3D Printing Tips
Latest update: Oct 2014.
I received my Makerbot Replicator (1) early 2012, and have been using a dual-head Makerbot Replicator 2X since September 2014. Below are a collection of tips and tricks I’ve picked up along the way for using them, specifically.
Other than my blog, you can see my latest 3d creations over on Thingiverse.
Single head or dual?
When my Replicator first showed up, it was a dual-head model: This seemed like a great idea for this one main reason:
- Could print two colors at once. Two is better than one, right?
However, it didn’t work out so well for me, for these reasons:
- When the second head would start printing, there would be a slight delay. This would cause the filament to not always stick where it should, and a lot of overhang issue became present because of it, a lot of ruined prints. I went back and forth with Makerbot support for quite a while trying to resolve this. While they were very helpful, the issue never got resolved. Seems to work ok for other people though, so maybe I just had a huge amount of bad luck.
- The nozzles constantly slightly “drip” when not in use (single head machines do this too), causing specs of each color to embed themselves in the print when the other color is printing. This just looks messy to me.
- In reality, two colors isn’t enough to make a print look ‘good’: You really need to finish it (sanding\filler) and paint it. And once painted, it really doesn’t matter how many colors you printed it with to begin with.
I started using ReplicatorG in 2012, but by 2013 moved to Makerware. It should be noted that the “Print Software” is a combination of both a ‘front end’ user interface, and a slicing engine. The slicing engine is what generates the gcode the machine actually consumes to drive the toolpath. Based on current firmware, the Replicator receives this gcode in a ‘.x3g’ format created by Makerware, or ReplicatorG.
Slicing Engine: Skeinforge
- Seems closer ‘to the metal’ of the hardware. More configuration options (that I never used).
- Can be used with Sailfish Firmware (which I have yet to switch to, but plan to someday).
- Generates gcode much slower than Makerware.
- Not sure how often it’s being maintained or updated. Becoming antiquated.
Slicing Engine: MakerBot Slicer
- Slick, simple interface.
- Easy to use low\med\high print settings for new users.
- Specifically tuned to use the Makerbot printers (but should be usable by others).
- Generates “accelerated” print code: Faster is better, right?
- Being actively developed by Makerbot.
- In the past, new releases could be pretty buggy. But since 2014 I’ve had no problems with updates.
Others (I’ve not yet used):
- Slic3r (many folks in the forum currently say it’s more trouble than it’s worth)
- Cura (Software for Ultimakers, haven’t heard much about its usage on Replicators yet, but read it should work)
- netfabb (A $$$ solution. Everything else here is free)
- Repetier-Host (Based on Reprap firmware, it doesn’t work with Replicators)
- Simplify3D : This software looks very full featured and promising. But at $120 and no demo/trial period, I’ve yet to try it.
Converting to .x3g
- Makerbot Operators on Google Groups is where I usually head. Moderated by MakerBot.
- Makerbot Users on Google Groups. Independent from the above groupe.
- Jetty Firmware Google Group (if you’re using Sailfish firmware)
Issue : Filament not sticking to platform.
- Make sure HBP is set to 110+ deg.
- Possibly need new Kapton tape applied.
All filament types:
- Make sure the build platform is perfectly flat. The first Replicator I got had a warped plate (that Makerbot replaced, and newer versions should have).
- Make sure print platform is properly calibrated\leveled: Even the smallest variance in distance can cause poor adhesion: Make it as close as possible.
- Make sure the extrusion temperature is correct for your type of filament (see Print Settings).
- Use fresh “Blue Painters Tape”.
- Switch to a lexan build platform. Since I switched to mine, this has been a non-issue. See tips section below.
- Use a glass build plate covered in glue-stick. This has been working great.
Issue : “Air print”: The print stops extruding (but the extruder keeps moving) at some point before its finished.
This is one of the most common problems I’ve ran into.
- Your extruder-gear could be getting dirty\clogged: Take it apart, clean it out.
- You could have bad filament: I received a roll of silver ABS that would pretty consistently stop extruding after a few hours. I could see tiny bumps\ imperfections in the extruded filament. Remove the filament, soak the extruder nozzle in acetone\lacquer thinner over-night, and scrub out all the gunk with an old tooth-brush\toothpick.
- Filament line is criss-crossed: I’ve had rolls, both right at the beginning and as they approach the end of the spool, get their lines all tangled to the point where the stepstruder can’t physically pull any more filament: I’ve had to unroll and re-spool entire spools before to get around this
- Not enough/too much tension in the stepstruder/drive-block. This is one of the most common issues I’ve read about, and I’ve encountered myself. When the Replicator was first released it had a poorly designed extruder, with a small delrin plunger that is used to apply pressure on the filament as the stepstruder grabs it and pulls it down through the drive block. Over time, a groove can get worn in the plunger, thus less friction, and no more extrusion. The only way to address this with the stock setup is to pull apart the stepstruder, clean it out, rotate the plunger, and re-assemble. But considering it could fail in the middle of a long print, this is quite a design failure. Since I’d had so many problems with that system, I switched to a prototype “grub-screw” that holds the delrin plunger in place, rather than the stock washer. Something that MakerBot shipped to me before they started putting them into the Replicator 2’s. Since you can adjust the tensions on the fly with an Allen-wrench, it’s great, since you can change the tensions as it’s “Loading Filament”. However, over time the vibrations from the machine will cause the screw to come loose. I even tried leaving the Allen wrench in the screw, and fix it in place with a rubber-band. But even that would jiggle loose over time. My final solution: Print the “Spring Loaded Drive Block“, and order the hardware kit from Makerbot (even though the kit is for the Replicator2, it works on the Rep1). I was surprised that they shipped the whole injected-molded drive block with the kit: Best $8 I’ve spent on my bot, air-prints have been a thing of the past. Note that any new makerbot has this problem solved, you’ll only encounter it with old ones.
- It’s possible that when printing PLA, and you’re getting “bend up” issues (see below), this could be caused.
Issue : The print stops (locks up) before it’s finished:
- If you’re printing via your computer over USB, don’t : Copy the print to the SD card and print from the card. If there is any glitch in the computer\usb connection, things can go bad really fast
- You could have a bad SD card. I’ve had SD card fails, and the side effect is a print “just stopping”.
Issue: While printing, the stepstruder makes a “tick, tick, tick” sound, and there are gaps in the extruded filament.
- There is too much tension on the filament line. Clean the stepstruder, make sure the tiny plunger has the correct amount of washers (spacers): Too much tension and you get the ‘tick’, too little tension and the stepstruder gear will notch out the filament causing the extrusion to completely stop.
- See notes on “Air Printing” above, especially “final solution”.
Issue: When I start extruding, nothing comes out.
- I’ve ran into issues that so much filament drips out of the nozzle before printing starts (usually with ABS) that it can go for a few seconds before laying the first bit of filament down. To help reduce this, I heat up the printer, and then “Load the filament”, which re-fills the print head. I then immediately “start the print”. Filament can still drip out in the process, but it really seems to help.
Issue: PLA will “bend up” during thin prints or overhangs.
- I’ve noticed when printing extreme overhangs, as the extruded filament comes out and the head moves away, as the filament cools, it will actually “bend up” as it cools. Newer printers (like the Replicator 2) have active cooling fans that will blow air on the extruded filament as soon as it comes out the nozzle. This returns it to its solid state sooner to reduce these issue. The Replicator (1) doesn’t have this. I’ve also had filament jams that I’ve wondered are related to this: As the filament bends up, and the next layer extrudes, it applies back-pressure to the extruded filament, making it harder to extrude, possible causing the stepstruder to notch out the extruded filament? (That’s just a theory) Here are a list of solutions I’ve come up with to work around this problem:
- Remove any enclosures on your bot. After posting to the forums, I confirmed that for printing PLA, you should have as much airflow around the bot as possible.
- Get a fan, and point it at the print surface. I got a 4″ fan, and have placed in front of the bot, and have it aimed directly at the middle of the build platform. This seems to help a lot.
- Print yourself a print cooler. This, or this (with extra fan).
To date I’ve printed with ABS, PLA, and Taulman 618 Nylon. Below are the settings I’ve had best success with, using any of the default low\med\high print settings in Makeware.
- Extruder temperature: 220 deg.
- Heated Build Platform temperature: 110 deg.
- Clean fresh layer of Kapton tape, cleaned with acetone or laquer thinner.
- Extruder temperature: 220-230 deg.
- Heated Build Platform: Off
- If printing directly on the HBP, a clean fresh layer of ‘blue painters tape’. Otherwise works great on Lexan, or glass covered with glue-stick.
- Extruder temperature: 240 deg.
- Heated Build Platform: Off
- Clean fresh layer of ‘Blue Painters Tape’ (I have yet to try this on Lexan).
- If you hear hissing & popping during the printing, the filament is to moist: Nylon likes to retain water apparently, and it will actually boil as it prints, reducing your print quality by introducing ‘holes’ on the print where the pop happened. Checking online, I read about people baking their filament, so I gave it a shot: 1 hour at 220F seemed to do the trick: No more hissing & popping. However, it did completely warp the spool the filament was on,… so now it has to sit next to the printer, rather than on the spool holder.
- It’s “Lego plastic”. When trying to explain this stuff to people, it’s something they can wrap their head around.
- Easy to paint.
- Slightly more flexible than PLA.
- Doesn’t biodegrade: Can be used in wet\hot environments.
- You need to use a heated built platform: This is bothersome since you have to wait for it to heat up, which can take quite a while…
- You need to enclose the bot to keep out drafts. Stock bots don’t ship with any covers, so you need to fabricate your own.
- You need to use & apply Kapton tape to the heated build platform. This is a time consuming operation that is really difficult when trying to get all the bubbles out. Optionally you can use a removable glass plate with hairspray, but I have yet to try this myself.
- Don’t need to use the heated build platform: Printing starts faster.
- Don’t need to use Kapton tape: Can use blue painters tape instead (or a removable Lexan build platform). So much easier to re-install.
- Easy to paint.
- It’s “green”: Based on corn, biodegradable.
- It’s biodegradable. Wouldn’t recommend it for anything that involves heat\moisture.
- Gets really soft and moldable in hot/boiling water. This could be a pro, or a con depending on how you look at it.
Taulman 618 Nylon:
- Flexible and strong.
- Don’t need to use the heated build platform: Printing starts faster.
- Don’t need to use Kapton tape: Can use blue painters tape instead. So much easier to reinstall.
- Isn’t biodegradable.
- Can’t be glued (parts need to be melted together) or painted.
- Even with blue painters tape, the prints can literally pull it off the platform trying to curl. I’ve only started using this material, so have no solution for this yet (plenty online).
- You sometimes need to bake it in an oven to dry it out, to remove hissing & popping that is caused by the moisture in the filament boiling as it’s printed (see above).
- If you’re printing with Taulman 618 Nylon, you can print out the “Customizable Spool Holder for Replicator 2” (works on a rep1) to hold the spools in the back.
- I modeled one myself, but here’s a similar one: “Replicator print head centering calibration thing“. It’s basically a large rectangular shape that prints near the outside of the print platform, allowing you to fine-tune the bed adjustment as it prints.
- Once you get the built platform calibrated\leveled, you really want it to stay that way. Print a pair of “Replicator HBP height adjustment retaining jigs“, and they’ll help hold the adjustment knobs in place during all the vibration of the print sessions.
- Sometimes it’s hard to get the prints off the platform: Make a “Razor Scraper” to help get them off the platform easier. This is especially helpful when using a lexan build platform.
- When upgrading firmware you have to press a very tiny button on the back of the machine. If you don’t want to have to try to get the end of a pen in there, print a “Replicator Reset Button Pusher” instead.
- Leveling the print bed can be tedious and difficult to get right. Try using a “Replicator Bed Level Jig“. This is one of the most valuable things I’ve printed for my own setup.
Helpful Non-Printable Mods & Tips:
- Make yourself a removable build platform for PLA. I document my experience doing this here: Lexan: The 3D-printer build platform of the future. It makes it so much easier to remove prints from the build surface, since the build surface is no longer attached to your bot, and you can flex the surface to get the print off.
- Even though its common sense, I always forget which way to turn the print platform level knobs: I simply drew some curved arrows on the platform showing which way goes up\down… made everything easier during calibration time
- If you have a large print that is really stuck to the print platform, and you don’t yet have a removable platform (discussed above), sometimes a lot of torquing needs to happened to remove it. This will often totally screw up the calibration: Always re-calibrate/level the build platform after such removals.
- Take a small chunk (1/2″ square) of a kitchen sponge, and cut a slice half-way through it. You can wedge this over the filament as it loads into the guide-tube on the back of the machine. This will help catch any particulate matter on the filament and keep it from getting into the machine, and into your print.
3D Printing Hardware Companies:
- The Makerbot tech support has been awesome to work with since I first received my printer: From shipping me parts to troubleshoot problems promptly and free, to doing entire printer returns, it’s some of the best tech support I’ve encountered, ever.