What's new
What's new

Lucas #41 HBM

Unfortunately no line boring bars came with it. I asked the shop owner that I got it from if it had any and he said no, but did get a box full of cutters and holders.

Have some bar material of about 2 1/2" diameter I plan to make into a boring bar. I have a long bed lathe that I can turn the end to fit the HBM. - Not as good as having a bar especially made for line boring, but should work.
It’s a mystery to me how the bars all go missing. Most big machines would have 3 or 4 bars when they were installed. 2” or 3”, 4” and 5” dia. The ones I worked on weren’t exactly hardened and ground but they were very tough and very stable. They need to be capble of withstanding the cutting forces with a minimum of deflection. You’ll also need a cotter slot in the Morse tapered end to stop the bar wandering of course.

Regards Tyrone
 
Tyrone -- about boring bars -- what type of steel were boring bars typically made of? Also what sort of runout was considered allowable? Learning, as I have a 3” HBM with a tailstock and wanting to maximize its line boring capability.
 
Tyrone -- about boring bars -- what type of steel were boring bars typically made of? Also what sort of runout was considered allowable? Learning, as I have a 3” HBM with a tailstock and wanting to maximize its line boring capability.
I can’t help you there as I wasn’t involved with the manufacture of the bars. However they were obviously made from a good quality steel, you could file them but not easily. They were quite tough. Probably somwhere up the En scale in the UK. What that equals in the USA I don’t know.
Regarding runout - not much at all. But a slight amount of runout isn’t the end of the world because the component being machined will be passing the bar.

Regards Tyrone
 
Not to mention the tailstocks that go missing???
Yeah, those too. That normally happens when the outer support ( tailstock ) gets taken off the machine to facilitate loading the table with a large component. Then the machine gets moved/sold and the outer support is left behind. Later on nobody knows what it is so it ends up going into the scrap.

Regards Tyrone
 








 
Back
Top