NathanaelXYZ, you are so right. There IS abrasion. Or was. A few observations: I noticed while running the threaded sleeves on non-canted axles, that the sleeves actually travel in the same direction as the filament. Wait. That can't be right. What happened to Newton's laws? If what I am seeing is true, I could epoxy a machine nut into my anus, sword swallow a matching thread rod, keep the rodby rq3 - Tech-Talk
Hopefully, the final path to the final design. My watchmakers lathe doesn't cut threads, so I had a local machine shop thread some steel bar stock so that it was precisely 10mm in diameter, with 28 threads per inch coming to a sharp apex. Normally a thread has a flat apex; these don't. I then bored the bar to 4mm to fit the precision shoulder screws (I didn't bother with ball bearings with this iby rq3 - Tech-Talk
Quoteobelisk79 Ok, so need some help brain storming. What are some easy ways to evenly texture the bearings for filament grip that doesn't require specialty materials ie aluminum oxide powder or a laser. Only thing I've tried so far was heatshrink tubing which was a big fail. Thoughts on perhaps using thinned plasti-dip? If you've been following this thread closely, you need some kind of posiby rq3 - Tech-Talk
You guys are fantastic! Having other interpretations of a wing nut idea can only be a good thing! And the YouTube videos demonstrate the real value of 3D printing - realizing an idea in almost real time. The YouTube guy certainly has his printing down pat, with some terrific results. It's pretty cool when a printer can get better repeatable resolution than a watch makers lathe, which I'm just getby rq3 - Tech-Talk
QuoteNathanaelXYZ I don't see how this newer design actually drives the filament-- it seems to me that the threads on the bearing sleeves would simply impress a "///////////" pattern on the cylindrical surface of the filament (much like a knurling tool) as they revolve around it, without any of the desired axial movement. The design will only function if the bearings don't actually rotate-- at thby rq3 - Tech-Talk
Quoteobelisk79 I like it, I was concerned that the screw being on a bearing would just sit in place as the carrier spins around the filament, but if its working like this then I stand corrected. My brain can only visualize so much I guess. What about just using a single stationary grub screw with 2 bearings as an alternative (and more off-the-shelf) approach? I think that could work well. I migby rq3 - Tech-Talk
Quoteobelisk79 Do you have a screenshot of the updated design? I've been mocking up some simple experiments using 10deg pitch with some 683zz bearings and heatshrink to provide friction, I'm still dialing in tolerances on my design/print. Attached is a shot of the prototype bearing carrier, printed in PLA just to see if the idea would work (it does). The bearings are mounted "normally" (not cantby rq3 - Tech-Talk
@obelisk79, great minds think alike. While watching the VDE in action, it occurred to me (face palm) that, rather than have a canted bearing that relies on surface friction, I needed a threaded sleeve on the OD of a smaller bearing. An Archimedes screw, if you will. Since my lathe doesn't having threading capabilities, a local machine shop is doing that for me. A prototype works on the bench, andby rq3 - Tech-Talk
QuoteAngelOfGrief This is a really old thread, but I decided to post here. Running Marlin on Prusa i3 metal frame. I too have encountered inconsistency using the bed leveling feature of Marlin. And I am using a standard inductive sensor obtained from Aliexpress and an aluminum hot bed. So, here's what I have discovered. The sensor itself is very stable, the M48 command reports something around 0.by rq3 - Firmware - Marlin
So, I mounted this thing on my delta, calibrated the extrusion rate, and printed a cube (results attached). My usual extruder is an almost stock Anycubic, which is a BMG clone, and quite nice and reliable. Some time ago, I converted all of the printer motors to 0.9 degree step units, and the current extruder needs 830 steps per millimeter. The "very different extruder" (VDE for short) needs 11,1by rq3 - Tech-Talk
As expected, this extruder idea tries to twist the filament to the extent of the bearing torque spec, which is milligram-millimeters, not much but enough to have to be dealt with. I tried various clamps and clips, but have decided that a simple single loop in the filament serves the purpose very well. It doesn't interfere with feed and retraction repeatability, and weighs about 5 grams, includingby rq3 - Tech-Talk
Dammit, Mike! Now you've done it! You actually made me go and think about all this! My primitive vector analysis indicates that there can't be any side load on the arms of a delta printer. The force from the carriage to the effector is always axial, either compression or tension. If this were not true, a hang printer wouldn't work, and neither would a delta, since the effector would head in direcby rq3 - Delta Machines
If the nozzle is tracing a path that is "bowl" shaped, or "dome" shaped, then the rod radius is likely incorrect. A web search on delta calibration should get you more information.by rq3 - Delta Machines
try changing lines that look like this: #define X_DRIVER_TYPE TMC2208 changed from A4988 to this: #define X_DRIVER_TYPE TMC2208 //changed from A4988 That will make the old A4988 driver type a comment, rather than part of the compiled code (which won't work).by rq3 - Firmware - Marlin
Quotejcs Quoterq3 Magnetically, there two issues with using a steel cup. The side of the cup stuck to the magnet gets the opposite pole induced into it. If the magnet face is, say, north, the sticking face of the steel cup is south. Of course, the other face of the cup is then north, and the ball is trying to stick to a north faced steel cup with a north faced magnet just under it. Not good. Anyby rq3 - Delta Machines
Quotejcs Just for anyone that's interested, I used the same geometry as leadinglights shows except I used spherical magnets as well, instead of steel balls. Along with the aforementioned mouse tape that works fine with no shifting. Of course you have to make sure the magnetic poles are optimally aligned. Magnetically, there two issues with using a steel cup. The side of the cup stuck to the magnby rq3 - Delta Machines
Based on the E3D V5 units, but dimensioned for my heatsink. Grade 5 titanium hot end threads, OFHC copper cold end, connected with 0.009 inch wall 316 stainless hypodermic tubing. A lot easier to make than the heatsink! I think I'll pop this puppy on a printer and try it out this weekend.by rq3 - Tech-Talk
QuoteGaou Quoterq3 About twice a year I pop the arms off the balls, clean everything, and fill the countersink in the magnet with Teflon loaded grease. so you are saying you are metal on metal, like mine ? you ve done great work with the rods for sure. i dont have the tools or the mechanical knowledge and experience to do what you did. i got myself a print today and it seems that i have a problby rq3 - Delta Machines
QuoteGaou i dont have a cup . I do have some countersink magnets glueed with instant glue on my effector and on top of that there are the the balls....! i have read what you are telling me some minutes ago on the forum . Seems very right . I do not know if that's the case on mine since there is equal force in a certain diameter on the ball. You can see that in the post for the delta i ve made.by rq3 - Delta Machines
6061 aluminum, 19 grams, probably half of which is the darn groove mount end not visible in the photo. Also attached is the FreeCad file for the latest, and hopefully last, bearing carrier. I've printed 19 of these things, with various tweaks, and machined one from 7075 aluminum. The cantilever spring slot is wider (0.5mm instead of 0.25mm), and there is a 3mmx0.5x5mm adjustment screw for the fiby rq3 - Tech-Talk
Quoteleadinglights Just a passing thought: Is it possible that this would work with only two wheels? At first blush, this sounds silly as the filament would pop out sideways as very under-constrained. However, the sideways force may possibly be easily constrained with guides if they were slippy enough or maybe with guide bearings just beyond the ends of the drive bearings. The question is, how biby rq3 - Tech-Talk
A couple of observations after playing with this idea, for any one else who may want to pursue it. I tried grit coating the bearing OD's by rolling them on a film of thinned JB-Weld epoxy on a glass plate, and then into a dusting of 400 grit aluminum oxide. The process worked fine, but oddly didn't really make the pull-out force on the filament much better, and made the repeatability MUCH worse (by rq3 - Tech-Talk
Some time ago one of the arms on my delta broke. I got tired of waiting for a replacement from China, so I made my own. The balls are 1/2" diameter 440C stainless steel bearing balls. I got a box of stainless steel 3mmx0.5 flat head machine screws, 10 mm long. I threaded the screws into an aluminum hex standoff to protect the threads of the screws, and chucked it in a lathe. Then I plunged a 1/2"by rq3 - Delta Machines
QuoteElectric ant Well, first I'll say thanks to Dust for the only reply I got. And thanks to everyone else for their total lack of interest. 170 odd views and only 1 reply (and that was around the 5th view). People on other websites have told me that the Reprap forum was a good place to go to get help with almost any 3D Printing problem. Boy were they wrong. Either that, or nobody else has eby rq3 - Firmware - Marlin
QuoteMKSA So ? Where is the hot end, and all the rest ? Seriously, I know how this "works", not a new idea. What would be new is a working and if possible better extruder ! Someone who boasts: "Very repeatable, and accurate to 125 nanometers (16 microsteps and a 1.8 degree stepper. 62.5 nanometers with a 0.9 degree stepper)." better proves it ! Actually, I don't have to "prove" anything, aby rq3 - Tech-Talk
@VDX, a superlative idea! Any thoughts on laser type and settings? I have access to a 100W CO2 unit with a rotating fixture. I know my 20W FAP 800 nm unit won't do it.by rq3 - Tech-Talk
With 10 mm OD bearings equidistantly spaced on a 11.6 mm circle as the center locator, they each try to "bite" the filament by 0.075 mm. It doesn't sound like much, but if you draw it out, you'll see it's an appreciable amount of the filament circumference. You could go to an 11.55 mm mount diameter and get a 0.1 mm bite on each bearing, and there would still be clearance at the bearing peripheryby rq3 - Tech-Talk
Mike, this idea is based on the Roh'lix linear actuator. Years ago I purchased several units to see if they were repeatable enough for a 3D printer. They were not. It then occurred to me to grit plate the bearing OD's like a Hewlett Packard drafting plotter. The idea is that the grit particles make tiny pits in the shaft on the first pass, which then automatically align with their respective partby rq3 - Tech-Talk
A shot of my prototype extruder, which weighs about 10 grams more than the 70 gram (11.6mm thick Sanyo NEMA 17) motor that drives it. Upside: Very repeatable, and accurate to 125 nanometers (16 microsteps and a 1.8 degree stepper. 62.5 nanometers with a 0.9 degree stepper). Very light. Very small. No gears or other hard to machine parts. Ferocious mechanical advantage (13.75:1), so a much smalleby rq3 - Tech-Talk
@deezums, there was an error in the latest releases of Marlin (both bugfix and 2.0.8) that caused probe errors. It was fixed yesterday (May 2). Try downloading a fresh copy of Marlin again. The error was in the motion.cpp file.by rq3 - Firmware - Marlin