Slow to start printing

rhaub101

I’m wondering if this is normal for an A5:

Scenario 1.

I pre-heat the machine to 195/60

Insert the usb flash drive and hit print

Machine takes about a minute then starts printing

Scenario 2.

I pre-heat the machine to 245/70

Insert the usb flash drive and hit print

Machine takes about 5 minutes then starts printing

Scenario 3.

I connect to Pronterface and pre-heat to 245/70

Hit print

Machine takes about 3 seconds then starts printing

I prefer to print from the flash drive but the wait time seems to be excessive.

What does your A5 do? Thanks in advance

Stephen Todd

My A3s V1 is the same whether printing the same file with proterface USB, Cura USB, SD card in adaptor, or USB memory stick

I'm thinking the problem is in the Gcode, but it is strange - I'd be looking at the pre-print Gcode in the the slicer settings

Edit: I suppose it could be the USB memory stick - maybe use a different one, or use a dedicated USB memory stick/SD card formatter, rather than computer operating system to format (there is a free download on Internet for SD cards, but not sure if it works with USB memory sticks) - but you could use a SD to USB adaptor)

Samuel Pinches

Can you please upload the Gcode here? @rhaub101

rhaub101

Thanks for the replies. It isn’t any one particular file it’s every print. It’s also strange that the higher the temp (245 vs 195) ( the longer it takes to start (5 min vs 1 min).

If it were a gcode problem, wouldn’t it do the same thing from Pronterface?
I have reformatted the flash drive and tried others with no difference. I’ll  look at the gcode (not sure what I’m looking for) and upload a file here.
Someone pointed out that the Pronterface connection goes right to the main board. Could there be a problem with the display board or the display board firmware? 

Samuel Pinches

It might be a procedure thing with the LCD firmware. I'm struggling to think of a reason why though...

Stephen Todd

Like Samuel, I'm also stuggling to find an obvious reason as it makes no sense, except the longer delay for higher temperatures - that is likely to be the printer struggling to maintain a steady temperature before printing can commence - has to be a certain number of seconds I think - so if your printer is not in an enclosure, it will be struggling and constantly turning on and off the heaters if no underbed insulation, heat block sock, external bed MOSFET

The start Gcode is in a text box in Cura - tells the printer to prime the nozzle, etc. before printing starts - are you using latest version 4.4 or newer? some versions are years old and outdated - also do not have the JGAurora profiles included

The path to the location of the Gcode text box is:

settings

printer

manage printers

machine settings (button)

You can copy and save the existing text to notepad and try new code from Internet and forums - I use the following, including M420 S1 to call mesh bed levelling settings:

; -- START GCODE --

G21 ;set units to millimetres

G90 ;set to absolute positioning

M106 S0 ;set fan speed to zero (turned off)

G28 ;home all axis

M420 S1

G92 E0 ;zero the extruded length

G1 Z1 F1000 ;move up slightly

G1 X60.0 Z0 E9.0 F1000.0;intro line

G1 X100.0 E21.5 F1000.0 ;continue line

G92 E0 ;zero the extruded length again

; -- end of START GCODE --

Stephen Todd

I used to use pronterface and USB to print everything, and never had problems with it, but drifted to memory sticks - I don't know if it talks directly to the processor or not, but it does seem to be more efficient in your case - so maybe your problem is the slicer putting trash in the Gcode (which pronterface is ignoring) - but there could be more than one thing going on - could be software and temperature issues combined

rhaub101

Stephen, my start code is the same as yours. It seems the bed and nozzle heat up quickly and maintain the temps easily. If it were garbage in the gcode, wouldn’t Pronterface have a problem also? I’m using Cura 4.1 but the same thing was happening with 3.xx. Does your A5 start immediately from the flash drive or do you have a delay also?

Stephen Todd

Not taken much notice - I'll time things when I do some printing tomorrow - but I don't think the flash drive is any slower

Stephen Todd

I upgraded my power supply to a higher power one, but the heat up time does not seem particularly quick to me

I pre-heat both the bed and hot end for about 10 minutes before starting to print - the bed thermistor is in the center of the bed, and it takes time to heat up all the bed evenly, not just the center

Have you sliced with prusa slicer? - It may be a Cura thing

rhaub101

So your usb seems about as fast as Pronterface at 195/60 and 250/70? Wow!
Good idea to try a different slicer. But i would think if it’s a problem in the gcode from Cura it would not start right away with Pronterface.  I’m gonna try it anyway. Thanks

rhaub101

So I sliced this file with Prusa Slicer. It starts in 12 seconds at 250/70
Also sliced it with Slic3r. It starts instantly at 250/70
This is the gcode file sliced on Cura 4.3 at 250/70. It still took 31 seconds to start.
Im lost.

Stephen Todd

I used to use Slic3r as my go-to slicer at one time, but switched to Cura 4.4 as it has the JGAurora configuration files built in - Slic3r did impress me though when I got the printer settings right

Pretty obvious from your comparisons that Cura is putting out dodgy code - I still use it, but lots of people say they have ditched Cura  completely for one reason or another - I read its programmed in Python, which is quite old and produces basic programs, whereas other slicers are using more modern programs that create slicers with better interfaces

Samuel Pinches

@rhaub101 Great to hear you have some new findings. Can you please upload the Slic3r code too? I would like to compare the starting gcode commands.

Stephen Todd

I looked at the Gcode, and see you are using .15 layer height - not a magic number for JGAurora printers

Magic numbers:
.12
.2
.3

Stephen Todd

I printed a test piece from thingiverse sliced with cura and slic3r and read off of a USB memory stick on my A3s V1

printer is in an enclosure and was left for 8 mins for hot end and heat bed to settle at 205c and 50c

Cura took 51 seconds to do anything
Slic3r took 34 seconds to do anything

Its a temperature thing - both hot end and bed have to be at right temperatures together - and they were alternatively going high and low, but not both at the right temperatures at the same time for long enough - eventually they were, and things started to happen

There are electrolytic capacitors on the MKS Gen L controller board next to the thermistor leads sockets - they slow down the speed that the processor sees the voltages changing on the analog sense pins - replacing with smaller or higher value capacitors is the only way I can see you can overcome the problem if it really bugs you - smaller values will change indicated temperatures more quickly, larger values will hold indicated values steady for longer

RT is the thermistor

rhaub101

Here it is Samuel

Samuel Pinches

Your slic3r code does not turn on the bed heater. This will save a lot of time, but will require you to manually preheat the bed yourself beforehand.

rhaub101

Well I didn’t check everything, I just downloaded it and sliced just to see how long it took to start. The bed and nozzle was already preheated tho, but I’ll try again with everything set as close to Cura as I can. Thanks for looking at it.

rhaub101

Here are the two files. Slic3r took 11 seconds to start, Cura took 32 seconds. Both at preheated 250/70.

Stephen, why is .12 the magic layer height? .15 is the normal in the Cura profile for the A5/A5s.

Stephen Todd

Its to do with the lead screw cut - z shift distance per turn - those are the most practical ones in actual use, but there are more - the info is from JGAurora facebook group users

I don't think JGAurora use a common lead screw pitch and the processor has to round up/down the calculations or something, whereas the magic numbers result in more accurate calculations

Stephen Todd

I found this from on here:
https://jgmakerforum.com/discussion/495/jgaurora-a5-magic-number

If you do an Internet search for "3d printer magic numbers" you'll find that there are different magic numbers for different printers