Atlas 3991 clean up

[wa5cab]

Ideally, the four lathe feet mounting points should be in the same plane and the six floor anchor points should also. Are you going to anchor the cabinet to the floor or slab?

One thing that you should do while the bed is unloaded is to replace the rubber grommets between the drip pan and the foot mounting points on top of the cabinet and right leg.

Also, when you start putting the thing back together, start with the headstock and make sure that the grooves in the spindle pulley and countershaft pulley line up. And that the belts have as much clearance as possible between them and the cutout in the pan. My 3996 came from the factory with the bed too far towards the tailstock end. It shreaded the right-hand belt within a month or two. And I discovered that the pulleys were not lined up. When they were lined up, the set screw in the countershaft pulley was clear of the end of the shaft. I've been running the machine for years with one belt in the left spindle pulley groove and right countershaft pulley groove. Sometime this Spring (I hope) I am going to pull the spindle to replace the belts and try to put everything together properly.

Robert D.

 

[nik]

Rather a hectic week, but still a bit of progress. Everything aside from the cabinet is clean and waiting to go back together, I'm almost completely convinced it did fall over at some point, the right front mount point on the bench was bent pretty badly, this correlates with the broken cover hinges, front left mounting ear, and dented tray. I really hope the bed is not twisted. Aside from that everything looks good, only missing parts have been the carriage lock and the half nut lever detent spring.
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[george wilson]

That model lathe,in the bench top model,was my first lathe.

 

[nik]

Happy easter to everyone. Through the coercive powers of beer and bacon, I was able to convince my friend to help me move the lathe cabinet onto its new platform, a 3"x22"x7' slab of sugar maple, which in turn is bolted down to the 3" old growth hemlock barn floor. And through the coercive powers of a 3lb cross peen hammer and some acetylene, the ripple in the cabinet mount point is back to being flat. It really feels like progress is being made, seeing it where it will live, and nearing the end of the cleaning.

Thanks again to everyone for the help and support, I will put up another round of photos once I round the horn, and start putting it back together.
N

 

[nik]

Hi again from the land of never ending winter, I have the bench pretty close to leveled and on the same plane, the flattened mount point is not exactly even with the other three, but it is nothing that a few thou of shim won't solve. I cut new rubber grommets (washers?) last night, and was thinking that with all of the trouble that I am going through to make the table and bed level, why would it be soft mounted? Is the isolation mounting just to prevent vibration transmission from the drive system, and if so, wouldn't it make more sense to soft mount the motor, and perhaps pulleys?
Perhaps there is something I am missing, I have been wrong before...
Any help would be great.
N

This is the current state of the lathe, the old level was in a pile of scrap wood that I moved to set up the shop in this corner of the barn, straighter and more accurate than the modern stanley I already had, adjustable too.

 

[wa5cab]

Nic,

The grommets are seals, not vibration isolators. You can get new ones pretty cheap from Clausing. Level the cabinet first with the carpenter's level. Then mount the bed and level it with a precision level. Shims go under the cabinet feet and under the bed feet, not the grommets or tray. The requirement isn't actually that the bed be level, but that both ways be straight and in the same plane. And the easiest way to do this is with the level.

Robert D.

Hi again from the land of never ending winter, I have the bench pretty close to leveled and on the same plane, the flattened mount point is not exactly even with the other three, but it is nothing that a few thou of shim won't solve. I cut new rubber grommets (washers?) last night, and was thinking that with all of the trouble that I am going through to make the table and bed level, why would it be soft mounted? Is the isolation mounting just to prevent vibration transmission from the drive system, and if so, wouldn't it make more sense to soft mount the motor, and perhaps pulleys?
Perhaps there is something I am missing, I have been wrong before...
Any help would be great.
N

 

[nik]

Hi again, I have been busy with some other projects recently, but finally managed to wring enough time out of this past weekend to get the lathe mostly put back together. It went pretty smooth aside from the woodruf key under the spindle gear not wanting to clear the outboard spacer and having one of my beard hairs getting wedged between the bed and carriage gib. I spent about an hour trying to figure out why it just wouldn't adjust right, only to find out that I am shedding, and that was causing the problem. I still need to clean and set up all the drive pulleys and associated bits, but progress is being made. With luck, I should be setting up to do the two collar tests and fine leveling this weekend, so long as no new insanity springs up.

Thanks again for all the help.
N