Fingers crossed it'll cut ally

[Jonathan]

...signal of interest is a PWM waveform, the voltmeter will be showing the average of the highs & lows of the signal...If the ESC wants a true analogue voltage input, a small value capacitor (1μF) between signal pin and ground will help

The ESCs we're using require a PMW signal with 20ms period. The range of the duty cycle used by the ESC is only roughly 5% to 10% - which means you don't get a very high resolution with mach3 connecting it directly. Only a handful of speeds in fact. Still probably sufficient in reality, but not ideal - hence why I'm still interested in investigating the servo tester adaptation. I agree a capacitor will certainly be required here, since the PWM signal is being fed into an ADC.

Just out of interest I connected my model car transmitter up to the parallel port yesterday in a similar fashion - it works fine which implies the servo tester conversion should also. I'm trying to control the parallel port in C now, so I can get the car driving itself around...

[blackburn mark]

there are two things im dreading on this build....
hole sawing 25mm for the Y screw and drilling and tapping the bed plate

up to now iv used my diy spindle to do all my drilling and i was gagging to to be able to say id done the whole build with it and a tiny cowells 90 lathe:dance: however.... i think i may need to stop f***ing around and borrow a heafty drill

there is probably loads more stuff i should be flapping about but at this point i cant see past the drilling and tapping..... more drilling and tapping.... and!!!..... b***cks!!


for now i decided not to support the floating bearing on the Z screw, the housing that came with it seem such a waste of valuable space... ill make a low profile one if i have trouble with it whipping around

[Jonathan]

Servo tester arrived :)
I dismantled it straight away and sadly the PCB is different. I guess it's not surprising, hobbyking.com are allways changing their inventory.
We will still be able to do the same modification to both of them though - the voltages are similar.

I'll let you know as soon as I've done it - got a fair bit of work to do at the moment :(

[blackburn mark]

dont be rushing it, i dont think either of us are in dire need of mach spindle control at the mo

have a crack at it in your own time jonathan, dont feel any pressure from me... im at least slack hand full of skinned knuckles away from fitting steppers never mind anything else

good luck when you do get to it :)

[Jonathan]

Ok then, it's just you sent it special delivery so I thought you were in a hurry!

'im at least slack hand full of skinned knuckles away'
You do think up some good expressions!

I'm going home for the weekend and I intend to get my router to the point of cutting stuff. I intended that last time I went home, but as is always the case with these things they take longer than expected and I ran out of metal.

Anyway, where did you get the long 1/8" cutter from for your little brushless motor? I'm warming to that idea for making PCBs...could use a really high feedrate with the cutter going at 60krpm (or more..) with one of the in-runner motors I've got.

Can't you get the existing spindle to drill nice grid of holes in the bed plate when it's all set up? That's what I'm intending to do.

[blackburn mark]

could use a really high feedrate with the cutter going at 60krpm

look on ebay for ceramic dental drill bearings(china), if i remember correctly about £25 for 5... iv not commited to those yet, my high speed spindle is way down my list at the mo but im looking forward to having a crack at making it work

Can't you get the existing spindle to drill nice grid of holes in the bed plate when it's all set up? That's what I'm intending to do.

im considering it........ im sh*t scared ill press go and end up with a road runner carved into my nice plate lol

ill need to stick a biro in my spindle and work on my confidence :)

[blackburn mark]

im starting to wonder if i know what im doing with this thing

iv got a 12v 30A power supply in there for the spindle (couldnt fit the 45A in)
a 24v 15A for the steppers and a 5 axis china special :)
an old pentum4 system shoe horned in with a low profile cooler and a right angle riser for the graphics card, looks like it might get a bit warm in there and im right glad iv used sheilded cable for home switches and steppers

i used to throw this motherboard out of my way a couple of months ago :whistling: iv been holding it with two hands and tiptoing back n forth with it like its a new born baby.... i did test it before i comssioned it for a new life, in fact all the gear has been tested but im still going to squint my eyes first time i flick the on switch

can anyone tell me if ill be ok leap frogging the mains on all three power supplies and using a 220v 16A switch to turn the whole thing off (after the pc side of things has shut down of course)

[blackburn mark]

i got one from germany (ebay) "Gravierstichel 3,175x115mm 60°x0,32mm VHM f. Pantograph"

then i found some cheeper ones in france (ebay) "1 fraise à graver(long taille) 3,175*60°0,25mm V-type"

iv been looking into sharpening them whilst still in the motor... it would need a jig making.... should get some good use out of them if they can be sharpend without to much hassle

the worry for me are the bearings on the nose, im convinced they will need cooling unless you splash out on ceramic ones and at those prices id still want to cool them, at 48000rpm they were very hot in under a minute, it might stay cool if you use one bearing but i think the runout will suffer, it needs some research

the other spindles are fine, i managed to hole-saw 25mm for my Y screw with the large one... had to take my time though, it keept tripping out my power supply

[ptjw7uk]

At full rating and 100% efficient thats only 1 kw so at 50% efficiency 2KW at max, I expect most times it will draw a lot less.
Peter

[blackburn mark]

2KW at max, I expect most times it will draw a lot less.
Peter

cheers man, wiring isn't my strong point