New Lathe User - Just Bought An Atlas MK2 6x18

My Mk2 also has the "backlash adjustment" carriage handwheel assembly. I have found that it doesn't really give much adjustment in
that regard; on mine at least, the gearcase has to be oriented to the extreme "down" position to obtain proper pinion to rack adjustment. Rotating
the gearcase either to the left or the right simply moves the pinion away from the rack. Perhaps the factory had something else in mind, or just miscalculated and didn't give enough adjustment range, I don't know. But it only meshes well in the one position.
I also found that the Zamak front gearcase half (that holds the handwheel pinion shaft) wears rapidly; I bored mine out to 13/32" and installed
a piece of 13/32" OD, 3/8" ID brass hobby tubing. Nice and tight now.
The belt idler pulley bushing also wears fast- keep it well oiled until you get fed up and replace it with a Torrington needle bearing and hardened steel shaft. Frankly the idler could probably be eliminated altogether; it tends to impart periodic "tugs" to the headstock which is not ideal for good surface finish on your turned parts. Another bean-counter compromise. A spring-loaded tensioner would have been preferable.
The sliding coupling from the step pulley to the spindle is another high-wear area. Bean counters strike again. They should have put two 180 degree woodruff keys instead of just the one. Hard to improve on this item, it is what it is. I do like the ability to pull the collar and twirl the spindle by hand, very handy when indicating a part in the 4-jaw chuck. I also like the backgear lever- no tiny pin to pull out- makes changing chucks a breeze. A nice machine in some ways, but a bit weak in others. Biggest improvement I made was a variable speed motor. :)
Mark S.
 
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When eventually I aquire a larger lathe, I thought I might modify the little Mk2 to make it a swiveling headstock a la the Unimat DB-200.
If a way could be found to drive the leadscrew with some type of flexible coupling, it would be great for turning tapers and making tapered threads
without needing a taper attachment.
Mark
 
Would you guys go to the trouble of taking this gearbox apart to clean and relubricate the gears? It's a bit messy and no idea how old some of this grease is, or how much junk is mixed in with it making a nice grinding paste...

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Yes you must , get every thing clean and re grease at assembly . When I got my machine the grease had turned to dried glue .
 
Yes you must , get every thing clean and re grease at assembly . When I got my machine the grease had turned to dried glue .

I think I may have answered my own question with the "grinding paste" comment, lol.

If anyone has tips about taking these gearboxes apart for cleaning, and reassembly please let me know.
 
Take pictures first(as you have) and pay close attention to which shaft/bolt they came off. I'm sure you knew that. Download the manual if you haven't already. One thing to watch for though is when you remove the snap ring inside the pulley assembly, watch for a SMALL ball bearing and a spring that are inside the collar to put it lock it into back gear. They can fly out and never been seen again. Ask how I know that:) Also when you remove that collar, don't rotate it while removing. I did that once on my 3950 and the spring gouged the collar.
 
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You could solvent-clean it without disassembly by making a "tray" of foil under it and using a brush. Much faster and
practically as good. It will get dirty again fast, so surgical cleanliness is not required.
Mark
 
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