Servos Instead of Steppers, Induction Heating

[tjschweizer]

I've been running my Rostock Max V3 for a few months now, and I have had some things I want to try. I've searched these forums and a few other 3d printing forums and haven't found too much, so I thought I'd just get a feel from users here.

First, has anyone tried to replace the stepper motors with servos? I'm a huge fan of closed-loop systems, and if properly tuned I think there could be quite a few benefits. The Repetier firmware doesn't support servos, do any of the others?

Second, I have been looking into using an inductive heating system for the nozzle instead of resistive. Any thoughts? I'm working through the equations now to try and optimize the dimensions, and so far my plan is to basically place a threaded rod like in the Prometheus inside a casted ceramic housing with the induction coils. If done properly, this can really reduce the size of the heating element. Also I want to implement a water cooling block for the plastic-transition area.

I'm mostly in the planning phase now, I plan to start designing within the next week. Of course I'm still debating if I want to try this on my V3 now, or order a Metal Max frame and basically build it up from there. 2 printers is always better, right? Just looking for any thoughts or if anyone has a link that I missed.

[Eric]

Re: servo motors, cost is generally why it's not done. How much are you willing to spend on motors and electronics? There's a lot of discussion on the topic out there, just not much in this forum. This page is a good intro, if you need an intro: http://reprap.org/wiki/Motor_control_loop

Re: water cooling. It's been done by a few here. Once you figure out how to make a suitable water block for your hotend, the rest is just like PC solutions.