Homing/Softlimit issue. Help please.

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Re: Homing/Softlimit issue. Help please.

Postby Delco » Sat Jun 03, 2023 9:10 am

tenfrozentoes wrote:Okay. but right now running Mach3 on the AXBB-E is just shy of painful.

Running Mach3 on anything is shy of painful , maybe look at getting a update from mach3
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Re: Homing/Softlimit issue. Help please.

Postby tenfrozentoes » Sat Jun 03, 2023 4:51 pm

When I purchased the AXBB-e and UCCNC that was the direction that I thought I was heading. I'm wanting to upgrade 3 machines. On the surface UCCNC looked like it'd be the likely answer- but since you have to actually buy the hardware, software, and retrofit your controller just to discover that the trajectory planner at the core of your new system doesn't even come close to producing the speed nor finish of the 'sub-par' hardware and software that you just upgraded away from- I'm a little disappointed having spent a considerable amount of time and $ with the mindset that if UCCNC wasn't the right fit- I could easily just revert back to Mach3 temporarily with the new hardware (ie AXBB-e) but now can't get Mach3 to operate properly either because of hardware/firmware issues....

I'm still open to someone 'showing me the light' with UCCNC but I haven't been able to achieve neither speed nor good surface finish with it. I've asked the 'community' and I have/am asking the company for help- all I keep getting is the 'Mach3 is bad' rhetoric. But simply put it's providing me the surface finish that I've come to expect as (what I thought was...) pretty much basically vanilla at this point- and it does that at good speed.
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Re: Homing/Softlimit issue. Help please.

Postby cncdrive » Sat Jun 03, 2023 10:49 pm

I already expained you the working of the trajectory planner and the UCCNC users manual also expains it.

Mach3 has bugs, so I would try to install a different Mach3 version.
Also you could post your Mach3 profile file to let us check the issue.
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Re: Homing/Softlimit issue. Help please.

Postby tenfrozentoes » Tue May 14, 2024 12:24 am

Well here's some interesting new information on this still ongoing issue. As per the OP- when setting my soft limits for the Z axis at 0 in and minus 4, the machine would be allowed to move 0.0063" and then trigger a soft limit. I have been wanting to get this figured out but haven't put much effort into it.

Today I made an interesting discovery when I started recording and analyzing the numbers. Previously I thought that I had tried changing the soft limit values to see if it was affected, but I'm thinking that maybe I didn't at that point. Today however I changed the soft limits to minus 10 and low and behold it affected where the soft limit was triggering. It was now triggering at -0.0155. okay so I found that interesting and then tried changing it to minus 100 inches on the soft min for Z-axis. And lo and behold I was able to jog the Z axis 2 - 0.1550

Off the cuff I thought there had to be something wrong in the coding where it was using millimeters instead of inch, but minus 100 mm would be closer to -4"

So then I took the value of 100 and divided it by 0.1550 and I got a ratio of ~645:1

I played with the 645 number bouncing it off other constants like 25.4 and 0.03937 but couldn't find anything that was making sense. Here's the odd part that I stumbled onto:

25.4 / 0.03937= 645.16129

So naturally, I took my value of 6.000" that was actually desired for my soft limit envelope, and multiplied it by 645.16129

6 x 645.16129 = 3870.9677

I entered -3871 and low and behold I am able to jog Z to -6.0000" where the soft limit stops it.

But the other oddity is that the home offset value is still looked at correctly. I have it set at minus 0.6250" and that is what I need, and what I get.

I'm going to guess that the issue with the homing speed is somehow related. The issue with it is needing to be set at 100% in order to achieve a somewhat reasonable homing speed. I measured and estimated (distance/time with stopwatch) that it is actually homing at about 15.6-15.7 ipm (max velocity is set at 400.02ipm) (homing speed is set at 100%)

400.02ipm ÷ 25.4= 15.748

So I'm going to say somewhere in the coding there is a mathematical error that is causing both of these problems. I'm curious if they even show up for a user that is operating strictly in metric....

Don't know what it all means but the numbers definitely point in this direction and I thought I would share.


(I'd be more than happy to provide any additional information needed.)

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