BP Disaster Solved -- giganto pita....

Awl --
Wound up drilling it out -- and a bit of a saga. I wasn't there (thank
gawd), but someone who knew a little about machines was.
They tried jamming the nut, to simply unscrew from the top, they weighed
disassembly vs. drilling, ito the time/hassle factor/putting it back
together correctly, etc, and opted for the brute force method.
I mentioned previously there was a second draw bar, in case the stuck one
was sacrificed, so they did file tests to see if it was hard, and where.
Soft. So, they commenced trying to drill out the thread/nut from inside.
But, it turned out it the test bar was a cheapie import, and the thread on
the original draw bar was hard like an sob, so the drill just skated.
So they took off whatever could be readily removed on top (mostly the motor
cover), cut off the hex, and drilled from up top.
Even THAT was hard, but not as hard as the thread. And then, there was a
roll pin, on top of it all.
All in all, about 3" or so had to be progressively drilled, up to about 1/2"
dia. Took hours, the whole thing got so hot the surrounding areas turned
dark blue. Boucou dulled bits.
So when the bar finally came out, they tested the r8 nut, and it was on so
tight....
HOW TIGHT WAS IT ON????
It was on so tight, that with the drawbar in a vise, and plenty of leverage
on a large wrench, the nut *still* barely came off!
All in all, about a 3-4 hour miserable miserable job.
Turns out, someone did remove the spacer washer on top, and the draw bar
bottomed out on the r8 collet, locking up good.
Then, when he tried removing it, it spun out the nut/thread part of the
collet.
Bleeve me, he is never going to use 2-pc R8s again. In our combined
collection of R8s, I would say at least half are 2 pc, in one style or
another.
Has everyone checked their sets of R8s??? :)
Again, thanks for all the input.
Reply to
Proctologically Violated©®
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Yep. Lydex are 2 piece, the el cheapo imports are often 1 piece.
Proctologically Violated©® wrote:
Reply to
RoyJ
Yup, absolutely classic! It gets cross-threaded, or maybe a chip wedges into the thread and binds it all up, the nut turns in the collet, and then pulls up into the spindle.
I doubt you can find anything but $50 apiece collets that don't have the 2-piece construction. Even the ones you THINK are all one part, may just have cleverly hidden joints. I don't know how they can have an open space behind the collet's gripping section without the separate nut piece.
The spacer is only to be removed after you have cut off an equivalent length of thread on the drawbar, so as to get two uses out of when the thread gets worn.
Still, iof he used a hand-operated wrench on the drawbar, didn't he FEEL something going wrong when he tightened it?
Jon
Reply to
Jon Elson
Good point. Hopefully "cleverly hidden" would translate additionally into "well made". :)
I don't know
Another good observation. This is a very very talented old-school machinist (if not a little odd), who often works behind various shleps in his employ. He proly should have noticed, but when you perenially exist in the line of financial gunfire, shit happens in the heat of battle. This is one of them.
Reply to
Proctologically Violated©®
=========== You can have the same problems with a one piece collet if you strip the threads.
Draw bars and collets are not the place to try to save money. Also if something is not fitting right, like the drawbar without the washer, don't just put a cheater on the wrench and yank, check to see what's wrong.
A useful accessory is a combination drawbar wrench with reasonable length handle and a hammer to whack the drawbar to loosen the collet. for an example see
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Unka' George [George McDuffee] ------------------------------------------- He that will not apply new remedies, must expect new evils: for Time is the greatest innovator: and if Time, of course, alter things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?
Francis Bacon (1561-1626), English philosopher, essayist, statesman. Essays, "Of Innovations" (1597-1625).
Reply to
F. George McDuffee
I've had great success using masonry bits for drilling hard steel. It is noisy, but does work pretty enough. I don't bother to re-sharpen the bits for cutting metal, just lean into it. It's useful to use flood cooling, but not essential, so long as the bit doesn't get so hot that the braze lets go.
Hmm. I had one R8 accessory (a one-piece shell mill holder if I recall) that allowed the Millrite draw bar to bottom, so I shortened the drawbar.
I'm not sure if Millrite MVI vertical mills are supposed to have a thrust washer, but mine does not. The manual is equivocal. There may have been a needle-bearing thrust washer. Does anybody know?
Half of my R8 collets are two piece, but none bottom.
Reply to
Joseph Gwinn
"Proctologically Violated©®" wrote in news:497c9195$0$20294$ snipped-for-privacy@cv.net:
Why not just split the threaded bit off of the end of the draw bar with a cold chisel and a hand sledge? Like on a car with a frozen lug nut and spinning stud.
Reply to
D Murphy
This is a good opportunity to TIG the collet back together and then try to break the weld. If it holds or you find a way to anneal them you have a fix for the 2-piece ones.
jw
Reply to
Jim Wilkins
that's good advice that too often goes unheeded; should be in big letters across the walls in a shop
Reply to
raamman
In article , snipped-for-privacy@hotmail.com wrote:
They are supposed to have that pin in the spindle, but it's often been sheared off. My mill is like that. Replacing the pin seems like a lot of work.
The pin on the 5C collet holder for my Clausing 5914 lathe was also sheared off, but was easily fixed, so I fixed it. Basically, machine a 1018 steel shouldered pin that just fits through the hole in the sleeve, and cold peen the pin top into the countersink. Use a junk but solid 5C collet in the sleeve as the anvil. Trim with small file.
Joe Gwinn
Reply to
Joseph Gwinn
[ ... ]
Perhaps not as bad as you think.
1) Lower the quill.
2) Look for a hole in the back of the quill.
3) rotate the spindle so an Allen socket lines up with the hole.
4) Reach in through the hole, loosen the Allen socket a partial turn, and reach through that socket to another behind it.
5) Unscrew both fully, and draw out (trying to not lose them inside the quill.
6) Replace the front one (a dog point Allen head setscrew where the dog point acts as the pin in the spindle. When it is set deep enough (check that it does not bind on the collet with the shallowest key groove), withdraw the Allen key slightly so it only engages the outer Allen head screw -- which is *only* socket and threads, no body beyond the socket) so it locks the dog point one in place.
Now -- I've only read about this, never done it, so I'm trying to remember whether you have to turn out the big nut at the bottom of the quill first. If so -- mark it so you can screw it back in the same amount. It has its own set screw holding it in place.
Good Luck, DoN.
Reply to
DoN. Nichols
The index pin is replacable and please remember, it is sacrificial. Do not make one of hardened steel!. They are tricky to remove, but not difficult, not time consuming. They are VERY important because they will prevent a spinning R8 tool from trashing the quill. It is wise to make up spares and have them ready to change when the occasion arives. It does happen all too often. Steve
.
Reply to
Steve Lusardi
so, now that we are speaking of index pins - what about the index for C5 collets - the one on my holder is nearly worn out, and it isn't a simple pin - are these available (if so, where)?
Reply to
Bill Noble
Steve, I think that a friend of mine has an index pin that sheared off. So if you know how to replace one, I think that he will be delighted to know. I also think that they are great safety devices.
Reply to
Ignoramus335
Might help if you give some information about your indexer.
For HAAS HA5C
P/N 22-4052 Collet Key HA5C
Tom
Reply to
brewertr
Think Don Nichols answered and at the end I copied page from Bridgeport
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And from Bridgeport
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Tom
Reply to
brewertr
More often than not they are simply an "extended point set screw" also known as "dog point" and/or "pilot point" set screws (as stated earlier by another poster use soft Steel, NEVER stainless or hardened materials).
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Tom
Reply to
brewertr
Yes BP come from the factory with a pin to hold the collet.
The first thing all the serious old time machinests I know and 2 guys my age who are working in machine shops in Salinas (Salad bowl of the world) do is remove the pin. They all say the first time you shear that pin and spin a collet ('cause it wasn't tight enough) wedging it tight with the debris and gall the shit out of things you'll be happy you did. The problem is the pin fakes you out into thinking things are tight when they aren't...
The old coot who refurb and sold me my BP offered to put the pin BACK IN if I want him too... but said the same thing... keep it out and learn the feel of your draw bar..
My 2 buddies currently working the in the shops also think it's better to spin an end mill in the collet 'cause you took to heavy of a cut rather than bust the flutes off, so cheaters are a no no.
FYI my BP is a standard J head step pully machine but has a really long draw bar that sticks up about 3 inchs. That 3 inch portion was soft enough for me to knurl... I keep my collet threads pristine clean and I can run the palm of my hand across that knurrled portion and spin the draw bar hand tight in one flick.. Then it's about a half turn with the wrench and I'm 'good to go'.
Also as some one pointed out a draw bar wrench/ hammer is the way to go, but whats this buy one bullshit... Ya cut the end off a 3/4 combo wrench and silver solder on a chunk of brass.. it's handy for whacking other things besides the draw bar...
--.- Dave
Reply to
Dave August
Yes, you have to remove the nut on the end of the quill.
Reply to
Alphonso
You mean "5C" collets?
I think that it depends on what you are mounting the collets in. The pins on the Adaptors from 5C to MT 4-1/2 in my lathe have what appears to be a press-fit one, though I have not needed to do anything with it yet.
The one in a Hardinge lathe spindle which takes 5C collets directly may be like the ones in the Bridgeport -- a dog-point setscrew plus a bodyless setscrew to allow locking it in position.
Have you removed it to see what it is like? It may well be simple enough to make in your lathe.
Who made the holder? If you insist on *buying* one, instead of making one, that would be a good place to start.
My adaptor for the Clausing lathe was made by Royal, FWIW.
Enjoy, DoN.
Reply to
DoN. Nichols

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