So I've recently started working on a new major revision of Replicape, rev B! And boy is it major in many ways! First of all, the stepper drivers are brand new, I'm going for the TMC2100 which have gotten a lot of buzz lately because of their many configurations for lower noise.
Don't believe the hype though, even though they are super silent with the StealthChop, that mode is all but useless for 3D-printing. Still, they offer a few more options for tuning the audible noise level, which I'm really looking forward to playing around with. Other than that, one of the major improvements is the price point. By changing manufacturer (see below), opting for a higher volume, doing some electronics voodoo (eliminating the DAC by leveraging some spare channels on the PWM chip etc.), the MSRP of $99 looks like it can be achieved as hoped. This does not mean that the board will be a worse product, quite the opposite. For this price, I've managed to add
- Brand new stepper drivers (TMC2100) for up to 256 times microstepping. (actually they are cheaper than DRV8825s)
- input protection on all end stops enabling up to 15V inputs (so you can use proximity sensors directly on end-stops
- reverse polarity protection on input (in case you get unlucky)
- four layer PCB giving lower EMC noise levels
- lower audible noise levels (ground return noise increased the audible levels)
- an additional fan output
- PWM enable (in conjunction with the Watchdog, increases safety in case of a kernel panic)
- Two 5V servo outputs, so you can add a physical Z-probe or Dual drive extruder (http://www.dglass3d.com/products/hpx2max/).
A second thing I'm excited about is the cooperation with Elmatica on the new revision prototypes. These guys have over 40 years of experience in the PCB business and they have been kind enough to do me a solid and help with the prototypes pro-Bono. They are also hooking me up with some sweet connections for the PCB production over in China, so the new boards will be top quality at a low price. In their words: "We'll hook you up with someone who will not screw you over!". Music to my ears. In fact, hearing that, I sort of felt like Jules in Pulp Fiction when Marcellus offers to send The Wolf. (See image below).
The plan now is to do a little prototyping for a few weeks and then kick off a Kickstarter to get the volume up to at least a couple of hundred boards which should enable a batch size of 500. By that time, the new Kamikaze CNC image should be stable with a Redeem V1.0