[djh82uk]

Hiya Guys

I am having trouble finding pcb end mills that work for me, i have tried chip breaker like the ones thinktink sell, and find they are too big, I have tried V shape cutters that leave loads of swarf, and also the 60 degree cutters from mega UK, the Mega Uk ones leave a very very smooth cut, but they always seem to snap.

How can i avoid this, i don't think the machine is missing any steps, tho i am sure my spindle is too slow (4000 rpm).

Any Advice?

What do you use for a swarf free cut?

DJH

[JROM]

What are you trying to cut? Need more info

[pminmo]

4000 rpm is really slow to cut pcb's. Your feed rate would need to be in the 5 in/min or less to get a decent cut. Tiny cutter and low rpm's don't mix well. Maybe some links that will help here: http://www.pminmo.com/wiki/index.php...NC_PCB_Milling

Think N Tinker has some excellent bits. Drewtronics has a very capable bits at a lower price.

[djh82uk]

Thank you, yes I am engraving pcb's

I kinda figured the RPM thing, just wanted confirmation, perhaps i should take off the big motor and fit a kress.

I just cannot find decent RPM AC Motors that run on 220V and have a 10mm shaft


DJH

[scavenger]

perhaps i should take off the big motor and fit a kress.
I just cannot find decent RPM AC Motors that run on 220V and have a 10mm shaft
DJH

A free source of reasonable speed (10K) AC 220/240 motors is a an unwanted washing machine. On some models with a fast spin they use a multi speed reversible motor for both wash and spin which is geared down about 10-1 to achieve good low speed torque for the wash cycle and can have 10,000rpm top speed for the 1000rpm spin. The motor I recently liberated from an old machine has a belt pulley which will easily drive a separate high speed spindle 1-1 or higher to give you 20K +. Or it might be possible to remove the pulley and make some sort of 10mm adaptor if you cannot accommodate or don't want a separate spindle, although I think you really need as much rpm as possible for PCB routing (not speaking from experience here yet... PCB milling is on my todo list! ).

As these motors have multiple connections (5 on my motor) it helps if you can grab the controller board and wiring harness too with a view to simplifying driving the motor. These are fairly chunky heavy motors to move around and they have more power than you need for routing PCB's but as you already have a large motor installed may be worth considering (if you haven't already)?

Phil

[Oldmanandhistoy]

I kinda figured the RPM thing, just wanted confirmation, perhaps i should take off the big motor and fit a kress.

I just cannot find decent RPM AC Motors that run on 220V and have a 10mm shaft

Are you thinking of running the original spindle at 10 000 rpm +? If so I would find out if the bearings are up to those kinds of speeds first.

The Kress spindle would be a better choice imho.

John

[project5k]

i just picked up an air spindle from harbor freight that spins something in the neighborhood of 56k rpm for $10(they were on sale, normally $30. they are air hogs but just might fit the bill on this one...
i think they call it a mini air die grinder.

[djh82uk]

Thanks guys

The only washing machine motors i could find were between 1000 and 1400 rpm, which is kinda the same as my motor.

The spindle is the ER-16 upgrade which is rated at around 10k rpm, so a 3000rpm motor would so the trick.

I am upgrading to the kress anyway, but I am waiting for L.S Caine to finish his dovetail mounts for the Taig before i buy it all.

What sort of compressor do you use on the air driven ones?

Thanks

DJH

[dcorbett]

What kind of end mill are you using? Fluted, carbide, etc.
Also, how deep are you trying to mill/engrave? single pass?
There are several tool companies specializing in that can supply the tool for your need based on the machine you are using (try Kyocera).
I can tell you that air spindles (usually 56k min., though 200k are common for small holes) are used almost exclusively in PCB drilling/routing.

[dcorbett]

What kind of end mill are you using? Fluted, carbide, etc.
Also, how deep are you trying to mill/engrave? single pass?
There are several tool companies specializing in that can supply the tool for your need based on the machine you are using (try Kyocera).
I can tell you that air spindles (usually 56k min., though 200k are common for small holes) are used almost exclusively in PCB drilling/routing.

[project5k]

the air spindle that i got sais that it uses around 2cfm @ 90psi and runs at 56k rpm. I'm using an industrial 80gal 12hp 2 stage compressor that has a 170psi turn on and 185psi turn off pressure switch. i just feed the spindle with a full pressure hose from the tank to the mill, and there i have a regulator and the spindle plugs into that..the spindle even came with an auto oiler, which is inline between the regulator and the spindle. i dont have a way to measure how much air i'm really using, but i know that when its running, it causes my compressor to cycle regularly. I'm seriously considering getting a second compressor or perhaps just another tank to reduce the # of times the compressor cycles... (i use the compressor for all of my shop needs, media blast chamber, powder coating guns, impact wrenches, plasma torch, etc.)

[Bubba]

I have (had) one of those spindles that I modified to work on my mill/drill. Worked great for a couple of months until I apparently got a piece of trash from the air line in the vanes.
I would recommend:
1. a regulator near the line to the spindle as this will also conserve air and reduce cycle times on the compressor.
2. Install a filter close to the spindle air line to minimize the possibility of what I had happen.
Most of the stuff you have indicated using will be more tolerant of small particles in the air than these pencil grinders.