Scaling Model - How to determine the size of object

Hello everyone.

My printer is the 3drag / k8200 

As recommend by the it is advisable to use .84 version.

I have downloaded an stl file from but the objects become too large to print, so I scaled them down to .1 size.

My question is: How do I know the exact measurements of the item with out printing it first?



  • I would not say that. On they offer 0.95f. You could also use 1.0.6 but will loose your printer settings as the custom installer has everything preset correctly.

    Between 2 lines you always have 10mm. You can also analyse the object which gives you the dimension. Not sure if 0.95 already hat this, but in 1.0.6 you click the gear next to the name and then the second tab.
  • "You can also analyse the object...". How does that (analyzing) happen? 
  • In object view you click on the gear next to the file name.
  • I have noticed the same thing with my prints. I have specifically measured an interior length to fit something I own and when I go to print it the entire print is about 10% larger that what I designed. For example, I need my print to have an opening of exactly 100mm. when I print it comes out at 110mm. I then have to scale it down 10% to get close to what I need.  This is with any slicer in Repetier.
  • 10% error is normally a wrongly set steps per mm in your printer. After all the host just send gcode with positions. So if gcode says move 100mm and printer moves 110mm it is a wrong defined resolution in printer firmware.
  • That makes sense that something is wrongly defined, causing the problem. So where do I find this "resolution" setting in the firmware? Is it a change in the configuration.h file? I noticed that the Repetier staff know their business, and are able to point us in the correct direction, but are short in "actually" helping resolve the problem.  For example...

    Problem - Prints not the right size

    Identified issue - Resolution in firmware wrongly defined

    Fix - redefine resolution in firmware

    How to fix - Unknown, Where in firmware do we find the value wrongly defined? We need more information on the actual fix.  Is there a resource available where a person can identify the different options and how to set them for the firmware of our printers?

    Thanks again,

  • That depends on the firmware you are using and you did not say that. For repetier-firmware you can do this in eeprom settings in host.
  • To compute steps per mm google the procedure for the formula.
    Open host - connect to printer-select Config tab - select Firmware EEPROM configuration - look down list to line that says X or Y or Z -axis steps per mm.

    Modify value and select OK.
    Test print - recalculate if needed.

    Alternatively, if EEPROM is disabled you need to use the Arduino program and modify the value in your configuration.h file (around line 66 or so)and reflash the firmware.That will make it available next time you flash firmware.

    I realize it can be frustrating......BUT......sometimes google is your friend also,
    Considering that these guys are doing a heck of a lot for FREE, a little legwork after their suggestions will help also.

  • Thanks, that took care of the problem. I just selected the default settings and it dropped down from 88 on 80 on some values, (those that I noticed). When I first got the printer a few weeks ago, I went into the tools pull down and selected belt calculator. It said I could step it up to 88, and I believe that is where I entered the value, causing my oversized prints. Now everything is just perfectly sized to what I need. However, I was into a 5 hours into a print job and selected the default values. Guess what, it takes affect immediately! It started extruding filament into a smaller design. Live and learn!

    How did you know where to look, was it experience? Other than Google, is there documentation that I can get to help me get better at printing?

    Thanks in advance!

Sign In or Register to comment.