There are many DIY 3D printer designs available on the internet. While there are dozens of designs out there, almost all of them require precision rails/bearings. Most printers require two precision rails and at least three linear bearings per axis, for a total of 6 rails and 9-12 bearings. Even so called “delta” printers tend to actually be linear-delta machines, requiring just as many rails/bearings. It’s these precision components that really drive the trade between price and precision in a DIY printer.
Many DIY designs require 3D printed parts. It’s pretty cool that you can build parts for a 3D printer on a 3D printer, but what if you don’t have a 3D printer in the first place?
This is our solution.
Design details to come... The printer has been our workhorse at Tropical Labs for over a year now. We feel that it is time to document the design.
Details
Components
1×
Arduino Mega 2560
the brains of the operation
1×
Ramps 1.4
popular 3d printer shield for arduino mega
4×
A4988 Stepper Motor Driver Carrier
these plug in to the ramps board and power the steppers
4×
Nema 17 stepper motors
I used 0.9 degree steppers
I seem to recall that the labels for the dimensions in the calculator are a little misleading, so be sure to double check the drawings in the first link.
Here's where you can enter those parameters into my modified marlin code on github (originally modified from an early version of the firepick-delta firmware). Starting around line 198 in Configurations.h:
#define DELTA_E 50.8//172.0//131.636 // End effector length#define DELTA_F 158.3//152.4//81.4//190.526 // Base length#define DELTA_RE 163.5//114.5//270.000 // Carbon rod length#define DELTA_RF 50.8//77.0//86.000 // Servo horn length
The un-commented values above are the dimensions used on this printer (in mm).
The coffee maker hotplate has a significant delay which causes control problems....
By the time the sensor sees a temperature change, enough energy has been put into the plate that it shoots up to a very high temperature. The process does not seem to stabilize with just PID control.
To correct this, we edited the PID algorithm. Now the hotplate is pulsed on between 0 and 1 seconds every 10 seconds according to the PID algorithm.
Do you have any plans for incorporating the Mechaduino into this printer - even just for fun? Would that allow you to use cheaper motors other than the typical NEMA 17's?
A similar machine with Mechaduinos is in the works. The motors wouldn't necessarily be cheaper, but you would get some combination of improved resolution or a larger build volume depending on how you dimension things. You would also avoid losing steps.
Yes, a solid state relay controls power to the coffee maker to regulate the bed temperature. The coffee maker itself did not need to be modified, so you can actually slide the delta assembly off and make a pot of coffee!
You are a step ahead of us on the motors though! We are using standard 400 step/rev NEMA 17 stepper motors to directly drive the delta mechanism on this printer. We've also built a second, larger delta printer where the steppers are geared down 5:1 with GT2 timing belts. Next up, we will be building a closed-loop version featuring our Mechaduino stepper based servo motors!
Gotta say... I love it. Somehow I missed this gem. You combined two of my favorite things. :)