I bought a Monster8 board some time ago because I needed a control system with 5-7 RAMP’s for my PnP machine. I got a bit surpriced that no-one else uses this for OpenPnP, so I might be up for a surprice. But, lets get cracking. This board is very powerfully and much cheaper than the alternatives. The only challenge is that it lack a few 6-12V PWM ports, so I added a very simple 4 x PWM board as well (not pictured).
I have a draft of the control system below:
My design is based on LumenPnP which is a variant of OpenPnP, but I have done so many adaptions that it is not much left of the original design anymore. I actually build the frame some 1,5 year ago and was a bit annoyed with some of the crappy mechanic solutions on the original. The new design they use is improved and actually implement some of the same modifications I already had done.
#1 Stronger Frame. I decided to add an extra 2020 frame to get the machine more stable.
#2 I added tank belts for wires and pneumatic.
#3 I moved all moving parts away from the working plate to achive less vibrations. Pumps and solenoids makes the machine vibrate.
#4 I designed a new head that easily can be expanded to a 4 or 8 head machine later. That said I will start with a modified version of the LumenPnP double-head (illusrated below) as a start because adding heads also need more RAMPS, Sensors and Pneumatics. I modified the head to match sensors and belts I was using.
The design abobe is different from the original design that had some crappy screws that needed adjusting below – something that is a problem since the working plate is straigh below.
#5 More End Sensors. I added end sensors everythere. And one extra on Y axis as well as a 2nd RAMP here. It is two steppers working together and over time they can get out of sync so it is an easy fix to have two RAMPS and two sensors to enable adjusting the frame.
#6 Linear bearings. The original design used rubber wheels, while the new design uses linear bearings as illustrated below. I will add the linear bearings, but I will not use my own head design yet – I will add the new heads as we move to a machine with more heads later.
#7 Standard End Sensors. I ignored the special LumenPnP sensors and designed for standard sensors available on AliExpress.
#8 Standard Control System. I ignored the special LumenPnP control system and decided on Monster8 as base. To be honest I also have two other 3D printer systems based on AVR, but I don’t want to work on AVR anymore and Monster8 uses STM32F407Rx.
To complete the machine I plan on using Raspberry PI with a screen and keyboard to run OpenPnP connected to Monster8 through USB-C.
I have lacked tim/motivation to start on this, but my latest CAN board is some 140 components and I really feel the main of not having a PnP machine.
I will have a dig into Marlin, Klipper and Smoothieware for a possible port – but, I have not decided on that yet.