Avid 4848 pro jerking, skipping and clunking

TLDR; When loading large G-code files, the
CNC behaves erratically. Smaller G-code
files work fine. I have a fully licensed.
version of Mach4 purchased from Avid.

I’m new to the CNC world. I only have about 5 very simple projects under my belt. My current project is a bit more complicated. It has 3 tool changes and about 166,000 lines of code. My previous projects has no tool changes and only around 20,000 lines of code.

I’m using V-Carve Pro 10 with the save visible toolpaths to one file option to generate the
My computer is a bit older
amd phenom ii x4 3.2ghz
8gb ram
Western Digital WD800JD-75MSA2 - 80GB 7.2K RPM SATA
Fresh Windows 10 install

Now to the problem. It only jerks and clunks when the G-code with 166,000 line is loaded. Not when the smaller G-code files are loaded.
Once I load the larger G-code file then try to jog it, it jerks and clunks on both the x and y axis.

It does this at seemingly random locations on both axis. Also, when running the G-code, Mach4 got stuck on a line of code. The spindle continued to spin but it wouldn’t advance to the next line of code. This happened several times, each time on different lines of code.

Maybe my PC just isn’t up to snuff?

If anyone has any suggestions, I’d surely appreciate it. In the meantime, I’m going to purchase and install an SSD and see if that works.

My first guess is that sounds like a communication issue between your PC and the ESS in the electronics box. That can be caused by your PC bogging down under load. That processor is at least 12 years old. I would recommend something newer. Something less than 5 years old and at least 4 cores. You can get away with less and older but you really need to be careful. Be sure to run the Avid SCU software. It is included in the install of Avid’s Mach4 bundle. It will configure your PC to work with Mach4 and minimize issues like you are having. You should not use the PC running your CNC for anything other than running the CNC in an ideal world. If you must use it for other things, you will need to use the SCU software to go back and forth from your configuration for general use and the config for CNC use. SCU will disable things like Windows update for the best stability.

I think there is? I also remember something about being able to go in and deactivate old licensed PC’s on Newfangled’s website in your account.

Thanks for your suggestions. I have already ran the Avid SCU software and that PC is completely dedicated to running only Mach4.

My suspicion is that my PC is just too old / slow to keep up with Mach4.

I have a few other newer PC’s that I can test with but I can’t dedicate them to my CNC.

Hopefully transferring the Mach4 license between them isn’t too much trouble.

Is there a limit on how many times I can transfer Mach4’s license between PC’s?

Thanks, I’ll look into it.

You will have to check on their site. I don’t remember for sure. It has been a while since I used Mach4. I left it for LinuxCNC because of issues like this.

Are the files large because the piece is large or because the moves are small? If the commands make for very small time-steps, then the buffer could be filled, and the machine has to halt as it waits for more commands. Avid discusses enabling smoothing in Fusion 360 to deal with command buffering issues in this YouTube video:

A better computer will also help. I haven’t done many 3D carvings, so I don’t typically deal with large files, but I did have the occasional clunk. I bought this computer and haven’t noticed any more clunks yet. @subnoize said it was important to get a Windows 11 machine.

I had to do this. Avid has instructions for transferring licenses here.

I don’t currently use Fusion 360, although I’d like to try it. I don’t believe that video applies to my situation because it also clunks when I jog the machine in either the x or y direction but only when the large g code file is loaded. If no file or a smaller file is loaded then it doesn’t exhibit this problem.

I may have found a work around, though. If I hide the tool path view window then everything seems to work properly. This is only a temporary solution, though.

Thanks for your suggestions. If anyone else can shed some light on this situation, I’d appreciate it.

What are you cutting? What do your vectors look like? This can be cause by lots of nodes on a vector when there could be much less.

It clunks when merely jogging the machine but only when the large g code file is loaded. For what it’s worth, I’m cutting sugar pine, which is extremely soft and the vectors do not have an excessive amount of nodes.

Computers are cheap these days. Look up how to build a performance monitor or “perfmon”. It’s a free customizable performance log monitor free with Windows for decades. It can help pin point your performance bottlenecks. Just throwing CPU or memory isn’t always the fix.

That sounds pretty definitive to me. You need more performance.

1 Like

Most of my problems where computer related.
I switched my pc twice (first pc was jerking as well) 2nd was running but crashing out of the blue. and now running a Nuc mini pc that was recommended by Avid. no more crashes and skipping tool changes. :smiley:

1 Like

Do you have a link to the mini pc?

Amazon.com: Intel NUC 11 with Newest 11th Gen Quad-Core - 16GB DDR4 RAM & 512GB SSD - Save Space Mini PC Thunderbolt 3, Bluetooth, Wi-Fi and Cooling Fan for Entertainment and Business - Windows 11 pro : Electronics

1 Like

You can actually go a lot smaller if you know how to manage Winders.

My Pro 4896 dates from the middle of 2019. At the time I bought a cheap ($550-ish) Inspirion laptop from Dell just to run Mach 4. I do all my CAD/CAM on a different computer in my office. The only job the laptop has is to run Mach 4. I do have wifi on so it can communicate with my local network - that’s how I move the G code files around. It has worked well, even with some quite large 3D caving jobs. The laptop does have an ethernet port so I don’t need an adapter to connect to the ESS.

As somebody else noted in the thread, computers are quite cheap - it might be worth buying a modern machine with enough (and it’s not much) horsepower to run Mach 4.

Hope this helps,

If you are running on windows, uninstall any MS add-ons. Also check your system for applications running in the background and delete them or disable them.
Uninstall all web browsers except the one you are using the most.
Check for games, utilities etc. These are really “fatware” meaning they eat up cache very fast, especially explorer, only use when necessary and CLOSE It.

The clunky-ness comes from large application running for a long time and building up lots of static. Every time you release static, that is when your system will stop, and never on the same line. Anything you do, like touching the metal parts, even through your Ethernet, can release static.

Been there done it, drove me up the walls. The clunky behavior is a sign of static being released.
Your solution. Start at the router, and earth it to the z-axis, the z-axis to the gantry, all the way to your control box, and then the control box to the external grounding wire.
Do not trust the gears or any two metal parts to ground themselves through their metal parts. The cost of wire is not that high, but in the end it is worth it.

Not sure if this is useful at this point, but I had similar issues when I first got my Pro4896, and on a hunch I bought a USB to Ethernet adapter instead of using the computer’s Ethernet port and it fixed the issue. I use a POS laptop I got on Ebay for 100 bucks and it works great.

Thank you. I’ll give that a try.