Boring Head

[KTD1]

We use the URMA Boring System. We hold +/-.0002" bore sizes on a regular basis. They are not cheap but we like them. Visit www.commandtool.com for more information.

[Cruiser]

I have in the past done many thousands of holes with tollerances of total .0006" in a large cnc lathe. The machine, bore gauge, the all important bore gauge standard ! (of which we usually made for the job) ALL were susseptable to thermal variations even by holding in the hand a bit too long, and during winter the machine was very kinky and during summer it all was worse ! Every hole was considered to be custom made and we had to back off and sneek up on each hole in process. The guys in the mill department had the same issues. If your part is cheap enough that you don't mind throwing some of them away then just shoot for it and adjust. If they are expensive then don't trust anything till it clears the final inspection process ! If you have climate control through the whole process then your job will be lots easier, our shop had some enormous doors that were always going up and down at the wrong time ! Good luck to you !

[cam1]

Hi:
1 question: What is the reason for the tight tolerance on the bore? For a dowel pin?
Reaming is an option, so is ball sizing.


regards

[artin51]

The current part is an aerospace hinge support that gets bushings pressed-in. It won't be high production. 15-20 parts at a time. I hadn't thought about ball sizing, having never used it personally. Might be an option. Anyone used this method successfully?

thx

[cam1]

Hi:

Try this link

http://www.precisionballs.com/Ball_Sizing.htm

http://www.precisionballs.com/

regards

[artin51]

Hi cam,
thx for the links. I'm just curious if it's plain precision, hardened balls that can be used. I think it's worth a shot seeing as how the balls are fairly cheap. Will definetly look into it.

thx again

[cam1]

Cheers

[cam1]

If it's 6061 T6, I'd go with unhardened run of the mill balls.
Keep us posted of your success/trials, as it will build the knowledge base.

regards

[fuzzyracing1967]

Just wondered artin what kit is it that your talking about from iscar? We just got a new boring head from valinite last week,the price went from $750.00 in 2005 to $1100.00 now ,and that was just the head!

[artin51]

I'll check on the exact p/n when i get to the shop tomorrow. But it includes the boring head, the boring bars, some inserts and adapters. It will do holes from .24" to 1.13", so you need a few different bars. I was a bit shocked at the price but managed to get the CAT40 adaptor thrown in the deal .
Also i just placed my order for the carbide balls to do some ball sizing. Any suggestions on how to push the ball through the hole? I was thinking drill press, but i'm not sure how much force i'm going to need to push a 1/2" ball through a .499" hole

[big_mak]

artin,

your tolerance can be achieved with the iscar kit no problem if you ar erunning it in a quality machine. I was running that kit in Matsuura's and got repeatability of 2-3µm in 6061. If you are using it for a repeat job and will never change the size, don't bother with the kit, and just buy what you need and save your company some money! I have the same D'andrea kit that cuts from .236"-3.3" and I wouldn't trade it for the world!!!!

Dicker with your supplier and tell em you can get it for sa $1500 from someone else on line and see what they say. Iscar is willing to deal!