Mono/Tricolour Mendel upgrades and improvements

Fan mount

This is our version of a mount for a cooling fan, directed at the printed parts. This should help the printing of overhangs and small parts. It takes a standard 40mm x 40mm x 10mm fan, and the fan wires connect to the ‘fan’ output of the Melzi. Check the polarity of wires when connecting to the Melzi. This fan will also fit on old, horizontal X-carriage Legacy Mendel printers. We use it on all our production machines.

Download from Github here (click ‘Raw’ then select File | Save File As…)

There are other, user-submitted, versions available on places like www.thingiverse.com

Alternative positions for extruders

Our instructions recommend fitting the extruders on the top bars, but this slightly limits the vertical movement that could be achieved. Also, it limits the placement of the filament spools for feeding in. In our print room we have experimented with a couple of other placements, which may be more useful to you.

The above placement is our current favourite, and just uses the tabbed clip from the extruder kit.

The above placement simply moves the extruder from top frame to the side triangle. It can actually go much nearer the top than this!

The above placement uses a bracket that used to be included on the Legacy Mendel (we had a load left over): get it from github here (click ‘Raw’ then select File | Save File As…). I removed the cylinder that acts as a stand-off, as it’s not needed.

Changing the position of the extruder may enable you to put the Bowden tube between the top bars, which can increase the maximum height you can achieve. We have managed to print 155mm high (X axis is a little limited at this height), but we also turned the Z motor mounts upside down, so the Z leadscrew coupling was a little higher. Then the next thing that hit is the X axis smooth rod on the top frame vertex, so it’s not going any higher than that!

Upgrade a ‘Legacy’ Mendel X axis to Mono/Tricolour style

You can upgrade your ‘Legacy’ Mendel to the Mono/Tricolour vertical X-axis design. We positively encourage people to experiment and adapt the printer to their own needs – it’s all part of the machine ‘evolution’. You can use most of the parts from your old X axis including the smooth rods, linear bearings, nuts and bolts, though there are a few of new parts. You can print your own axis parts, the files are available here: https://github.com/reprappro/Mendel/tree/master/Print-mendel/Individual-STLs

Extra parts needed:
MXL belt
MXL motor pulley
623 bearing (for the idler)

From the github repository, you’ll need to print out:
nozzle-mount-front.stl
nozzle-mount-rear.stl
x-carriage.stl
x-end-idler.stl
x-end-motor.stl
x-idler-cover.stl
endstop-holder.stl

You’ll find build instructions here: HERE.