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. 

WFMY 2 Good Morning Show

I had a chance to take my printer and demonstrate it live on the Good Morning Show today.  It was a lot of fun, and the whole group was very excited to see the printer and learn all the things it can do.

This is just getting me all pumped up for the Burlington Maker Faire in April.  I want to make sure that this year I have plenty of things to give away and no one has to wait for something to print :)

Video clip of the interview

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!!!

Printing on etched glass

Well I've had a chance to print three plates and three single parts, and the etched glass with slurry is working quite well. It holds well without being hard to remove the part after printing. I think I may try printing without slurry again and bumping up the heat to see if that helps with adhesion, it would be really nice to not have to use slurry.

The durability of the glass compared to window tint is apples and oranges, unless I break the glass I think it's going to last a long long time.

Experiments in RepRap

Finally got some free time to do some experimenting with the RepRap again, well I chose to do some experimenting. I've actually got quite a bit I should be doing :)

The first was switching the Bumblebee II over to the new 512mb Raspberry Pi that I got today.  Shut down the old one, moved the SD card over and plugged everything in to the new one and it was up and running.  The memory does make it a bit snappier, but more important I can load almost all the gcode files into pronterface without an issue.  It's still just a bit much for the full MendelMax part plates, but I have those on an SD card anyway so it's not really a problem.  I'm still waiting for the new WiFi dongle to come.

The next thing to experiment with was kind of driven out of necessity.  The window tint once again started to come off the bed, and I decided to go ahead and try the glass plates that I etched at TechShop in Raleigh.  I had about 4 different patterns to experiment with.

I tried the plain checker one first.   It seemed to do well except on the parts where the glass was still smooth.  After several layers that part of the print started to peel up.  So I ended up stopping the print on that one (and yes, I'm using RoundTuit's as my test prints)

Next I decided to skip the other patterns that had smooth glass in them and go to the 100% etched piece.  While it did much better it still had some trouble starting a thread of plastic, it ended up pulling it up off the glass as it moved away from the start point.  So I ended up applying an extremely thin coat of slurry and that seemed to do the trick.  Nice matte finish on the bottom, no warping, and it came off the bed very easily.  A nice side effect is that the rest of the slurry left was easy to scrape off with a razor blade.

So for me right now the 100% etched piece with light slurry is a huge improvement over the window tint I've been using.  No worries about having to replace the tint when it get's damaged or starts to break apart, and it seems to work great with no warping.

I'll probably buy another month at TechShop and etch the borosilicate piece I have for both the Bumblebee II and the Hippie printers.  I also have a few other things I want to cut before I have my laser cutter up and running (I've started ordering the last pieces I need)

More on the Raspberry Pi and the Mendelmax

Well I've been printing using the standard (well slightly modified) pronterface on my raspberry pi straight to my mendelmax. I have not been able to get the wifi working, but I do have a shared drive that I can access with my Mac Pro. So my tool chain is to download the stl, slice it then save it directly to my raspberry pi. I then use vnc to run pronterface and load the file and start/monitor the print.

The one big issue I've run into is the memory on the Pi. I still have the 256mb version and it will do fine for probably 75% of the things I've printed. But on complex objects, most notably the x carriage for a mendelmax, it runs out of ram and shuts down pronterface. I can still print from the sd card, but a newer version of the Pi with the 512mb will be ordered shortly :)

Other than that the latest distro is much faster, I'm seeing much better performance when I vnc in, and I can actually move windows around and use it while on a 4g connection.

I'll probably be ordering my new pi this week, and then anxiously awaiting its arrival :). The current one will probably be going into my CJ as the main controller for all the devices I want to add in it.