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.

Raspberry Pi and my Mendelmax

Well I had tried previously to use my Raspberry Pi to run my Mendelmax through Pronterface.  It worked ok until I tried to print something, then the visualization totally killed the Pi and the prints would be impressionistic blobs :)

I saw an article recently about how to setup a Raspberry Pi to run a RepRap style printer, and it basically combined a bunch of different installation steps into one guide.  There were a few hiccups with the steps but I was able to figure it out, the most important part was how to disable the visualization in Pronterface!  Basically you just search through the pronterface.py file and remark out any line with gviz in it.

I've been printing since this morning and it's been running great.  Another nice thing is that the latest version of the Pi image includes a WiFi configurator, and the ability to overclock the pi, along with some major speed improvements.

Before even opening up a browser would almost kill the Pi, now it's zippy and even in the middle of printing it usually hovers around 25-30% cpu usage, so I'm very happy with the results.  I've got a WiFi adapter on order which should be here tomorrow, and then I should be able to make my RepRap totally stand alone!

One more thing...

I noticed that when I use the super thin slurry if the bed is hot I can peel the slurry right off the bed and I can have a nice pristine surface to reapply the slurry on. 

Also the parts come off very easily while still preventing any warping!!

Today's Ah Ha moment

While I was printing the parts for the fix bot I was using my normal window tint instead of Kapton tape and a slurry of about 5% abs with acetone. 

I was running low on slurry, and I added acetone but forgot to add more abs. I also had to resurface my bed with new tint. What happened next was interesting. After heating up the bed I poured some of the slurry on the tint and it made a super fine layer on the tint. I went ahead and printed my part and made a note to add abs to the slurry. 

Well the print finished and it had no warping like I expected, but when I pulled the part off the tint I was very surprised that almost all the slurry came off in a single sheet. I was able to peel all the slurry off and have a pristine surface again!  

In the case of the slurry, it seems like less is better. I'm right now printing with 3 oz of acetone and a 8 inch piece of abs melted in it, and that seems to be just about perfect. I also don't need to use any rag to spread the slurry like when it was thicker. 

Fixbot build :)

This weekend I finally got the last of the parts I needed to build my FixBot.  I did decide to make a minor change, mine won't have any Sugru.

I printed the parts and in the process decided that instead of the 'finger' that it comes with normally it needed a gripper :)  After a quick search on Thingiverse I found an appropriate gripper to use.

After printing it and assembling it I found a few things I wanted to change.  The first is the servo tray is too small to fit the servo I have.  So I ended up scaling it a little bit larger to fit my servo.  The other thing was that the gripper arms are in two pieces because they originally were made to be cut on a laser cutter or CNC.  A quick bit of work in OpenScad and now the gripper is double height and a single piece.

I'll be printing the new gripper tonight, and doing some assembly tomorrow night and hopefully have it up and running.

FixBot Frame with Servos

Gripper Hand Small Version

Testing different slicing software

Well after reading a post about a problem that's occurring with Slic3r 9.2 creating some random banding in certain situations. Sound is right on top of it and is testing the patch already, but in the mean time I decided to see what else is available and how well they work. 

I've chosen Slic3r 8.2 (which is one of the best versions even though it doesn't have support working), Slic3r 9.2, KISSlicer, and Cura. I've chosen a model of an owl that I like because it has a lot of variation from square at the bottom to a very small point at the very end with the ears and a lot of complex shapes going up. 

I sliced the model with the same settings with each program and I'm printing them with the same printer, filament to provide a consistent test between the slicers. 

I should finish the prints tomorrow, and then I'll be taking some photos of the different areas that show differences between all the programs. 

Back again

Well after some changes in the things I've been working on I'm back to posting here.

Quick summary of what's been happening since I finished my Prusa:

1. Tweaked and got it running really good

2. Did some modifications with the Z-axis, and the Y-bed to make it run smoother and heat faster

3. Switched to Borosilicate glass with Window tint on it.  PLA prints directly on the window tint and for ABS I'm running slurry which works really good, sometimes too good.

4. Purchased a Ramps set and a control panel to upgrade the prusa.

5. Built a new Mendel Max machine, first with the default Y-axis, and recently upgraded it to use MakerSlide, more details to follow.

6. Z-axis on the Prusa has died, so it's waiting for the Ramps upgrade now instead of troubleshooting the Sanguinololu.

7. Just upgraded the hot end on the Mendel Max to a new J-Head Mark VB and I'm extremely pleased with it's performance.  I also went ahead and moved back to a .5 nozzle because I really didn't need the .35, and it was tougher to maintain and run.

8. Got most of the parts for a laser cutter, which is going to be my next project.  But I am going to do two things before I work on the laser cutter.  First I need to setup my workspace at my house in my old computer room, the second is I want to get my CJ-5 running again, I really miss it :)

I've started to experiment with some timelapse videos which you can view on my YouTube channel.  I'm enjoying the videos so much I'll be using another webcam that allows an external trigger and hook it up to the arduino and use the M243 command to trigger a capture at each layer change.  That should make for some much more interesting and consistent time lapses.

I also have purchased the components needed for Wildseyed's hot end and may experiment some with that.