How much deflection to expect...

**cropwell** · 03-02-2014

I tried various cutters, speeds and feed rates with ali and the best cutters I found were these :- Sorotec - Werkzeuge. Cutter geometry seems to be the crucial factor. Downcut spirals didn't work as the main problems seems to be chip clearance. Rapid and light cuts seem to work better, with a spray of paraffin. I tried 1-cal cooking oil but it just made me want a bacon sandwich

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Cheers,

Rob

**Clive S** · 03-02-2014

Wal Looking like a very nice and cable machine, don't scratch it lol , I remember Dean saying more than once that some of the best machines are achieved by people with daytime jobs with no mechanical back ground because they will listen and learn. Well done. ..Clive

**EddyCurrent** · 03-02-2014

Yes, cutting nicely in the video, sound like you have some bagpipes going

**Wal** · 03-02-2014

Clive, listening and learning is half the story - not only is this site a great resource, but I've said it before and I'll say it again - to have been able to come over to yours and have a look at your build and learn from you was an invaluable privilege - I've no doubt that this project would have taken me considerably longer and been weaker for it had you not spent the time and effort patiently talking me through the stuff I didn't have a clue about. Thanks again!

Wal.

**Jonathan** · 03-02-2014

Originally Posted by Wal

The other day I tried milling these switch mounts out of the ali that Apple use for their Mac Pro towers, which just shredded up like this:

Any recommendations on the grade of 3mm aluminium sheet I should be looking at for this kind of profile cut?

Were you using any coolant? A little spay of anything wet can make all the difference. 6082 is a readily available grade that's easy to cut. Avoid 5xxx series grades.

**Robin Hewitt** · 03-02-2014

It sounds like bagpipes :D

**Wal** · 03-02-2014

Heh, yeah - I guess it is a bit bag-pipey - should've had it sprayed tartan..!

I didn't use coolant on the profile cuts into the sheet, Jonathan. I may give it a go sometime, but to be honest the tearing was brutal from the moment the mill touched the surface, whereas the 6082 billet cut very nicely! I'm trying to get hold of some 6082 sheet (ali warehouse don't carry it) so if there's anywhere you can recommend then do let me know!

Cheers!

Wal.

**Jonathan** · 03-02-2014

Bear in mind coolant doesn't just cool - it lowers the coefficient of friction (i.e. it lubricates) between the tool and the metal. That means less heat is generated to start with...

**Wal** · 03-02-2014

True. Just a thought - I use EXACT cutting paste for drilling and tapping (looks a bit like a giant Pritt Stick) which has a slightly higher viscosity than grease - would a smear of that over the surface to be cut be of any benefit? Or is it going to turn into a grinding paste as soon as the chips starts accumulating..? I guess I should just give it a go!

Wal.

**Lee Roberts** · 03-02-2014

Wal, congrats on the machine !

I would think a grinding paste would be a bad move, what you really want is some of this: Castrol Cooledge Cutting Coolant I use this for drilling/tapping and so on.

.Me