Yoter

What I tried that worked was drilling and tapping a second grub screw into the opposite side of the pulley and using two set screws with some blue locktite on the shaft of the stepper on install. It's way overkill and I'll probably never be able to remove the pulley again, but I have a drawer full of pulleys and I was rage-building after losing a 45 hour print in hour 40. Not the best from a serviceability standpoint, but I've never worn out a pulley thus far and it hasn't needed any tightening in six months of 24/7 operation since so I'll take it!

I help several local schools with 3D printers, I've donated some and supported a few. I have a few schools asking for project ideas for elementary level students, and was hoping I could post here and see what ideas some of you have seen. I have three elementary level students, but they grew up in my shop, and I am guessing the projects they take on are not a good guide. I am putting together a sheet with project ideas and a teachers guide. I am hoping to tap the community for ideas they have tried/want to try to get as many projects in the guide as possible. I then plan to develop the guide further by performing the projects with my own kids and some of their friends over weekend and modifying the step by step guide to highlight areas where little ones run into problems and how to resolve them. If you have any projects you've done that worked out well, post them so I can look at them, please. At the moment, I plan to just document and print out copies of this guide, but am considering putting them on a site where I can link videos etc... which format do you all think would be most appropriate?

I just flashed a new board using 15.x on one of my UM2s, I had to reset and re-hook the printer a few times before it saw it. I am not sure why, but it did take a few tries. Same spot as you, I run that machine tethered to a metal plus every day, but it just took a few attempts before it saw and updated the Ultimaker.

I second gr5's suggestion for a larger nozzle, as well. I use a .6 for brassfill, woodfill, and lots of other exotics. It seems the quicker you can get them out the nozzle, the better luck you have. The thicker layers bridge better a lot of times, as well. What retraction setting are you running? I like to retract hard and fast, but sometimes have to back it down when I'm printing exotics, I would think 4.0-4.5mm at 40mm/s.

What settings are you running? When i run into issues like that, the first thing I do is slow it down. I would also look at the filament if I saw something like that. It looks too hot or like over-extrusion. Make sure your nozzle isn't worn or your nozzle size is set wrong...I've changed nozzles to a .25 and gone screwy when I sat down at the computer and sliced for a .8mm nozzle before. I'd really look at the filament, though. Did this just start recently? Your pics are kinda fuzzy, but if I knew my nozzle and filament were good, I'd slow my print speed first, then start looking at other settings depending on what you're running.

What settings are you running? What filaments? It looks hot, I wouldn't expect to see layer droop like that unless I was way hot. Without knowing anything more of your settings, it's hard to say. Could always be the filament...did you change filament? Do you have pics of the other print?

That's what it's all about! We print lots of parts, only to tweak, redesign and print again. We have in-house manufacturing, but I have found that the printer doesn't gripe about going from V1 to V1.1...V1.2...V1.3 like an operator does. It may take longer than machining, but the important thing is it takes longer all by itself without an operator watching it and doesn't take longer in the middle of my production flow!

Be sure to check the glass when heated. When I have prints I need to get real dialed in, I will heat my plate, check my glass then flip and repeat. I find using a machinist straitedge and feelers gauges, I can typically find one side that is close enough. I hate to say it, but I have found I need to check each print, as the glass will move over time. I thought I could be slick and etch a "A" and "B" on the plate and note the +/- deviation and use that as a cheater, but over a year, side "A" is now where side "B" used to be. I have to say neotko is right that printing on a raft is your best bet for popping it off the build plate and running with it. I hate rafts, so I usually the print, then let Simplify put support with a few dense layers on top. I find that peels easier than a raft. If I am slicing in Cura, I'll lift the print and play with support infill to get it where I need. I've had one too many prints where I have used a raft only to have it refuse to come loose in places and take parts of the print in other places. Typically, if I am that concerned about my first layer being dead-on-flat, I can't afford to lose/add anything. By far my easiest solution so far if I need it to be that close is to make the piece slightly tall where it touches the buildplate, then sand/file/grind the base of the print to spec.

I always love/hate when switching filament makes a problem go away. I love that my machine is okay, I hate that I spend all that time chasing a problem that is just the filament being stubborn.

I have not run the Bondtech feeder before so I can't chime in on how it does with flexible, but I have run kilos through the E3D-V6, the Printrbot Ubis Ceramic and Ubis 13S hot ends, as well as through my UM2 with an Olsson Block. I've also messed with flexibles through a few different TAZ5/6 machines with their hexagon hot end, I liked them but don't own them so I can't go into too much depth about their reliability over many prints. I gotta say the E3D-V6 does remarkably well with it. While I don't necessarily have experience with with the Bondtech, I do have a lot of time "playing" (read messing-up) with prints from different direct-drive extruder setups. What I have found is that a lot of direct drive machines do well with flexibles, but the filament has to be supported directly after the drive wheel. The Printrbot Aluminum Extruder (V2) is a good example of this compared to their older aluminum extruder. Their older extruders did mediocre with inserts which could be printed, or any tube you found that could be cut to length and fit as a filament guide. The V2 has the extruder machined much closer to the gear to eliminate the gap between the feeder wheel and the guide. What I see flexibles do is mushroom between these two joints and jamb. The TAZ extruder handles flexibles very well, as well...but it sounds like you're looking for a off-the-shelf, non-printed solution. If printed parts are okay, LulzBot offers a TAZ flexystuder toolhead with their all-metal hex hotend on their site, which I would imagine does a pretty good job. From what I have seen of the TAZ extruders modified to print flexibles, I wouldn't hesitate to hack that to a machine and go to town. One thing I typically recommend when picking an extruder or extruder design and are planning on printing flexibles is to make sure whatever you use is easy to take apart and get to the filament path in case you do have mushrooming. I looked at the Bondtech site, but didn't see much at a quick glance about the inner-workings...at least not as far as cross-sections of the filament path go. I do have a buddy who prints a lot of flexible filaments on his bowden self-source machine. He swears the best way to do it is to mount the feeder directly over the printer and the spool about 12" directly over that. He ends up feeding almost straight down the tube and into the hot end, removing the bends/friction. I've been meaning to try it, but have a pile of repairs/upgrades already waiting for my machines, I was thinking of building an extruder to mount and adding a pigtail with a connector where I could swap between it and the on-board extruder for my UM, it has a permanent home now where I could do something like that, swap the connector/bowden and swap setups in a couple minutes....gotta try it first and see if it as awesome as he says. I finally started feeding from the floor and am gonna enjoy that setup a few more weeks before I play with it again. Sorry for the long, rambling reply...I did a lot of playing with flexibles a year or so ago so had a lot to spit out!

I buy my parts and nozzles from George Roberts (GR5) at thegr5store.com He has lots of different nozzles and always seems to have cool new things that cause me to start impluse-buying. Don't know how many times I went to his site to buy two nozzles, only to leave with a half dozen items ordered. He's also excellent at responding to emails and questions. If you're in the US, he's who I would go through!

I use 3-in-1 on my machine. It always leaves a light film of oil and I don't see any shaft wear. We use the same oil on a bunch of our machines in the shop, which is the primary reason I use it. As Jameshs pointed out, only get the drip kind! There is a 3-in-1 garage door lubricant, and I believe some other iterations that are spray on. Most of these have silicone or lithium additives to leave a heavy coat of lube, which attracts dirt quickly and makes the black mess. This is fine on garage doors with a lot of slop, not so much on linear guides. The main thing to remember is to clean your guide rods!!!! Any lube that stays on any surface WILL attract dust and give you that black cloth when you wipe it. When you oil your machine, wipe the surfaces down with a little isopropyl alcohol, then again with a clean rag with isopropyl. Then wipe on your oil. Lubing dirt does not do anyone any favors.

I plan to transfer my heat sinks. Should I add breather holes to the board mount enclosure? I was even considering drilling the outside housing some to allow air to pass over the board, as my current active cooling system does seem to be a bit of a dead end, air goes in but there is no good way for it to come out. Does anyone know what the "spongy weird cool material that dissipates heat" on the UM3 is? I run a lot of machines and do so successfully, mainly because one of my quirks is I take every failure in turn, analyze the hell out of it, and make sure it never happens again. If I can order some dissipating material and help prevent this in the future, I am more than happy to! I was also wondering about the shelf I am sitting on. Right now, it is on top of an Ikea cabinet with a rubber mount under it to reduce vibration...mainly coming in, it sits next to two large prusa-style printers that can really shake things. I plan to put dampers on the feet I am printing, which will lift it a fair amount. When I do this, I was considering cutting a hole under the printer where the board sets and adding a large 110V cooling fan on a switch. I want to say the fans are about 6" across. We use them in some of our products. I was thinking I could set this up to blow air under the shelf to propagate more airflow under the machine, but at this point am I going too overboard? Also, I plan to keep the X-Y current at 1100mA when I install the new board. Do I need to do anything with the Z or extruder stepper current? I plan to enclose the printer for some prints I am doing next month. This may be another post, but how does everyone here do it? Right now, I have a door made of multiple layers of foam sandwiched between two pieces of cardboard that serves as a door, then a box with a slot cut in the back to slip over the Bowden that serves as a hood. It does a good job, even if it does look horrible. I do worry about stepper temp when I run this setup, but it doesn't seam to seal the board in with the heat.

Definitely the PCB! Came in today and the printer had stalled. With the steppers removed from the axis, they only turn 1/4 turn before stalling out. Honestly, I'm glad it happened now while the printer has been listed on the injured/disabled list than after it had ran great for a week or two and I had told the bosses we were all good...always quicker to say "all fixed" online than to the guy who signs my checks! I'll get a PCB board coming and I think I'm gonna leave the steppers at 1100mA on the new one. I imagine with them turned down and the cooling on a new board, it'll be bulletproof going forward.

I've had similar problems before (we've all been there!). Here's what I've seen in the past: My PTFE coupler deformed over time. This is easy to check, remove the bowden and the nozzle from the head and straighten out a piece of filament, does it pass through the head with no resistance? I have had the feeder get clogged with dust from filament on my first printer. I blow it out with canned air every week when I do my weekly checks/maintenance. Check to make sure there are not filament strings/debris inside your bowden tube. Check your filament diameter. You're using good stuff, but if the problem seemed to start when you started a new roll or new brand, it's always worth checking. I once had a single roll out of a batch order that was out, the other nine were great. Check your feeder tension. There are a couple different settings and you can find the proper one for the build date of your printer with a quick search of the forums, I forget when the split was. As a rule, I power down the printer and see if I can move the filament manually with the motor de-energized without too much pressure. You want to be able to push the filament, but not crimp it so tight it is out of round/grinding. My nuclear check for extrusion paths error if all this doesn't solve it is to start with the bowden pulled out of the head, heat the head and push filament through by hand. There shouldn't be too much resistance and you should be able to get a steady stream of filament out the nozzle. If this works, secure the bowden to the head, remove it from the feeder and repeat while pushing the filament through the bowden. This will indicate if there's friction in the bowden somewhere. Next, pass through the feeder and see if you can still feed. Basically, eliminate problem areas from the head back one by one. Also, if you have a space you can do it, print a spool holder and feed the printer from the floor. Running a straight angle into the feeder does wonders. I use my spoolholder when I am visiting schools or taking the printer somewhere, but at the office, my printer sets on a cabinet with a hole in the top where my filament feeds from a spool holder sitting on a shelf underneath. I had seen GR5 mention before how great it was and I saw him post it again and again and it took me an embarrassingly long time to finally do it and I wish I had done it a year ago. When printing a spool holder, don't over-think it. Lots of models out there have bearings, adjustable spacers and such. I just use one that lets the spool turn on a shaft. None of the printers I've ever run came with spool-holders with bearings, so I always figured if it made that big of a difference the manufacturers would be one of the first to adopt it. I believe this is the one I am running right now: http://www.thingiverse.com/thing:32204