Tuesday, March 22, 2011

Major Updates - Stepper Extruder, New Electronics

This is coming a bit late, but I've made some significant changes to my 'bot. I've got a RAMPS setup from Ultimachine. They're a great company to deal with btw, highly recommended. I am running Tonokip's firmware with RepSnapper, and using SkeinForge 40. I also printed out a Wade's extruder as well as a mount, and am using a MakerGear hot end. See pictures below.

The hot end is their 0.35mm nozzle, V3 hybrid hot end. I have been using it for a couple months now with great success. I print with 0.25mm layers which gives great resolution, comparable to commercial machines which usually print around 0.2mm layers. The small fan you see behind the hot end is to cool the PEEK thermal barrier, without it my PLA extruder gets too warm and starts to warp.

I also just received some new PLA from Ultimachine, in translucent blue, black, green, and white. I have yet to experiment with any of them, and I still have a couple pounds of the natural PLA left.

Wednesday, October 13, 2010

New Poast - With Pictures!

So here we go, I've finally got some pictures up. First is my extruder.

I was previously using nichrome wire as the heating element, but it can be a pain when rebuilding the hot end. To make the heating block I simply used a small scrap of aluminum, and drilled two 3/16" holes perpendicular to each other. I tapped the hole that goes through the thinner thickness with an M6 tap to screw the heater barrel into. The recommended hole size for a M6 tap is 5 mm, but I found that with a 3/16" hole the threads grip the barrel better with less of a gap. I just had to back out the tap a few times to clear the shavings. The resistor I used for heating was mentioned in my last post, p/n CWC-5.0RCT-ND. I wrapped it in aluminum foil and shoved it in the hole. I am using a standard 3mm 100k thermistor.

In the picture above you can see the PEEK/PTFE hybrid insulator. I had issues with the stock MakerBot PTFE insulator so I decided to go with this. The PTFE is normally held in with a snap ring, but I was unable to get a good seal between the heater barrel and the PTFE without pushing the snap ring out. So I decided to just do without the snap ring and tighten the barrel in until the PTFE stuck out a bit over the top of the PEEK. Then I tightened it to the extruder to hold it in. This way if the PTFE expands, it will only seal better against the barrel.

Here is my overall 'bot. As you can see I'm using a MakerBot MK4 extruder.

The four pictures above show the belt drive I use. The screw drive that the McWire usually uses is just too slow to be useful. I bought the pulleys and belt from SDP/SI. For the idler pulleys I simply used nylon spacers with a couple nuts on each side.

Here you can see the electronics set-up. I am using Gen 2 electronics. Eventually I plan on upgrading to an Arduino Mega with Pololu stepper drivers. For now this is working well, however.

I decided to do away with the weak acrylic retaining piece and bolt the hot end directly to the extruder.

Any questions please ask!

Sunday, October 10, 2010

It's running

I totally forgot I even had this blog. Anyways, I have my McWire RepStrap up and running, with belts driving the X and Y axes. I'm using a hot end with a hybrid insulator made by reifsnyderb. His machining is awesome. The heating element is a small piece of aluminum with a small wirewound power resistor embeded, a la Nop Head. My hot end is a standard brass one though, not stainless steel. The resistor I am using is part number CWC-5.0RCT-ND at Digi-Key. Any similar resistor should work just fine. When I have some time soon I will post pictures of my overall setup, along with some better explanations.

Wednesday, June 24, 2009

First Poast

I have become obsessed with the RepRap project. Read up on that site if you don't know what it is. It's basically a replicating 3D printer for the masses. I already have a McWire RepStrap cartesian bot practically finished. I figured that I would start blogging about it, as I know many other people are working on similar machines. I'll share all my frustrations and things I have learned in the process. My next post will be full of pictures and explanations of what I have done, and I will try and list as many discrepancies as I can with the official McWire plans. Stay tuned!