Monday, December 28, 2009

Print succeeded

Used the tumble dryer as an air humidifier and sucesfully printed the first part. The other four are (as you have guessed) printed with too dry air conditions and Rapman reset after ±20 layers.

Design for the extruder (on short hold)

Made a design for the extruder that needs to be printed but am unable to print it at the moment due to very frequent resets of my rapman due to static electricity. These resets started occurring with multiple people around the same time and are related to the dry winter air. At the moment the only thing that helps is running the tumble dryer in the same room, hope I have enough laundry to finish the two extruder parts this week.

I am using an old baseplate from my rapman extruder as a base for the syringe holder. On top is a printed part that holds the syringe, Ill probably just glue the two together. The syringe goes in from the top and is locked in place by the upper part. The upper part has the valve mounted on it and a tube running true it. At the base is a system on which the rubber plunger with drilled true hole snap fits. This closes the syringe air tight. Both parts need to be fixed together with some kind of clip, I could also use screws but I rather have something that is easily opened to refill the syringe. Will see how this design behaves when we can test it.

The bottom part is finished, the top needs some extra work like screw holes for the valve and I need to draw the clip to hold both parts together.

Saturday, December 12, 2009

claystruder 1st test

So here's a quick first test using 3 bar in the first seconds then 6 bar. At 6 bar there is too much pressure at start but thats solved now, there was a 10m hose in between the compressor and the 1/8 inch tubing. There was to much pressure building up there. Now I need some sample sizes of short, blunt luer-lock needles but unfortunately they come in boxes of 100 pc.

Claystruder 1st test movie

Wednesday, December 9, 2009

Claystruder parts

Our plan with RepRap has always been to use it as a tool in our design practice and to experiment with materials and RP techniques. The first goal was to extrude ceramics, that got a bit in the background while we discovered the wonderful things you can do with the default ABS extruder :-)
But now we are on track again to build a claystruder! We where first working on a stepper based syringe extruder but never finished that one, Bits from Bytes is developing one so we rather wait for that one instead of losing time on the same thing. After talking with Bre Pettis about their Frostruder MK2 experiments I dived into it. Its a much simpler machine in terms of mechanics and has the advantage of instant on/off, so no ooze.
So we ordered a 12v 3/2 solenoid valve, this is much cheaper and easier than the two 2/2 valves Makerbot uses. Zach used two 2/2s, one to pressurize and one to depressurize because they where easy to find. A 3/2 valve is made to do that, an extra outlet is used to release the pressure when the valve is closed.

Here you see the solenoid valve with the transparent tube running to the compressor and the black tube will go in the syringe. On top is the exhaust to depressurize and on the back is a quite large 12v connector.

The bad news is you need a compressor, which makes a LOT of noise and is a lot more expensive than a stepper :-). We had non in the studio here but we could really use one so went out today and spend some cash.

Did a quick test today and everything works perfectly! Now I need to fab a mount for the syringe an we can test extrusion.

Photo Gallery

We have a photo & video gallery showing the construction and use of our Bits from Bytes RepRap: