Milling a slot, with light equipment

Thread view:

Enable EMail Alerts

Start New Thread

Thread rating:

MikeH_QB - 25 Feb 2008 13:16 GMT

Simple query, but interested to hear opinions.
I only have a modest sized bench lathe with vertical table available
for light milling. It works fine within its capabilities.

I'm just nearing the end of building Harold Halls' basic tool grinding
table (as described in his book), and have a couple of 6mm dia slots
to do in 5mm thick steel.

Just wondered if it was a) worthwhile b) quicker c) less wearing on
cutters to:
Chain drill and saw out the bulk first (eg to around 5mm) then mill
with me 6mm cutter, or just to go straight to milling starting with a
5.5 and finishing with a 6 (which is the way I did it for a similar
slot in the main table)

These 2 slots are in fact only for sliding adjustment of the mounts so
are not critical - accuracy wise.

Any useful thoughts greatly appreciated
regards
Mike

Reply to this Message

Dave Baker - 25 Feb 2008 16:08 GMT

> Simple query, but interested to hear opinions.
> I only have a modest sized bench lathe with vertical table available
[quoted text clipped - 13 lines]
> These 2 slots are in fact only for sliding adjustment of the mounts so
> are not critical - accuracy wise.

I'd do it exactly as you describe doing it last time. Tool wear mainly
occurs when you push the tool hard so you aren't going to hurt your milling
cutters if you take it steady. Drilling and sawing and then still having to
mill anyway strikes me as having a dog and still barking yourself.

Signature

Dave Baker
Puma Race Engines

Reply to this Message

MikeH_QB - 26 Feb 2008 09:14 GMT

> > Simple query, but interested to hear opinions.
> > I only have a modest sized bench lathe with vertical table available
[quoted text clipped - 23 lines]
>
> - Show quoted text -

Thanks Dave
I think I have a bit of a mean streak (& not a lot of money) so I tend
to err on the side of - milling cutters are (relatively) expensive,
whereas drills, sawblades & my muscles come cheap(ish).
But you are right, I think I'll just mill it
many thanks
Mike

Reply to this Message

David Littlewood - 28 Feb 2008 16:23 GMT

In article
<1a74907a-bc6c-49e6-9220-bead45cae155@m23g2000hsc.googlegroups.com>,
MikeH_QB <MikeHur_2005@yahoo.co.uk> writes

>Simple query, but interested to hear opinions.
>I only have a modest sized bench lathe with vertical table available
[quoted text clipped - 17 lines]
>regards
>Mike

I agree with Dave, sod the chain drilling. I suspect you are more likely
to damage your cutter by trying to plough through a series of drilled
holes, as it may (depending on how much you can saw out) be experiencing
"breakthrough" conditions at each hole.

BTW, if you wish to cut a slot in one go, do be sure to use a slot drill
rather than an end mill; they are designed for this. An end mill (unless
very much bigger than 6mm) will almost always give a wobble at the end
of the slot, as the forward tooth leaves the work. Your way (5.5mm then
6.0mm) should be fine with an end mill, just twice the work.

David

Signature

David Littlewood

Reply to this Message

Model Forum / General / Models / February 2008

Milling a slot, with light equipment