Is this normal? It’s acting like it is stalling out then resuming
It’s been explained to me a few times that if you increase the ram of the host system this behavior goes away.
I’m stuck with the RAM as it’s a Windows tablet operating this I will see if I can increase virtual memory
Which tablet are you using?
I’m not sure what could be the problem and how smoothieboard handle it, but I believe that it may be a buffer issue. But even though the movement are slower, it looks like buffer is fine as there is no space or strange results (skipped steps or anything).
Any idea @StephaneBUISSON @Arthur_Wolf ?
Can you try printing from the SD card ?
This is a stock controller and software
Smoothie conversion will happen when my level shifter arrive in the mail. At that point I will put in the 4xc board
@Alex_Krause This explain that 
I believe this is a non issue then, normal behaviour of the stock board.
I can’t tell, I did not use it to engrave any pictures. Sorry for confusion 
@Jean-Baptiste_Passan I agree. In fact if you watch the Windows status bar on the lower right you should see msgs pop up about it sending various passes to the laser. (There’s actually a little applet loaded that you can see if you click down there - not really needed with LaserDRW but with CorelLaser if you lose the icons for starting/stopping/reset/etc for the laser you can still do that by clicking down there and getting into the laser applet/status thing that’s loaded down there.) If you’re not watching, you may miss those messages as they display for a few seconds and then automatically disappear.
I’m still stock and do not have that issue when doing large raster. I think it’s more of a computer issue.
I’ve had this issue on large complicated rasters, with 16gb of ram on the computer so I do not think it is a ram issue. I would throw my vote in it being the buffer size on the stock controller as the issue.
@Tony_Sobczak I think it’s not so much regarding the physical size of the raster, rather the complexity of the raster. I can’t say for certain, but I imagine rastering a solid square would be a lot less complex in regards to the commands that are sent to the machine, as opposed to something that was more complicated.
Mine with occasionally pause on larger things, but only once or twice when doing a very large engrave. Still comes out flawless though. Even still see it now and again after I upgraded to 4gb from 2gb RAM.
It´s a combination of RAM and USB2 buffer, often occurs on tables or laptops with low amount of ram and alot of other stuff running at the same time.
To prevent this, remove as many USB-devices you can, and close all softwares running in the background.
If it doesnt help, well, not much to do other than live with it or change the unit you are using.
@HP_Persson That may have been my issue (not the RAM as I have 16gb & usually nothing else open but CorelLaser, but the USB) as I have been running everything through a 4 port USB hub. The cord to the controller + the USB security key + my 2x USB webcam (to watch the laser + the tube) all on the same hub. It is a USB 2 hub in a USB 3 port. Would changing to a USB 3 hub minimise this issue?
@Yuusuf_Sallahuddin_Y Try a own cable from the computer to the control board, and leave the USB-key in the hub.
Cheaper than buying a new hub, you probably wont see any difference in USB2 performance either.
Is the hub powered? if not, that might help too
@Yuusuf_Sallahuddin_Y
Not really, keep in mind your peripherals are still USB2.0 and the buffer will keep that limit too.
Also @HP_Persson I’ve never heard of buffer issue coming from too much usb peripherals.
unless you use a HUB as there is one buffer for the whole hub. But generally speaking, hub are something from the past, and it’s been a while since I’ve seen one. But yes, it may be the problem here as I imagine the tablet @Alex_Krause use might not have enough usb port (one for the key and one for the machine), well thought 
@HP_Persson The hub is not powered, just running from the usb port. I will just run the controller cable on it’s own port in future & everything else off the 2nd port.
@Jean-Baptiste_Passan I’m using hub as I only have 2 usb ports on the macbook. A couple of thunderbolt ports too. I intend to switch to a different device just for the laser in future (tablet/stick pc/desktop pc, depends what I get at a decent price).
Buffer issue depends on how the computers mainboard is built, on some (old/cheaper) laptops, older desktops or pad´s there is one controller for all ports, while new computers has one controller per port or two ports.
Also, some controllers revert back to USB1.0 if a 1.0 unit is plugged in, having other stuff connected to that controller makes them 1.0 too.
Thats why i suggested to remove all other devices, to be sure. (pretty rare, but i´ve seen it)
@Yuusuf_Sallahuddin_Y And check if your hub can be powered, most of them have a option for it. That will help your webcams, they are flooding the controller like crazy and are pretty power-hungry
Not sure how the macbook is built, unsure if it has one controller for both ports, but relieving the controller from some of the power isnt a bad idea anyways
If you run a virutalized setup, also check if that has any kind of USB optimization settings, may help.