One of the problems I’ve encountered in the past when using RAMPS electronics to control a dual-extruder printer is the lack of sufficient fan support. Dual extruder setups can require a few fans, usually one controlled fan (for cooling the print) and one or two always-on fans for cooling the hotends. Adding a second hotend takes up the 12V MOSFET usually used for running a controlled fan, leaving no option but to solder directly to the 12V lines on the board – which removes any control over these fans.
If your printer has an always-on power supply (like a regular LED-style power supply as found on most printers) then these fans are going to be running 24-7 unless you manually switch off the power. I had to deal with this for a few days while testing the MK2 printer, and I decided to play around with the problem and see what solutions there are.
I thought I’d take the time today to talk about a few of the things I’m doing during development of the MK2 printer to address a few problems in the MK1, and how I’m trying to keep the design as flexible as possible.
I’ve been selling Prusa Mendel i3 kits on Aus3D for a while now. The kits I’ve been selling so far (which I’ll refer to as MK1 kits from here onwards), are fairly decent kits. I didn’t design them, they were designed and manufactured in China – I’ve been buying them in and making a few improvements before shipping them as the Aus3D Prusa Mendel i3 kit. I ended up reverse-engineering CAD files for the frame so I could print / cut replacement parts locally, and I’ve had these files available on GitHub for a while now.
As a business strategy, this approach makes sense. China is good at making stuff, and these kits work pretty well – better than most other Chinese printer kits I’ve tried. As someone trying to run a business, I’ve been happy to attach my business’s name to them.
As an engineer, I know we can be shipping a much better kit.
As I’ve mentioned previously, I recently put together a Printrbot Simple Makers Kit 1405 for a weekend project. In my earlier post, I discussed designing and printing feet to fit the 1405 in order to stabilise it, without interfering with a mounted Raspberry Pi running OctoPi.
Swapping to a Raspberry Pi B+ proved to be more challenging than I expected.
I recently put together a Printrbot Simple Makers Kit 1405 – what a great little printer! Assembly took less than two hours, and it was printing away soon after
By default, it’s a pretty stable printer. However, I had an issue where the wiring underneath was lifting the printer up a little bit, introducing some ‘wobble’ into the printer. I could have just shortened the wires, but I decided to print some feet instead to stabilise the Printrbot.