Atlas 618 Measurement Needed Please

markba633csi

Mark Silva
H-M Supporter Gold Member
Joined
Apr 30, 2015
Messages
12,245
Could someone with a 618 lathe tell me the center to center spacing of the two screws that mount the left side leadscrew bearing/bracket to the bed? For a possible conversion project...
thanks
Mark S.
Mt. View, Ca
 
I don't have a 6" bed to measure (101.07301 bed would be the same) but if no one answers in a day or two, call Clausing, ask for old Atlas parts, and ask whomever answers to look at the drawing and give you the answer.
 
1.250 . What is the conversion ? Let me guess ball screw for CNC . Did I get it ?
 
Actually (just a second while I finish this jelly donut) I was looking into the feasibility of putting a 618 head on a Mk2 bed. There are two issues with the Mk2 design: first, the spindle deflects easily due to the close bearing spacing. Secondly, the driving force from the main step pulley is coupled to the spindle through a single small woodruff key and zamak coupler which is a high wear point. The 618 is better in both respects, and would fit providing two more holes were drilled in the bed; I'm not clear about the leadscrew and tumbler fitments however cuz the 618 spindle sticks out so far to the left compared to the Mk2.
Are you sure it's 1.25"? The pictures I've seen sure look closer to 1.5" (the Mk2 is 1.25")
Mark S.
 
I measured mine as well but you had already gotten the first reply. Anyhow, my 618 measured at 1.25" as well.

-frank
 
Thanks Frank. I may not do this conversion in the end, I like my Mk2 and have done some good work on it.
Might make more sense to get a bigger lathe. SURE! says my bank account :)
M
 
Nice looking machine.

If you do decide to go ahead with the conversion, I think that you will also need to know the location of the holes, probably from the left end of the way.
 
Thanks Robert; you're correct of course, it all depends on the left-right position of the headstock mounting holes and whether the leftmost pair can be reused. I wouldn't try it if I had to redrill all 4.
Mark S.
ps These cnc mill conversions look so much fun I might do that instead, just need a mill...
 
Hey Mark that is a clean machine , sorry a little OT . What is that motor ?
 
Back
Top