No. Unless the machines threading table showed gears actually mounted in the radiused slot, I would call this a 2-slot. See below for a typical Atlas 3-slot banjo with some associated parts for perspective. Note that the 4th (radiused vertical) slot is for the adjustment lock.
Wayne,
The original was pretty bad and I still haven't cleaned it up as much as I can but take a look in the Downloads under Atlas for the 918 parts list. It has listed two each 96T gears and page three is a threading chart that shows them.
Any chance that your machine might actually be a 9" instead of 10". Check the distance between the spindle center and a flat laid across the ways.
Robert D.
Wayne, et al,
I split the posts applicable to your machine out into a new thread.
Your machine apparently matches 10D below S/N 3970. Technically, it might also started life as one of the "Unit Plan" machines 10A, 10B or 10E. If anyone cares to know what that means, ask. But as with all the accessories, they became a 10D so I won't define them.
At S/N 3970, the cross slide, compound and milling attachment changed from the 2-bolt and slots to the pintle style. If you have any interest in a milling attachment to fit your machine, someone on the Yahoo Atlas_Craftsman list had one several weeks ago.
Robert D.
Wayne I have a 50's Atlas 10" TH42 here's a picture of the geartrainIs this what you would call a "3 slot" ? I always thought of this as having 2 slots for gears and not counting the curved adjustment slot.
View attachment 47198
Wayne F