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Messages - MN300

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231
General Mach Discussion / Re: Mach3: Expose APIs from Mach4.Document
« on: April 09, 2019, 01:53:34 PM »
The API list should be in Mach4Hobby/Docs/Mach4CoreAPI.chm on your hard drive.

232
I don't think the following is involved in your main problem but it should be of interest.

From page 18 of the UC400ETH manual,
Quote
Ethernet communication is isolated and power is not transmitted on the network on the
ethernet cable and therefor the UC400ETH board needs an external 12 to 24Volts DC
powersupply to be connected to the plug type green 2 pole power terminal on the side of the
board.
I am assuming you have the LPT-CNC-H plugged into the UC400ETH.
This would seem to say that the opto-isolator board is redundant unless you are isolating the 2 UC400ETH ports from each other.

Also the schematic of the LPT-CNC-H opto board show the earth and ground, and the +5V and VDD5V are jumpered together by zero ohm resistors R30 and R31.
Unless those resistors are removed and two separate powers used, the board is just a buffer.

The power-in terminal called 9V to 12V on some documentation and +24 on the schematic connects to a voltage regulator that provides 5V to the PC side of the circuit. The earth terminal seems to be associated with that supply input, you could verify this by using an ohmmeter to show a connection from the earth terminal to an earth pin on the DB25 connector.

The IO to the machine is powered by the VDD5V terminal and probably the GND terminal. There is no regulator on this side so you would need to connect to a 5 volt supply.

I think you could remove the opto board and run successfully. If you want isolation between the stepper drives and the rest of the IO then you would have to take the steps mentioned above.


233
Very nice construction, congratulations on a job well done.
However I do see one problem. There are 3 power supplies with fans in the bottom area. I hope you have a plan for filtering the sawdust out of their cooling air.

234
xx.x shows where you enter the distance you want to the tool to travel before the probe command.
If it's 80mm from the longest tool to the pad after you set Z to zero and you want a safety margin of 2.5mm you would replace the x.xx with 77.5

mc.mcCntlGcodeExecuteWait(inst, " G91 Z-77.5")

235
Mach4 General Discussion / Re: Auto tool zero...manual tool change
« on: April 04, 2019, 05:48:45 AM »
I have been thinking about safety. The script supplied by Bryanna is slow but safe. The auto script lines move the Z axis up clear the tallest workpiece. In most cases there will then be a lot of clearance to be traveled while probing.

The DazTheGas script is faster because it estimates the extra clearance and travels it at high speed, but it could crash the tool into the touch pad if the tool table length entry is too short.

A compromise would be to start the probing by assuming the longest tool length and making a rapid move to put the tip of that tool some small safety margin away from the pad. Then do the slow probing move to the pad. Shorter tools still will have some extra distance to travel.
The distance to travel at high speed could be calculated by mounting the longest tool and setting Z to 0. The existing script sets Z to 0 before showing the message  'Now in Tool Change Position. Hit Cycle Start!'
Measure the distance to the touch pad and then subtract the desired safety margin.

Add the new line between existing lines as shown below.
        mc.mcCntlSetLastError(inst, "Probing in Progress!")
        mc.mcCntlGcodeExecuteWait(inst, " G91 Z-xx.x") -- xx.x = distance from the pad to the longest tool minus a safety margin
        mc.mcCntlGcodeExecuteWait(inst, " G91 G31 Z-5. F5.")--probe the new tool

236
There are 4 parts to the DazTheGas videos. He show hows each function works as he builds up the script. It's also a good education on how to do Lua script. If it's more than you want to do right now I'll look into what to borrow.

237
The DazTheGas script uses the tool length from the tool table to pre-position the tool for faster probing. You could borrow from that part of his code to speed things up. His method determines the difference between the next and current tool and adjusts the Z accordingly. The one from Bryanna assumes you started with the first tool zeroed to your touch plate and does the same with the next tools. It shouldn't be to hard to take the best of both.

238
DazTheGas has also published a tool change script.
Video         https://www.youtube.com/watch?v=m1eMEec0N-E
Script text  http://www.machsupport.com/forum/index.php?topic=31032.0;wap2

A difference is that DazTheGas uses the tool length stored in mc.MTOOL_MILL_HEIGHT to pre-position the new tool to minimize probing time.
The Artsoft video stores the Z coordinate from probing in that variable. It's not referenced elsewhere in the script so it's not obvious why.

DazTheGas detects if a zero length is in the tool table with 'if toollen == 0'.
However this can fail because a tiny, but not quite zero, value floating point value is sometimes returned for a zero tool length.
Changing to 'if toollen < 0.01' fixes that problem.

The Tool Change LED flashes when M6 is called but the LED is not addressed in the script. I'm curious about what piece of code does that. Is it accessible and are there other hidden functions?

239
General Mach Discussion / Re: Mirror probing
« on: April 01, 2019, 07:45:33 PM »
I  interpreted Don's comment to mean the diameter is not consistent. If the barrel is not round then my suggestion doesn't apply. The geometry problems involved in converting the measurements still apply.
I'm curious to know how you would generate G code.

240
General Mach Discussion / Re: Mirror probing
« on: April 01, 2019, 07:11:17 PM »
Hi Craig,

I think you may be misunderstanding what I suggested. One line of measurements taken along the X axis would give you the radius of the barrel at many points. To do this you would setup the center line of the rifle to be in line with the X axis.

Regardless of how you get the measurements you would eventually need to know where the center line is, either by measurement or calculation, to make the G code. This is because you need to consider the radius of the probe and the tool and the angle to the center line. If you measure with a thin probe in line with the center line of the barrel the probe radius could be considered to be zero. This allows the use of a simple probe like you have described earlier.

John

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