Fingers crossed it'll cut ally

[Jonathan]

I don't think mach3 will interface with the thing you've bought, not without a lot of effort. I might be wrong though. You could just run it in the background and adjust it manually on the computer anyway?

Servo tester, still trying to trace the PCB. I think it'll work with the parallel port...

[Jonathan]

Hmm, before you do that measure the voltage between the pin of R32 that's not connected to the pot and ground whilst twiddling the potentiometer and see what the range is...


Ooh, is that a programming connector I spy on the PCB! Could be handy for something.

[Jonathan]

Disregard steps 1 and 2, that's not safe to do if the parallel port outputs over 5v. Measure the max voltage as I said in the previous post then just desolder the switch and solder the signal output wire from the parallel port to the PCB pin of the switch which was connected to R31. Then adjust the pot untill it gives the same reading for voltage with mach3 at 100% spindle speed as it did with the pot at 100%. Good idea to remove R32 whilst you adjust the voltage, then put it back when you're sure it's right - that guarantees not to break anything. Quite tricky soldering though!

[blackburn mark]

hahaha!! yove been busy jonathan... hope you werent late up this morning

iv still got loads of drilling to do so i cant afford to pull my servo tester apart at the mo but iv orderd one exsactly the same for you to experiment with (if you agree) , PM me your address and ill send it over to you once it turns up here.

if you manage to solve the issue then let me know how you did it and we'll call it even

ps: dont worry about it if its more than you can be botherd with :)

[Jonathan]

iv orderd one exsactly the same for you to experiment with (if you agree) , PM me your address and ill send it over to you once it turns up here.

if you manage to solve the issue then let me know how you did it and we'll call it even

That sounds like a good plan :) I've sent the PM. I'll work it all out properly and take some photos of what I do when I get it.

If that voltage is 3v max then we can use the existing potentiometer to scale the voltage from your parallel port to be the same.

[blackburn mark]

just for a refrence iv mesured the voltage between both sides of R32 with the resistor still in place

0.24v both sides 0 speed
3v both sides flat out

thats with 5.57v coming in from the ESC battery eliminator

[Jonathan]

jonathan double check youve sent him the pm as ive some how ended up with it,your address etc..

Sorry about that! I've sent it to the right person now

[blackburn mark]

ok jonathan the pm got to me :) ill get it off to you as soon as it turns up to mine and we can all look forward to you smoking the thing

no pressure :lol:

[templecorran]

Excuse me,
The PC parallel port outputs a binary signal, meaning it has two levels, off / on; or 0 / 1. The 0 is represented by a voltage less than 0.8v The 1 represented by a voltage greater than 2.4v.
Because the signal of interest is a PWM waveform, the voltmeter will be showing the average of the highs & lows of the signal. PWM means Pulse Width Modulation. By varying the proportion of ON time to OFF time in a given interval (20ms) the resulting effect is an analogue voltage. If the ESC wants a true analogue voltage input, a small value capacitor (1μF) between signal pin and ground will help.
If you have access to an oscilloscope this would all be really clear.
Thank you class for being attentive. Now, run along and play with your nice machines!

Oh! I just answered my own problem! Use the oscilloscope to monitor the output of the PWM line (from Mach3), and see how similar it is to the DCBLM drive module requirement!!

[blackburn mark]

Oh! I just answered my own problem! Use the oscilloscope to monitor the output of the PWM line (from Mach3), and see how similar it is to the DCBLM drive module requirement!!

errrr.... let us know if you make any sense of the problem or if you use the capacitor, im asuming you already have an ESC and servo tester ?