My 3D printing is proportional but not accurate

Hello, I'm using Prusa i3 mk1 and SolidWorks 2016 for 3d printing, as you probably know SolidWorks is an accurate software that is working by exact dimensions of certain objects.
So before a couple of days, I made a rectangular object and I printed that and the part's dimensions were 27 x 18 mm but the part's dimensions on Solidworks that I've designed were 25 x 35.
So as you can tell my printer/software is printing at proportional dimensions but not the original dimensions that I'm designing in my software.
Does somebody know how to fix that problem?

Did your printer ever print correct dimensions? - If not check your steps/mm

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Dancer
Did your printer ever print correct dimensions? - If not check your steps/mm

No, it never did.
And how can I change/check the steps/mm ?

Hello dindibo4,

What software are you using to control your printer?
What firmware are you using to configure your printer?

If you tell your printer to move 150mm (any of the axis in any direction), does it move that distance? Obviously this is where you should start and if it is wrong you must change some values in the firmware of your printer.
If your Prusa is using a RAMPS board you are most likely using Marlin firmware. Locate the Configuration.h file on your computer (and figure that it is the correct one which will be used when writing to your printer) and
go down to about halfway. There will be some values you can change for steps per mm, read the comments or google where it is. You will have to start there and work your way though the problem.

I would then use a valid calibration file like this one to test the calibration of the printer. Then at least you know your file is correct.
Your printed values will also depend on the slicer that you are using, and the settings on there.

I hope this helps, as you have given very little information about your printer, if it is of no help, sorry!

Good luck

Quote
v1talogy
Hello dindibo4,

What software are you using to control your printer?
What firmware are you using to configure your printer?

If you tell your printer to move 150mm (any of the axis in any direction), does it move that distance? Obviously this is where you should start and if it is wrong you must change some values in the firmware of your printer.
If your Prusa is using a RAMPS board you are most likely using Marlin firmware. Locate the Configuration.h file on your computer (and figure that it is the correct one which will be used when writing to your printer) and
go down to about halfway. There will be some values you can change for steps per mm, read the comments or google where it is. You will have to start there and work your way though the problem.

I would then use a valid calibration file like this one to test the calibration of the printer. Then at least you know your file is correct.
Your printed values will also depend on the slicer that you are using, and the settings on there.

I hope this helps, as you have given very little information about your printer, if it is of no help, sorry!

Good luck

Hello and thanks for your respond,
I'm using Repetier-Host as the software to control my printer and I am not quite sure what the firmware is, but I'm quite confident that this is Arduino and if it is, all I have to do is to locate the steps per mm parameter in the configuration file of the Arduino board that inside the printer?
if so, how do I get access to that file because I already have the software and I have a little experience but where is it located on my computer while the printer is connected?
Thanks for the help.

Send a M115 to the printer, this will report what firmware you have installed.

In repetier host, clik the config button)top left) and select firmware eeprom config, if the eeprom is enabled in firmware you should be able to edit the steps directly .

Hopefully you can follow obewan's advice and get closer to solving your problem.

I would imagine that the person or place you got the printer from provided you with the configuration files for your printer. This is very important. If you do not have any such files you will have to calibrate the printer yourself, but I am almost certain you were given these files. Use your operating systems search function to search for "Configuration.h" or "Arduino", anything to strike it lucky to find that file. I doubt it would be there if you did not install anything besides Repetier-Host for your printer though. If you can find it, great!

I would first check that the printer does not move the correct distance, as commanded by Repetier-Host, before considering reprogramming the firmware (FW). The problem with FW is that once it is written to the EEPROM of the Arduino board it can not be reversed and you can not undo the process. This means that all your current printer settings will be lost, and there is a great deal of settings to really properly customise a printer. Unfortunately you can not save the current settings stored in your printers EEPROM (well you can, but it is a tedious and difficult process).

Writing Firmware to the Arduino board in a nutshell:
1) Download the Ardiono IDE
2) Download the Marlin FW - I suggest you leave this step and find the configuration file for your printer from the person or place you got it from.
3) Once you have the configuration file (it should come with many other files, just open the Marlin.ino file with the Arduino application from step 1 ) change the steps per mm values to calibrate you printer (go to the "X & Y scaling and steps/mm calculations" section).
4) Repeat step 3 until every axis and the extruder performs adequately.

Quote
v1talogy
Hopefully you can follow obewan's advice and get closer to solving your problem.

I would imagine that the person or place you got the printer from provided you with the configuration files for your printer. This is very important. If you do not have any such files you will have to calibrate the printer yourself, but I am almost certain you were given these files. Use your operating systems search function to search for "Configuration.h" or "Arduino", anything to strike it lucky to find that file. I doubt it would be there if you did not install anything besides Repetier-Host for your printer though. If you can find it, great!

I would first check that the printer does not move the correct distance, as commanded by Repetier-Host, before considering reprogramming the firmware (FW). The problem with FW is that once it is written to the EEPROM of the Arduino board it can not be reversed and you can not undo the process. This means that all your current printer settings will be lost, and there is a great deal of settings to really properly customise a printer. Unfortunately you can not save the current settings stored in your printers EEPROM (well you can, but it is a tedious and difficult process).

Writing Firmware to the Arduino board in a nutshell:
1) Download the Ardiono IDE
2) Download the Marlin FW - I suggest you leave this step and find the configuration file for your printer from the person or place you got it from.
3) Once you have the configuration file (it should come with many other files, just open the Marlin.ino file with the Arduino application from step 1 ) change the steps per mm values to calibrate you printer (go to the "X & Y scaling and steps/mm calculations" section).
4) Repeat step 3 until every axis and the extruder performs adequately.

I am bit confused, do I even have to do steps 1-4 if I can just go ahead and change manually the printer configurations like obewan said?
I can just screenshot the initial settings of the EEPROM and that way I can save the initial settings just in case that anything will go wrong.
Oh and by the way the person I have bought the printer from didn't send my any configuration file setting so I guess I'll have to do it all manually.
Also, I did try to move the printer axises and see if it is according to the command that I have sent, but unfortunately it's not even close, it was at the start point (all axises were on 0)
and I sent to it G1 X50 which is according to what you say suppose to move on the x axis 50 millimeters, but in reality, it just moved along the X axis just 32 millimeters.

Ahh ok.

I am not very familiar with Repetier-Host, but I would definitely say take a screen shot yes! Try and keep a copy of every change you make to be able to 'undo'.
I would suggest do as obewan said yes. Again, I am not familiar with Repetier-Host, but imagine that the process obewan suggest is to calibrate the printer.
That would be (as an example to your response) the (current steps*50mm)/32mm. Put this in Repetier-Host and see if it improves. If so continue doing this until your printer is calibrated.

Just remember the algorithm for the z-axis and extruder is a little different.

A last thing to note: I am not sure if Repetier-Host sends the values to the EEPROM or just a temporary buffer. If it does not send it to the EEPROM then your calibration values will be lost every time you power cycle the FW (switch on and off).
Maybe Repetier-Host do provide a function to save it to EEPROM, I just do not know.

You seem to be on the right track though!

Edited 1 time(s). Last edit at 08/17/2017 04:54PM by v1talogy.

If repetier recognises the eeprom then any changes you make using the eeprom configuration is automatically stored to the eeprom.
If your printer has belt drives on the X and Y axis it is a prity fair bet that the steps/mm should be 80

Ok thanks I'll try this, and I'll update you as soon as I can if it indeed worked.
I can't try this now though because my printer isn't working, I accidentally erased the arduino content and I'll have to find the .ino file online for the arduino and update it with the reprap file.
does somebody have the original file?

Might be a good time to install an up to date firmware either marlin [marlinfw.org]
or Repetier firmware [www.repetier.com]

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obewan
Might be a good time to install an up to date firmware either marlin [marlinfw.org]
or Repetier firmware [www.repetier.com]

Yeah I know that I have already done this by the time you answered but thank you for your answer anyway.