Machining A New Counter Shaft

[joeau]

Hi folks,

A couple of months ago I picked up my first lathe, a 1948 Hercus 9a. It's a very close copy of the Southbend 9a.

The lathe is generally in good condition. One issue is that there is a significant amount of vibration coming from the countershaft. It's a 3/4 inch steel shaft running in cast iron blocks and has worn both the shaft and the blocks.

I've obtained bronze bushings and plan to sleeve the bearing blocks. My question is around the countershaft itself. If I machine a new one, does it need to be hardened? Do I use standard mild steel or something else?

Appreciate any assistance!

Thanks,
Joe

 

[Charles Spencer]

I looked at Hercus lathes on lathes.uk

http://www.lathes.co.uk/hercus/index.html

They do look quite a bit like the South Bend lathes. However, I couldn't see from the pictures what provision they have for lubricating the countershaft. I did find this manual:

http://www.bbssystem.com/manuals/Lathe-Tutorial.pdf

That had this information:



It indicates some had plain bearing while others had roller or ball bearings. My South Bend 9A has plain bearings and gits (oil cups). It also has a groove in the bearing for a felt wick that is fed by the oil cups.

You will want to make some provisions for lubrication.

By the way, my countershaft does not appear to be hardened, but I could be wrong.

 

[fixit]

if it's a straight .75 dia just get a piece of drill rod .75 dia then just finish the ends.

fixit

 

[12bolts]

Hi Joe,
I had a similar problem on my Hercus also. Shaft looked like this
But instead of a bronze bushing I made a bearing carrier for each end

I did make a post about this repair job, but I cant find it atm. Let me know if you want some more details

Cheers Phil

 

[joeau]

Gunrunner you need to order a set of these for the Z axis hand crank. Bill did you just spit coffee on your monitor? :rofl:

View attachment 253356

 

[12bolts]

I think drill rod is what is referred to as "silver steel" over here.

Although I just used, (from memory) a piece of 1018 cold rolled.

I'd like to retain the original cast bearing blocks but I think they could accommodate needle bearings like the ones in your picture.

Yeah I considered that too but I couldnt machine the old cast blocks without my lathe. And I wouldnt have my lathe without the old bearing blocks. Stuck between a rock and a hard place.....
You do get the added bonus of upping your lathe spindle speed with better counter shaft bearings

Cheers Phil