RepRap

WhoDat Festival Fun

Had a wonderful time yesterday going to the WhoDat festival at Doodad farm in western Greensboro yesterday with the Alamance Makers guild.

I took the Hippie out and was printing Yodas, Round Tuits, nautilus gear puzzles, and a few Doodad and WhoDat coins. Had lots of great visitors stop by and chat, and lots of kids with AMAZING questions and tons of enthusiasm.

Thanks to everyone who stopped by!

Upgrades and improvements

Well the makergear hot end I installed on the hippie was apparently one I had problems with before, so I just went ahead and got two new J-heads.  One is for the hippie and the other is for the bumblebee.  I did try the chess head ceramic hot end from 2engineers, but after messing around with it and talking with them I realize that it's not really suited to use with ABS/PLA, so I'm just going to keep them for the Nylon and Polycarbonate printing.

There was a recent post and update to Marlin that has me EXTREMELY excited.  Basically it's true auto-leveling for the bed, but it's actually more of a compensation instead of actually leveling the bed.  You install a servo with a microswitch on the end, and it will swing down and measure the bed height at 3 locations.  Then with this measurement and the configuration of the offset of the microswitch to the hot end tip it will automatically adjust z-height dynamically while printing to provide a perfectly aligned print with the bed.  The really nice thing is that it appears to be very straight forward to implement, and it works with silly mis-alignments.  The video on Youtube shows almost an inch of tilt left to right, but the printer compensates not just vertically but actually tilts the object so it's perpendicular to the bed.

I was just going to install this on the bumblebee thinking that the hippie wouldn't have room, but after desiging a holder for the servo and switch I test fitted it and it will be just fine on both my printers.  The only drawback is the hippie is still running a sanguinololu, so I took the RAMPS from the bumblebee since it's already torn down and I'm in the process of upgrading the hippie.

For the bumblebee I decided to go ahead and do the upgrade to the RAMBO board from ultimachine.  This is an all-in-one solution that Made In Space is using for the 3D printers going to the ISS.  The advantage is you don't have seperate boards, a mega, the RAMPS board and the A4988's so there's less chance of an issue with connections.  The drawback I've heard was that if you blow a stepper controller you have to get a new board, but in the 3 years I've been printing I have yet to have a board go bad (knocks on wood).  It has some other really nice features, like seperate power bus for the heated bed, extruders, and motors. digital trim pots for the steppers, screw connectors for hot end, heated bed, fans that make it very easy to install.  The one thing I'd really like to see is screw connectors for the stepper motors.  Almost everything else is a screw connector and I think it's time for the steppers to follow suit :)

My friends Ordbot is coming along well, he has all the mechanical parts and is assembling it now.  I gave him one of my backup extruders with geared stepper motor while I printed his in a color to match his printer.  I expect that in the next two weeks I'll be heading over to help him with the calibration and initial setup.  He also has mentioned that he likes the Ordbot design, very solid and easy to align and assemble.

Back to normal printing and the Ordbot

Well I've finished experimenting with nylon and I made a few parts for my jeep that I'm really happy with.

I've started the upgrade of the bumblebee printer, installing a new bed, heater, new extruder nozzle and basically cleaning up everything from when I first got it running. I've decided that for now I'm going to use .4 nozzles as a good compromise between detail and speed.

I've been printing parts for an ordbot for a friend who wanted to build a reprap and I really like the design. It's going to be easy to align and also easy to enlarge the axis if you want too. It also has a lot of open space around the extruder, which is going to be important for the new enhancement to marlin. They have finally got auto leveling working really good, and it just requires a servo and another end stop switch mounted on the extruder. My next printer will be an ordbot with that feature :)

My hot end on the hippie printer, a standard Prusa , finally failed so I've switched back to another MakerGear hot end which is my last one. I'll be putting a j-head on it just like the bumblebee as it's been performing great.

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. 

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.