Made some quick change tool holders

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liveaboard
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Re: Made some quick change tool holders

Post by liveaboard »

Thanks guys;
Drilling and tapping, aka boring... I put a regular tap in a drill chuck and just plunge it through. There is risk of breakage of course, but after many holes my numbers are pretty good.
A dozen broken taps, a few thousand threaded holes.

1.80 euro threaded rod;
threaded rod bad.jpg
2 euro threaded rod (8.8 DIN)
threaded rod good.jpg
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seal killer
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Re: Made some quick change tool holders

Post by seal killer »

liveaboard--

I love it!

--Bill
You are what you write.
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Bill Shields
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Re: Made some quick change tool holders

Post by Bill Shields »

Tapping technique very valid.

I have been driving taps with a Bridgeport quill for decades.

Do not make the chuck too tight and the worst thing that can happen is the chuck slips... assuming you have quick fingers and a nimble mind.. both of which you obviously possess.
Too many things going on to bother listing them.
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seal killer
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Re: Made some quick change tool holders

Post by seal killer »

Bill and liveaboard--

Do you slow the spindle down as much as possible?

--Bill
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GlennW
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Re: Made some quick change tool holders

Post by GlennW »

seal killer wrote: Sun Nov 27, 2022 9:59 pmDo you slow the spindle down as much as possible
That's what I do. Or at least to a speed that you can control the depth of the tap.

Too fast, and it will draw the tap into the hole so fast that you won't be able to control the depth!

Run it in to the desired depth, quickly flip the switch to reverse (3 phase motor) and run it back out. Mill or lathe.

Single phase motor takes a bit more planning, as you need to account for the spool down time of the spindle.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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seal killer
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Re: Made some quick change tool holders

Post by seal killer »

Glenn--

Regarding single phase and spool down . . . I could see cranking it up, then shutting it off almost as soon as the tap engaged.

Like liveaboard said, some experience and broken taps would teach you a lot.

--Bill
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liveaboard
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Re: Made some quick change tool holders

Post by liveaboard »

My big old drill press didn't have a reverse when I got it, I added a switch and relay mainly for tapping.
Now I have a VFD on it, this has made life better but my VFD doesn't have a braking resistor. It does a little braking but if I ask it to stop hard it shuts off completely.
Before the VFD I used to momentarily reverse the (3-phase) lathe motor to stop it. Tricky to get the timing but it stopped faster than with my VFD.

Mostly I use power for through holes. For blind holes I'm more timid, sometimes I'll just let the drill or lathe run a few rotations to establish a decent line, then dismount and finish by hand.

When tapping with the lathe, I leave the tailstock free to slide.

On a ship I have, I needed to tap a few hundred 8mm holes to bolt down deck planks. I used a handheld metabo drill. It did the job but reversing before stopping cooked the armature. Drill motors are a bit sensitive to that sort of thing.
big drill tapping.jpg
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Bill Shields
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Re: Made some quick change tool holders

Post by Bill Shields »

Yes on slow speeds. I have never done it with a VFD...only 3 please motors that instant reverse.

I also have a tap matic reversing head that can be used in a drill press - the reversing is done in the unit and is controlled by tap position. These were very popular back in the 50's and 60's. I got mine cheap (scrap) in the early 70's

Many ways to skin a fish
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arborist
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Re: Made some quick change tool holders

Post by arborist »

If you need them in the future, dog point grub screws (socket set screws) are often easier to find than square head dog point tool holder bolts. They also have the advantage that there is less for the swarf to wrap around.
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tornitore45
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Re: Made some quick change tool holders

Post by tornitore45 »

I can't say whether the "crappy" thread is what you get for a 0.2 euro difference or the fact that the cheap rod is meant to mate with imperfect nuts.
Mauro Gaetano
in Austin TX
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liveaboard
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Re: Made some quick change tool holders

Post by liveaboard »

arborist wrote: Mon Nov 28, 2022 11:57 am If you need them in the future, dog point grub screws (socket set screws) are often easier to find than square head dog point tool holder bolts. They also have the advantage that there is less for the swarf to wrap around.
I hunted far and wide for dog point screws of any kind; I only found them at very high prices, like 2 euros each.
The "normal" cap screws were 25 cents each. Even then, they were the biggest single expense of this job (I had to buy a box of 100).
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liveaboard
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Re: Made some quick change tool holders

Post by liveaboard »

tornitore45 wrote: Mon Nov 28, 2022 12:52 pm I can't say whether the "crappy" thread is what you get for a 0.2 euro difference or the fact that the cheap rod is meant to mate with imperfect nuts.
I suspect that someone bought a huge lot of factory seconds, probably supposed to be scrapped. Then sold it to a distributor.
I pointed it out to the salesman at the Wurth specialty screw shop (supposed to be for professional people). He seemed quite shocked.

Probably no one else will notice.
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