Fingers crossed it'll cut ally

[blackburn mark]

yo jonathan.... sounds interesting, a bit complex for a simple soul like me id need walking through the whole procedure

have you had any joy with the brake ? i found a vid on youtube where someone had used a mechanical calliper on a disk
Actuated pneumatically,,, id prefer to use a motor and screw with a spring as a buffer

if you have any old slit saws you could use one of these as the disk
i havnt desided whether ill take the simple road and use a rotary table or build a fast mover with a disk brake

[blackburn mark]

though id have a play with my attempt at an engraving spindle
the motor is 4000kv so in theory it should run at 48000rpm at 12v
i managed to find an extra long engraving bit 115mm and mounted it straight through the motor and put three plain ball bearings at the nose




i ran it flat out for a couple of min's and both the motor and the bearing housing got pretty hot pretty quick
im not overly worried about the motor getting hot its to be exspected IMO but i think the bearings on the nose are soon going to be way above 110 degrees..... i think ill test it to destruction before i look at water cooling i just cant bring myself to do it just yet, ill admire its simplicity and form for a while longer and have a think about it :)

another problem i might have... when i run it up i can hear a bearing skidding now and again, im pretty sure its one of the motor bearings (only paid £7.50 for it new) so that will need upgraded bearings pretty soon

has anybody had a go at sharpening an engraving bit ?????? this one cost me more than the motor

[blackburn mark]

Why is it that no matter how careful i am measuring and marking out i allways end up having to oval a slack hand full of holes, each time i start a new project i think " this is it now, im on it, iv learned by my mistakes and THIS time its all gona work like a bobby dazzler"...........Bollocks!!! there must be a tare in the space time continuum cause im buggard if its me! :)

anyway, its starting to look like my drawing now, i drilled all the holes using my larger diy spindle and my Y axis up-ended as a sort of pillar drill (didnt want to be swinging around with a hand held)

im pretty sure ill have to oval a couple more holes when it comes to trueing it up but iv got a sh*t load to do before its finished and i dont want to think about it :)

(anyone thinking of useing helli mode on a RC speed controller, dont bother, it dosnt seem to hold revs any better than standard and it has a slow wind up to speed so every time you jam your drill you have to pause for it to catch up)

[Jonathan]

(anyone thinking of useing helli mode on a RC speed controller, dont bother, it dosnt seem to hold revs any better than standard and it has a slow wind up to speed so every time you jam your drill you have to pause for it to catch up)

Slow wind up to speed - isn't that the govenor setting, if so surely it can be switched off?
I think the only way to hold revs if to have some sort of direct feedback (optical or something) of the motor RPM, and get mach3 to control the RPM as I detailed earlier.

I should really buy the ER25 collet for my massive brushless motor....it's occured to me that I can still get the 100mm one and make it longer. Drill an 8mm hole in one end, and whack a piece of 12mm with one end turned down to 8mm and knurled into the hole. The annoying thing is the motor only does 6000prm, which isn't so good as a router...but nice for machining aluminium.

Oval holes: same here, the worrying thing is I *did* use the CNC mill for the holes! I didn't make them oval though, just drilled the 8mm holes out to 9mm