arbor question

[normalbill]

good morning.

first, i would like to thank you folks for the warm welcome. Marv Klotz, i have used your web site for years. thank you for it and thank you also for fixing my screw up with my first post.

ok. the question: i have a Cincinnati #2 h/v mill that was made in 1934. when i bought it, the only 1-1/4" arbor we could find was 30" long. i had originally thought that i might cut it off some and rethread the end. however, it is harder than chinese arithmetic and i have rejected that plan. this arbor really hangs out in my shop and i am afraid that i, or someone/something else is gonna get hung up on it. so i need a shorter arbor. machine has a 50 taper spindle.

i am wondering if i could use some o-1 drill rod to make an arbor that would fit in an end mill holder and was 12-18" long. i am thinking that i would want to start with maybe 1-1/2" drill rod so as to make it as round and true as possible. then i would clamp it in a t slot groove and mill the keyway and flats for the end mill holder. i doubt that i could properly harden something of that size, but does it really need to be that hard?

with all that said, i *could* just go buy an arbor, but where is the fun in that?

thank you in advance for your assistance.

peace.
bill

 

[Dave G]

Hi Bill, I would try to find an arbor the right size for your machine than make one. O-1 is a thru hardened steel and would be too brittle for an arbor. If I had to make one it would be from 4140 preheat treated steel. There are 40 to 50 taper adaptors available also, so you could buy a 40 taper arbor and use the adaptor in your spindle. Try to check the arbors for straightness before you buy, alot have been in mishaps over the years, especially the longer ones. Good luck, Dave

 

[picclock]

>>> i had originally thought that i might cut it off some and rethread the end. however, it is harder than chinese arithmetic and i have rejected that plan.

It may still be a good plan if you anneal the part then reharden if required. Easily cut off with a grinding wheel (hard or soft). + Very low cost and you know what you are working with

Best Regards

picclock

 

[Holt]

Hello Bill
You might be surprised at how thin the hardened layer can be. I did some alterations on an arbor at work, and when i was through the hardened layer, it machined really well.
You have two options when turning case hardened steel, you could take shallow cuts with a very sharp tool, or large cuts with inserts (you have to brake trough the hardening in first cut in option two)

Holt