How to solve stuttering and pauses when printing via USB?

Hello, I was wondering how many people print using a USB connection instead of an SD card. I actually have a laptop dedicated to my printer and I do all the prints straight from the computer. But, I am having serious issues with Pronterface and/or my Mega unable to keep up causing A LOT of pauses and freezing in prints. So far I disabled "Monitor print status" to free up some horsepower and I went into my Control Panel and Tweked the USB settings and switched to high performance mode. Has anyone else found any remedies for this issue because I dont plan on using an SD card unless I have to.

Set your baudrate to 250000

Disable any LCD's you have wasting cpu cycles (128 64 dot matrix are particularly bad at wasting cpu cycles)

make sure any curved parts don’t have insane numbers of segments.

Look in to using arc commands (not well supported, but replaces thousands of short segments used in curves with one arc command)

replace ramps mega with re-arm controller (has virtual uarts, so baud rates are ignored and it goes full usb speed)

reduce micro stepping on Z to 1/8th, if using 0.9 steppers reduce micro stepping on X and Y also.

There are also other things you can do if this is a delta

Edited 2 time(s). Last edit at 01/10/2017 11:05PM by Dust.

Thank you I am definitely going to look into these tips. I have the baud rate at 250000. I was actually just thinking about whether that should be changed or not so thanks. No its not a delta. Turning down the microstepping is a great idea I am definitely going to do that probably on my z and e. I disconnected my smart controller a while ago because it mysteriously went blank. I have Mega/Ramps/DRV8825 @ 1/32/ to Nema 17's. I think I may be running into an 8 bit wall. I looked at the Re-Arm and quadruple the power wound def smooth things out but I don't know if I'm ready to take on different software after just getting everything running. This is my first printer and I just got it running a few days ago so I am learning a lot and have a lot of tuning to do. It's a DIY build. I think I understand what is going on now. Can't expect too much processing power for $10 bucks I guess lol.

When you play around with microsteps, make sure your RAMPS boards isn't one of those, that has traces between the jumper pins. Use ohm-meter to measure between pins.

There are several ways to get rid of the traces. My favorite one is burning them away with a single cell LiPo battery ( just shortcut the pins for a second )

PS: Unplugging the LCD doesn't help reducing CPU cycles. It will still send them AFAIK. You have to disable the LCD in marlins configuration.h ( but keep the SD-Card support if you like )

Edited 1 time(s). Last edit at 01/11/2017 04:52AM by o_lampe.

Yes, you have to disable the LCD in firmware, or it still twiddles the IO pins, even if the hardware isn’t there

Oh ok I'm glad you let me know. I'm gonna see if that helps performance. I am a little uneasy about using your method for the possible tracks it seems like it would take a skillful touch and I only have one Ramps but I think I am ok I haven't noticed any issues with microstepping. Changing my Z to 1/8 definitely helped thanks. Right now I am trying to figure out why my printer is retracting for no reason and thereby failing to extrude, and the weird thing is it is only doing on the right edge of the model. It's really weird. It prints fine, relatively speaking, then as soon as it gets to the right edge to make a pass it starts a clicking noise which I found to be it pull the filament up.

I turned the V ref up and it seemed to help but there is a noticeable difference in extrusion quality as soon as it hits the right side. I definitely have some strange problems but when it wants to it runs great I have been tuning it for days. I just need to get these issues sorted out so I can focus on tuning it's performance. It's difficult to fix several different issues that seem to intermittent. When I started printing today it did the stuttering again and after a complete reboot it was fine. Last night it printed great with the exception of occasional freezing. I think I might have to look into a different option in the brains of the printer. I was using cheap Ebay jumpers before which I believe was a bad idea, but know I have my PSU going straight to my buck convertor and the 12v going to my Ramps via 16awg speaker wire. seems to have helped. Right now I am trying to figure out the retraction issue and also why the extreme stuttering and power interference comes back at random times. Switching to a beefier PSU doesn't seem to help, almost the opposite.

Not sure if this site will allow it but I think I am going to record a clip of my setup if any of the intermittent issues resurface so maybe I can get someones opinion on it.

I hope it isn't the buck converter causing these issues.
I've never heard someone using one between a switching PSU and the printer. Would be interesting to use a 12V battery for a change.

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Draytology
Hello, I was wondering how many people print using a USB connection instead of an SD card. I actually have a laptop dedicated to my printer and I do all the prints straight from the computer. But, I am having serious issues with Pronterface and/or my Mega unable to keep up causing A LOT of pauses and freezing in prints. So far I disabled "Monitor print status" to free up some horsepower and I went into my Control Panel and Tweked the USB settings and switched to high performance mode. Has anyone else found any remedies for this issue because I dont plan on using an SD card unless I have to.

This is a very common problem. One reason (not the only reason but probably the main reason) is that almost all 8-bit controller boards use a USB-to-serial converter with no hardware flow control. This means that the application program (Pronterface in your case) has to wait for an "OK" response from one command before it can send the next one. General-purpose operating systems such as Windows and Linux can't handle this efficiently.

If you are determined to print over USB instead of from SD, then the best solution is to upgrade to 32-bit electronics that provides a proper USB port instead of USB-over-serial. You will also need to patch Pronterface to not wait for the "OK". Other 3D printer host programs such as Repetier and Simplify3D provide a configuration option to not wait for the OK so they don't need a patch.

As long as you are using an 8-bit board, the best advice I can offer is:

- Make sure the laptop is not doing anything else at the time. Close all other programs, and turn off WiFi to prevent Windows and applications trying to download updates.
- Repetier Host has some output buffering options that if I understand them correctly may make it more efficient than Pronterface in dealing with the flow control issue.

Alternatively, print from SD card like most people do.

Edited 2 time(s). Last edit at 01/12/2017 05:35AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Just to add to this.
If you have a 2nd computer then you could run repetier server on the laptop and connect to the server via lan, i use this
on my mega and have not suffered any pauses or stutters during printing

Ok thanks guys I am going to look both of your recommendations. I am finding ways to work around the problem as I get to know my set up better. Sometimes it is hard to tell whether it is Pronterface or the Mega, or both, but I think if I upgrade or patch Pronterface it will help a lot. Yesterday when I loaded an average design, not very complex at all, it said it was out of memory in the command text area, and the model pic did not load, which until then I did not understand what the cause of that was. Directly after I loaded a very simple rectangle case for the Mega and it loaded fine and my printer ran very well. So I definitely have room for performance upgrades, which is great because I would prefer that over what I previously thought was a problem with my setup or programming, etc. I am going to look into repetier and maybe simplify 3d but I heard that was very expensive.

To answer O-lampe:

I believe I ruled out the buck converter as a source of any problems. Early on I suspected it so I removed it and it did not improve the problem. It works great. By the way you were definitely correct when you questioned the wire gauge in my setup. It was about as bad as possible lol. Super anorexic Ebay jumper cables I was using so I could easily wire the buck converter and voltmeter in. Major improvement since I switched to some brand new 16awg speaker wire I had laying around. The reason I use the buck converter is because I use a laptop charger as my PSU which puts out 19.5 v. I like the buck converter because it puts out a very smooth 12v and has a max of 10a I believe which is adjustable so its also a makeshift fuse. I got it turned up to make sure it is not bottle-necking my current. I have another much more powerful DIY PSU that consists of a microwave transformer bridge rectifier and a 10amp fuse inline for safety but I prefer the laptop charger because it automatically shuts off if there is a short or voltage spike or anything like that so it adds another layer of safety to my more important components. I like having both in place because I removed both of my fuses, and also my D1 diode to protect my Mega.

12V/10A max!! is not enough, when you use a heated bed. I think you should look for a beefy 12V supply. 12V/350W/ 19A is what I have and my 12V LED ring is still flickering when the bed-heater goes on/off.

I don't have a heated bed. I cleaned up and upgraded all of my wiring today since I noticed a significant bump in performance when I increased to 16awg. While I was at it I wired my volt/ammeter into the system, after upgrading it's wiring. So now I have nothing less the 16awg and I cleaned up the power wires running from the buck converter. My voltage stays constant at 12 now, before it would sometimes drop to 9 when the extruder heater powered on. The current averages 1.5-2.5a and I have never seen it go above 3.5 believe it or not. I have it running pretty good now I'm not missing steps or anything so I guess the motors don't have much of a load on them. The 12v 10a that the buck converter is rated for isn't much I know but it is more than my laptop charger I have as my PSU can put out. I know if I add a heated bed it's not going to cut it but for now it is actually very good.

I am downloading Repetier right now, hopefully it helps because right now I can not even print most things because Pronterface just can't do it. I am printing a nema 17 mount right now and it is fine for the most part but earlier it refused to print a tiny filament filter case. Anything that isn't square is a nightmare at the moment. I am also thinking about reducing the microsteps to 1/16 on x and y. My z is at 1/8 and the rest 1/32. I am having an annoying issue with my motor particularly x shuddering quite hard for no apparent reason. It turns slowly and vibrates pretty hard. I think once I add better motor mounts it will gretly reduce the volume of it but I still want to eliminate it if possible. Not sure what the cause is though.

I don't have a heated bed. I cleaned up and upgraded all of my wiring today since I noticed a significant bump in performance when I increased to 16awg. While I was at it I wired my volt/ammeter into the system, after upgrading it's wiring. So now I have nothing less the 16awg and I cleaned up the power wires running from the buck converter. My voltage stays constant at 12 now, before it would sometimes drop to 9 when the extruder heater powered on. The current averages 1.5-2.5a and I have never seen it go above 3.5 believe it or not. I have it running pretty good now I'm not missing steps or anything so I guess the motors don't have much of a load on them. The 12v 10a that the buck converter is rated for isn't much I know but it is more than my laptop charger I have as my PSU can put out. I know if I add a heated bed it's not going to cut it but for now it is actually very good.

I am downloading Repetier right now, hopefully it helps because right now I can not even print most things because Pronterface just can't do it. I am printing a nema 17 mount right now and it is fine for the most part but earlier it refused to print a tiny filament filter case. Anything that isn't square is a nightmare at the moment. I am also thinking about reducing the microsteps to 1/16 on x and y. My z is at 1/8 and the rest 1/32. I am having an annoying issue with my motor particularly x shuddering quite hard for no apparent reason. It turns slowly and vibrates pretty hard. I think once I add better motor mounts it will gretly reduce the volume of it but I still want to eliminate it if possible. Not sure what the cause is though.

Your motor shuddering could indicate that the corresponding driver is overheating, which is a common with plug-in drivers. In which case, either turn the motor current down, or use a fan to cool the drivers. Don't be tempted to use stick-on heatsinks.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Without a heated bed your printer calibration must be spot on, or the first layer will fail more than once.
I recommend it only for experienced users or people with infinite patience

dc42 that makes sense because I actually turned the current up on X only recently. Are the little stick on heat sinks not effective. Would I really be better with no heatsink. I will be using a fan either way. One thing I was considering was trying to remove the double sided tape that is on the heat sink and replacing it with some thermal paste I have from when I had to fix my old laptop. I believe it's call artic silver thermal paste. Or maybe I should remove the heatsinks and cool the chips directly with my fan?

O lampe yes I have noticed the difficulties of getting the first layer right, and reliable. I have invested several hours just to trying to calibrate my z home position. It's good but def not perfect. I wont have any money for a heated bed for a few weeks, so I was thinking about throwing something together in the meantime with things I have laying around just for fun.

Quote
Draytology
dc42 that makes sense because I actually turned the current up on X only recently. Are the little stick on heat sinks not effective. Would I really be better with no heatsink. I will be using a fan either way. One thing I was considering was trying to remove the double sided tape that is on the heat sink and replacing it with some thermal paste I have from when I had to fix my old laptop. I believe it's call artic silver thermal paste. Or maybe I should remove the heatsinks and cool the chips directly with my fan?

There are essentially three thermal configurations of plug-in drivers:

1. RAPS128 drivers (and any others that use the THB6128 chip - I don't know of any). These are designed to be cooled from the top. They should always be used with heatsinks. Using a fan as well will improve the cooling.

All other driver chips are designed to be cooled via the thermal pad on the bottom of the chip, and thence the PCB. Which leads us to:

2. Driver modules that mount the driver chip on the underside, and have thermal vias through the PCB to the top side, where you can fit a heatsink. For these drivers, a heatsink helps, and a heatsink + fan is even better.

However, most plug-in drivers are:

3. Driver modules that mount the driver chip on the top side (and don't use THB6128 driver chips). To cool these, you need to cool the PCB. Unfortunately, the PCB has far too little cooling area to be effective. If you don't use a fan, sticking heatsinks on top of the chips may help a little, but not much because the plastic top of the chip doesn't conduct heat well. Using a fan to cool the PCB is better, and stick-on heatsinks may make the cooling worse because they get the way of the airrflow.

HTH David

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

OK thanks for the info. I think what I will do is remove just the heat sink from the X driver and pay attention to it's performance. Also I am going to try to position my fan to blow on the end opposite the power plugs so I can try to get a draft moving underneath the chips as opposed to just over them from the side. I heard about some drivers that I am interested in upgrading to. I forget the exact name but it is the ones with the chip mounted on the underside and the pot is accessible through a small hole. I believe they are capable of 1/128 microsteps which is awesome, even though I am reading you lose torque and accuracy below 1/16 so I am not sure which level of microstep to set up. I am also looking at the Arduino Due. I want upgrades that will be compatible with my current set up(Mega,Ramps, Drv8825,Nema17 at 1/32,1/32,1/8,1/32). I have a couple extra components I might swap in like one of he 84oz/in Nema 17's I am thinking about putting on my X axis. I also have a bunch of those other drivers the a4988 but I am not using them.There are an enormous amount of variables involved in tuning a 3d printer it is quite the challenge for a beginner.
Any suggestions on ways to improve performance using what I have on hand?

I finally took the time to get Repetier up and running. While trying to print a fairly basic design, just a square shaped robot cell phone holder I found on Thingaverse, Pronterface completely started to fail. The print started to get very slow and choppy and evenually the screen went blank and I had to close the program to dissconnect. Needless to say I was ready to give Repetier a try. The only thing I miss is how it would show the entire model to be printed and each completed line would turn green, as opposed to just showing the completed lines. Other then that, it is running fantastic! Major difference in performance so far!

I'm glad you got an improvement using Repetier Host. I suspected you would from what I know about Repetier, but I haven't used Arduino/RAMPS for a couple of years so I never tried it.

Upgrading to 128-microstep drivers is pointless as long as you are using 8-bit electronics, because the electronics can't generate the step pulses fast enough. Although you can get TMC2100 drivers that interpolate to 256x when you feed them with 16x pulses.

Arduino Due doesn't work reliably with RAMPS unless you make a number of modifications, because RAMPS was designed for 5V signal levels and Arduino Due provides 3.3V. If you want to go to higher microstepping and 32 bit electronics, I suggest you look at the 32-bit boards with on-board (= properly cooled) drivers, not Arduino lashups.

Edited 1 time(s). Last edit at 01/14/2017 04:51PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hi DC.
How about a Arduino Due with a Radds board. looks an interesting combo.

I haven't heard of the Radds board I will look it up. Right now I am definitely leaning towards the Due. I was thinking going with the Ramps FD because that is very similar to what Ihave now. I have been reading to find out what is involved in using it with Ramps 1.4. If it is too much work I will just grab a new shield too.

I've heard that Arduino Due + RADDS works well, especially if you use the RAPS128 drivers. You can even run RepRapFirmware on it. But you don't get a web interface, or software control of the motor currents.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Dont go near the Ramps FD (its meant to be just like a ramps but for due vs a mega2560)

Certain manufacturers rushed it to production before it was ready, the v2 fixed all the issues, but no one is making them... (as far as I know)

Main issue is if you turn it on with usb disconnected both hotend and heated bed are on and heat uncontrolled.

Edited 1 time(s). Last edit at 01/16/2017 12:43AM by Dust.

I think I am going to just grab another Ramps and a Due for $20 and mess around with those while I read up on my options for a few more weeks. Thanks for letting me know I was about to get one off ebay.....something's telling me that would have not been the V2.

Quote

Ramps and a Due

Good luck!
They are not really compatible. That's why Ramps FD was created. You better save the money and look for RADDS and Due or a Duet board or another 32bit board.