Messages

1801

General Mach Discussion / Re: Physical buttons for plasma

« on: April 26, 2016, 02:22:14 AM »

Looking good.

A downdraught would be best I think - no dross caused by the water hitting the plate, no worries about gases building up, no rust on the machine or plate....

BUT (and thats a big but)

you WILL be standing in a wind-tunnel! I have to have the window or door open for make-up air when cutting, this is great in summer but in winter it brings a new meaning to 'cold workshop' 

There is no smoke at all on my table, even when i cut a 500mm square lump of 12mm plate in the middle of the 1250x1250 bed. The machine is clean -no brown soot anywhere.

1802

General Mach Discussion / Re: Please Help... Homing Switch Problem...

« on: April 24, 2016, 03:38:46 AM »

In ports and pins see if you have all the axis limits and home inputs set up on the same port and pin.

1803

General Mach Discussion / Re: Shielded Cable to Earth Ground?

« on: April 23, 2016, 03:29:08 AM »

Generally you want to connect the shields to the star ground point in the control cabinet - this is the single grounding point for all ground connections.

Only connect the shields at the source end of the cable - the driver end, insulate the the motor end or you risk forming ground loops - circular paths for earth current that can cause a lot of problems.

You were right to not daisy chain the supplies.

1804

General Mach Discussion / Re: Proximity Sensors, do they need to drop to zero volts when triggered ?

« on: April 21, 2016, 02:19:16 AM »

I would opt for a 12v supply - these are NPN so they drop to low level when triggered, the different voltages from sensors to BOB will not matter as only the grounds are tied. They do not need to drop to zero as logic levels for high and low are well defined and are rarely 0v and supply v.

You can do this with 3 sensors for all six positions - limits and homes. Just make the switch move towards two fixed targets - I have this on my mill and it really simplifies wiring etc, also less to go wrong, just think backwards - moving switch, fixed target

1805

General Mach Discussion / Re: Bought license program works fine but cannot unlock demo mode

« on: April 20, 2016, 02:21:58 AM »

Copy the license file into the Mach3 folder, restart Mach and you should be good to go

1806

General Mach Discussion / Re: Z Acceleration

« on: April 20, 2016, 02:20:29 AM »

Ok, i'll wind the acceleration back a bit.

This is how i do my TOM before each pierce...

G91 (switch to incremental mode)
G01 X24.00 Y2.00 F6000 (position probe switch)
G90 (switch to absolute mode)
M1050 (trigger the probe cylinder)
G04 P0.3
G28.1 Z5.000 (probe the surface)
G92 Z#15045 (apply the probe switch offset from settings screen DRO)
M1051 (raise the probe)
G91 (switch to incremental mode)
G01 X-24.00 Y-2.00 F6000 (put the axes back to where we came from)
G90 (switch to absolute mode)
M99
%

It runs as a subroutine. I have a separate probe switch on a little pneumatic cylinder, works well and has practically zero downforce which is great on thin stuff.

1807

General Mach Discussion / Re: G00 my CNC losing steps, Buy jog it moves grate

« on: April 19, 2016, 03:25:14 PM »

Ok, try those figures and see what you get

Also what motors, what supply voltage?

1808

General Mach Discussion / Re: G00 my CNC losing steps, Buy jog it moves grate

« on: April 19, 2016, 03:09:31 PM »

I am guessing this is inches per minute?

So for 200IPM velocity in motor tuning try putting 20 in acceleration and see what happens

Is this a mill? Plasma? Heavy gantry? Light gantry?

1809

General Mach Discussion / Re: G00 my CNC losing steps, Buy jog it moves grate

« on: April 19, 2016, 02:26:56 PM »

But what is high? What is low?

1810

General Mach Discussion / Re: G00 my CNC losing steps, Buy jog it moves grate

« on: April 19, 2016, 01:57:32 PM »

What settings have you currently got?
What size machine is this?
Any pictures?

Motor tuning is pretty simple to get close to good but need some more info i think.