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Ref All Home & Auto Square Not Working
« on: July 09, 2016, 10:43:10 AM »
First time post and fairly new to CNC & Mach3
X & A slaved
"Home slave with master" is unchecked
"Ref All Home" script - RefCombination(9)
No limit switches on Y & Z yet
X & A are reversed so they work correctly, home negative is checked for both
X & A are identical in the motor tuning setup

I installed 2 hall effect proximity sensors on the X & A axis - separate pins on BOB (pin 13 & 12 respectively)
When the magnet approaches the sensors the light on the sensor goes out and the light on M1Home & M4Home activates

Problem is when I "Ref All Home" the gantry moves toward the sensors (negative) as it should
one of the sensors will activate, the other side will stop moving, still not activated
the activated side continues moving negative and racks the gantry

What am I doing wrong?

Thanks,
Joe

Offline ger21

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Re: Ref All Home & Auto Square Not Working
« Reply #1 on: July 09, 2016, 10:18:55 PM »
What version of Mach3?
Parallel port?
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Ref All Home & Auto Square Not Working
« Reply #2 on: July 10, 2016, 06:49:49 AM »
Im having same problem. I have uc-100 to usb. Cant seem to get it to do the "squaring". I have home neg checked and auto zero, when a g28 is executed the z goes up then both x and y/a slave go home but im not seeing it hit the switch and then back off the switch. I made a couple home switches with pogo pins and nylon nuts, works great.
Re: Ref All Home & Auto Square Not Working
« Reply #3 on: July 10, 2016, 08:43:21 AM »
Hi,

3.042.020 & parallel port

thanks,
Joe

Offline ger21

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Re: Ref All Home & Auto Square Not Working
« Reply #4 on: July 10, 2016, 09:15:50 AM »
Can you post your .xml file?
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Ref All Home & Auto Square Not Working
« Reply #5 on: July 10, 2016, 01:23:56 PM »
Hi Gerry,

I THINK i have it figured out. After trying every possible combinations of every button I could find with no luck I erased the Ref All Home script and typed it again.
it appears to be working now. Being totally unfamiliar with the macro language and formats I'm not sure if ther was rouge space, return, etc. somewhere that was causing a problem.
That leads me to another issue with the proximity sensors. Definately struggling to get any sort of repeatability/ consistency out of them. They are a Chinese NPN NC 3 wire sensor.
I'm chasing to get them to activate at the same time. I get them absolutely perfect, withing .0005", and then the next try they are off by .015". I'm thinking that since I'm trying to square the gantry that the accuracy of them coming off the sensor is more important than when it goes into the sensor. Any thoughts on that?
I've read numerous posts and it's split on whether I need to add a resistor or some other electrical component to make them operate properly.
Do you have any advise on them? Are they supposed to be the most accurate and repeatable of the options that are out there?
Can you also point me in the direction of a good tutorial on the Mach3 macros? Again, I've looked and can only find references to the commands, nothing explaining what they really mean and how to use them. Mach3 macros for dummies (does it exist?)

Appreciate the help

Have a great day,
Joe

Offline ger21

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Re: Ref All Home & Auto Square Not Working
« Reply #6 on: July 10, 2016, 01:52:31 PM »
Quote
I'm thinking that since I'm trying to square the gantry that the accuracy of them coming off the sensor is more important than when it goes into the sensor.

Correct. Sorry, but I've never used proximity sensors.

Have you looked through this manual?

http://www.machsupport.com/wp-content/uploads/2013/02/VBScript_Commands.pdf
Gerry

2010 Screenset
http://www.thecncwoodworker.com/2010.html

JointCAM Dovetail and Box Joint software
http://www.g-forcecnc.com/jointcam.html
Re: Ref All Home & Auto Square Not Working
« Reply #7 on: July 10, 2016, 08:02:13 PM »
Proximity sensors don't have anywhere near the accuracy and repeatabilty you are looking for, at least not at a price you'd be willing to pay! Really accurate limit switches are available, and they will likely be normally and forced open as that is generally more repeatable. In thinking about this issue I would be concerned about setting the squareness using microstepping. I think I would set the drives for full step and mechanically adjust the motor to screw or belt position to be perfectly square at full step. I believe they would then be much more likely to move together accurately.

Offline RICH

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Re: Ref All Home & Auto Square Not Working
« Reply #8 on: July 11, 2016, 12:09:43 AM »
Quote
Can you also point me in the direction of a good tutorial on the Mach3 macros? Again, I've looked and can only find references to the commands, nothing explaining what they really mean and how to use them. Mach3 macros for dummies (does it exist?)

It does not exist. If you do, or have done programming, then the learning experience will be rather quick.
I will be the first to admit that I am not the sharpest tack on macros, but, I learned a lot just by looking at all the stuff you will find posted in the Tool Box or screen sets, etc .
You be amazed at just how dangerous you can become.

RICH

Re: Ref All Home & Auto Square Not Working
« Reply #9 on: July 11, 2016, 10:47:47 AM »
Hi Gerry, Gary & Rich,

Appreciate the feedback.
I have no programming experience but will definitely look thru the VB scripts and start lurking thru the Tool Box & screen sets. You never know where it might lead me on my quest to figure this stuff out.

It has become apparent that the proximity sensors I bought are not capable of doing what I intended. That said there is little doubt that I am getting carried away with some of the things I'm doing. I built the CNC from SidewinderCNC. Had a blast building it, using it for a bit so far and furthering my knowledge on the whole CNC world. The accuracy of the machine is probably far less than I'm worrying about with these sensors. I plan on building another machine, hopefully much for accurate in the future. I'm using what I have to learn about different things so I can make informed decisions when that time comes.

I'm using the Xylotex controller and motors, is there a way to change the microstepping?
I'll do some reading about microstepping but what are the pros & cons of it? Is accuracy diminished going to full steps?
Can you provide a link or some names of accurate limit switches?

Really appreciate all the effort everyone puts into these forums. They have been a tremendous source of information and hopefully someday I'll be able to repay the favor to someone that needs help.

Have a great day,
Joe