Crafty 12x42 Daily Change Gears Used, (Not threading.)

[LX Kid]

Just finished restoring a Crafty 12x42. Been suggested that my lathe was mfg between 1939-1942. I looked thru various literature for what is recommended for just general daily use other than threading. Anyone have a suggestion for banjo gear selection for A-B-C-D locations. My lead screw has a 64 tooth and is slow as molasses.

 

[Nutfarmer]

I would look for a quick change gear box that fits the lathe. It is worth the frustration it saves. My atlas lathe is hardly used in favor of a lathe that has a quick change box.

 

[LX Kid]

I would look for a quick change gear box that fits the lathe. It is worth the frustration it saves. My atlas lathe is hardly used in favor of a lathe that has a quick change box.

Yes there is no doubt that a CG Box is a better idea "BUT" right now $300-$400 plus lead screw will just have to wait.

 

[bill stupak]

follow the link, it will show all change gear settings.

Change gear table

I often see questions about what gears are needed to cut odd TPI and metric threads. For example I was reading a post about not being able to cut a 3.5mm thread on an inch lathe. 3.5mm is 7.2571 tpi. Atlas printed a manual for their quick change gear box that lists probably every thread you...

www.hobby-machinist.com

 

[wa5cab]

Also, although coming up with the funds right now may not be possible, one correction - if the existing lead screw is OK, you do not have to change it in order to install a QCGB. The same lead screw is used on all Atlas 12".

 

[LX Kid]

Good to know lead screw information. "Should that QC Gear Box ever come about for me!"

 

[pdentrem]

Do you have the Threading Chart that is in the MOLO book or most had it riveted to the inside of the change gear banjo cover?

The charts are different between early lathes and the later ones. Early had 96 tooth as the largest change gear, while the later ones stopped at 64, and used a 16/32 stud gear that sat behind and below the spindle gear. In any case I tended to use the last set up at the bottom of my chart. See photo from my early 10” Atlas.
Pierre

 

[LX Kid]

Do you have the Threading Chart that is in the MOLO book or most had it riveted to the inside of the change gear banjo cover?

The charts are different between early lathes and the later ones. Early had 96 tooth as the largest change gear, while the later ones stopped at 64, and used a 16/32 stud gear that sat behind and below the spindle gear. In any case I tended to use the last set up at the bottom of my chart. See photo from my early 10” Atlas.
Pierre

Yes I have that chart but have never had cause to cut a thread with my lathe. Just wondering what gear selection for just average daily use. ( If there is such a thing! ). Tublacain, on Youboob, suggest fig # 6 on the chart top line for average use. So that is probably what I'll use once I get around to checking my gears. I'll take a close look at my chart to see if I have the early or late one. Still doing a "shake down" for problems on my lathe. Every time I turn around it's this little problem or that little problem to fix!. Thanks

 

[pdentrem]

The lathe is works very well within its limits.
It depends a bit on finish you are looking for and the tool in use. The radius on the tip of the tool and the feed rate come into play. Smaller the radius, smaller the feed rate. If you have a .030” radius tool, a .010” feed rate works fairly nice. That is why I settled on the bottom for most work.
Pierre