Here is a 50mm calibration angle used for calibrating your machine. This is designed to be small and fast to get calibrated quickly! I printed it on my Printrbot Jr.
The outer X and Y are 50mm.
The inner spaces are 30mm.
The whole thing is 5mm thick.
Each arm is 10mm wide.
Look at the instructions -->
This works pretty well. Within 2 prints I had my printrbot jr fully calibrated to .1mm tolerances. Well enough to print an iPhone case that fits. I've included the STL and a sketchup file if you want to mess with it.
In case your new to calibration, I'm going to break it all down for you:
Usually in the custom Start g-code area in Slic3r you'll have 4 calibration values for X,Y,Z and E for Extruder.
If you don't have custom g-code in there, you'll want to add it. Here is what mine looks like for a printrbot jr.
G28 ; home all axes
M92 X63.0242 ; calibrate X
M92 Y62.7669 ; calibrate Y
M92 Z2071.4959 ; calibrate Z
M92 E650 ; calibrate E
You are welcome to use these as starter values. Just paste them into the custom g-code section of slic3r. (note: direct drive extruder starter value should be M92 E100)
To calibrate you first print this puppy out. When it's finished you'll want to measure it with a caliper, digital preferred. How close to 50mm for X and Y are you? X is the side to side when facing your printer. Y is the back and forth. And Z is the up and down. Bust out your calculator and run this calculation:
(Don't be scared, it's easy)
First multiply the current value of X by the length in the STL, 50mm. Then divide that number by what you actually measured. The result is your new custom-gcode value for X.
So in my case, say I measured the X of my print to be 48.25mm, I would do
63.0242 X 50mm = 3151.21 (current X value times the value in the model)
3151.21 / 48.25 = 65.3101 (result divided by my measurement)
So in my custom G-Code I would replace 63.0242 with 65.3101
Do the same for Y, and it works for Z too!
Re-slice by exporting it to G-Code and reprint that bad boy. Check your measurements, and do it all over again if you are off by more than .5mm
I hope this has been helpful, I know it's tough when you are first getting started.
For speed, I printed this object with 1 perimeter, 1 shell top and bottom, and infill of .1 (10%)