Crashed my lathe twice today !!

woodchucker

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Today was a bad day, I crashed my lathe twice. I haven't crashed it in years. And never a serious crash. I always look at your projects and figure out if there is a problem to warn you ahead of it. Well I didn't do it for myself.

I was making a washer for the surface grinder. I found a slug for my clausing mill that I had used to send my brake out for welding. I made the slug so they could get the weld correct after they V'd the break. It was cast iron, so I knew they would be preheating and need to have the slug to correctly size it.

The outer area was interrupted so I was going to trepan a disk out of it. The first crash was my 4 jaw had the jaws reversed so the longer end was stick out and during trepanning I had a small stick out.. While moving in, the jaws started hitting my cross slide ear. The SB has ears to lock the compound. The damage was not too severe.. more my ego, and bad enough... I'll explain later.

Ok back to work, I'm coming to the end of the trepan, almost through. I figured the part would just drop out. What I didn't think about (stupid) is the interrupted part would collapse and cause the crash. When it happened it appeared the chuck jumped up. Everything was locked up the chuck stopped.

I am now 10 thou off on the face of the 4 jaw, and 5 thou on the side.
I put my 3 jaw on and it's fine, so it's not the spindle. I think the chuck is trashed. 5 thou out on the side is not a problem because it's a 4 jaw. but the face being out is serious stuff. The 4 jaw is an integral 1.5 -8 .. it's an atlas chuck.. It has served me well, I use it quite a lot, since the 3 jaw doesn't have the reverse jaws, and is much less acurate as it's 80 years old, it's worn.

The aluminum inside the cast iron brake, this is the piece I was trying to use. The cut out was so they could V notch and do some nickel welding.
Taking a break from BREAKING THINGS.

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Ouch! Some days just aren't as smooth as we'd like.

This is one of my fears as I start using the bigger 25" swing Monarch. With 10HP, (originally 20HP but I downsized to make the RPC), the amount of force involved in a bad crash gets scarier.

Can you imagine something like that on the 40HP series 90 monster lathe bcbloc02 uses?
 
Ouch! Some days just aren't as smooth as we'd like.

This is one of my fears as I start using the bigger 25" swing Monarch. With 10HP, (originally 20HP but I downsized to make the RPC), the amount of force involved in a bad crash gets scarier.

Can you imagine something like that on the 40HP series 90 monster lathe bcbloc02 uses?
Ah, so you went to Brian's youtube... no, I can't imagine it. You just don't crash something that big... when you do its more than an ego that is hurt.
 
Ah, so you went to Brian's youtube... no, I can't imagine it. You just don't crash something that big... when you do its more than an ego that is hurt.
Yep. He did drop that radial drill when unloading it.
He's about a 2 hour drive from me ...
 
Did you check the chuck body face and O. D. for runout? It might be only the clamping inserts that are damaged. That would not be the end of the search, the slots for the clamping inserts also may have been damaged. Check that chuck out carefully...
 
Did you check the chuck body face and O. D. for runout? It might be only the clamping inserts that are damaged. That would not be the end of the search, the slots for the clamping inserts also may have been damaged. Check that chuck out carefully...

I have only checked the body.... I noticed when I spun it back up it was wobbling.
I'm taking a break, and will check again tomorrow. Feeling very depressed right now.
but the body is out...
 
I’m sorry to read this and understand the feeling. I’ve had a similar issue with a plug jamming in the mill, fortunately ruining only the hole saw. (OT: And I’ve crashed a few cars.) Sad about your chuck. Ultimately it isn’t disastrous, in that it’s an interchangeable component piece. Considering the things that can go wrong, you came out okay.
 
Not being familiar with the term trepan, I looked it up.
This is Hieronymus Bosch’s depiction of trepanning.
I wouldn’t want to be the poor bastard in the chair when the guy with the funnel on his head does ‘trepanning” on him.
YMMV, cheers, Harvey
 

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If your Atlas 4 jaw chuck is like the ones I have seen, you didn't lose much, they are pretty poor in design, I'd look for a replacement.
 
If your Atlas 4 jaw chuck is like the ones I have seen, you didn't lose much, they are pretty poor in design, I'd look for a replacement.
I did look on EBAY... nothing out there USED in 6". Used to be loaded with possibilities...

edit: btw, originally I liked it thinking the integral spindle threads would make this a better chuck. But I don't think this is as stout a chuck as it could be. There's a lot of empty space in the chuck back, I don't think the little amount of ribs provides as much support as it should. So I agree now with your opinion. live and learn.
 
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