Atlas 4804 something bent or wrong

kc0dwx

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So a few months back I purchased an atlas 4804, which as I understand is a Clausing lathe. At 12" there is probably .010 inch or more runout. Something that is very visible, might be more then I'm claiming. This is with the 3 jaw chuck. I have also a 4 ja2 and a face plate but have been unable to get the 3 jaw off. So is the small chuck the problem or do I have a bent spindle?

I have checked that the run out is not the stock but rather the chuck by rotating the stock. All bearings feel tight with no play. Run out is less at chuck then 12" or more out by a long shot.

I've tried using hex stock with a cheap air impact wrench to get the chuck off so I could try the drill chuck or 4 jaw but that hasn't worked as I've been unable to break the chuck loose.

I'm guessing somebody crashed this at some point however I can find no other signs of damage. Maybe(I hope) this is just a really crappy chuck.
 
To measure the spindle runout you must measure the spindle runout, not the chuck runout. You will need to get the chuck off before you can do that. Measuring one thing to check another is confusing and hopeless. Accuracy checks should be done in as simple a way as possible that gives good results. Stacking tolerances tells you nothing useful.
 
It is much more likely that the jaws or scroll on your 3-jaw chuck are worn. 3-jaws are not all that accurate to begin with, so .010" runout at 12" out doesn't sound crazy at all. I would bet that doing the same test with a 4-jaw or collet chuck would yield much better results.

I feel your pain. My first lathe, a Logan 10", came with the chuck stuck. The previous owner had used it for turning wood. :eek 2: I used lots of penetrating oil and a heat gun on the chuck to finally get it loose. After I got it off, I found sawdust and traces of wood glue inside. :mad:

GG
 
Don't use the back gears to stop the spindle from turning while you pound on the chuck or use a big wrench to get it off. Don't pound on it at all. Go easy and with patience. It probably took many years to get stuck like that. You can spend a few weeks working at getting it off if necessary. Gears prefer to have all their teeth... Be kind to your machines and they will be kind to you...
 
You can test the spindle by opening up the chuck, cleaning the spindle taper, and putting a shell reamer arbor in it. Then you'll know whether it's the spindle. I have a spare spindle that will come available sometime in the next couple of weeks btw. It isn't perfect, but it will run.

If your machine is original, you have an indexing hole at 9 o'clock from the chuck. That may be a way to get the spindle held enough to get the chuck off. Penetrant from the inside may help too.
 
It is much more likely that the jaws or scroll on your 3-jaw chuck are worn. 3-jaws are not all that accurate to begin with, so .010" runout at 12" out doesn't sound crazy at all. I would bet that doing the same test with a 4-jaw or collet chuck would yield much better results.

I feel your pain. My first lathe, a Logan 10", came with the chuck stuck. The previous owner had used it for turning wood. :eek 2: I used lots of penetrating oil and a heat gun on the chuck to finally get it loose. After I got it off, I found sawdust and traces of wood glue inside. :mad:

GG


Sorry it is more like .1" at 12" It is crazy visible to the naked eye. I don't recall the exact amount but it was a lot. I'm still hoping it is something with the chuck however.
 
Don't use the back gears to stop the spindle from turning while you pound on the chuck or use a big wrench to get it off. Don't pound on it at all. Go easy and with patience. It probably took many years to get stuck like that. You can spend a few weeks working at getting it off if necessary. Gears prefer to have all their teeth... Be kind to your machines and they will be kind to you...

Yes I realize you shouldn't use the back gear to stop it. What bad is that is exactly what the manual says to do. I have basically been using a cheap air impact wrench with 7/8 hex stock at about 12" long so just the stock is absorbing a great deal of the shock... Been holding the spindle with both the drive motor and belt an/or a rubber strap wrench. I figure the rubber will give long before a gear or pully.
 
Yes I realize you shouldn't use the back gear to stop it. What bad is that is exactly what the manual says to do. I have basically been using a cheap air impact wrench with 7/8 hex stock at about 12" long so just the stock is absorbing a great deal of the shock... Been holding the spindle with both the drive motor and belt an/or a rubber strap wrench. I figure the rubber will give long before a gear or pully.
Your chuck is soaking up the impact forces via inertia.

Consider making up or buying a split collar an putting it in place of the first change gear. You can destroy a split collar and not hurt the spindle.

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Yes I realize you shouldn't use the back gear to stop it. What bad is that is exactly what the manual says to do. I have basically been using a cheap air impact wrench with 7/8 hex stock at about 12" long so just the stock is absorbing a great deal of the shock... Been holding the spindle with both the drive motor and belt an/or a rubber strap wrench. I figure the rubber will give long before a gear or pully.
The manual assumes that the chuck will come off easily, like all the new ones on new factory lathes did... Those old Zamak gears and other parts are fairly delicate as well. They never thought those lathes would still be in service after all this time, and after sometimes decades of neglect. Work some penetrating oil into all the access places for the spindle threads and register. Turn it toward loose, then toward tighter, more penetrant, repeat at intervals. Time and patience helps a lot. Eventually they just spin free.
 
The manual assumes that the chuck will come off easily, like all the new ones on new factory lathes did... Those old Zamak gears and other parts are fairly delicate as well. They never thought those lathes would still be in service after all this time, and after sometimes decades of neglect. Work some penetrating oil into all the access places for the spindle threads and register. Turn it toward loose, then toward tighter, more penetrant, repeat at intervals. Time and patience helps a lot. Eventually they just spin free.


Pretty much my approach so far penetrating oil loosen, tighten and walk away without get mad. I'm not a machinist by trade by any means. My dad is and he has both a Swedish or Swiss large lathe as well as a large milling machine that does both horizontal and vertical setups both 3 phase machines, so I've become interested and hate asking him questions that make me look like an idiot and he isn't really capable of coming to location to help anymore.

I started with a very small atlas a couple years back and have used it very successfully. I've even done some work for my place of work.

Much can be accomplished and learned with patience.
 
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