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Author Topic: XHC WB04 plugin  (Read 17642 times)

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Re: XHC WB04 plugin
« Reply #80 on: October 12, 2021, 11:43:23 PM »
I just got my XHC WB04B last week and set it up, also with an Avid rig. In step mode I am seeing that steps at 0.01mm and 0.1mm appear to work consistently and correctly. Steps at 1mm using the jog sometime step a bit more than 1mm. I have never seen this using the GUI to do 1mm steps, which I have been doing quite a bit lately doing some probing and setup work with some dial indicators.  That said, the Z axis step is 0.0002" on this machine, which is pretty close to 0.005mm at 0.00508mm. The X/Y axis step is 0.0005", which is 0.0127mm. As I understand it, the physics of the machine mean you cannot step by any clean metric values like 0.01mm, 0.1mm or 1mm even. That said, the GUI stepping consistently reports the metric value as correctly stepping, when stepping using the GUI. I wonder if Mach4 is in fact driving the hardware to the nearest matching point when using the GUI and reporting the desired metric value as correct. This does explain a bit of variation I see on metric dial indicators when stepping by 1mm at a time (I'm using an indicator that goes down to 0.01mm here). The closest the hardware can actually step would be 1.0033mm. I'll have to try running in inches mode (most of my work is in metric) and see if I see the same behavior, and maybe play with some metric and imperial indicators as well to see what appears to be happening.

Otherwise, I'm pretty happy with the MPG, just waiting for the z-probe button to get hooked up now, but I can use a macro key for that if I need to :)
Re: XHC WB04 plugin
« Reply #81 on: October 13, 2021, 12:24:09 AM »
I bet we're not the only large format Avid owners who have been itching to break free of cables 😁

I've been distracted by some non-cnc work over the last couple of weeks so havent had a chance to do any more digging yet.

I did check the motor config though. The x/y motors are indeed inch based as you say. The machine units are actually set as metric though, so x/y are defined in mm despite the imperial rack&pinion geometry. But z is true metric - 10mm pitch ballscrew and 2000 microsteps per rev gives us exactly 0.05mm resolution. So we really should see exact .1 and 1mm steps on z with G20 but do not.

Hoping to get some free time on the cnc this week to test a bit more.
Re: XHC WB04 plugin
« Reply #82 on: October 13, 2021, 02:21:35 AM »
Yup, I really like being able to walk around the machine without cables, and jog while I can see what the tool tip is doing, so I'm loving having the wireless MPG working.

Good catch on the Z axis. I missed that looking at the specs. I've been doing a bunch of work on fixtures and alignment the last month or so, once I realized by X/Z axis was bowed to the back of the table by about 0.020" and starting tuning things up to correct it. Two-sided machining was giving me a horrible time until I figured out what was wrong.

I wonder what Mach 4 and the smoothstepper do with machine units in mm, but steppers driving in imperial? Rounding to nearest microstep I would imagine? I would guess that would show up in physical measurements on the machine though, and not in the DRO on mach. Also, at the bottom I would imagine the machine has to count steps anyway. Otherwise relative motions by amounts that are not integral steps would start causing drift as rounding errors accumulate.

I have been using a metric Haimer taster to do a lot of my alignment checking against known flat surfaces. The Z axis, I think, has been remarkably consistent with being able to step by 0.01mm, 0.1mm and 1mm accurately, but I have not watched it super closely with this in mind. Stepping on the X/Y axis though by 1mm seems to give me a shade over 1mm in step. It always returns to 0 where I expect it to if I step away 3 or 4mm and step back to 0, at least using the keyboard jog.

When I get a chance, probably next weekend, I'll try doing some testing with the jog wheel on different settings in imperial and metric mode.
Will be interested to hear if you get any information in the meantime. Right now I just set the jog to 0.1mm, and spin the wheel a bit more. That seems to keep the DRO readout in increments of 0.1mm without and drift.

I have also noticed a difference when stepping up to the soft limits. The keyboard jog will run right up to 0. The wheel jog will not run to zero sometimes in continuous mode. It gets close, but not quite, and then says that a further step would drive past the limit. This is a bit annoying when I actually do want to move the head to one of the limits.

Re: XHC WB04 plugin
« Reply #83 on: October 13, 2021, 08:11:02 PM »
I found some time to work on this today.

First the good...

I was having some issues with my PC, which was interfering with Mach4 and causing it to lose steps. I've switched out to another system, temporarily, and I am now seeing the steps track perfectly. In fact all 3 axis show clean 1mm steps, matching the GUI jogging behaviour. So I am guessing that Mach does indeed show the commanded position, not the actual achievable position.

I am also not seeing any extra steps in STP mode. I can even use fast moves, spinning the wheel from 30 to 60 rapidly, and the axis settles to exactly 30mm from the start position. So, I think all my previous issues were the PC getting in the way.

Then the  bad, for Steve ...

Neither build 4758 or 4759 work in step mode for me. This seems to be utterly repeatable. I get no motion at all. Switching to 4746 works every time.

Also, I can trigger the limit switches with with jog wheel, even with SoftLimits enabled. I would guess this is the related to the issue reported by EricSchenk, although the exact opposite symptom, since he was seeing a refusal to jog to the limit. Not the end of the world, but maybe something to look into.

Still, I have a working pendant ;D Now I jut need to buy a new PC:-(

Jon
Re: XHC WB04 plugin
« Reply #84 on: October 16, 2021, 01:31:47 PM »
jrbloom raises a good point on the PC in use. I'm using a fairly underpowered A6 CPU right now, and I had missing steps problems on this machine when running programs until I raised the buffer sizes. It is entirely possible that the little $100 PC I've been using is just underpowered for the task here. I'll try swap in a more powerful machine in a few weeks when I have one available.

In the meantime, I've now seen the jog both blow past the soft limit, hitting the limit switches, and stop short of the soft limit, so I guess I'm seeing inconsistent behavior. This is with the driver from build 4746. No obvious pattern there so far, but I haven't done extensive investigation or anything. It's possible that what is happening is stopping short of the limit in continuous mode and blowing past the limit in step mode. I'll check that out today.

I'll also probably try to drop a Z tool probe onto one of the macro buttons and see how that works.

Cheers,

Eric
Re: XHC WB04 plugin
« Reply #85 on: October 16, 2021, 02:00:58 PM »
I've been using the pendant for real work over the last few days. The limits issue is very strange...

On several occasions I've seen a refusal to jog below WORK position 0. Mach tells me the jog would violate the soft-min of the axis. But i am way down the axis. Jogging the other way and then coming back fixes it.

I wonder if these are all symptoms of the same underlying bug?

Hitting the limit switch is proving more of an issue than i expected. I seem to have a neuron miswired, and constantly jog Z the wrong way, hitting the limit switch. Home machine - jog to WCS lication ready to touch-off - jog down - oops wrong way - limit hit - home machine again ...

Also, START doesn't resume after a tool change. This could be Avid's customizations. I see the START button in the gui toggle, but nothing happens.

And, just once, immediately after powering on, and homing, a single jog in Y sent the gantry off to the back of the machine at high speed. I had to jump on the estop to catch it. *Be alert*.

Still, i am really enjoying the new pendant despite these teething troubles.

Jon
« Last Edit: October 16, 2021, 02:03:45 PM by jrbloom »

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Re: XHC WB04 plugin
« Reply #86 on: October 16, 2021, 05:02:15 PM »
I've been using the pendant for real work over the last few days. The limits issue is very strange...

On several occasions I've seen a refusal to jog below WORK position 0. Mach tells me the jog would violate the soft-min of the axis. But i am way down the axis. Jogging the other way and then coming back fixes it.
That was a general MPG (wireless or not) issue that has been fixed in the later dev builds.  We were trying to support lower resolution machine better and that bug crept in there.  (Wishing everyone would use higher resolution machines these days...)

Also, START doesn't resume after a tool change. This could be Avid's customizations. I see the START button in the gui toggle, but nothing happens.
Start certainly works in the stock Mach config.  So I be you are onto something here.

And, just once, immediately after powering on, and homing, a single jog in Y sent the gantry off to the back of the machine at high speed. I had to jump on the estop to catch it. *Be alert*.
This sounds like a soft limit configuration issue if soft limits are enabled after the home.

Still, i am really enjoying the new pendant despite these teething troubles.
I'd really love to blame everything on the pendant because I'm not to happy with the XHC company not writing their own Mach 4 plugin and leaving lots of Mach 3 users wanting to upgrade hanging.  But no.  LOL  The initial jog thing was definitely a Mach bug that I introduced.  :( 

Re: XHC WB04 plugin
« Reply #87 on: October 16, 2021, 05:10:45 PM »
Start works to begin a program. Just not to resume after a mtc. Are these different operations in the stock configs?

Can you elaborate on the suspected soft limits issue? Why would that cause an eratic jog? Some kind of arithmetic underflow? They certainly look correct to me and I've never seen this before.

Also, i cant update to latest because Step does not work after 4746.
Re: XHC WB04 plugin
« Reply #88 on: October 16, 2021, 08:33:47 PM »
Just realized what you meant wrt latest dev. It's a fix to the core program, not the plugin. Any idea when that fix might hit the release?