I’ve had a chance to get pretty familiar with the mechanical design of the Printrbot Simple Pro. It is a straightforward and memorable design, and makes great prints.
This printer is a classic Brook Drumm - tight clearances and compact spaces are a design goal. Built like a tank and hits the sweet spot between rigidity and portability.
I got my hands on a Simple Pro chassis; mechanical parts only. You may have picked up one of these when Brook ran a “rolling stock” sale on the Printrbot store.
I wanted to put together electronics for a printer from scratch. This post is not a guide - if you aren’t comfortable starting a “kit” project with only 80% of the materials and knowledge you need to finish, you should not consider a project like this.
That said, I found it to be a great learning experience and wanted to share my work here so people knew what parts I sourced and how I approached this project.
I am in the process of assembling and tuning a new printer. This one has a 14:1 geared stepper driving the z-axis.
I ran into a problem where my prints were looking squished, like so:
The white cube on the right is in the right range, dimensionally (20mm^3). The blue one on the left is 20mmx20mmx6mm.
Internet searches on this were not helpful at first. There's a lot of discussion about how to properly set your steps/mm for the z axis.
This wasn't my problem though. When I jogged the print head around and measured, movements were accurate. My steps/mm were correct.
Finally, I found a super-helpful post on the reprap forums. My thanks to konwiddak, jamesdanielv, and the other contributors on the thread.
If you are having a problem where your printer movements are correct, but actual printed parts turn out way too short, try the following (especially if you have a geared stepper driving Z):
Tune down your z-motor current and make sure your controller board is properly ventilated.
