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J Tiers
01-29-2008, 09:01 PM
Yep, more tooling.....

Had another run of 115mm standoffs with M5 threaded holes in the ends to do.

Last time I got so annoyed at the drilling then tapping and feeding the parts 115 MM after cutoff, that I had to make a tool this time. I'll have to improve it, it's more-or-less proof of performance this time.

It is a releasing tap holder, that can be set to power tap a hole any depth (within reason) and automatically stop at that depth. After it stops, it can be backed-out under power again.

Picture:

http://img.photobucket.com/albums/0803/jstanley/rls_hd.jpg

The hardened rod bears on the hardened block, driving the tap as rod slides on the block. When the depth is reached, the rod falls off the end, and the holder spins with the work.

To back out, the lathe is reversed, and the ram advanced enough to pick up the rod again, then backed up enough to avoid jamming when the tap feeds out all the way.

The depth setting is done by adjusting the rod which is clamped with a set-screw. The depth is the total extension of the rod.

I got the idea out of an old tool-making book, but I didn't feel it necessary to make the elaborate back-out means they showed.

pntrbl
01-29-2008, 09:27 PM
I've read that 4 times and still wish I understood how it works! :( Dummy on me ....

SP

Frank Ford
01-29-2008, 09:47 PM
JT-

You're a schmarty, alright - good work!

On the other hand, thanks a bleedin' lot - now I have another tool to make. . .

J Tiers
01-29-2008, 09:53 PM
PNTRBL:

Here's a pic of it moved to be in position to just about release. Maybe that helps?

It slides easily, so the tap screws itself in as the work turns.

http://img.photobucket.com/albums/0803/jstanley/rls_hd2.jpg

mochinist
01-29-2008, 09:57 PM
Thats great, definitely have to make one of those. Nice work:cool:

DancingBear
01-29-2008, 10:00 PM
Very clever! I like it!

Walt

pntrbl
01-29-2008, 10:11 PM
PNTRBL:

Here's a pic of it moved to be in position to just about release. Maybe that helps?



Yeah! That helps. I got it now. Thanx.

SP

torker
01-29-2008, 10:16 PM
JT...WOW! That's so simple...it's just brilliant! Thanks!
Russ

John Stevenson
01-30-2008, 04:13 AM
JT.
If you put a one way roller clutch in the block so its free to rotate going forward it will automatically grab and wind back when reversed saving having to advance the ram to pick the pin up.

I have some commercial turret tooling like this.

.

Your Old Dog
01-30-2008, 07:51 AM
Nice going JT! Pretty slick idea for those who don't need a $2-300 dollar setup for occasional use.

Lew Hartswick
01-30-2008, 08:50 AM
Neet-O. Only problem I see is tap shank slipping in a drill chuck.
Will have to see about making one of those (with a few mods) :-)
...lew...

lazlo
01-30-2008, 09:11 AM
Nice job Jerry.

That's the same mechanism that BadDog posted here for his Releasing Die Holder, but you've added the adjustable stop, which is a nice touch!

hornluv
01-30-2008, 11:04 AM
Great idea. How is it held in the tailstock? Is it just a reduced shank held in the drill chuck or did you put a morse taper on it?

sconisbee
01-30-2008, 11:54 AM
Slick way of doing it, relativly simple and very functional just how a tool should be

Chipslinger
01-30-2008, 12:18 PM
Sweet, but as cheap as they are on Ebay, why build one?

Oh wait, BECAUSE WE CAN !

BobWarfield
01-30-2008, 07:10 PM
Nice idea!

Same technique could be used to set up a tapping head on a drill press (or mill) so it quits tapping at a predetermined depth.

Best,

BW

jkeyser14
01-30-2008, 07:33 PM
Very cool, I'll have to add this to my list of tricks to remember

Fasttrack
01-30-2008, 09:01 PM
AHHH Its brilliant! It makes me excited just thinking about it - a nice easy bit of tooling that is super handy!

Seriously awsome little bit of tooling - simplicity and functionality, i like it!

J Tiers
01-30-2008, 09:33 PM
Needed improvements.....

1) yes, morse taper shank is needed. I have it held in a large chuck, but that is clumsy and leaves little provision for:

2) the anti-rotation arm that probably needs to be used to prevent the morse taper from slipping in the tailstock.

This was a quickie tool, to get thru a job quicker with less hassle.

Cheap on ebay? Maybe, but I don't DO ebay, so I never look and can't buy one there even if I saw it.

Slipping tap? not so far...... If you slip the tap (or spin the taper, for that matter) you likely have a problem.

Either you are misaligned, or you are tapping too high a percent thread, you are trying to use too big a tap, or you are power tapping some material that you shouldn't. I am using an M5 to tap aluminum, at 75%, so that isn't much of an issue now, but future usage of larger taps might be more so.

One could always use a tap holder with a square drive socket, but the chuck holds the tap straight. a holder to drive the square AND hold the shank straight is more of a project.

I must have missed BadDog's releasing die holder.

But that idea was in the same tooling book this came from, and, naturally, is probably a future project when I need one. After all, it's already half-done.

BadDog
01-30-2008, 09:52 PM
Yeah, I didn't invent mine either, I've seen (several) dozens in various slightly different forms.

Still, a neat little idea on that adjustable depth, and that's one I don't recall seeing before. I have to (vaguely) chase mine staying close enough to keep the dog engaged until I'm happy, then let it "trip", reverse, pick up the dog, and off it goes. Setting a stop for the TS or quill (both already have them) would also work for an adjustable depth stop on mine if needed. Looks like it might have a slight knuckle buster risk as well, so watch those hands and loose shirts...

Edit: Oh, and mine has a 3/4" straight shank with a removable slip fit torque arm. So I can use it in the big 20" VSG drill press (which could pretty much push any reasonable tap/die) mounted in an 18N SuperChuck. Or or on the Bpt in a collet, but wouldn't want to push the back-gear TOO far; maybe 3/4" max? And the same MT3 18N fits my lathe TS, which having no tang catch, is the only place that needs the torque bar at all (haven't even used it like that yet, no need...). And finally, it will also fit in my 1" bore Bed Turret using a bushing (or chuck should I so choose). That last option would be the shiznit for doing a bunch of threaded parts!

lazlo
01-30-2008, 09:53 PM
that idea was in the same tooling book this came from, and, naturally, is probably a future project when I need one.

JT, what book was it from?

J Tiers
01-30-2008, 10:26 PM
It's in several, actually, but the prime one is

"Tool Making 1935" by International Textbook Corporation

re-printed by Lindsay Publications

ISBN 1-55918-026-9

Their version does NOT have the adjustment, and the back-out is very different. Better, actually, since it is for an automatic, and actually can pull the tool out. Mine simply stops when it has exited the threaded part.

lazlo
01-30-2008, 10:41 PM
Thanks Jerry -- I need to put in another order to Lindsay.

I've been really enjoying the other book you recommended: Advanced Machine Work in .PDF, but I'd like to have a paper copy to read in bed.

BobWarfield
01-31-2008, 12:24 AM
Son of a gun!

Is that "Advanced Machine Work" by Robert Smith?

I found a copy in a used book store and love it. Until I took up machining, I had no use for used book stores, but I find they often have interesting stuff for machinists. This particular book was a textbook at MIT in the 30's, and mine still has the student's class notes with it.

Best,

BW

J Tiers
01-31-2008, 07:59 AM
That is the one I recommend, yes. I have gotten a lot of usable info out of it.

hornluv
01-31-2008, 10:22 AM
What speed are you running it at when you use it?

Furnace
01-31-2008, 01:00 PM
Thats just too cool. I just got home from having sinus surgery and this is the first post I read, should be a fun project when to do when Im healed.

J Tiers
01-31-2008, 08:38 PM
Speed slow, but not back gear, slowest standard speed on the Logan, which is around 150 RPM.

With the automatic release, there is no need to go extra slow. You just don't want to go so fast that you overspeed the guide rod thru the middle when it releases and starts to spin.

BadDog
02-01-2008, 01:13 AM
Well, on the strength of the recomendations here, I just bought the "Tool Making 1935". I rather enjoy making tools like that releasing die holder (along with other interchangeable attachments), the MT3 sensitive drill, and a variety of others; so this book sounds like it's right up my alley...

Also downloaded "Advanced Machine Work" by Robert Smith from Google Books. That's gonna take a while to read...

lazlo
02-06-2008, 07:13 PM
Son of a gun!

Is that "Advanced Machine Work" by Robert Smith?

I found a copy in a used book store and love it.

As an update on "Advanced Machine Work", by Robert H. Smith -- there's a 9th edition, published in 1925 that Lindsay reprints for $29.99.
But I found a 12th edition published in 1940, which is supposedly greatly updated and modernized. Still MIT Press, and still authored by Robert H. Smith.

I just bought a hardback copy of the 12th (1940) edition for $27.95. My copy won't show anymore (because I bought it), but here are the Alibre listings:

http://www.bookfinder.com/search/?st=re&ac=pg&qi=q2V43OKh03XDV5pkNfMzDN,tCvc_7176342183_1:1:6:1: 0

Black Forest
10-14-2011, 04:04 AM
JT.
If you put a one way roller clutch in the block so its free to rotate going forward it will automatically grab and wind back when reversed saving having to advance the ram to pick the pin up.

I have some commercial turret tooling like this.

.

John could or would you give a description of the roller clutch you are talking about?

EVguru
10-14-2011, 04:35 AM
John could or would you give a description of the roller clutch you are talking about?

He means one of these;

http://www.arceurotrade.co.uk/Catalogue/Bearings/Needle-Roller-Clutches

Highpower
10-14-2011, 07:54 AM
John could or would you give a description of the roller clutch you are talking about?Also referred to as "one way" clutches. Often used in things like planetary gear sets for automatic transmissions etc.

DR
10-14-2011, 11:22 AM
Good job on a simple to make, useful tool.

For ver 2, my suggestion is to replace the drill chuck with the head off a T-handle tap wrench or other such device to prevent the tap from slipping. As the mechanism is, it's capable of tapping small and large sizes, but no way will the drill chuck hold something like a 3/8 NC tap going into steel.

Black Forest
10-14-2011, 02:58 PM
I made this today. I will replace the chuck with a tap holding chuck tomorrow. Ran out of time today. I attached the tool to a MT5 I had laying around. Overall it worked good. I only had time to try one hole before the wife beckoned!

http://i853.photobucket.com/albums/ab91/burnandreturn/tappinghead.jpg
http://i853.photobucket.com/albums/ab91/burnandreturn/tappinghead2.jpg

Black Forest
10-14-2011, 03:46 PM
A short video showing the release of the chuck.

http://www.youtube.com/watch?v=alz0aezFtSY

lazlo
10-14-2011, 04:35 PM
This thread is so old, I don't even remember seeing it, let alone replying. Very cool JT! :)


If you put a one way roller clutch in the block so its free to rotate going forward it will automatically grab and wind back when reversed saving having to advance the ram to pick the pin up.

I don't remember seeing that either John -- brilliant! I have an ancient Formsprag series 50 sitting here on the junkpile on my desk...

John Stevenson
10-14-2011, 04:45 PM
Not new and not my idea, loads of capstan lathes employed this idea in their tapping fixtures.