Plastic Welding Gun (Plastruder MK4) by donutman_2000

This is the sixth in a series of posts about ways to get even better print results from your 3D printer.  The prior posts provided information on calibrating hardware, upgrading hardware, calibrating software, maintenance, and finishing by abrasion.   Your hints, tips, hacks, and suggestions have been awesome!  Keep them coming!  Today’s post is about a less common finishing technique, heat:

Heat.

1. Since ABS is flammable gives off a black toxic smoke and PLA will melt at relatively low temperatures I would never use an open flame to improve the look of a printed object.  However, the RepRap wiki has some documentation and information (with similar warnings!) if this is something you want to learn about.  Fortunately, there are several safer ways to use heat to help get a better printed result.
2. A heat gun can apply heat in a relatively safe and controllable fashion to smooth out rough spots on a printed object or even just help spots melt together a little better.
3. You can use a welding gun from the parts of an old extruder.  I have to admit that I’ve actually held two broken parts under a hot extruder to weld them back together.  Effective?  It was once I had the extruder extruding plastic essentially using it as a hot plastic glue gun.  Smart?  Probably not. 
4. Koiti suggested placing a finished object that had been removed from the raft back onto a hot Automated Build Platform to improve the finish.
5. Another suggestion that’s probably not a good idea is molding the printed object shortly after the print job is completed.  I’ve accidentally deformed more than a few prints by removing them too early.¹  Then again, in a few rare circumstances I’ve managed to fix a bad design or bad print by gently molding the still-warm plastic immediately after a print job.  For this I typically use a pencil or pliers.
6. You may also find that you want to try turning the heat down slightly on your Heated Build Platform or Automated Build Platform.  The reason for using a heated build platform is to keep the lower layers on an object warm while the top layers are being deposited.  If the bottom layers cool before the higher layers, the object can curl at the edges as it cools.  However, Nick Starno discovered that applying too much heat could lead to some slight warping in the object further up.  I would point out for any Automated Build Platform users that you might need to run your ABP slightly warmer (by about 1-2C) than a Heated Build Platform due to minor insulating effects of the belt or other materials placed on the belt.

Have you used heat to improve your 3D printed results?  Please share your ideas and tips in the comments section below!

How to get better results from your 3D printer – Part I (Calibrating Hardware)

1. How to get better results from your 3D printer – Part II (Upgrading Hardware)
2. How to get better results from your 3D printer – Part III (Calibrating Software)
3. How to get better results from your 3D printer – Part IV (Maintenance)
4. How to get better results from your 3D printer – Part V (Abrasion)
5. How to get better results from your 3D printer – Part VI (Heat)

1. As in, yanking it out as soon as the print job stops.  I can’t imagine why I don’t have the patience to wait 30 seconds… [↩]

Maintenance of your 3D printer

This is the fourth in a series of how to get better print results from your 3D printer.  The first three posts focused on calibrating hardware, upgrading hardware, and calibrating software.  If you are just tuning in to this series, check out the list of prior posts at the end.  And if you’re only following along via an RSS feed, you’re really missing out.  There have been literally dozens of amazing comments with many many more suggestions from other roboticists.  Even if you think you know every trick in the book, you’re guaranteed to find something you haven’t thought of before.  And if you’ve got an idea, a hint, trick, or hack – leave a comment and help out future roboticists!

• Maintenance. A well treated 3D printer should give you years of trouble-free printing. ¹  Here are some suggestions on how to keep your pet 3D printer well maintained.

1. Oil your X, Y, and Z rods.  I do this about once a month.  Since the Cupcake uses plastic bushings, I see a black plastic residue accumulate over time.  I wipe this off at the same time I oil the rods.
2. Periodically tighten nuts and bolts.  Again, monthly.
3. Periodically test and tighten belt tension.  I check and adjust belt tension rarely – usually only after I see a printing problem develop.
4. Periodically test your filament tension.  There’s a sweet spot to filament tension that’s a lot easier to set with a MK5 style plastruder than it was with a MK4 plastruder.  Too tight and you’re putting extra strain on the extruder motor.  Too loose and you’re not really getting the best extrusion possible.  As plastic filament actually has a slight variation in its diameter, this is something I monitor whenever I am printing.  It’s partially a way for me to fuss over my robot as it is happily printing away. ²  If I notice that the extrusion is suddenly too thin, a quick adjustment to the filament tension screw will fix this.  I’ve heard that adding a second nut to the filament tension screw prevents the screw from loosening slightly over time.
5. Repair or replace.  Having a 3D printer means that if a part breaks or wears out you can actually replace it.  Just accept the fact you’re going to bend, pop, snap, crackle, or pop a part.  When that happens you’ll need to rig or hack a temporary solution while you print up a replacement part.  One benefit to a solid plastic replacement part to a component that’s assembled out of layered plastic and/or plywood is that there are no parts to loosen over time.
6. Floss extruder gear.  Use something soft-ish like a toothpick to pop the plastic bits out of the gear’s teeth.
7. Clean out the plastruder.  The plastruder can accumulate very small plastic chips which fall out from the extruder gear.  If you leave your hot too long, you can develop a blockage that will cause plastic to ooze up into the plastruder.  Disassembling the plastruder is the best way to pull the extra plastic out.
8. Keep firmware updated.  The firmware has come a long way and I’m pretty sure it to go even further.  Don’t forget to update the extruder firmware too!
9. Keep software updated.  ReplicatorG is constantly under development.
10. Replace warped build platforms or build surfaces.  A flat even build surface will ensure nice flat builds without having to worry about the extruder head crashing into the platform.
11. Keep your plastic in a cool, dry place.  As mentioned above, the filament’s diameter can very slightly.
12. Check wire connections on any moving axes.  The cable clips attaching motors, endstops, and various other bits to the XY stages can work themselves loose after time.  I check these whenever I see that a cable might be working itself loose.
13. Cupcake – Clearing extruder nozzle blockage.  This is really only relevant to the MK4 style plastruders.  I’ve never had a bad blockage after running a MK5 plastruder for the last six months.
14. Thing-O-Matic – Clear the inside of your robot of any plastic boogers that might get wiped off.

1. And, if you’ve build the robot yourself, you can make sure that it will be running forever!  Isn’t DIY great?! [↩]
2. Just think of it as the roboticist version of a mom dabbing a corner of napkin and wiping your cheek. [↩]

ReplicatorG is your friend!

This is the third in a series of posts about ways to get even better print results from your 3D printer.  The absolute best part about the two prior posts, on calibrating hardware and upgrading hardware, have to be the voluminous comments.  Please keep your hints, tips, hacks, and suggestions flying in!

• Calibrate Software. Once you’ve got your 3D printer hardware tuned up, it’s time to look to the software, especially the Skeinforge settings for your machine.

1. Skeinforge calibration.  There are a number of guides out there, but the one I would recommend is the series written by Dave Durant.
   1. Skeinforge basic settings
   2. Five critical Skeinforge settings
   3. Configuring the latest version of Skeinforge
   4. Creating a new Skeinforge profile
   5. Tuning a new Skeinforge profile
2. Find the best print temperature for your choice of plastic.  The ideal plastic temperature would be hot enough that it will stick to the platform and to the layer underneath.  It should also be cool enough that by the time the next layer is laid down the prior layer isn’t too molten allowing it to deform.  I print PLA at around 195-205 for small to larger objects, respectively.  I print ABS at around 220-230 for small to larger objects, respectively.
3. Find a good build platform temperature.  Not so hot that the plastic is kept molten, but not so cool as to allow warping.  A good warm build surface also allows the plastic to adhere to the build surface better.  When printing in PLA I like to keep the build platform at about 70 degrees and at 135-140 for ABS.  There’s very little warping with PLA even without a warm build surface, but the PLA sticks so much better.
4. Even after your machine is well calibrated, there are still a number of ways to improve Skeinforge calibration.  There are just dozens of little settings to tweak.  Configuring the Skeinforge Oozebane setting can remove the little plastic strings that get left between parts. ¹
5. Calibrate Skeinforge for printing with a higher Z-axis resolution by trying to print with thinner layers.  The main downside is that printing overhangs may become more difficult.  Reading Dave Durant’s posts should help with this.
6. Tune your “start.txt” and “end.txt” files in ReplicatorG.  You can add some pretty cool things to the start and end files.  You’ll need to read up on your GCode, but it’s well worth the trouble to fine tune the start routines for your machine.  Perhaps you need a longer extrusion time?  Need to adjust where the wipe procedure homes in?  This is the place to get to work!
7. Experiment with using the “outline” plugin either in conjunction with or in lieu of the “wipe” command.  Thanks to Riche for e-mailing me this tip!
8. Skeinforge 0006 or 35?  It’s tempting to stick with an older version of Skeinforge once you’ve got all of your settings dialed down.  Switching to the latest Skeinforge version within ReplicatorG allows you to use the latest features, improvements, and plugins.  Yeah, it’s more work.  But, then again, if you were afraid of a little elbow grease you wouldn’t have build your own 3D printer, would you?
9. Cupcake:  Can you build a set of “start.txt” and “end.txt” files to replicate the auto-homing behavior of the Thing-O-Matic using your stock Generation 3 electronics?  I bet you can!
10. Thing-O-Matic:  Calibrate your starting height in Skeinforge.  Obviously you don’t want to smash the print head into the build platform.  Neither do you want to start building10mm above the build platform.  You may find that it’s best to start at different heights depending upon the material you’re printing on and the plastic with which you’re printing.

What am I missing here?  What software calibration tricks and tips do you have to share?

1. Some have referred to Oozebane as a dark art, not without some cause. [↩]

Z-Rider by Twotimes

The last post dealt with ways to get better print results from your 3D printer through hardware calibration. The suggestions and comments were easily the best part of that post, so keep them coming!  As before, some of these tips are more important to the Cupcake, but they’re all considerations when trying to get the best possible prints from your robot.

• Upgrade Hardware.

1. Make or buy a good feed system for your filament.  Some people use baskets suspended from the ceiling, coils sitting on lazy suzans, or filament spindle boxes.  I used a DIY filament spindle for about nine months before switching a filament spindle box.  The elimination of tangles was dramatic.  A simple tangle can completely screw up a print job by stopping plastic extrusion or yanking the Z stage or entire robot out of whack.  The investment in a good trouble free filament spindle box will make sure you can walk away from your 3D printer with peace of mind.
2. Whether you get a filament box or make your own, definitely get a “feeding tube” for the plastic.
3. Cupcake:  There have been many Z axis cranks, but the original by Zaggo is still my favorite.  This was the first printable 3D printer upgrade of which I really took note.
4. Cupcake:  If you’re upgrading from a basic Cupcake CNC kit, the most important upgrade you can get IMHO is definitely moving to the MK5 Plastruder.  This single upgrade will make your life easier than you can imagine.
5. Cupcake:  Source, print, assemble, and install Twotimes’ XY lowrider for quieter and smoother printing.
6. Cupcake:  Upgrade to the Automated Build Platform or source, print, assemble, and install the Pfierce Robotic Build Platform by Chooch for flatter and automated printing from a heated build platform.
7. Cupcake:  Source, print, assemble, and install the epic Z axis riders by Twotimes or TheRuttmeister for smoother printing and less Z wobble.
8. Cupcake:  Source, print, assemble, and install the Zydac’s Z Axis Extender Kit or the Pfierce Z-axis extenders by Chooch for extra build height.

What am I leaving out?  How would you upgrade your hardware?

How to get better results from your 3D printer: Calibrating Hardware

With the recent launch of the Thing-O-Matic, I’ve collected a number of ways to get a better result from a 3D printer. ¹  If you’ve got a suggestion, please let me know in the comments!  Some of these tips are more important to the Cupcake, some are really only applicable to certain versions of these printers, but they’re all considerations when trying to get the best possible prints from your robot.

• Calibrate Hardware. The most obvious way to get a better print is to calibrate your machine’s hardware.  These kinds of tweaks could take a number of forms.  You could:

1. Make sure all of the bolts/nuts are tightened properly.
2. Make sure all pulleys are tightened properly to their bolts.
3. Get the right tension on the belts by setting the proper tension on the pulleys.  There are a few pulley tensioners on Thingiverse that could help with this issue for Cupcakes.
4. Make sure the bearings on the X and Y axes slide smoothly.  If the hole the bearings slide into are too tight, they will cause the bearings to bind up on the precision rods.  The solution is to sand the hole slightly to widen it.
5. Insert something springy between the X or Y axis end caps and the X or Y axes. ² This reduces play, noise, and will ensure a slightly better print job when it comes to small details.  There are printable end caps that help reduce this problem.³
6. Make sure the extruder has the proper filament tension.⁴
7. Adjust your stepper motor torque for the Thing-O-Matic or Cupcake.  You want enough power that the stage moves in a responsive manner and won’t lose steps, but low enough that you’re not overheating the motor or operating in a needlessly noisy way.
8. Thing-O-Matic:  Make sure the endstops are properly and securely adjusted.  If there is any wiggle, you could get variable starting build heights.
9. Thing-O-Matic:  Make sure the cables running to the X and Y stages have enough slack to work and but not so much they will get caught on something.
10. Thing-O-Matic:  Make sure you’ve run the wires down the proper sides.  Even if you have your Thing-O-Matic wired properly, running the wires near to the wrong wires can lead to EM noise which could case printing problems.
11. Cupcake:  Level your build platform.
12. Cupcake:  Level your Z stage.
13. Cupcake:  Reduce the play between the XY axis stage and the XY build platform.
14. Cupcake:  Make sure there is no grime in the Z rod threads.
15. Cupcake:  Replace warped Z rods.
16. Cupcake:  Add Z axis wobble arrestors.
17. Cupcake:  Widen the Z axis holder on the Z platform by sanding the notch if you’re having a problem with just one bent rod.
18. Cupcake:  Take the clamp off the worst Z axis rod and double-clamp the best Z axis rod (via the MakerBot Support Stream and Charles Pax).

More tips on getting better print results tomorrow!

1. Photo courtesy of MakerBot [↩]
2. I use little bits of paper towel [↩]
3. I’m having trouble locating these Things.  If you can leave a link in the comment, I’ll update the post. [↩]
4. This is SO much easier with a MK5 Plastruder it’s not even funny [↩]

Robert Hunt's second Thing-O-Matic print

Thingiverse citizen Robert Hunt recently posted a picture of his second print – a Coin-op Bottle Opener.

My second print on my Thing-O-Matic #86 with the default settings, no tweaks yet. Printed pretty well.

That’s really excellent print quality right out of the box!