MakerBot Industries

Hot on the heels from contributing the mind-blowing Thingiview functionality to Thingiverse, Veteran MakerBot Operator Tony Buser (“tbuser“) is up to more hijinx, currently designing and printing a Laser Target Scanner on his newly built Thing-O-Matic #3745.

His project is quite gorgeous, and so is his love for his new MakerBot Stepstruder. Here is a tbuser tweet that has been making the rounds in the BotCave, and touching the hearts of all of us involved with launching this new product:

tbuser: More Stepstruder love http://j.mp/fnaQEp Seriously, I want to have it’s babies. #makerbot

Tony Buser, we hope that you and your Stepstruder are very happy together and live long and happy lives!

Plastruder base top plate - with ooze!

Yesterday I tried to print in pink plastic (a bath hook for my daughter) only to discover I was unable to back the black ABS out of my MK5 plastruder.  I could extrude, but I just couldn’t back it out with the motor or pull it out after loosening the Delrin plug.

By way of background, and in the interests of experimentation, I had recently tried a few things with my Thing-O-Matic that are kinda contra-indicated by the assembly and usage instructions.  In no particular order, and at different times I had:

• Kept the plastruder warmed up and let it sit for a while
• Let a filament run all the way into the plastruder and shoved another filament in after it

After trying the above and a few different filaments recently, I noticed a  whitish smear along the inside of my plastruder.  The smear was between the toothed pulley and where the filament entered the heater barrel.  I didn’t think anything of it since I had still been able to extrude and print.

Obviously, being unable to remove filament from my plastruder is not really an option.  In order to fix this problem I disassembled my plastruder.  I quickly discovered that the white smear wasn’t just along the path of the filament.  Apparently I had managed to ooze some plastic up out of the heater barrel, around the top of the heater barrel, around the circular hole in the acrylic base to the plastruder, and around the entrance to the heater barrel all along the inside of the plastruder.  This had the effect of “gluing” the acrylic plates of the plastruder together.  Fortunately, there wasn’t a lot of plastic and it came apart rather easily.

The only explanation I have for this is that I must have kept my plastruder hot for too long without running the extruder motor.  This would allow the heat from the extruder to travel up the barrel and essentially liquify the plastic.  Then, once I started up the extruder motor, it must have squished the plastic out of the heater barrel and up into the plastruder.  I also suspect that jamming one filament in after another exacerbated this problem by squishing the filament entering the the barrel with the new filament. ¹

With the plastruder disassembled I found white smear could be scraped off.  It had a gooey residue-like consistency – like old toothpaste.  It was easy enough to scrape it off with a putty knife.  Since I already had the plastruder disassembled, I flossed the extruder toothed pulley.  I also was able to remove the filament with everything apart.  I discovered that the black ABS filament was also covered with the white plastic residue.  The extra width created by the residue on the filament probably contributed to my inability remove the filament in the first place.  I also noticed a few notches ground into the filament from when I was trying to back it out.

Once done, I reassembled the plastruder, reinstalled it, fired up the Thing-O-Matic, heated the plastruder, and did a test extrusion.  All in working order!

1. Perhaps it even squished the first filament up against the sides of the plastruder causing the smear in the first place. [↩]

PLA jam!!!

My MK4 Plastruder is made of entirely stock parts, except for a printed insulator retainer, and worked great with ABS.  My first attempts with PLA about six months ago were alternately wondrous and horrific.  While trying to dial in the proper temperatures for my Plastruder for use with PLA I cranked it too high, the PLA tried to expand inside the insulator retainer, and liquid PLA was forced around the threads of the extruder barrel.  As I said, it was a horrific mess.

How horrific you ask?  Just take a look at this picture of my MK4 plastruder after I tried to extrude PLA:

BLOCKED

Yeah.  It was that bad.  Well, this weekend I gave PLA another shot with my MK5 Plastruder.  At one point I realized I was trying to print while still using the ABS profiles – and heating the PLA up to 230 degrees Celsius.  This was also happening while I left the area to put my daughter to bed.  The result was the extruder was operating way way too hot for way way too long.  These are not good things.

The result is the extruder kept the heat at 230 degrees Celsius, the PLA formed a blockage, and extruder motor kept forcing new PLA down into the extruder barrel.  However, due to the way in which the MK5 is designed, there was no place for the PLA to create a mess.

When I realized what was going on I shut down the extruder and pulled out the filament, pictured at the top of this post.  What you’ll notice is the area of the filament to the right is still clear/translucent while the filament to the left, which was down inside the extruder barrel, is a milky color.  Interestingly, the clear area of filament is still just as flexible as a normal piece of filament while the milky white section is extremely rigid.

This situation, running the extruder too hot for too long, would have been catastrophic for my MK4 plastruder and was basically shrugged off by my MK5.  All I had to do was loosen the thumbscrew for the Delrin plug, yank out the filament and blockage, cut that section out, shove newly cut piece of filament back in, and tighten the thumbscrew again.  This was the difference between a 30 second fix with my MK5 as compared to a problem that actually ruined my MK4 insulating barrier and kept me from printing until I got a replacement.

I’m still dialing in my temperature settings for PLA and will be posting some of my results later today.

On Wednesday Bre revealed MakerBot has a new printer in the works. ¹  Frankly, I have a tough time imagining what a new printer would be like. ²  With an Automated Build Platform, which incorporates a heated build surface, and a MK5 Plastruder you’ve got just about everything you could want out of a 3D printer.

I’ve been really impressed with my MK5 Plastruder.  I’ve been pretty lucky and rarely have filament jams, so I haven’t seen any improvements going from a MK4 to the MK5.  However, it’s given me a really smooth, even extrusion.  With my MK4 I noticed very slight imperfections in the ABS rafts and layers – like small bubbles and imperfections in the extrusion every few millimeters.  With my MK5, these have been almost eliminated.  I’ve also noticed that the minor blobs that used to occur when the Cupcake raised the Z platform have gotten smaller.  I haven’t made many changes to the Skeinforge profile, so I tempted to attribute this improvement to the new plastruder.  Perhaps one of the coolest improvements is the ease with which I can now swap filament.  The MK4 system for pulling out a filament required me to slowly back the filament out using ReplicatorG.  The Paxtruder-inspired Delrin plug can be loosened, filament yanked out of a warm plastruder, new filament jammed in, and the plug tightened back up in 10-15 seconds.  I can definitely tell you this makes me far more likely to swap out colors.  In fact, I’m tempted to try swapping out colors part way through a build, just to see what happens.

Unfortunately, I haven’t had a chance to fire up my heated or automated build platforms yet, so I can’t comment on their utility.  However, I’m keenly aware of just how much even a minor temperature increase can improve a build’s quality.  I’ve noticed that after about two print jobs my acrylic build platform is slightly warm to the touch.  This might be due to having a few warm layers of plastic on it – or might just be due to the slightly increased ambient temperature inside the Cupcake caused by the warm plastic, power supply, and from the plastruder.  In any case, even this slight temperature increase has been enough to cause a second and especially a third print job to noticeably more flat than preceding print jobs.  Having a print bed that gets more than just slightly warm must be pretty great.

I’ve never wanted or needed to print anything larger than my current build size.  Besides, that would also increase the build time.  I’m just not that patient. 

So, just what the heck could a new printer possibly bring to the table?  Or, more importantly, what would you want to see in a new printer?

1. Photo courtesy of jmtimages [↩]
2. I guess that’s why I just blog about their developments and they’re the ones who actually dream up new robots! [↩]

Are you rocking the Five?

When the Plastruder MK5 I ordered hadn’t arrived this last Friday I was a little disappointed because I was hoping to build it over the long weekend.  Luckily it arrived late Saturday!  Huzzah!  My weekend was saved!  I had put off soldering the Relay Board I got with my heated build platform since I haven’t gotten around to picking up a hotplate yet.  However, since the Relay Board was needed to run the Plastruder MK5, I busted out my soldering kit and got to work putting together the Relay Board and Plastruder.¹  Without further ado, here are the things I learned assembling and building my Plastruder MK5:

• When attaching the thumb wheels to the bolts, definitely use a vise.  I tapped the bolts into the thumb wheels with a hammer – and smashed the threads just enough to make the bolts useless.  :/ ²  If I did this again, I would definitely put the nut partway onto the bolt and tap the NUT rather than the bolt itself.  This would keep the force away from the threads and probably keep them from being damaged.
• When threading the nuts onto the retainer mounting plate, I found it easier to put the nuts about halfway onto the bolts – rather than almost all the way to the plate.  If you put them halfway on, it’s easier to tighten each bolt individually.  If the nut is nearly to the plate, you have to simultaneously tighten all screws or tighten them each a little at a time.
• The MK5 thermistor preparation instructions direct you to the MK4 directions for wrapping the thermistor.  The MK4 directions suggest you essentially sandwich the thermistor leads in between two long pieces of Kapton tape.  This is exactly how I built my MK4 plastruder – and it’s just not easy to trap these two thin leads in between pieces of thin sticky tape.  An easier way, and what appears to have been done in the MK5 pictures, is to separate the thermistor leads and wrap the Kapton around the leads – making sure they never touch.
• I would test the thermistor’s resistance and temperature measurement before attaching it to the plastruder.  If there’s something wrong with the thermistor, I would want to know long before I taped it to the plastruder, insulated it, and mounted everything inside the ‘bot.  Both tests are quick and easy to do before you assemble everything – just check the resistance with your multimeter then plug the unattached thermistor leads into the extruder board.  This quick sanity check could save you a lot of time and supplies by not having to undo a lot of work.  This would be a good time to test resistance on the power resistors too.
  With all the wires running from the plastruder and relay board, it can get confusing.  I picked up some heat shrink tubing the last time I was at an electronics store and am using them to color code each of the sets of wires – one small band at each end.  This helps me keep everything straight.  By just looking at the end of the wires and doing a sanity check against the bands on the motor, thermistor, or heating element I can quickly verify I’m wiring everything up correctly.
• I braid the wires together to keep them all in check.  There’s no particular reason for braiding over twist ties other than it just seems more elegant.

What did you learn while building your Plastruder MK5?

1. Photo courtesy of WoodleyWonderWorks [↩]
2. I’m just that strong. [↩]