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Polyethylene is the other common olefin, I guessed he meant that.

I have done some printing in POM (acetal) which has very much the same issues as olefins. It is very slippery, and very high shrink rate which means all it want to do is curl and peel off. Incredibly strong when it works though, I have made several complex plastic spring prototypes with it that would be very difficult to make any other way. My best results were with a 120degC bed, painted with ABS slurry, and the key bit is to repaint over the first layer of POM with slurry again, which effectively glues it down. I then close the enclosure, which sits at about 60degC, any less and the high shrinkage will give you delamination. Hope this helps. Good luck. Andrew

I bought a roll of POM from a Chinese suplier (ebay vendor bilalzafar82), and whilst it seems good quality, I have never been able to get it to stick long enough to get a full print. Everything else works fine, feeds well, detail is excellent etc. etc.. I have a heated bed and chamber, and have tried ABS slurry, cardboard sheets, various types of tape and various temperatures, and nothing works! POM has around 2% shrink rate compared to ABS at 0.7% and PLA at 0.4%, this gives an idea of the issue. I'm very surprised (and jealous) you have had so much success. I'll try and get some birch ply and have another go. Andrew

Dear Markus, I had new UM1 teflon pieces made by a local CNC machine shop, and got 10 for 35 GBP, including delivery. It was some hassle, and I had to draw it first of course, but because it was so easy for them to make, I basically only paid the setup charge on the machine. That was a couple of years ago. I do encourage you to phone a couple of local machining companies. I was using ABS, and the teflon pieces wear out quickly, so there was no way I could pay UM prices for them. From what I am reading here, it's tempting to go into business making UM spares!

I am only in the UK and I refuse to pay their shipping costs for parts. I have had a PEEK and PTFE hot end parts custom machined for me cheaper (and quicker!) than to have it sent from Ultimaker. Most other parts have compatible equivalents on eBay for a fraction of the cost. Its a shame because I want to support their company, but they make it very hard.

I've got one of those Sainsmart controllers. You have to put one of the connectors back to front (cut the alignment pip off) then it works perfectly on the UM control board.

Hi Jonny There is no need to change the PID, if you are using the ultimaker block and heater. If you use the E3D, then yes, as the mass is different, and the heater rating, you need to optimise the settings. The tube fitting is bulky because they selected a panel mount style with an O seal in the base, so in my design of head it doesn't fit as I wanted the head as close to the linear bearings as possible. In other mounts, you may find this is not a problem. They are cheap enough, any 1/4in fitting will do for the UM bowden, or 6mm if you have changed to 6mmOD-4mmID bowden. I think the thread is 1/8 BSP, but please do check. Yes E3D are a refreshing change to dealing with Ultimaker at the moment! They have always been very professional from my dealings with them. Andrew

Nylon is the classic material for parts like this, as it has high resistance to organic solvents such as petroleum. You can print it yourself but you might find it too flexible, if so, get it sintered in glass filled nylon. Try your local prototyping shop, there are a lot of places MUCH cheaper than shapeways!

I have been using these for a few months as we had a bunch of them lying around at work, and to be honest the biggest benefit seems to be the noise reduction. Even printing from SD card, it still occasionally stutters as you describe because the arduino can't handle the step rate. I have been meaning to drop them back to 16 microstep and see if the noise improvement remains. If you set the outer layer speed low, to get the best quality, the stuttering becomes less of an issue because it is inside, but still its annoying.

Guys, I think you're overcomplicating this. All of the 350/400/500W Chinese power supplies I have used from ebay can be adjusted with a preset on the board down to 19v, which can power your whole setup with no issues at all. I have run like this for 18 months now. After a while I changed the 7812 to a switching one, and put the volts up, but outside of a marginal change in warm up time, it makes no difference, 19v is plenty into a reprap PCB/Al heater, and I subsequently turned it back down to 19v to keep the power down. If you solder direct to the tracks, the on board mosfet is quite capable of driving the bed directly, with bang bang or PWM.

This is absolutely classic symptom of ABS not in a heated chamber. Try draping a blanket or wrapping your machine in bubble wrap, you need to get it up to about 40degC. Your heated bed is plenty enough to achieve this, you don't need any other heat source.

Hi lean, I've used UG and NX for over 15 years now, but I've had to use various other systems at intervals for specific clients. Catia is the only thing I have ever used that comes close. I think you are going to be deeply frustrated using anything that is available free. Once you've used the real stuff, the rest seems, well, limiting. Sorry, not the answer you wanted! Andrew

I have to disagree with: "It's definetly not going to work with any normal PCB" It works fine with the normal 12v reprap pcb heater at 19v. I have mine sandwiched between a 3mm alu plate below, profiled same as the acrylic bed so it uses the UM leveling method, and a 5mm alu plate on top, the size of the PCB, which has been milled flat. Works Perfectly and has done for over a year. Very neat solution, and it heats to 100deg for ABS in about 4 mins. No where near smoke temperature, the solder resist on the PCB isn't even discoloured. I imagine that the ALU reprap beds would be very similar to what I have. PSU I got from China is fine, and they are so cheap that if you found a reseller in EU, it would likely be a Chinese one they are reselling anyway! If you are worried about blowing the MOSFET because of overheating, replace it (for about £4) with a modern very low Ron version. There are ones now that are rated at over 600W in a TO220 package. Alternativly put a small heatsink on it! Personally I would not give up the simplicity, stability and control of the PWM via the MOSFET by introducing a relay. You must bypass the 5A DC connector though. I soldered leads direct to the PCB behind the connector.

Sounds good, but I do have a heated bed... I'll look up M42 though.

Thanks Jonny, thats kind of what I was thinking. The only drawback is it stops me doing a dual extruder in the future, but I'll give it a go.

I use a 24v 400W PSU from China cia eBay. It adjusts down to 19v, same as the UM power supply, and can drive a 12v reprap heated bed PCB very nicely direct from the existing MOSFET. Draws around 350W during warm up with everything on full. Very neat, no relays, fast warm up and dead stable temperature if you make Marlin use PWM for the bed. Andrew

Hi, Yes I have a 2A switching regulator in place of the 7812, so no problem there. Is there an easy way of making the heater2 output active only when printing?

I am running a water cooled head on my UM, and I want to find a way of cutting the power to the pump once the print has stopped, for example if I run overnight. Ideally I need a pin that can switch a MOSFET on the 12V line as an aux-out for the pump. It needs about 500mA so its more than could run from the existing fan outputs. I know Daid did a suicide implementation a while ago which could do it by shutting the whole machine down, but I can't find this now, and I don't think it made it into the main Marlin build. Any thoughts? Thanks. Andrew

My E3D was good too, although I have now moved onto water cooling, it still uses the e3d s/s tube and nozzle, I just replaced the e3d heatsink with an aluminium block with water through it. The later nozzle I got from e3d has a small 'pip' in the centre, thus making the engles around the hole much steeper. This works really well and prevents the sticking.

I agree with Nick, I reamed out the aluminium, and added more chamfer to my E3D, primarily to use slightly oversize nylon strimmer filament, but this stopped any jamming. It is also key not to over retract, you don't want to remove the molten material from the head, just remove the pressure. Andy

It looks to me like it can't retract. This would pretty much eliminate it from use in a bowden setup as there is no way to remove the tension in the filament so it would dribble.

You can improve it a little with settings, particularly slow or switch off the fan, but the only real answer to this is a heated chamber. Try wrapping your UM in bubble wrap or towels as a test, often this is enough just to retain some of the heat bed energy.

Just another 2 cents... I normally run kisslicer with 0.5mm z lift on retractions, with the Z acceleration set high (900mm/s/s from memory). This snaps up and down so fast in the retraction you can hardly see it move. I tried a job last week with the latest Cura, because it wasn't slicing well with kiss, and I couldn't find any z lift feature, so went without it. The banding was much, much worse. This to me supports the theory that there is a stiction and breakaway factor in the Z nut as the z lift would remove that.

I use Kisslicer as it gives so much better control and better supports than anything else I have tried and has the 'wipe' feature, so some of the numbers might not directly translate to anything else. 265deg first layer, 245deg otherwise 0.8 seam hide layer between 0.04 and 0.12 depending how long I'm prepared to wait and what detail/ overhangs the part has. I have a 4mm ID bowden tube so as to allow thicker nylon filament, so I use a larger retract, 6.5mm at 100mm/s The firmware limits this to 40. 10mm wipe flow tweak 1.11 sparse every 2 or 3 layers (pro feature, not needed but speeds things up) for best quality, skin 40mm/s infil 90mm/s sparse infil 110mm/s. Will go up to 200mm/s but you get a lot of artifacts from belt jitter etc. at that speed. 15s minimum layer time, but I have never found this to be particularly useful. Hope it helps. Andrew

Thank you. Its a gear pump, like an oil pump in an engine, just two meshing gears and a 12VDC motor. It has the right blend of throughput and pressure to push through the small (3mm) bore tube. Search brushless self priming pump on ebay and you see a ton of them from China. They are not brushless though, its just a normal brushed DC motor, so I have no idea why they are all listed as that. Works OK though. I started with a centrifugal pump from the PC cooling kit I had, and it couldn't push through the small bore tube, then I got a small diaphragm pump and it was really noisy and generated a pulsing flow such that the tubes were always twitching. This seems the perfect compromise. If you do it, plumb the pump to suck not push through the ultimaker, that was any leaks entrain air, not leak out water.