Re: [CAD_CAM_EDM_DRO] Dumb question on the drilling of holes

Marv,

I had a similar problem over the weekend. The remedy was to significantly
decrease feed and increase RPM when plunging. This gave more time and force
to throw the chips away from the cut. This was with a 4 flute center
cutting end mill. Obviously a 2 flute would have worked better for plunging
offering more room for chip evacuation, but I didn't.t have one at hand.
Also, a bit of cutting fluid at the plunge location helps to keep the chips
from sticking and can delay the packing problem.

Regards,

Howard Bailey

----- Original Message -----
From: "Marv Frankel" <dcdziner@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Tuesday, October 22, 2002 11:15 PM
Subject: Re: [CAD_CAM_EDM_DRO] Dumb question on the drilling of holes


> Jon,
> Thanks for your input. My spindle is tight, so are the bearings, and
> the 1/4" end mill is held in a pretty new collet. When I tried plunging
the
> end mill through an 1/8" wall aluminum extrusion, I could feel resistance
on
> the quill. Then I realized that, as the cut started, the chips built up
> between the end flutes, and caused some galling and hole distortion, since
> the chips, unlike a fluted drill which gets rid of it's own chips, had no
> place to go. I'll try to do some testing, and document my findings, to
> arrive at the best solution.
>
> Marv Frankel
> Los Angeles
>
> ----- Original Message -----
> From: "Jon Elson" <elson@...>
> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> Sent: Tuesday, October 22, 2002 10:25 PM
> Subject: Re: [CAD_CAM_EDM_DRO] Dumb question on the drilling of holes
>
>
> >
> >
> > Marv Frankel wrote:
> >
> > >Tim,
> > > I'm pretty familiar with reaming holes for proper fit, but the
> holes
> > >I'm talking about, are sometimes so misshapen, they almost look
> triangular.
> > >They're 1/4" holes, and I've even tried cutting them through with an
end
> > >mill, and that wasn't great either.
> > >
> > >
> > A properly sharpened drill bit will not do this except on very thin
> > sheet. A dull drill bit can
> > sure do things like this. End mills generally make VERY round and
> > smooth holes, even when
> > plunged. If you are trying to plunge an HSS end mill into tool steel,
> > however, that could cause
> > deflection. Are you sure your spindle is solid? A bad spindle bearing
> > or loose quill could
> > do this. I hope you aren't holding a 1/4" end mill in a Jacob's chuck.
> > That really won't work,
> > and isn't safe, either!
> >
> > Jon
> >
> >
> > Addresses:
> > FAQ: http://www.ktmarketing.com/faq.html
> > FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> > Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
> >
> > Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> > Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> > List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> > Moderator: jmelson@... timg@... [Moderator]
> > URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> >
> > OFF Topic POSTS: General Machining
> > If you wish to post on unlimited OT subjects goto:
> aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it
if
> you have trouble.
> > http://www.metalworking.com/news_servers.html
> >
> > http://groups.yahoo.com/group/jobshophomeshop I consider this to be a
> sister site to the CCED group, as many of the same members are there, for
OT
> subjects, that are not allowed on the CCED list.
> >
> > NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
> DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> > bill
> > List Mom
> > List Owner
> >
> >
> >
> > Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> >
> >
>
>
> Addresses:
> FAQ: http://www.ktmarketing.com/faq.html
> FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
> Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com
>
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
>
> OFF Topic POSTS: General Machining
> If you wish to post on unlimited OT subjects goto:
aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if
you have trouble.
> http://www.metalworking.com/news_servers.html
>
> http://groups.yahoo.com/group/jobshophomeshop I consider this to be a
sister site to the CCED group, as many of the same members are there, for OT
subjects, that are not allowed on the CCED list.
>
> NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM.
DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
> bill
> List Mom
> List Owner
>
>
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>