Here's what works for me, and works wonderfully well. Quoting from the other thread. QuoteSettings on my i3v Prusa 10" were very similar to ABS: J-head 0.5mm at 225 degrees, bed at 80 degrees (i.e. lower than ABS). Same print speeds: 30mm/s perimeter, 60mm/s infill. I used 3mm clear PETG filament from user "leox-life" on ebay. The bed for above is clean, plain glass. Retraction 1, no brim, hoteby stamasd - General
Something else I've been playing with. Unfortunately I won't have much time to experiment for the rest of the week, but I thought I'd put it out there, perhaps it will be useful for someone else. For printing difficult/slick materials I came up with something which I call "hotswap". Esentially the idea came to me observing what happens when you change the filament in the hotend. Usually a smallby stamasd - General
QuoteJamesK I'll have to get myself a roll to try. Delrin is great to work with on the lathe, if I could print with it as well that would be really useful. One thing I'm not clear on, are you printing with an enclosure or out in the open? Trying to deal with high shrinkage in the open sounds like a pain. Open.by stamasd - General
To sum the past few days of experiments. The ONLY way I found to keep the POM reliably attached to the printbed is with a thick layer of ABS glue. Using any other method has resulted in sooner-or-later the object detaching while being printed. The simplest system that worked is a clean glass plate coated with ABS glue. Downsides: the adhesion to the ABS glue is very strong, and the glue will cby stamasd - General
Anyway, here's the answer: POM does NOT stick well enough to PEI. My best out of 6 tries went to layer 10 then detached. Nozzle 230 degrees, bed 120 degrees (1mm PEI on top of 3mm glass), print speed 20mm/s. The same bed works amazingly well for ABS and nylon though so I don't regret the purchase.by stamasd - General
The replies to the questions I had in this thread lately have been positively underwhelming. I will go ahead and do what I think. If/when I get results I may post updates.by stamasd - General
TBH these days there is pretty much the same variety of filament available in 3mm than in 1.75mm. I use 3mm, and always find what I need. As for hotends, unless you plan on printing high-temperature materials like polycarbonate, you can't go wrong with the original J-head. Make sure it's not a Chinese knock-off though, here's how to tell them apart: I'm getting mine from makerfarm.com, Colinby stamasd - General
Great timing on this thread. I'm testing new materials, and I just happened to do my first PETG print today. (for the other material I'm testing see my separate thread on POM). From the start I have to say that I'm in love with PETG after this print. I think it will become my new go-to all-purpose material. I used Greg's extruder small gear as my test object, as it has become my standard testby stamasd - General
Quick update: I received the PEI sheets I had ordered. That was much quicker than I expected, coming from China. They are 250x250mm, 1mm thick. The surface is scratched but not badly, I don't think it will impede function. The scratches are very superficial, none seems to be more than 1/10mm deep. They are not perfectly flat either, having a slight concavity. They are quite flexible though, so thby stamasd - General
I go the conventional way. I have large plastic totes, the kind with a locking lid, in which I store my spools. Inside each tote I keep 2 rechargeable dessicant units (Eva-Dry E-333 ) Works very well.by stamasd - General
So I did 2 more attempted prints. 1. Used the enamel-coated bed plus a layer of kapton, then a thin coat of ABS glue. The object detached at about 50% completed and started rocking under the print head. It looks like the point of failure was between the kapton tape and the enamel underneath, or between the enamel and the glass. At this point I scrapped the enamel as a usable printbed layer altogby stamasd - General
Small update, I found a seller on aliexpress that has 1mm PEI sheet and will custom-cut it to my bed size; the price is good, so I ordered two. But it will be shipped from China, so I don't expect that I will have it before 2-3 weeks. I am otherwise very busy this week, so I don't think I can attempt another print until next week anyway. I am however encouraged by the strong adhesion I got to theby stamasd - General
Yes. They chose the neodymium magnets for that "test" because they are particularly brittle. Think sugar cubes. I would like to see that "test" done with steel balls. Quotebolsoncerrado So you basically trash all the failed prints to your dust bin?? No, I put them in my composter. PLA is biodegradable. I use it the next spring to grow tomatoes.by stamasd - General
Pictures as promised: 1: gear being printed. 2. after printing finished still attached to bed 3. same from different angle 4. detached (sorry for the lighting, phone camera) 5, 6 zoomed in 7. bed after object was detached. All of the ABS glue on top of the kapton came off. 8. spare glass coated with heat-resistent silver enamel 9. printing on the enameled bed; Seemed fine at first 10 hby stamasd - General
I've had limited success printing a POM object today. To get this out of the way, the glass coated with enamel didn't work. At first it looked OK, but then around the 3rd layer I noticed that the object was actually rocking as the print head was going around it, as it had completely detached from the printbed. Failure. What did work though was the following. It wasn't a complete success, the obby stamasd - General
QuoteMutley3D Why not just use PC filament - its hard as nails and slippery You could also use Igus filament - again hard as nails I haven't had much luck with all-metal hotends (I actually built my printer originally with a Hexagon hotend bought from Colin at Makerfarm, but it went bad very quickly - the metal itself became warped to the point where filament wouldn't pass through it anymore; tby stamasd - General
Quoteo_lampe Could we print POM on a sheet of POM? I'd then print the part with a raft and hope to separate them easily later. -Olaf I have read somewhere that it has been tried, and it works, but separating the printed object from the sheet (even with raft in place) is very likely to damage the sheet therefore you don't get much mileage out of it before it needs replacing. Quoteetfrench Has anby stamasd - General
Well I have one of my spare glass beds coated with a heat-resistant enamel (the ones not marked as "heat resistant" are only rated to 93C/200F). Dunno if it's acrylic or polyurethane, the clerk at the store couldn't tell me and it's not marked on the can. It's not clear either, they only had black and silver - I went for the silver. We'll see tomorrow or the day after, when it dries up. I plan onby stamasd - General
Actually I've just looked at the pdf on printbite's site, they mention acetal (=POM) as one of the materials that cannot be printed on it. It however mentions printing POM on glass covered with acrylic lacquer... I'm off to the car parts store.by stamasd - General
I haven't tried PEI yet, and I see no mention anywhere of it being used with POM. I have asked in the printbite thread about using it with POM but haven't received any replies yet. One problem with both is they come in 6x6, 8x8 or 12x12 inches, but my print bed is 10x10. Either I have to buy a sheet smaller than my bed and limit what I can print - which would not be much of a problem, I only intby stamasd - General
So I'm trying to expand from printing just PLA and ABS into a bit more exotic materials on my i3v Prusa. The first one I tried so far is POM, as I need some gears and bushings and I thought that this material's toughness and low friction coefficient would be what I need. But the low friction coefficient is causing me trouble as so far I haven't been able to find an adequate combination that wilby stamasd - General
Any experience with printing POM on this material? I am having a horrible time trying to print POM, as it doesn't seem to stick to ANYTHING reasonably well. But 18 pounds plus shipping is a bit steep if the material isn't known to work well with it. (edit) I found it noted on the site, the material won't work with acetal/POM. Bummer.by stamasd - General
Unfortunately I won't have time to work on the project again until some time next week. The Arduino power is clean, it comes from my computer (USB ).by stamasd - General
The a4988 drivers have been tested in the printer. The motor has not but it came from the same box as the motors I'm using in the printer. The Arduino Pro Mini and the Uno have been used in other projects before and work fine.by stamasd - General
You're welcome. I generally print my own pulleys, but if you don't have access to a printer while building one it leads to a problem of the-chicken-or-the-egg unfortunately. Good luck with your build. Actually, since I like to have many spares I just ordered another set myself.by stamasd - General
It's in my first post. These are the same drivers and motors that I'm using in the printer. They work well together there. This setup is for a different project that I'm building up.by stamasd - General
I tried all of your suggestions already. I went up to 1us pulse with 20ms between them, no change; I tried longer pulses, up to 10ms, no change. Microstepping is off, no need for that in my application. I did vary the current a bit, not very far from what I know works for these motors in my printer (usually 0.8A, I went from about 0.65 to 1A). None of this made it better.by stamasd - General
Quoteimqqmi What does the rest of the schematic look like? Is the Arduino powered from the same PSU and is the step stick decoupled with 0.1uF capacitors? Maybe it's a flyback current from the motor coils you're seeing? See the typical application in the datasheet. If you don't use acceleration, starting the motor at a high speed instantly produces some current spikes. You can try using the x varby stamasd - General
I actually tried pulses as low as 1us using delayMicroseconds(1); the motor wouldn't step at all with this. Yes, I am quite sure there is a -5V pulse at the beginning; the oscilloscope is correctly calibrated and shows a distinctive -5V pulse with absolutely no positive deflection at the beginning of the loop, and a +5V pulse at the end. I don't understand either how can an AVR board generate -5Vby stamasd - General
Quotedc42 Quotestamasd However the example code in step 3 does not do what it's supposed to do. You have not told us what it actually does. It's supposed to send 200 pulses to the motor, which would make it spin for 1 complete turn, then pause for 1 second. It's all in the code that I linked to. Here's a copy below. It doesn't do that. // Run a A4998 Stepstick from an Arduino UNO. // Paul Hurlby stamasd - General