nick-foley

Pics, or it didn't happen. Really though, without photos, it will be very hard to help you.

Apparently it comes in a bottle. I will probably order some from the guy and report back.

Has anyone tried this, or have any insight on how it works? I'm interested in purchasing some from this guy, but have very little info on what it actually is...

I made this upgrade about a month ago, and am appreciating it more and more as I use the machine next to others which haven't been upgraded. XY motion by hand is much, much smoother - and much easier - at the same belt tension as well-functioning (ie concentric) Ultimaker MXL pulleys. The prints that come off of this machine are definitely much better prints than the ones that come off our other two Ultimakers with MXL pulleys. The printhead is different though, so it isn't a direct comparison, but the XY system is helping, no question. Another major advantage is sound - the machine is much quieter using GT2 vs. MXL. As I've said in other posts, the biggest reason to upgrade is simply the fact that Ultimaker's stock pulleys have some pretty sloppy tolerances and can be extremely eccentric, but I think the other touted benefits of GT2 (lower backlash and smooth, silent motion) are probably worthwhile.

If you're having problems with your machine, I think the extruder drive is probably not the source of the problem, unless it is assembled incorrectly. I have 3 machines running with the same version of the extruder drive as you and they work very well on filament diameters of 2.7-3.4mm, ABS, PLA, Acetal, Nylon. We have made other mods to our machines, but the extruder drives have been kept stock. I agree that there are improvements that could be made, but there are many things I would upgrade on our machines before spending time on the extruder drive. Exactly what problems are you having?

This support material method is a huge improvement. I just finished a new part which I printed a week ago with the old support and the difference is incredible. Default settings. The old part took 15+ minutes of carving to get all of the support off, and the surface finish under the support was terrible. The new part was cleaned in under a minute and had a much improved surface finish. Some of the support even came off perfectly when simply removing the print from the bed!

True. The acetal filament is so rigid and strong, though, that I think the possibility exists for some great retraction qualities, and I'd like to test them. My prints today with the fused filament came out very clean, but they weren't prints that benefited much from retraction. I'll try some stuff tomorrow with more jumps to see how things come out.

As an update, I've started fusing filament rods together using a flame and a file - the results are extremely clean and easy to achieve. This should solve the retraction problems for now. I'm also mid-print with Black 1/8" acetal rod from Amazon.com, and the print seems to be going well. It is definitely a different polymer mixture, as the filament has a different feel, stiffness, weight. Will post results when the print is done.

Over the past few months, we @ Social Bicycles have been blown away by the quality, speed, and reliability of our Ultimakers. The parts coming off of the machines have changed the way we make products - not only how we develop and test them, but even how we mass produce them. PLA is a great material, too, and with the right settings and a high quality filament (Printbl FTW!) we've been getting beautiful, precision prints with ample strength for both prototyping and real-world requirements. Nonetheless, our application (bike-sharing systems) frequently demands something higher performance than what PLA is capable of delivering. I've experimented with other materials, like ABS (smelly, tough to get good prints from a stock UM) and Taulman Nylon (awesome material, strong, but not as rigid as PLA, and a lot slower to print) but what I knew I really wanted to print, from the beginning, was a material we already make many of our production parts in - Acetal. (As a quick overview, Acetal (or Delrin, or POM) is a strong, rigid thermoplastic with excellent wear resistance and very low friction. It is frequently used for gears, bearings, and moving parts.) After several weeks of testing, I am happy to say that we are 3D printing in acetal. We are getting amazingly strong, slippery, rigid, complex parts with only very minor modifications to our stock machine. It is frequently said that 3D printing is limited in its ability to replace traditional mass-production because of the limited materials it can utilize, but Acetal is one plastic for which there is generally no superior, and the parts we have been able to produce are certainly as strong as their injection-molded counterparts. Here are a few photos of one part I printed. More details about the process below. Print in progress A buttery-smooth helical focusing mechanism for a camera lens I have (Printbl Grape PLA, White Acetal) Will post thingiverse model soon. The "filament". ACETRON. Lawl. Machine Mods: After searching around for prior examples of acetal being used in 3D printers - or a source for acetal filament - and finding nothing, I turned to McMaster-Carr to see if they had what I needed. Of course, they did. Mcmaster stocks 4' lengths of 0.125" (~3.2mm) white acetal rods - and while that diameter is too large to fit in a stock Ultimaker without clogging... Mcmaster also has 3.4mm drill bits for opening up that pesky hot-end's ID, and thin-walled teflon tubes for replacing the bowden. Bowden Replacement: 5239K12 3.4mm Drill: 30565A254 Acetal Rod: 8497K11 Bowden Stiffener: 5239K13 ( ^ Sleeve this over your new, thinner bowden in order to increase rigidity and improve retraction when printing in floppy filaments like ABS, Nylon, PLA) Print Settings/Process: The hardest part about printing acetal is getting it to stick. A heated bed would probably help here. My best results come from printing on a wooden platform (birch ply) and a large raft with very thick lines. Temp of 258° seems good, although thin sections (<1mm) can get layer adhesion problems, so higher temps might work better. No fan, 30mm/s speed (much higher is probably possible). 0.1mm layers gives amazing detail. Acetal seems to hold heat very very well, which means that thick sections (>4mm) get messy, quickly. Parts that are designed as if they were to be injection molded (ie with uniform wall thicknesses) seem to print great. Apart from first layer adhesion challenges, the only real problem with Acetal is that it (currently) only comes in 4' rods. The problem here isn't running out of filament - it's easy enough to feed them into the machine as necessary. The problem is that unless you fuse the rods together, it is impossible to use retraction once there is more than one filament section inside the machine. This makes prints with fine detail and many jumps more challenging. Going forward: My next goal is to try to find a source for proper acetal filament - there are probably manufacturers that will do custom lengths. There are also many different Acetal copolymer mixtures with very different melting points, so it is entirely possible that a different blend of Acetal could be even more 3D printing-friendly. I'm also excited about setting up a dual-extrusion machine so that first-layer adhesion can be solved by printing a few layers of PLA first. A heated build environment is something I would also like to try. Would love to hear about the results from other people who try printing in Acetal and have a heated build environment.

This definitely works. I've used the same technique to get a variety of materials to stick to the bed. One reason I'm excited to get a dual extrusion kit from Ultimaker is to have PLA + another material in my machine, so that I can always print a few base layers of PLA and then print whatever else I want on top and not have to worry about bed adhesion. Of course, like Joergen says, you still need to have your print settings tuned to the material you're going to be printing in, but for many objects and materials, the burden of getting it to stick to the bed is 80% of the problem, not getting it to print correctly once it is actually stuck.

Nozzle temp isn't an issue, I've been printing Nylon and others (245°+) on a more or less stock machine for a few weeks now and it's been great. Stopped trying to use ABS since it was weaker and harder to make stick than Nylon. Regardless, I've found that I can get a lot of stuff to stick if I use a wooden build platform and set the Z height a little too high.

Soooo excited for this. I think this is a much smarter way of doing support. Totally speculating here, but it might also be helpful to add intentional weak points into the outer wall of the support skin, so that it could be broken apart easily if necessary.

Yeah, the minimum req. to launch a city is a problem. We're still the only 3 printers in NYC!

I get the same thing with the latest versions of Cura. I don't think the newer versions are adequately compensating for desired extrusion vs actual extrusion rates when changing speed and density. Low % support structures and infill settings (sub 40) almost always turn into a fluffy mess for me unless I'm printing at 60mm/s or lower.

He's talking about a redesign, essentially integrating the black (grey in your case) bowden fitting into the printhead itself. I like the idea a lot. Might try to rework my design to accommodate that, as it will be more universal and we won't have to worry about mismatched bowden clamp sizes like you are dealing with now.

Bummer that the coupler doesn't fit with your hotend. Is it the same black one they show in the photos? I didn't use the E3D bowden because of the diameter reason you mention. You can re-use the Stock bowden just fine. I followed the E3D instructions step by step during assembly of the hotend and haven't had to make any adjustments in the 100 hours of printing that I've done with this setup. The tighter bore of the hotend definitely makes it more failure prone due to ground filament, however, so make sure your retraction settings are turned down and your extruder spring is very tight so you don't ever get any filament slipping. That being said, I still love this hotend, because the reduced weight allows it to be driven FAST while maintaining awesomely high quality prints.

Yeah, ultimately, the eccentric pulleys are a manageable problem. Don't worry too much about smooth head movement - you can get great prints without it. Check your belt tension more often, as that cyclic loading is going to speed up any problems related to movement there. Mostly it just makes the machine (unnecessarily) feel like junk.

Your pulleys are not concentric. This is major problem with Ultimakers. The pulleys they ship with are total crap. Read the (long) thread "Fixing Pulley Inaccuracy" and you'll see what some of your options are. I switched one machine to GT2 pulleys and belts and the movement is much, much smoother. Not (just) because of the tooth profile, but because the pulleys are actually higher quality. I also built one machine where I picked the 10 most concentric pulleys from all of the pulleys that came with 3 ultimakers. That machine also is very smooth.

Yeah, this has been a nuisance for me as well in the latest versions of Cura. Changing skin thickness or part wall thickness can help, but for me, there are plenty of cases where I have smoothly transitioning wall thicknesses (say, a long, thin wall that goes from 1mm to 2mm) and those areas inevitably have some crazy dotting behavior on them, regardless of the number of skins or actual wall thickness.

I had this problem tonight. Not sure if your cause is the same, but for me, when I was re-assembling the heater block, the amount of force I put on the heater/thermocouple set screw was crushing the wires of the cartridge heater and causing an internal short. The breaker in the power supply would trigger every time I turned on the machine. I was able to remove the heater, manually separate the wires at the 90degree bend, and delicately reinstall the heater, solving the problem. Try removing your heater cartridge wires from the main board and turning on the machine - see if that's the problem. Remember to unplug your power supply first to reset the breaker.

Hmm, yeah, that's an interesting problem. I'm sure it has been solved by some industry... but my first thought would be to use a braided aramid, like this 2mm spectra: http://www.backpackinglight.com/cgi-bin/backpackinglight/aircore_1_spectra_cord.html#.UfsW55K1Gzk and then splice it together with some old school rope technique. They actually describe doing this on the product page. Could work well.

Hmm, good to know. I'll definitely play around with lower settings then. I did build this firmware 2 or 3 weeks ago, from ErikZalm. That is the source, correct?

I've tried 40mm/s and 55mm/s. I'll try something slower and see if it can handle it any better.

So, after another week or so of testing, I've got to say - This E3D hotend hates retraction. Even small retraction values (0.5-1.5mm) will cause underextrusion if it is a retraction-heavy part of a print. The end doesn't seem to be clogging when small values are used, but it starts (and continues) to underextrude until it gets a few layers of retraction-light printing in. It's a shame, because the lightweight printhead I've built this hotend into allows fantastic detail even at high speeds, but without the ability to use retraction, the fine details are frequently just lost in strings and blobs. Any tips?

Well, if that's your goal, why not just use compressionless housing from a bicycle and make a "reverse bowden" - that acts in compression instead of tension, with a metal or aramid wire rope running down the center - which is compressing a plunger when pulled - and is getting wound up onto a spool by a stepper motor on the back of the Ultimaker. Or, if you're trying to get away from the plunger entirely, you could probably use two compressionless tubes and power your paste-pushing mechanism by wire drive with the stepper still on the back of the machine.