe
Bryan 17th July 2012, 09:56 PM Joe, can you take a closer look at the logo on that unit? I think it's an 'Efem' like mine. See here: Fahrion - History (http://www.fahrion.com/en/fahrion/history/). It's a sweet unit, I just wish mine went a little bigger than 8mm.
I can see some advantages to the square design in terms of making it, except maybe for the square hole at the top. Could be a job for a shaper. :)
Edit: This link may be more interesting: http://www.practicalmachinist.com/vb/general-archive/how-does-automatic-tapping-head-work-152859/
jhovel 17th July 2012, 10:42 PM I'm about to go in the shed to check, but you may be right! The chuck body could be made in 3 parts: the top "back plate", the body with 3 rectangular grooves milled or shaped or bandsaw cut screwed to it and capped off with the thinner bottom cover plate with the hole in it screwed to the body.
What do you think?
Joe
jhovel 17th July 2012, 11:21 PM I'll be buggered....
not only is it indeed an 'Efem' tapping chuck - with a very florid script font 'E' and lower case 'f' - but it IS made in three parts! The slotted 'body' is pinned and screwed to the 'back plate', which is integral with its drive spindle. The rectangule section jaws are identical and both slotted slightly on one side, wider than the bigger side of the rectangle. Assembled, the slots face each other and so prevent the jaws falling out when not in use.
By the way, the body and the jaws are cast iron.
This one has a MT3 drive will take my 3/4" taps. The markings on the frivction clutch ring go to 18 - I wonder if they are settings for thread sizes in mm?
I think that design is pretty easily replicated actually....
Joe
Bryan 18th July 2012, 06:51 AM Brilliant. This has got to be the simplest design yet. Thanks Joe.
Michael G 18th July 2012, 08:20 AM Bryan & Joe, are your tapping heads auto reverse? My drill press is only one direction and I can't find an Efem or Fahrion catalogue to find out. I know that some Tapmatics are and some aren't, so I'm keen to find out more.
Michael
Oldneweng 18th July 2012, 09:11 AM Brilliant. This has got to be the simplest design yet. Thanks Joe.
Agreed. Even I could do that with my lathe milling attachment.
Dean
Bryan 18th July 2012, 10:10 AM Bryan & Joe, are your tapping heads auto reverse? My drill press is only one direction and I can't find an Efem or Fahrion catalogue to find out. I know that some Tapmatics are and some aren't, so I'm keen to find out more.
Michael
Yes mine is. At least, when you reverse the feed (lift the lever on the drill press) the rotation reverses. Is that what you mean by auto reverse? I think forward rotation is 1:1, and reverse is a bit faster. I thought I had found an old Efem catalogue with these heads in it but can't find it now. Maybe Bob's got one? :)
jhovel 18th July 2012, 08:28 PM Yes, mine are (Efem a, Arch No2). I thought most tapping heads were reversing by reversing their feed direction. Both mine all I have read about, have a clutch to prevent tap breakage - if they are adjusted right. Some, like the Efem, are easier to set than others, like the Archer.
Joe
jhovel 18th July 2012, 08:32 PM About the Efem chuck design: seems to me the only thing that determines the runout avvuracy is the centreline accuracies of the slots on the body and the tear-shaped holes in the two jaws. Everything else sets itself to run true. Right?
Joe
Michael G 4th August 2012, 09:41 PM After reading this thread I thought that these are nifty little gadgets and like others thought that I could make a tap holder for the lathe at a future date. Yesterday I was in my favourite Adelaide tooling shop (General Tools) buying a 12" digital caliper (M&W - on special at $169 if anyone is looking for one) and looked in the second hand tooling section.
For the exorbitant sum of $60 I snared a Piper MT2 reversible tapping head. Looks to be the flight rusted twin of Bob's in post 4.
I made up an arm for it today and tried it out with an M8 spiral flute tap, first on a block of PE and then on an offcut of Al. Works beautifully. The only issue is that the horseshoe shaped bracket I made up for it interferes with the rack on the side of the drill press column when I lower (it was one of those might/ might not things. The coin landed on "does").
All I have to do now is come up with things I need a number of tapped holes in, although the speed at which it operates I think that if I need any more than about 4 tapped holes it would be quicker to set up rather than tap by hand.
Michael
Anorak Bob 4th August 2012, 09:45 PM After reading this thread I thought that these are nifty little gadgets and like others thought that I could make a tap holder for the lathe at a future date. Yesterday I was in my favourite Adelaide tooling shop (General Tools) buying a 12" digital caliper (M&W - on special at $169 if anyone is looking for one) and looked in the second hand tooling section.
For the exorbitant sum of $60 I snared a Piper MT2 reversible tapping head. Looks to be the flight rusted twin of Bob's in post 4.
I made up an arm for it today and tried it out with an M8 spiral flute tap, first on a block of PE and then on an offcut of Al. Works beautifully. The only issue is that the horseshoe shaped bracket I made up for it interferes with the rack on the side of the drill press column when I lower (it was one of those might/ might not things. The coin landed on "does").
All I have to do now is come up with things I need a number of tapped holes in, although the speed at which it operates I think that if I need any more than about 4 tapped holes it would be quicker to set up rather than tap by hand.
Michael
I know you have a camera Michael because you posted some photos of the CVA. How about a snapshot of the Piper and the bracket.
BT
Michael G 4th August 2012, 10:09 PM Here it is then - the head
218267 218269
and the bracket.
218268
Nothing special there - a bit of 1/2" rod threaded 1/2-20 UNF to go in the tapping head with a piece of flat bent into a u shape at the other end (a bit quick and dirty because I wanted to try it out). I was almost going to just have a bar but then realised that when it reversed the reaction forces would change and I could get a nasty surprise. To fix the bracket I'll just need to put a joggle in to clear the rack. I tapped the bracket so I could get it off if needed but once I have the joggle sorted I'll weld and paint it I think.
Michael
Michael G 4th August 2012, 10:28 PM I just spotted this (while looking for something else)
T0119 | MTB-150 Magnetic Tapper | machineryhouse.com.au (http://www.machineryhouse.com.au/T0119)
Magnetic base to secure, fabricate a swan neck, a couple of brass bushes on a shaft and a home made tap chuck as we have been discussing and there you go.
Could be a handy little gadget to make up (Damn. Another thing on the list)
Michael
Bryan 5th August 2012, 09:56 AM Michael that Piper is gloatworthy. From what I've seen these usually go for hundreds. Good score. The mag base tapper is a neat idea too.
Anorak Bob 5th August 2012, 10:33 AM Michael that Piper is gloatworthy. From what I've seen these usually go for hundreds. Good score. The mag base tapper is a neat idea too.
Definitely gloatworthy, a saving of 190 bucks on what I paid for mine. :no:
( Hey Michael, you'll love this, a bit more insult to injury. Yesterday there was a set of brass Gravograph 20mm high number fonts on German Ebay. Shipping to Australia was 7 dollars. The bidding had 5 hours to go so I headed up to the shed. 8 hours later I remembered the fonts. They sold for 7 dollars. I'm still numb.:doh: More payback. Ha Ha.)
JohnQ 5th August 2012, 01:08 PM Michael G
I used one of those years ago at work. You don't need the U bracket, they come with a staight bar only. Only the tap reverses direction, not the whole unit.
Regards
JohnQ
Michael G 8th August 2012, 08:36 AM Have any of you guys with tapping heads got an electrical clamp meter?
I was just wondering last night how much power is used to tap a hole (say M12 in steel) and does it vary much with tap size/ material. It may be possible that one of those really cheap low power drill presses would be able to run one - a (semi) permanent tapping set up perhaps.
Michael
(PS - Thanks for the info John, but it's made now. Most pictures I see of tapping chucks do have the U bracket on them - I wonder why?)
Ropetangler 8th August 2012, 11:43 AM Michael G
I used one of those years ago at work. You don't need the U bracket, they come with a staight bar only. Only the tap reverses direction, not the whole unit.
Regards
JohnQ
But John,
Even though the drill spindle still turns the same way and the tapping head reverses the rotation as the pressure is released, wouldn't the torque reaction caused by the now reversing tap and the relatively high friction level between the tap and the workpiece, still want to rotate the unit in the opposite direction, thereby justifying the 'U' shaped end on the torque link? As is often the case, I speak having had no experience in using the equipment in question.:D:D
Congratulations on you purchase Michael, I'm green with envy,
Rob.
JohnQ 8th August 2012, 11:16 PM Rob
Having only used one of these is a workshop producing comms gear (25yrs ago), I didn't use it a lot. It was mainly used for taping brass/copper buss bars 3/16" thick. Never had any problems with the whole unit swinging back.
Maybe someone with a fuller understanding of these may be able to enlighten us.
JohnQ
Ueee 9th August 2012, 12:13 AM Have any of you guys with tapping heads got an electrical clamp meter?
I was just wondering last night how much power is used to tap a hole (say M12 in steel) and does it vary much with tap size/ material. It may be possible that one of those really cheap low power drill presses would be able to run one - a (semi) permanent tapping set up perhaps.
Michael
(PS - Thanks for the info John, but it's made now. Most pictures I see of tapping chucks do have the U bracket on them - I wonder why?)
Thats an interesting idea Michael.
I still have my first el cheapo ryobi drill press rusting away under the house. It probably has 1/4 or 1/3hp. Of course i don't have a tapping chuck...:(
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