BP disaster: snapped r8 collet?

Awl--
Ok, y'all know how you tighten the r8 collet/em in.
Here's what happened:
Upon tightening sed r8/tool, the thread of the r8 popped out, the r8 collet
body/em fell out, and the drawbar and the r8 thread/nut are now just
spinning in the machine, with nothing to lock it so the drawbar/threaded pc
can be removed!!
So the hex draw bar/r8 nut just spins freely!
Cheap chinese collet.
I never knew the threaded part was separate! Now, upon looking, in some
r8's they are indeed one piece, in others the threaded insert is held by two
set screws, and in others, the collet is just peened over a threaded insert.
This did not happen to me, but to my buddy across town, and I'm being
commissioned to deal with this, as I can climb up and about the machine, and
he can't.
So what's the prognosis here? One guy said to remove some plate or another
up top, and we might be able to hacksaw the drawbar off below the hex,
letting the draw bar/r8 nut fall down.
True? Sumpn else?
giganto pita.
tia.
Reply to
Proctologically Violated©®
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I would be looking to find a way to hold that threaded insert. I think I would find a block of wood or plastic that will fit up into the spindle and capture that bugger with some friction. Use the knee crank to make the table hold it up inside. Then spin the top with an impact wrench. Wrecking the drawbar would be my last resort.
Later,
Charlie
Reply to
Charlie Gary
How does the broken collet look? Can you insert it back into the quill, and push on it as well as on the drawbar, so that it would not turn while you unscrew the drawbar?
Worst case, I think, you can drill the drawbar out from top.
i
Reply to
Ignoramus15648
That would work if you remove enough of the drive portion of the head. Is this a step pulley or variable speed head? Step pulley is a lot easier.
I think in either case it would be easier to pull the entire quill/spindle ass'y and cut the drawbar on the bench. Remove the quill feed shaft and, if my memory is right, the quill will drop out. The worst part is messing with the counterbalance spring, especially getting it reset after reinstallation. Use a block of wood between the spindle nose and table to control the removal and replacement of the quill.
I think Iggy has manual scans, which should have blowups of the head.
Reply to
Ned Simmons
"Proctologically Violated©®" fired this volley in news:497764e0$0$25418$ snipped-for-privacy@cv.net:
PV, did the nut hit the dead end of the thread on the drawbar, or _just_ pull out of the toolholder? My inclination is to think it _couldn't_ have pulled out, and also have jammed on the screw.
If it's not jammed on the drawbar thread, then a toothed tool (like a small hole saw) might be jammed up against its lower surface, and provide enough friction to unscrew it.
Even a small screwdriver or punch might be brought into play.
LLoyd
Reply to
Lloyd E. Sponenburgh
Yes. Jam a long thin screwdriver between the threaded part and the quill ID. IIRC the lengthwise groove cuts across that part, do you have others like it to examine?
Reply to
Jim Wilkins
Variable speed head.
We dread dis-assembly. But you are talking about just removing the crank handle/spring, right, and this will drop the quill? Yeah, I've screwed that spring up myself on another BP!
I think Iggy's idea might be good, esp. if perhaps we can shove the broken r8 back up with some good strong epoxy on it. 2-part epoxies can have incredible shear strength, depending on the formulation AND on thickness -- you need between .010 and .030 on the radius, for a good set.
Epoxies are used preferentially to press fitting bearings, in some cases!
The wood/knee ideas and impact wrench sound good too, and I think some combination of all would be feasible -- mebbe shove some wood up through the re-attached collet for add'l friction on the nut.
We are in fact getting a cheapie impact wrench, which can come in handy for other stuff.
But, my buddy, who is perty experienced with BPs (but not as a mechanic per se) is hemming and hawing, dudn't think this will work, and may not pick up the air impact wrench. What a pita....
Reply to
Proctologically Violated©®
Sounds like a great way to epoxy the collet to the inside of the quill. Am I missing anything?
Hold the bottom of the broken collet in a vise, press on top of the drawbar with a wood clamp or something, and unscrew the drawbar with a wrench, it just might work.
Reply to
Ignoramus15648
Hey, it's a huge problem that has to be addressed - Google takes all sorts of very effctive measures to stop E-mail Spam from reaching our Inboxes - but they are the most pernicious source on Usenet.
I've complained. If you, and everyone else who is affected by it complain, perhaps they'll fix it.
Even something as simple as a Captcha and all users start with a probationary account with an initial posting limit would work - and an easy way to report the spam that gets that probationary account immediately cut off.
Apply the same heuristics they use on E-mail, and the account would get bounced on the second or third spam post.
Slowing the spew to a trickle is just as effective, the spammers don't want to spend fifteen minutes setting up an account per piece of spam payload delivered, it ruins the economies of it.
-->--
Reply to
Bruce L. Bergman
Without the Google Groups filters, I see a lot of spam (shoebuydirectchinawholesale.com or whatever). With the filter, almost never any spams. Hence why I do it. It is not really political in any sense. I do try to unblock any specific posters who use google groups if I notice.
I
Reply to
Ignoramus15648
"Bipolar Bear" fired this volley in news:gl814k$1q5k$ snipped-for-privacy@alt.net:
Well... YOU might honk on the drawbar until it broke the tool. I'd try to finger-loosen it .
LLoyd
Reply to
Lloyd E. Sponenburgh
There have been lots of other good suggestions; but maybe the simplest approach would be worth trying first.
With the collet body no longer attached to the threaded insert, there's no tension on the threads, and the thing might turn very easily (assuming the insert and the drawbar were clean and in good shape when the collet was installed). If that's the case, then maybe a pair of long-nose pliers to grip the insert, and a set of fingers on the drawbar, are all it'll take to get the thing out.
I say try this first because if you use expoxy, or do any of the jam it squeeze it cut it things first, then you'll probably bugger it up enough that it won't turn easily, and then you'll need the epoxy, or one of the jam it squeeze it cut it solutions.
KG
Reply to
Kirk Gordon
Unlike the spamer who says you can get free manuals here are a couple real free ones.
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Tom
Reply to
brewertr
snipped-for-privacy@aol.com fired this volley in news: snipped-for-privacy@4ax.com:
couple
And unlike the vendors who sell complete manuals, the ones on bbssystems are mere excerpts, sometimes of only a single page. They're NOT manuals, they're copies of pieces of manuals.
LLoyd
Reply to
Lloyd E. Sponenburgh
snipped-for-privacy@aol.com fired this volley in news: snipped-for-privacy@4ax.com:
And sadly, both of these sources supply incomplete manuals, as well. At least askmisterscience admits it.
LLoyd
Reply to
Lloyd E. Sponenburgh

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