Before an year I decide to make my own 3d printer instead of baying one as all printers on the market for makers do not offer troubleless dual extrusion and are overpriced. I also decide to use diffrent mechanical system to prevent ringing.
So I end up with ballscrew modules bought second hand from ebay, Duet Wifi board with custom extension, E3d v6 Gold and Bondtech BMG Bowden extruders.
At the end I manage to nail everything and start printing. Thanks to my Printerbot Metal Plus and my CNC I manage to do rest of the parts I need.
So the result:
Pros:
Dual extrusion without anty-ooze structures like shield, tower or anything. No ringing at all.Aligment of extruders before every print and everytime perfect first layer.
Cons:
Lower Jerk and Acceleration settings due to almost zero elasticity of the system. Bowden setup with long tubes.
Very nice. I like the lifting dual extruders. I’m a bit surprised you went with a cantilever based design for the X-axis if reduced ringing and accuracy was your goal though. I’m personally not a fan at all of the cantilever design unless your goal is lowest cost possible.
I’m thinking you could probably reduce the travel distance of the nozzles when raising/lowering them by at least 1/2 and probably increase the speed of that movement dramatically That should help reduce print times on prints with a lot of “tool changes”
I increased the speed of the auctiators 3 times, so now they are fast enough. I need this distance as I block the nozzle with flat spring you can see it on the video. Without this spring I need to use ooze shield as hot ends will leak on the print. This prints on the picture are produced with PETG.
The idea is that when the nozzle goes down the spring goes down and backward and at some point it goes so back that nozzle goes bellow the spring with 2 mm. This is absolutely passive nozzle blocking system that is simple and reliable.
I was skeptical too for cantilever design. But I decide to give it a try as I was advised from my friend who is mechanical engineer. Z Axis is double bearing so the contact area is huge and those linear modules are with two rolls of balls per side so they form square contact and really they are very rigid and heavy. I can’t notice quality degradation in different speeds or any Z wobble. I have Printrbot Metal Plus and I can see z shift but with this printer sides are perfectly aligned. And yes they are expensive if I need to go for second Z axis I should spend probably 300 euro for second hand one plus I will need one more driver and motor as single TMC2660 will not survive two Z motors.