Messages

71

Show"N"Tell ( Your Machines) / Re: Zero gravity Z

« on: November 30, 2013, 06:34:45 PM »

Not a particularly safe system if Z drops at all. How is it moved and held in normal use?

You may want to set the air pressure a bit high so that in the event of estop or losing the axis for any reason it rises out and clears the cut. Just my thoughts

72

General Mach Discussion / Re: Gcode help need?

« on: June 03, 2012, 10:21:05 PM »

Hi, this will depend on how your machine is wired up.
I'm thinking you could use the spindle and flood coolant outputs to control the valves. Your Gcode will depend on what positions and rates you want to use but I have an outline here if it is useful. I think you can get the job done with just conventional coding.

If you only use valve 1 for tool changes, why not just use a switch? Hardware solutions are robust, cheap and easy to fit.

Usual caveats apply: ymmv.

1- go to tool position - simple G0 commands
2- activate valve 1 to lock tool( stay locked till need change tool) use M8 command, usually flood coolant (or hardware switch)

Lines 3-10 need to go in a subroutine. Line 3a goes here: command M98 P1 L1000 (repeat subroutine 1 a thousand times)

M30 (stops and rewinds when the 1000 cycles are complete)
% (ensures the program rolls over the M30 correctly)


Subroutine here:

o1 (marks the start of the subroutine)
3- go to waiting position (stay till input signal come on line 4) G0 commands and M1 optional stop
4- input signal to enable job start - Click cycle start
5- go to circle start position - G0 commands to position
6- lower Z to position - G0 again
7- activate valve 2 to dispense glue - Use M3 (spindle forward)
8- start circle job - G02 OR G03 depending on direction. you can't have spindle commands in the middle of a move. But you can program delays for spindle on/off which may be useful as the glue gets going.
9- deactivate valve 2 at the circle end - Use M5 (spindle off)
10- go to waiting position on line 3
M99 (end of subroutine)

You will need to do some of the programming - Be careful and see how you get on.

73

General Mach Discussion / Re: weird parallel port issue

« on: June 03, 2012, 09:57:34 PM »

the add-on card can have a port address forced by moving it to a different slot on the board. Or remove it, run the computer, then refit it.

74

Tangent Corner / World's finest work holding system

« on: May 30, 2012, 07:52:03 PM »

At first I was like   
But then I was like

http://www.ebay.co.uk/itm/Robust-Clamp-Fixture-for-Milling-or-CNC-machines-Secure-items-up-to-45mm-deep-/300714176245

I bet this would be just fine when I clamp down a chunk of 40mm square section steel and drive an 18mm slot drill into it at 1000rpm. Obviously "robust" has changed it's meaning some time this week.

75

General Mach Discussion / Re: calling subroutines - (corrected post)

« on: May 30, 2012, 07:33:18 PM »

I frequently use this. Ie, use parametric values to define Z movement during a circular cut, and decrease that value every time the subroutine is called. Result: helical paths for boring, thread milling etc. Parametrics can save you a lot of time and coding.

Remember that a parameter will persist between cycles ... Make sure your program resets the parameters to a safe starting point before they are called for the first time in the movement phases.

76

General Mach Discussion / Re: Kasuga NC mill to CNC ?'s

« on: May 25, 2012, 08:58:42 AM »

Either way, this should be a be a very capable machine when it's sorted out. Do keep us informed

77

General Mach Discussion / Re: Auto Open Program

« on: May 25, 2012, 08:52:34 AM »

Nice, didn't realise this was possible.

I can get my operator starting runs without me now

78

General Mach Discussion / Re: Charge Pump & Mach 3

« on: May 23, 2012, 06:38:59 PM »

You can use an earphone to detect the 12.5khz signal but detecting dropouts or intermittent errors is out.
If it fails for some reason such as a software bugger-up, will it stop altogether or recover itself?

79

General Mach Discussion / Re: Can you help me make 2 identical components in one sheet?

« on: May 17, 2012, 08:44:38 PM »

Why would you bother? Write the cutting part as a subroutine, use two fixtures, cut one part then change fixtures and cut again. Five minute job to code that.

80

Show"N"Tell ( What you have made with your CNC machine.) / Re: Using Biodiesel as a machining fliud - Video

« on: May 07, 2012, 10:24:20 AM »

if it is vapourising and making "smoke" then it will be at or above its flashpoint. If any portion of the work sparks or becomes incandescent there is a high risk of a flashover.

You can get vegetable based water soluble coolant - Ometa make it in various flavours.

As an aside, i used to run my old diesel Escort on waste vegetable oil, it smelled of kebabs and nasty meats but it worked surprisingly well. the cost of fresh veg oil and indeed used veg oil in the UK has murdered any chance of saving money by making biodiesel but WVO can still be had for running as a straight fuel.