First print not working so well

I am trying to do my first print. I have a reprap i2 with a Sanguinololu rev 1.3a and Sprinter firmware. I am just trying to print a 20mm cube that I made in OpenSCAD and used Slic3r to create gcode that I loaded into Pronterface.

My pattern keeps shifting. My layers are off of eachother by about half of the width of the cube in different directions after each layer.

I am also getting errors randomly. "Checksum mismatch" and "no line number with checksum." I attached a screen shot of the error.

The layers that I do get thru are very clumpy looking. They dont look like what I've seen on YouTube. This is causing the filament to get all over the tapered part of the hot end.

Here is a picture of the print.

Looks like you're extruding too much plastic.
Steps per mm calibrated?
Proper width on filament?
I have my extrusion width in Slic3r at 0.67 even after everything was properly calibrated. Try stepping that down by .1 until it looks decent. I took about 2 hours of sitting there and printing simple first layers over and over until I got it fine tuned to as perfect as my old Solidoodle will go.

It seemed to be too close to the glass blocking plastic from coming out on the first layer, then to much after so I offset z up .2mm. Then not enough plastic was coming out, so I set width to 1.2.

the pattern was shifting during infill only. So I slowed that down to 45.

Still have the errors though.

Hello,

Ditto what MrDoctorDIV said. Would suggest finding Triffid Hunters calibration proceedure and following it, I know it helped me alot. Do you have a micrometer and are you checking the filament diameter? I set my z home height with the bed up to temperature and I home my z axis(in the middle of the bed where most of my printing is done) until I feel a nice drag with paper between the nozzle and bed. I don't use the slic3r offset.

Things that are very critical

1) Esteps calibrated
2) Layer height, I run .25 layer height. First layer height .3. No matter what nozzle I use .35, .4, .5, .6, .75, I use the same layer heights on my BergBot and LulzBot Taz and home the z axis the same way on both. I set the extrusion width to the width of the nozzle. I calibrate the esteps and multiplier in Slic3r until I get what I'm asking for.
3) Filament diameter consistent? Measure with a caliper in several different spots and take average reading. Use that average in Slic3r.
4) x and y steppers tuned correctly? I have seen this shifting issue when a motor stalls and then takes back off, shifting the entire pattern. These are open loop setups with no encoder feedback, meaning we assume the stepper is doing what it's told to do and there is no proof coming from a feedback circuit. So if the motor stalls the gcode sender doesn't know not to count the stepper pulses, it assumes it went were it was told to go. Then it starts creating the pattern in a different spot.
5) Slic3r settings, I had lots a problems when I first started "slicing", It would also help seeing your slic3r settings.

Here are all of my settings. As you can see I had to change the axis steps in sprinter by quite a bit. Is that normal?

1) After making several attempts to print, I seen that the pattern shift was not consistant. It shifts at different times within the first 2 or 3 layers, and shifts in different directions by different ammounts every time. Twice, it took off on Y until it hit the endstop and another time in the opposite direction. Occasionally, it even forgot to position Z and started printing a few mm above the bed.

2) I have my drives tuned as high as they will go before the steppers start jerking when triggered. If I go lower, they whine and dont move.

3) Within the first 3 layers, again at different spots in the print, the printer stops itself with checksum errors as stated in previous post. What do these errors mean?

4) Also, While moving manually, once with Z and once with E, they just kept on going until I stopped them

I'm not familiar with the Sanguinololu and Sprinter firmware. I had similiar issues on my first build with the motor starting but not stopping due to wiring issues and not having the microstepping jumpers in place. Also had print shifting issues due to steppers stalling due to tuning. Are you using GT2 belts and pulleys? The steps per unit look way off if you are. I use the GT2 belt (2mm pitch) with 20T pulleys. So basically one revolution of the stepper will move the heated bed 2mm x 20T= 40mm. 1.8 degree steps (360 degrees/ 1.8 degree steps) = 200 steps per revolution x 16 microsteps = 3200 steps per revolution. 3200 steps per revolution / 40mm physical travel per revolution = 80 steps per mm for x and y. The z-axis is using 6mm x 1.0 threaded rod. Makes my setup real easy. Z is 3200 steps per revolution. Greg wades reloaded extruder. So my steps are (80, 80, 3200, 796)

As far as the checksum issue, I noticed your baudrate is 250000. Maybe try the next lower setting, I've read where some people have issues running the higher baudrate.

Yes I am using gt2 with 16 tooth pulley.

I know those numbers are way off but that's what I set them to so I get the right travel. If I tune differently the motors don't work.

I think I did slow the baud before but I can try it again just in case.

115200 seems to be the most reliable baud as far as I can tell.

I'm not sure how you setup microstepping in the controller or firmware you are using, do you use jumpers? Are they in place? 16T pulleys will travel 32mm per revolution, if x16 microstepping is being used you should have values for x and y of ~100? Sounds like jumpers, wiring, and.or firmware setup.

The board came assembled. There are jumpers in there but I don't know if they are wrong or not.I didn't touch them. What should I look for in the firmware? I have the wires set according to the schematic. I use pronterface and didn't see any micro stepping settings in there.

It looks like there should be 3 jumpers under each driver. [reprap.org]

Not familiar with Sprinter. Will have to download and look through it.

i just tested the voltage of my stepsticks and they were all different but under .5V. What should they be? I read 1.45V somewhere but when i tuned X to 1.45, it is whining and grinding.

Quote
blbergeson
It looks like there should be 3 jumpers under each driver. [reprap.org]

Not familiar with Sprinter. Will have to download and look through it.

they are all there

Good section here [reprap.org]

I found these excerpts interesting

"First of all, note that there are usually two types of NEMA 17 motors :
high voltage stepper motors, that work usually on 12 to 14V, the working current is usually below 1A. These don't work well with microstepping chopper drivers and are not recommended.
low voltage stepper motors, that work usually on 2 to 4V, the rated current is usually over 1A."

"Symptoms of not enough current are skipping steps and poor microstepping linearity. Too much current will cause the motor or the driver to overheat. When the driver overheats it shutsdown for a few seconds and then restarts again when it cools. This makes the motor twitch when it is stationary and pause during motion."

My X, Y and Z are 1.7A. E is 2.5A

I have 42byghw609 and 42byghw811

I'll have to tapout at this point and let someone with more stepper experience to help out.

So I am getting 42byghw609 Vref=.476 and 42byghw811 Vref=.7
Is this correct?

Based on their example that's what i come up with also, looks like the 811 might be pulling too much for the driver. This is beyond my knowledge to help you. It will take someone with more technical stepper ability.

I got my Vref's all set, switched baud to 115200 and I still have the same problems. Pattern is shifting, getting checksum errors and serial errors.
Serial Error: Line Number is not Last Line Number+1, Last Line:0

Resend:1 What should I try next?



Edited 1 time(s). Last edit at 05/07/2014 12:42PM by kevbme.

Try a better USB cable and keep it away from power lines

I read that if you don't have a steady reading on the hot end that the printer can malfunction while printing. My temp does fluctuate. Do you think that could be my problem. It moves up and down by 5 degrees. I have new thermistors on order.

Edited 1 time(s). Last edit at 05/07/2014 09:47PM by kevbme.

When I first tried calibrating the drives, I shorted them out because I used an all metal screwdriver. I replaced them and then when I set my steps per unit, they were way off from what they should be as you can see in the screen shot above. Could I have also messed something else up causing my steps to be so far off?

My x and y have the same steppers, belts and pullys so the numbers should match. But they are way different from each other.

Edited 1 time(s). Last edit at 05/13/2014 11:56PM by kevbme.

Anybody???

Ditto what cnc dick said about the USB cable having cross-talk and causing your checksum problems. Re-route it away from all power cords and motor wires. Also, use the shortest quality USB cable that you can get away with, preferably one with magnetic ferrules on both ends for additional interference damping.....

I was getting a lot of communication errors using Slic3r after having updated it a few times and corrupting my settings. During my testing I discovered Cura and haven't gone back to Slic3r (even though I did sort out the comm errors by doing a clean install). I believe the root of my problem was Slic3r trying to generate GCode for the initial layer at a certain percentage of reduced speed.

Give Cura a shot and see if you've still got communication errors!

Well, I stopped working on my printer for a few months and now have returned to it. After trying the above suggestions without any sucess, I hooked up a LCD 2004 and now everything works fine. It just didnt like my computer I guess. My steps per unit worked perfectly using the calculated values. Thanks for the help everybody.

PS I do like Cura better Vitaminrad. Thanks