makerbot replicator | AK Eric

Posts Tagged ‘ makerbot replicator ’

Latest Prints: Innsmouth Monster, and the Hulk

First, a disclaimer: I modeled neither of these prints. Everything up until now were simple designs I’ve come up with. But after showing the work around the office, it piqued the interest of one of our extremely talented modelers, Franco DeRosa. He had interest in turning his ZBrush sculpts into something physical, and I have interest in trying more challenging prints Based on that, the below prints were born. First, the final (painted) results from my Makerbot Replicator, then I’ll cover the process to get there:

Before any of the prints were started, Franco went through the pains of booleaning all the mesh together (since it was originally modeld for visual beauty, not 3d-printing consistency), making sure it was water-tight, and running it though both Meshlab and Netfabb Cloud to make sure of the consistency of the 3d models.

Innsmouth Monster

Franco did an amazing sculpt of the Innsmouth monster, based on the fiction of H.P. Lovecraft. By the end, this print ended up being the largest one (volume-wise) I’ve done to date (but not longest print time). Before I printed the large 9″ version, I printed out multiple smaller ones changing the print orientation : First I tried slicing it bottom to top, but this produced many artifacts under his chin I didn’t like. So I laid it down on its back and printed it that direction, with support material: While it deferred most of the errors to its back, the front looked great, so I decided to print the large version this way. Here are 3.5″ examples I printed at varios resolutions to check how it would look:

Left: 3.5" 100 micron, printed back to front. Middle: 200 micron, back to front. Right: 200 micron, bottom to top.

After I figured out the back-to-front print direction was preferable, I set out to print the large versions, at 100 micron. This process ended up being fraught with problems. I had multiple “air print” failures on both of the prints, which I think came down to a couple issues: A. The orange Makerbot filament was tangled, a lot, on the last 1/3 of the spool. I didn’t realize this until later, and ended up unspooling the remainder, and respooling it. After that, no more print problems. B. The print didn’t seem to like printing the front flat base of the pedestal. It would quit (air print) right at that location. My only guess is that all the fine detail caused the printer to slow down, and somehow jammed the print nozzle(?). In all cases I was able to catch it and reload the filament (by random luck), but on the print I kept for myself, I ended up having to fill in the errors with putty & sanded it, before painting.

The large 9″ 100 micron versions, in the printer:

The final painted version looks like a pewter monster-bust:

Print Info:

Material: Makerbot Orange PLA
Print temperature: 220c
Slice height: 100 micron
Print time: 25hr, 15 min
Print weight: 183g, additional removed support weight : 53g
Print surface: Blue Painters Tape (hadn’t yet switched to removable Lexan)
Print/slice software: Makerware
Other: Raft, support material

Hulk

Just like the Innsmouth Monster, Franco did an amazing job on Red Hulk. And like the monster, there were a variety of “air print” problems on the Hulk. To condense my findings, it came down to this: I switched to some gray filament from ToyBuilderLabs (who I’d read a lot of good things about) that Franco had picked up. And just like the previous orange filament, it had multiple tangles (when I reported to this to ToyBuilderLabs, the responded promptly and offered to replace the spool), but this time, the tangles were immediate (the tangles on the orange didn’t show up until the last 1/3 of the roll). But I didn’t realize until another air print happened, and I noticed that the spool on the back of the machine was higher than it should be: the stepstruder had physically lifted the whole spool against the strain of the tangle. So, I again began to unspool the filament, and hit one tangle so strong it physically broke the line. Ironically, that was the last tangle in the spool. Secondly, I replaced the default Replicator delrin plunger with a prototype “grub screw” version (that the Replicator 2 now uses) Makerbot had shipped to me last year (before the Rep2 was released), so I could better control the tension of the filament. However, even that failed on a print, when the vibration of the process vibrated the grub screw loose. Frustrated, to fix it, I took an allen wrench, shoved it in the screw, then affixed the allen-wrench to the stepstruder via a rubber band. 50 hours of printing later, it still seems to be a good solution to anchor that thing in place

The Hulk was such a ‘square’ shape, I printed it from bottom to top, but still went through the process of creating a 2″ version @ 200 micron,, a 4″ version @ 100 micron, and finally a 5.7″(ish) version @ both 100 & 200 micron. Once all the air print issues were resolved, I printed out all those versions no problem.

Here is the 5.7″, 100 micron hulk mid-print, and final with support:

Comparison of 5.7″ 100 micron hulk, 5.7″ 200 micron painted hulk, and 100 micron 4″ hulk:

And the final painted version:

Print Info:

Material: ToyBuilderLabs Gray PLA
Print temperature: 220c
Slice height: 100 & 200 micron
Print + support weight: 198g (for 5.7″ 100 micron)
Print time: 5.7″ 100 micron: 36 hours. 5.7″ 200 micron: 26 hours. 4″ 100 micron : 16 hours
Print surface: Removable Lexan
Print/slice software: Makerware
Other: Support material

Final Thoughts

It took a couple weeks to get each print “tuned in” and to get past all the “air print” issues. But as I type this another 36 hour hulk is being printed out. With these printers, its either feast or famine 😉

2013: 07/08
CATEGORY: art
CG
projects
TAGS: 3d printing
hulk
makerbot replicator
monster
sculpture
zbrush
2 comments

Lexan: The 3D-printer build platform of the future

Before we get started, here’s the end result:

Now let’s go back in time….

Being a Makerbot Replicator (1) owner, I don’t have a removable print platform: The results are printed directly onto the HBP (Heated Build Platform), from which you have to remove them upon completion. If it is a large print, and stuck on there really good, it can totally screw up your leveling\calibration for the next print, based on all the torquing that you inflict upon the platform getting the print off. Furthermore, if you print in ABS, there’s a good chance you’ll somehow mangle the Kapton tape stuck to the HBP, or printing with PLA, rip up your blue painters tape.

While browsing the Makerbot Operators Google Group, I read about people using glass as a cover for the HBP: Not only does it give you a completely level surface, but by putting down a layer of hairspray on it, your parts can stick to it as well. I was about to go out and and get some glass cut, when I ran across another thread talking about Lexan (a polycarbonate) being used as a build surface (that guy is selling it pre-cut for the Replicator 2, but since I’m Rep1, I’m out of luck and have to come up with my own solution). Plugging that keyword into the Googles, I found many other people had used Lexan successfully, so I thought I’d give it a shot: I liked the idea of something that couldn’t crack and slice my hand open under stress as my print bed. All that being said, I read many arguments for the pro’s and con’s of each (glass, Lexan, acrylic, etc). This post is mainly about the pro’s I’ve encountered with Lexan (no con’s yet).

Went to Home Depot, and picked up an overside sheet since I’d never worked with the material before: Wanted to make sure I could do some test cuts before I did the real thing. Here’s an example of what I purchased.

It turned out to be really easy to slice up on my table saw. Armed with some binder-clips, I had it mounted to my Replicator in no time. But then the first problem dawned on me: the platform is now 2.35mm higher than before. How can I compensate for this height adjustment? The adjustment screws weren’t giving me enough play. Querying the forums, I found out you can actually adjust the z-axis switch location. On my bot, it is mounted in fixed holes on the back wall. But unscrewing it, you can move it over to a variable position system (which I’d never noticed before) which sovles this problem: I moved it down the desired amount, re-leveled the whole platform, and thought I was in business.

Then the second problem appeared: After clipping it to the build platform, the Lexan was warping. As it turns out, the bolts that hold the HBP together actually stick up a small amount above the platform. I’d noticed this before when applying the tape, but since it’s on the extremities, never thought much of it. But when the clips press down on the lexan, they flex around those bolt-heads causing for an uneven surface. I took a close-up shot of the problem:

In the above image, you can see the calibration bolt, and you can see how to the right, the lexan has risen slightly above the build surface. This made for some really bad initial printing tests.

I got the thought in my head to mill out the area around each bolt-head using my drill press: I used a black sharpie to mark the position of each bolt-head on the lexan, and drilled out a few mm if the Lexan at each spot:

I should note that it’s important to have your lexan on some other hard flat surface when drilling: My drill press has an open-space on the platform below the drill bit (normally you want that so you don’t drill straight into the platform’s steel bed). But I found that the area beneath the carved-out zone would bulge under the drills weight\heat\pressure, which is obviously no-good. Putting another piece of lexan under the first, and drilling very slowly solved this bulging issue completely.

Clipping that back to the HBP gave great results:

The Lexan mounts completely flat to the HBP now. When I level it with my awesome calibration tool, I can get it within .01mm across the whole platform.

The final print results are great: PLA sticks to the Lexan super good. For smaller items (yet to print anything ‘big’), I need use my razor blade scraper to get them off. And for bigger prints, since the Lexan is flexible, they should be much easier to bend and ‘pop’ off. And of course, the whole thing is just held on with binder-clips, which means in theory I won’t need to keep re-leveling my platform after a tough print fails to release. Plus I can cut back on my blue-tape usage…

So here are some shots of the end result. Overall, extremely happy with the results.