Messages

51

General Mach Discussion / Re: Non-continuous motion

« on: November 16, 2017, 08:43:27 AM »

Sounds like it. Change this in Config>General config or just insert a G64 command in the start of your program.

52

General Mach Discussion / Re: Alright fellow campers...a frankenstein moment!!

« on: November 16, 2017, 04:46:51 AM »

^ Put each pair of wires in a shielded cable, so if you have a switch or a DC motor, use 2 core shielded. A block of 2 switches can use 4 core shiielded. A 3 phase motor uses 3 core shielded and so on. The idea is for the current on one conductor to cancel out the magnetic field produced by the other while the shield reduces the effect of external influences. Equally, external RF and noise will affect both conductors equally and oppositely, reducing its harmful effects.  Just twisting pairs together goes a long way towards this, shielding increases your margins even further.
This goes both ways - shielded/twisted wires will radiate less trash signal than loose single cores. 

53

General Mach Discussion / Re: General question about small CNC mills

« on: November 15, 2017, 11:22:26 AM »

Well, one possibility in the absence of a home switch is to bolt a block on one corner of the table and square it up with the cutter, then to get your "home" positions in X and Y just touch off it with a wiggler and set the zeroes by hand.
It's a nice little mill though, you should be able to make some tidy work with that.

54

General Mach Discussion / Re: General question about small CNC mills

« on: November 14, 2017, 01:25:40 PM »

^ There's your problem, it's a little outside its comfort zone.

To be honest when I saw the drawing I thought it was an excellent part for a profile cutter. I get quite complex parts WJ or laser cut all the time and just do finish machining for bearing fits and precision locations. It's so much easier. I'd go for laser cut A2 stainless and practice on the mill with some nice 6082 aluminium, it's so much more satisfying and your tools will last way longer. Happy learning

55

General Mach Discussion / Re: This is just plain... WRONG

« on: November 14, 2017, 01:18:58 PM »

They still hang you for plagiarism and it's getting easier to spot electronically. Fear not. There's software that will do it automatically.

Let's see, a superman logo in G-code. That's what, a day's work doing it by hand? Let him send his PMs to me, I'll send him a quote and lead time, that should end the discussion. No I and J words eh, that could get messy.

56

General Mach Discussion / Re: Alright fellow campers...a frankenstein moment!!

« on: November 14, 2017, 01:09:40 PM »

One thing to consider is fitting some resistors across the input pins of the drive board if this isn't already done. This will drop the input impedance of the board and help dissipate any spurious signals while allowing the more powerful signals from the PC to get through uninterrupted. The resistor value depends how much current you can get through from the paralell port or controller board. Equally you can fit pullup resistors to pins that are grounded to activate, reducing their susceptibility to spikes and noise and of course coolant leakage. Gotta keep them angry pixies in check.  

Edit: If all this is in a wooden box you may want to consider a metal one, this will help a lot.

Be scrupulous when grounding things, bring everything back to a single point, no loops.

57

General Mach Discussion / Re: Torch relay turns on and stays on when I start mach3.

« on: November 03, 2017, 11:57:55 AM »

Re: Emergency stops: If it helps, I have a mains contactor set up which is opened by the NC contacts on the estop button. The driver watchdog circuit is in series with the big red mushroom and the spindle overload, and the extra contacts in the estop button also signal to mach3 that an Estop has been initiated. Thus, if the button is punched, Mach gets signalled and the mains circuits drop out. If Mach *********s itself, the driver watchdog shuts it down; mains off as before.
The mains contactor shuts off power to the spindle and the stepper drivers, so everything stops instantly in the event of any sort of emergency.

58

Tangent Corner / Re: Whoops !

« on: January 18, 2017, 01:42:48 PM »

It seems it's harder than it looks to derail a train.

https://youtu.be/D-8gV4DJZUw

59

General Mach Discussion / Re: Why Not The Same

« on: July 21, 2016, 09:50:04 AM »

^ I was thinking that. If you set and modify parameters during a program they will persist to the next run.
You need to explicitly set parameters to their desired starting point at the beginning of each cycle.
Also, offsets and fixture positions. Cancel all these in the first few lines, then set the ones you want. Cancel them again at the end of the run as a matter of good practice.

60

General Mach Discussion / Re: Using Android device as a 'pendant' for Mach3 (Working)

« on: July 21, 2016, 08:17:54 AM »

Very nice! helpful also that many newer Android devices are waterproof. I'm waiting patiently for one that can resist having a copper mallet dropped on it, but maybe I ask too much.