Printing with nylon!

I recently heard about the new ceramic hot ends that 2engineers have been working on. They are very simple hot ends made of ceramic, a brass nozzle and a small ptfe tube if your printing with abs. I didn't see any nozzles in 3mm so I contacted them and explained I wanted to experiment with it. He put up some 3mm nozzles and I bought two, one in .4 the other a .3.

I finally installed it on the Bumblebee II this week, and tried it without the ptfe tube for abs and of course it didn't work well at all. But when I switched to nylon it worked great. I had to experiment a little to find a good combination to print with and ended up with 240 c hot end temp, 80 c bed temp with a lite ply wooden bed.

The first round tuit came out pretty darn good, and I'm printing some door latches for my jeep and it is awesome. I'm using nylon from taulman and I'm very happy with the quality and consistency.

Picture of my jeep latch.

2Engineers
Taulman 3D

Bowden surprise :)

I've been thinking about converting the Mendel max to use a Bowden system. A first I'm going to use a single filament, but I definitely want to do multiple print heads for dual extrusion and more later.

I'm going to try the pneumatic press fitting first, and I also took another look at the quick change carriage. If I create the carriage that I mount the extruder on it will give me the same x travel as what I'm using now. On advantage is that I'll be able to switch between the Bowden and a regular one as I do my testing so I'll always be able to print if I need to. One other advantage is the fan mounts on the side so it's easier to see what's printing.

I'm hoping to have everything ready to install by this weekend and do my first test prints.

Awesome change for Pronterface

I've been running my MendelMax called the Bumblebee II using a Raspberry Pi 512 lately.  It runs the printer great once I commented out the visualization display.  The one issue I was having is that when it loaded the gcode file, apparently it was still doing some processing to estimate how long it would take to run and the dimensions of the print.

While that is a nice feature to have, there were two HUGE drawbacks to this on a small system like the Pi.  The first was it would take a while to load up a gcode file to print, and if it was too large it would run out of memory.  

So I dug into pronterface.py tonight and I found the call to do the previsualization when it loads a file.  A simple comment out of this line and now my GCode files load instantly into pronterface, and I can print any size file my printer can handle.  I need to make a minor change though and display a message that it's read the file and display the filename in the console. 

Hair Spray and Glass Bed

Well, I've been printing a bunch and I have to say that I think I found the combination I like best.  The Aqua Net hairspray on a smooth glass bed works great.  Absolutely no warping at all, and when the spray builds up a bit a rag and a bit of alcohol cleans it right off and I can re-spray it.

That build up wasn't that bad, but I wanted to see how easy it would be to clean.

So now that I'm happy with the solution, I'm going to cut my Borosilicate sheet to size, print some clips and mount it to my current heated bed.

The next enhancement will be to use the Open Rail and make the new thinner Y Bed.  Then I'll finally go ahead and clean up all the electronics and neaten everything up.

More experimenting with print bed

Well I decided to give the Aqua Net hair spray a try instead of slurry to keep parts attached to the bed.

My first attempts were not very successful, either with clean glass or with the etched glass so I had temporarily switched back to slurry.

This morning I decided to give it another try, and this time I used much more than I did the last time.  Using more definitely seemed to do the trick.  A few nice things about the hair spray.

1. I can print directly on glass, no etching required
2. It smells much nicer than slurry (and yes, I got the non-scented but you can still smell it)
3. It's very cheap, a large can was a little over a dollar at Wal-mart
4. Taking it off is very easy, just spray a bit more and wipe it off, or scrape it off if you want to
5. Even with extremely thin tall parts it didn't warp or peel up, and this was with 110 c bed temp.

So for now I'm going to keep using this as an option for printing, until I have some problems, or I'm satisfied that it's working well with all different types of parts.

Once I've reached that point I'll be cutting a new bed from my piece of borosilicate glass and use that.

Raspberry Pi and WiFi

Well I pulled out my 256mb pi and plugged in the wifi dongle with a clean install to try and get it to work.

I did all the updates and firmware updates, then instead of the built in wifi manager I gave wicd a try. Lo and behold it worked perfectly on the first try.

I went ahead and tried wicd on my pi connected to my RepRap, and after a few changes to what I had tried before to get my wifi to work I was able to get it connected as well.

So I think I'm going to do a clean install and document everything with wicd instead of the built in wifi manager, and I'm also going to see if I can optimize PrintRun a little more. I think that it's not displaying the gcode correctly, but I have a feeling it's still parsing everything in the background and using up memory.

Printing on etched glass part 3

Well, I've had mixed results so far printing on the glass. It seems like more complex shapes at the start of an object causes problems with it curling and getting caught on the hot end.

I have read that some people are using aqua net hair spray with plain glass, so I may give that a shot as well.

Even if I do need to use some slurry with the etched glass, it's a very good option compared to having to use any kind of tape or film and slurry.

I also found out that my OpenRail should ship this weekend, and I can't wait! I've decided to modify my y carriage design to put the delrin wheels on the outer to pieces of the frame, so their wont be any kind of carriage rail in the middle. It will be nice and open, and the wider width should give it tons of stability in that axis.

Printing on Etched Glass part 2

I really wanted to be able to print without any slurry whatsoever, so I went back and did some more testing tonight.

First I tried running the bed colder, and that seemed to make things worse.  I went back to my normal bed temp and tried to run the nozzle slightly cooler, and that had a little bit of improvement.  I was still having trouble with the first layer peeling up, so I dropped the speed way down to 10mm/s and that worked beautifully.  So my next test I heated the bed higher and low and behold I got a nice print of my standard test print a RoundTuit.

I've been experimenting a little with the nozzle height, and basically you just need your nozzle adjusted correctly, and it seems to print well.  I've gone back up to my normal nozzle temperature of 220, and I'm printing with a bed temp of 140 right now.

Time to do some other prints and see how those do, if they work well then I need to etch my borosilicate glass and install my new bed and I should be all set!!!