All I can tell you about running multiple printers from one computer is my personal experience. How others do it I can not say.

#'s 1 & 2 are running identical boards & firmware, and as I noted before, plugging them in to the same USB source causes problems. Using different USB sources there is no problem.
on my computer, there are 4 USB slots on the back, 2 in the front.. the back is one source, the front is another (different places on the mainboard). I can run a powered hub from the back, and it counts as a separate source. #1 is plugged into the back of the computer directly, #2 is plugged into the hub, which is plugged into the back... it works.

I do run multiple instances of RH - one for each printer in operation - and i try to orient them on the screen (2nd monitor) in a similar pattern to where the printers are to make it easier to keep track of which one is which.
example: when looking at the 2 SD4s, #1 is on the right, #2 on the left.. I will place the RH for each in the same way.

heartless wrote:

seems most members on here have not yet enjoyed their 3D printer loosing its com port due to other USB devices that sync or use bi directional com port being installed or used while 3D printer was off line and the other device permanently high jacked its com port.

ok, here is the thing, when setting up my printers COM ports - I manually change the COM number to something higher.. leaving the lower level numbers for other devices.. this is SUPER easy to do and then you no longer have that issue.
SD4 #1 is COM 13 (yes, I deliberately chose this number, lol)
SD4 #2 is COM 15, and everything else is higher from there.

When you first connect the printer, yeah, the computer will assign a number, but once that is done, you can change it to whatever you want that is not currently in use (up to 256) and the computer will remember that COM setting for every future connection to that printer.

As for the LCD/SD thing - those are not that hard to add to pretty much any printer. You don't want to be tethered, add one!
Or, Look into setting up a pi & Octoprint.. There ARE other options out there.

Yes, I run mine tethered to the computer, it works for me - for now. I like the control I have over ever aspect of the print job - i can adjust the hotend and/or bed temp, feed rate & flow rate on the fly with just the click of the mouse.
With a print running from SD card it is not quite as easy to do - too much digging through menus for my tastes. (yes, I have a printer that has the LCD/SD card reader - i never use that part of it)

I am frequently running both of the SD4s at the same time, and, recently, could have used a 3rd one... which I now have in my possession.

On the other hand.. the Duet & Panel Due touch screen combo is very nice! super easy to make adjustments on the fly. But I rarely use the machine that has this setup for "production" stuff because it has the Volcano on it, and most of the stuff I am running needs the smaller nozzle size for the details and/or needs smaller layer heights..

well like I posted above mine did loose its com port after connecting a syncing device while printer was off. and it was NOT easy to fix like it would be if done when 1st installed and even SD techs on remote share had no clue (I never remote share after that mess).

dont want to use win 10 ever again. nor string RPs etc just to run 2-4 printers at same time either. what about running multiple RH windows if they can keep from mixing up which printer to talk to? heck solidoodle ran over 24 SD3 units at same time on 1 PC & didnt see anything hanging on them to do it.

so how long has the Quick reply window not been posting reply's? only quotes do

seems most members on here have not yet enjoyed their 3D printer loosing its com port due to other USB devices that sync or use bi directional com port being installed or used while 3D printer was off line and the other device permanently high jacked its com port.

ok, here is the thing, when setting up my printers COM ports - I manually change the COM number to something higher.. leaving the lower level numbers for other devices.. this is SUPER easy to do and then you no longer have that issue.
SD4 #1 is COM 13 (yes, I deliberately chose this number, lol)
SD4 #2 is COM 15, and everything else is higher from there.

When you first connect the printer, yeah, the computer will assign a number, but once that is done, you can change it to whatever you want that is not currently in use (up to 256) and the computer will remember that COM setting for every future connection to that printer.

As for the LCD/SD thing - those are not that hard to add to pretty much any printer. You don't want to be tethered, add one!
Or, Look into setting up a pi & Octoprint.. There ARE other options out there.

Yes, I run mine tethered to the computer, it works for me - for now. I like the control I have over ever aspect of the print job - i can adjust the hotend and/or bed temp, feed rate & flow rate on the fly with just the click of the mouse.
With a print running from SD card it is not quite as easy to do - too much digging through menus for my tastes. (yes, I have a printer that has the LCD/SD card reader - i never use that part of it)

I am frequently running both of the SD4s at the same time, and, recently, could have used a 3rd one... which I now have in my possession.

On the other hand.. the Duet & Panel Due touch screen combo is very nice! super easy to make adjustments on the fly. But I rarely use the machine that has this setup for "production" stuff because it has the Volcano on it, and most of the stuff I am running needs the smaller nozzle size for the details and/or needs smaller layer heights..

well like I posted above mine did loose its com port after connecting a syncing device while printer was off. and it was NOT easy to fix like it would be if done when 1st installed and even SD techs on remote share had no clue (I never remote share after that mess).

dont want to use win 10 ever again. nor string RPs etc just to run 2-4 printers at same time either. what about running multiple RH windows if they can keep from mixing up which printer to talk to? heck solidoodle ran over 24 SD3 units at same time on 1 PC & didnt see anything hanging on them to do it.

You can also install OctoPrint server on windows 10 or linux machine, but I'm not sure if OctoPrint identify printer by serial number or COM port.

You can assign different printer name in firmware or with M550 command, you can find out which printer you connected to in the log window.

For more advanced user, you can change product ID in the firmware, and then modify the USB driver .inf file add corresponding product id and product name assigned to different printer. Then your printer will be recognized as different product from same vendor and whatever name you want will show up after the COM port in device manager.  Major disadvantage is you need to disable windows driver signature enforcement.

seems most members on here have not yet enjoyed their 3D printer loosing its com port due to other USB devices that sync or use bi directional com port being installed or used while 3D printer was off line and the other device permanently high jacked its com port.

ok, here is the thing, when setting up my printers COM ports - I manually change the COM number to something higher.. leaving the lower level numbers for other devices.. this is SUPER easy to do and then you no longer have that issue.
SD4 #1 is COM 13 (yes, I deliberately chose this number, lol)
SD4 #2 is COM 15, and everything else is higher from there.

When you first connect the printer, yeah, the computer will assign a number, but once that is done, you can change it to whatever you want that is not currently in use (up to 256) and the computer will remember that COM setting for every future connection to that printer.

As for the LCD/SD thing - those are not that hard to add to pretty much any printer. You don't want to be tethered, add one!
Or, Look into setting up a pi & Octoprint.. There ARE other options out there.

Yes, I run mine tethered to the computer, it works for me - for now. I like the control I have over ever aspect of the print job - i can adjust the hotend and/or bed temp, feed rate & flow rate on the fly with just the click of the mouse.
With a print running from SD card it is not quite as easy to do - too much digging through menus for my tastes. (yes, I have a printer that has the LCD/SD card reader - i never use that part of it)

I am frequently running both of the SD4s at the same time, and, recently, could have used a 3rd one... which I now have in my possession.

On the other hand.. the Duet & Panel Due touch screen combo is very nice! super easy to make adjustments on the fly. But I rarely use the machine that has this setup for "production" stuff because it has the Volcano on it, and most of the stuff I am running needs the smaller nozzle size for the details and/or needs smaller layer heights..

also its an extremely over priced lease agreement that you never own is why its dormant still. who wants to pay $10,000 for a dumb training course then 3 year lease @ $40,000 per year for a borrowed 3D printer when industrial powder printers are available for less to purchase.

hence I stick with what I have that gets the job done good enough til better affordable option comes.

Tin Falcon wrote:

Carl that is fine if the printer has an sd card as most of mine do. but heartless and N2ri have multiple solidoodle printers. they do not have that option.

That was my point. If the SD has such issues then it might not be the best to consider for a print farm of say 5 plus printers. Of course since I only have three and they all have unique purposes I am probably just flapping my jaws. I personally cannot imagine ever finding a market or enough customers that would require me to run 3 printers at the same time, much less 200. I guess Texas is just not on the 3d printing parade yet. The only business I have been able to drum up is printing custom made light pipes for my employer. Even then they only need one or two a year.

well if I didnt have SD2 printers already which as Heartless explained have to 1st find said printers virtual com ports each time powered on and cant do that if they look the same to PC.
then if I had money for 4 newer costlier FDM printers I would likely use 1 of  the new liquid resin 3D printers that use air to help speed normal process by 100x therefore only needing to run the 1 printer to output faster than 4+ high end FDM printers at more efficient  cost and less investment. so lets stay focused on my OP please and not adlib pipe dreams ok? dont know of any FDM printer that can finish an item normally taking several hours to print, in under 8mins.

SD cards are just another option on some higher priced printers which should also have a pause/continue print feature too for power outages or other interruptions like any high end printer including my old Alps MD1300 paper die-sublimation photo/decal ready unit has for ink cartridge replacement. also need UPS battery backup so prints can finish if power goes off. but all that is not what I asked. so We still need more info for my OP question.

Carl that is fine if the printer has an sd card as most of mine do. but heartless and N2ri have multiple solidoodle printers. they do not have that option.

That was my point. If the SD has such issues then it might not be the best to consider for a print farm of say 5 plus printers. Of course since I only have three and they all have unique purposes I am probably just flapping my jaws. I personally cannot imagine ever finding a market or enough customers that would require me to run 3 printers at the same time, much less 200. I guess Texas is just not on the 3d printing parade yet. The only business I have been able to drum up is printing custom made light pipes for my employer. Even then they only need one or two a year.

The only time I have a computer connected to that machine is when I am tuning it and need access to the firmware or control of it.

running two different boards makes it a bit easier as they use different drivers for the COM ports - thus the computer knows the difference.
I have run as many as 4 printers from one computer - 2 with the exact same controller board/firmware setup (the SD4s), but running from different USB sources (1 front, 1 back), and the other 2 running different boards.. one was a RAMPs (the FT Kossel) the other was an MKS board (the FT-5).

Now, the SD4 I just brought home is still running on the stock Printrboard.. so I can easily run it from the same computer as the other 2, just need to find the correct driver for it again, LOL