Router related questions.

[jazzcnc]

For Acorn there are several techniques to square a paired axis gantry, they are all mechanical in nature. basically you must square the gantry axis mechanically before releasing estop and homing the machine, since once you do that the two motors are electronically paired from then on. some guys make up hard stops and simply drive the gantry close to the hard stop and finish it up by turning by hand into the stop, then release estop and home the machine.

For my own use no problem but Not a good selling point when building for others.

I'd recommend using a hybrid motor drive system for any gantry since they reduce the necessity to constantly be homing (and squaring the gantry ) the machine.

Do use Hybrid sometimes but not always possible on lower budget machine or machine with existing steppers/drives.

there is a crude work around for Acorn if you really want a software/electronic solution to square the gantry, warning: you've got to jump thru some hoops for this one..., basically you home the gantry off one limit switch on one side in 3+1 axis paired mode, (at this point it will not be square). then restore a report that puts cnc12 back to 4 axis mode, run a gantry G&M program that now homes each side of the gantry separately off its own limit switches (that you have arranged to be square) now it will be square, then restore a report back to the 3+1 paired axis mode and home out right where the machine is sitting. now its square and ready to run.

This axis decoupling hack was my hope if couldn't be done easily. (Which is basicly how Mach3 did it using PP) Don't mind getting dirty so long as the end result gives the desired affect and looks professional and is invisiable to enduser.

Thanks Keith I can see I'm going to enjoy this controller.

[jazzcnc]

The axis homing is one of the most significant differences between mill (and their controllers) and routers (and theirs). To me, it may be the most important item in how the "routerhead" world accepts Centroid Control in general and possibly the Acorn system in particular. Virtually all prospective purchasers (myself included) will usually have the expectation that commonly used router conventions are available, just as those seeking mill or lathe control would.

100% agree it's game changer for Acorn to break into the Router world if it can independantly home. Without it just won't be taken seriously by router users. Which is shame because the DIY router market is crying out for stable motion controller with reliable quality software which can be trusted, which centroid clearly have built up over years.

Properly Impliment just this one feature and Centroid will Crush Mach3/4, UCCnC and all other players currently providing router users purely for it's trusted professional software.
Adding this feature will payoff Big time for Centroid because there are far more DIY Router builders than DIY Mill builders or Lathe converters. Just go look around the Popular Forums and see how active the router sections are.!
Look at the number of Chinese 6040 3020 pieces of junk being sold on Ebay. Just these alone are responsable for Massive increase in Router users and they break very quickly so either endup upgrading or more often the case DIY building something better. Or better Still Ask me to do it for them.

From what I've seen from just brief look all the Other router users requirements are easily achieved with few router specific Macros and VCP tweaks.

Mach3 became the success it was by providing what users required, Just Art Fennerty went too far and gave so much he was forever breaking it. Give users the basics which work reliably and they'll be happy.

I'm looking forward to this controller and honestly haven't been so pumped to getting hands-on controller has this one for quite some time. Hope it doesn't dissapoint.

[Gary Campbell]

"For my own use no problem but Not a good selling point when building for others."

I concur, this would be difficult to sell and possibly more important, a tech support nightmare. Some of these guys that have weak motor/drive combos will home their machines a dozen times a day.

"Do use Hybrid sometimes but not always possible on lower budget machine or machine with existing steppers/drives."

Same here but as a system builder I am at the mercy of a rather frugal user group. That said, I do install closed loop stepper systems in a bout 40% of my higher end builds. Those customers that pay more, expect more. It Is less likely I could sell them on a system that didn't square itself during the homing process.

The following are a couple snips from one of the higher end PC based controllers showing the options available 1) during the homing routine and 2) adjustment for dual axis. OF course adjustment can be negative or positive

[martyscncgarage]

Gentlemen,
Glad to have you "router heads" here! It is my least understood method of CNC operation and I am interested. I intend to build a heavy duty machine.

Your thoughts on what should be done to accommodate the router users are appreciated. Suggestion s on how to accomplish that at well. One thing to wish or complain but another to offer a suggested solution. You are barking up the right tree. Centroid does listen and if it's possible, with the hardware they may consider it.

Excuse the router newbie suggestion, but it seems I have seen proximity sensor uses on each side of the Y axis. It seemed that if one was hit that one would stop and the other would continue until the proximity sensor hit it and that squared up the gantry and called it home.

Do I have that reasonably right? The issue being the axis need to e independent of each other for homing and then coupled together after the machine is homed?

I'm doing this from my smart phone and need to go back and more thoroughly read Gary's and Jazz's comments in front of a PC with a bit more time to soak it in more and see how it could be accomplished.

[Gary Campbell]

Marty...
We posted a few seconds apart or I would have answered in my previous post. Let me explain the dual axis homing as I know it. In generic machine terms. Assume Y is dual drive axis

Send Y negative (speed builder set) (both motors) (Fast pass)
SW1 hits and backs off (preset amount) (both motors) (SW 2 is not active)
Negatve move into SW 1 and back off (slow pass)
SW 1 is now not active, SW 2 is active
Negative move into SW2 and back off (same amount) (Motor 2 only) (slow pass)
Move motor 2 the adjustment distance (+ or -)
Move (squared) gantry the preset axis distance to table corner
G53 (Machine Coords set to XY zero)

Logic behind these actions (as I have been told)
Speed of initial (fast pass) can be increased to shorten homing time on 10'-20' tables
Slow pass to increase accuracy
Does not require precision placement of switches
Allows builder (OEM, system build or DIY) to calibrate homing to physical variations in machine

[jazzcnc]

One of the reasons I use Cslabs products is because of feature called Geometry Correction when Homing slaved axis.
This is THE best homing methods I've used on any DIY controller. The feature is optional and can be turned on/off as required.

It's a two-stage process but seamless to user.
Stage#1: Approach both switches until Hit then move off switch and measure the difference between switches. Backoff set amount if required.
No adjustment done at this stage. ( The measurement side also works as safety by only allowing set travel amount after first SW is tripped in case of SW2 failure)
Stage #2: Now Geometry correction can take place if turned on. Here you have the option to set the amount of each axis so can tweak each Axis to square gantry.

To the End user it just happens and nearly impossible to see correction happen because often the switches are 10'ths mm apart and if well built machine gantry shouldn't be too far out of square. Thou Like Gary says I've seen machines 0.5" or more out square.

Now, this homing approach is Excellent BUT it's not required for most DIY Router builders. Simply using the switch placement to square the gantry is enough and all that's needed for 95% of users. KISS approach works for us "Routerheads" (Who by the way often run CNC Mills & lathes as well.!! )

Simple Decoupling of the Motors after hitting the first switch then backing off set amount and rehoming each side independantly. Then Recouple motors is all that's required.

Here I differ from Gary's take slightly in regards what's required from Homing. To me Homing process is just referencing the Machine zero coordinate.That's all it needs to do in it's simplist form or at most position MC Zero and offset amount for SW.
Anything extra is optional and often machine specific so can be implimented by tweaking macro's etc to specific needs.

However it would be good that if in the wizard it had section which allowed specific parking places to be setup for ATC and/or Tool change locations etc and tied to VCP buttons. (Probabaly does already but I've not got Acorn yet so can't see wizard settings)
For instance I build a Vertical router and one the requirements when shuting down the machine is to park the gantry at specific location so when Depowered the head doesn't drop. Providing park position in the wizard and again tieing to VCP button would be most useful but not required.
What is required and believe can be done already is the abilty for "Me the builder" to make this happen by allowing access to macros etc and use the Aux buttons.

Just let Homing be homing and Routers need independant axis homing when slaved. Only the Centroid guys can make this happen.!!
The positioning stuff etc we can do for our selfs and provide to others if required so lets not burden the busy bee's at centroid.
BUT it must happen if Acron is to be taken seriously in the router world.

[Gary Campbell]

When Dean says: "
"Just let Homing be homing and Routers need independant axis homing when slaved. Only the Centroid guys can make this happen.!!
The positioning stuff etc we can do for our selfs and provide to others if required so lets not burden the busy bee's at centroid.
BUT it must happen if Acorn is to be taken seriously in the router world."

I wholeheartedly agree. My work is to provide retrofit solutions mostly for those that do not have the time or knowledge for a DIY experimental approach. All of these (mostly) commercial users have a number of functions that they use in their own ways to get their products out the door. If I can provide them with a system that can accommodate those functions, I sell the job, if not..... you know.

It's nice to hear the higher end products support independent axis squaring. Hopefully the difference is firmware, not hardware. Unfortunately, my stepper customers cant use the Oak or Allin1, I must be looking for a stepper version of the Oak, maybe the "soft maple"

[martyscncgarage]

When Dean says: "
"Just let Homing be homing and Routers need independant axis homing when slaved. Only the Centroid guys can make this happen.!!
The positioning stuff etc we can do for our selfs and provide to others if required so lets not burden the busy bee's at centroid.
BUT it must happen if Acorn is to be taken seriously in the router world."

I wholeheartedly agree. My work is to provide retrofit solutions mostly for those that do not have the time or knowledge for a DIY experimental approach. All of these (mostly) commercial users have a number of functions that they use in their own ways to get their products out the door. If I can provide them with a system that can accommodate those functions, I sell the job, if not..... you know.

It's nice to hear the higher end products support independent axis squaring. Hopefully the difference is firmware, not hardware. Unfortunately, my stepper customers cant use the Oak or Allin1, I must be looking for a stepper version of the Oak, maybe the "soft maple"

There are a number of factors at play here. Is it reasonable and practical to ask Centroid for high end features in a motion controller (Acorn) at the current price point? Does it make good business sense? Acorn came with many features and frankly I think its a heckuva baragain. It is still in its "infancy" its only been out 4 months. So give it time and see where it goes. We can make suggestions, but at the end of the day Centroid needs to do what makes sense for the viability of the product (and the company).

So for the time being, we can be creative and see if there is a way to make what we have work. Just like the gamepad controller until a pendant comes out. Maybe there is no way to make it work and you have to resort to a higher end control system. I am about to retrofit a Phoenix 4x4 router. Customer makes custom motorcycle parts and does fiberglass work. He expects it to make him money by saving time, so I am refitting it with an Acorn and DMM DYN4 drives and 750 NEMA 34 AC servos. Fortunately, there is a single ballscrew driving the Y axis. Machine is pretty rigid. I will use the ZRI output of the DMM DYN drive to precisely home the machine.


Just my .02 on the subject. You really have to ask yourself is it reasonable to ask for the high end features on a controller of this price point. I bet many of you are here because you found how much of a bargain Acorn is what you get for the money given all its standard features. It won't work for everybody but I think for a good majority it will or they will find a way to make it work.

Marty

[jazzcnc]

Just my .02 on the subject. You really have to ask yourself is it reasonable to ask for the high end features on a controller of this price point. I bet many of you are here because you found how much of a bargain Acorn is what you get for the money given all its standard features. It won't work for everybody but I think for a good majority it will or they will find a way to make it work.

Marty

That's my point. Asking for independent homing of the slaved axis isn't "high end" or shouldn't be. IF providing the ability to slave axis then It should be a standard feature just like homing is for a single axis.
I agree that doesn't need to be advanced homing and automatically square etc but MUST do simple homing if to be taken seriously for router usage.

Routers or better phrased Gantry Style machines are very versatile machines which have a wide varied range of usages other than cutting wood.
Which is where we probably differ in seeing things regards whats MUST HAVE feature.

I've built Custom gantry style machines for cutting Paper, fiberglass, Neoprene, Fabrics, Glass, Stone. Foam and plasma, some of which have been 40' long 10' wide. So on a machine like this it becomes very important slaved axis can independently home.
The machines are often only ever going to cut one material all it's working life and don't need to be massively built or require high end hardware. So using high-cost servo's isn't practical. So low-cost stepper motors are a perfect match, however, this means independent homing is MUST have feature on such large lite framed machines.

Often the Machine users have very specific needs regards positioning etc. Be this for ATC, tool changing or work loading or holding etc but all of this is MY job to provide in form of macros/code etc which is easy enough done. BUT IMO the basics of independent Homing should be provided by Centroid if slaving feature is included in software/hardware.!

Personaly don't think it's asking too much for simple homing method.

[cnckeith]

we had a huddle today on Acorn paired axis CNC router "Auto squaring while homing" capability.
good news is that is can be done with existing firmware and CNC12 software, but it does require some code to be added to the PLC program.
So we will add this solution to the v4.12 release.