deep bore

[fro_matt]

Hi, just looking for some opinions

 

I have to cut 1.500/1.5005 bores, 5.250/5.251 (flat bottom) deep on my mill, I don't think they have any business on MY mills, but nothing I can do about that.

 

I was thinking of using 1.25 boring bar and helixing up, but the time would be forever! In a boring head I can only hold .75 bar

 

Any ideas?

 

Thanks

[taperlength]

Turn the end of the 1.25 bar to .75 to fit in the boring head.

[dolphin1]

use a 1.375-1.438 insert drill to blow most of the material out. then use a 3/4in 5fl carb mill to do the semi-finishing on the dia and finish the bottom the use the boring head to finish the dia.

[Goldorak]

can you mount the part on a face plate and finish the bore on a lathe ???

 

so you can finish the bottom flat on the mill leaving .03 on the id , then finish the diameter on a lathe , it's way easier to adjust taper and dimensions on a lathe,to get your bore strait

[fro_matt]

Thanks for the input guys

 

Goldorak, I should have mentioned, 2 parts with 2 bores each, 68.000 apart. Even better, 40/20 mill is all I have. BUT I do have a job, so I don't want to complain

[Bruce Caulley]

Shell reamer?

[Gary]

Could sleeves be inserted for the holes? Otherwise it will suck. Maybe a dampened bar?

[Andy]

Criterion makes a boring head with a single point insert. It will bore from 1.5-2.7 Dia. With an extension cat 40 holder (we made our own extension) to get the depth. This boring head is very accurate and rigid and would do the job. Cri-bore system.

 

OOOOPS! 1.574 min bore. Sorry.

[Salt4cad]

Insert drill to 1.375

3/4 em mill bottom

3/4 em sperial mill to semi finish dia.

bore use Wallhopther multi-bore

done

good luck