Messages

1

Mach4 General Discussion / Re: Help with some basic controls for homing

« on: March 28, 2018, 05:15:25 PM »

I'll try moving to deliberately moving to machine coordinates 0,0,0 tonight and see what happens. 

I just realized what will happen, nothing. My machine 0,0,0 is slightly off of the edges of the table. I have the homing settings adjusted to put the center of the spindle directly over the corner of the table surface. The coordinates where the limit switches activate are all negative. So in effect I have set my home position offset from the configured homing switches.

-Freeman

2

Mach4 General Discussion / Re: Help with some basic controls for homing

« on: March 28, 2018, 05:08:26 PM »

Now you have the problem you describe....go to machine zero and your limit switches activate...as they are supposed to.

Interesting, I don't ever remember trying to go to machine coordinates 0,0,0 other than when homing in the four years of owning the machine. On a 48"x48" (closer to 48"x46") table I typically drop my stock in the middle somewhere convenient for work holding and probe for work offsets.  I'll try moving to deliberately  to machine coordinates 0,0,0 tonight and see what happens. 

Your point on the number of I/O on the ESS is well taken. I just haven't bothered using more than I needed. It's even more pronounced when I have free I/O on the normal two ports that the ESS interfaces with the PMDX-126 with and there is a completely unused third port on the ESS I haven't touched yet.

-Freeman

3

Mach4 General Discussion / Re: Help with some basic controls for homing

« on: March 28, 2018, 03:52:21 PM »

Hi,
is there any reason not to have separate home and limit switches?. Combining them used to be important years ago
when no one had many spare inputs but with an ESS you have plenty. Why not take advantage of it and use them.

Failing that you'll have to use some sort of limit override.

Craig

Originally I had separate homing and limit switches. Still do, I have disabled the homing switches since I decided I wanted to home my system from the front left corner (where my limit switches are) instead of the middle of the table. My choice was really driven by how I used my machine. I'll probably pull the proximity switches and use them on my 9x20 lathe CNC conversion.

In my situation I don't see a need to have separate switches for limits and homing. Your mileage may vary.  I would rather use the I/O pins for other uses -- activating the dust system, multiple probes (touch off and laser tool measuring), etc.

-Freeman
 

4

Mach4 General Discussion / Re: Help with some basic controls for homing

« on: March 28, 2018, 03:37:04 PM »

I'm using the ESS on my CRP-4848 router table with the limit switches for each axis wired in serial (Normally Closed) and acting as homing switches. Back when the Mach4 was released I had problems similar to your own. I recently revisited using Mach4 with the ESS and the homing problem is gone.

I'm at work, so without looking at the actual machine I suspect you may need to run the current ESS plugin. Use the ESS settings for homing and set a back off value. If you are running a slaved axis with separate homing switches for each motor, you can set that in the configuration and the ESS is now smart enough to home both motors on the axis independently. It's very cool to watch. I suspect you need to have your homing/limit switches close to the same position on the axis. I used a gauge block to set the distance between the bumper and the limit switch body on my machine. Slaved axis also support providing an additional offset to correct for any angle in the axis, which can be helpful if your limit switches are fixed but slightly off from each other.

-Freeman

5

Mach4 General Discussion / Laser tool measuring

« on: March 19, 2018, 09:24:38 PM »

I got this crazy idea the other day to try building a DIY laser tool measuring system. A quick search of the Internet showed that commercial solutions were in the thousands of dollars, and only one guy on Youtube has a working DIY example. I found the laser sensor he is using on Ebay for $75.  Now it's in my shop and I have to make good on the attempt. Anyone else tried doing this? Anyone got any advice?

Measuring tool length should be easy, use the same procedure as with a touch plate. The diameter may be a bit more difficult. Cutters are not always symmetrical within the volume of their rotation. I figure I would need to spin the tool to get an accurate measurement. This would avoid with asymmetry  and would only require measuring laterally from one direction.

Edit: I forgot to mention that it has a 80mm throat opening and is repeatable within 5μm. It takes 10v to 30v DC and acts a PNP switch.


-Freeman

6

Mach4 General Discussion / Re: Stop on probe signal for G0/G1 moves to protect probes...

« on: March 19, 2018, 07:26:38 PM »

As my homemade probe can accept an overtravel of 3mm in Z and 6mm in X and Y, I have a safety factor of about 3:1, and conclude that this is an entirely viable method of protection which I shall continue to use.

Allan

Most excellent, Allan.

7

Mach4 General Discussion / Re: What is the "Instance" and "Scale Method" properties used for on UI controls?

« on: March 18, 2018, 05:59:21 PM »

The Scale Method is in any component that has an image associated with it. Steve (Smurf) said it was used to select a method of scaling images. Some methods work better in different situations. It is used to help deal with the fact that screen sets are built for one resolution but get used in others. Scaling is particularly a problem when scaling up, you have to add data to the image. Scaling down usually easier.

I still haven't heard what "Instance" is used for.

-Freeman

8

Mach4 General Discussion / Any plans to move up to a newer release of Lua than 5.2?

« on: March 18, 2018, 12:37:21 AM »

I need math.type() which was introduced in Lua 5.3. Any plans to update Lua any time soon?

-Freeman

9

Mach4 General Discussion / Re: Is there a bug with mc.mcProfileGetDouble()?

« on: March 18, 2018, 12:25:10 AM »

Is 0 not a value? The way I read it is that if the value does not exist ie null then it would return your default.

Yes in this case 0 is a value, but not the one the API docs suggest should be returned. If you supply 0.5 as the default value, and the Section/Key doesn't exist in the profile, it is suppose to return 0.5 not 0. I deleted the section using mcProfileDeleteSection() to make sure it didn't exist.

10

Mach4 General Discussion / Is there a bug with mc.mcProfileGetDouble()?

« on: March 17, 2018, 10:20:09 PM »

What am I missing here? I'm trying to use mc.mcProfileGetDouble() and the default value is a fractional value. I get back a numeric value of zero. The API docs claim it should return the existing value or the default value if the property doesn't exist.

Code: [Select]

hgProbing.params = {
   ...
   ['StepOffDistance'] = math.abs (mc.mcProfileGetDouble (inst, 'hgProbing', 'StepOffDistance', 0.5)),
   ...
}

I have to do an explict mcProfileWriteDouble() to get it to work. Now when I do the mcProfileGetDouble () returns the expected value of 0.5.

This looks like a bug with mcProfileGetDouble(). Can anyone confirm?


-Freeman