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Printing issues ...
Re: Marlin - MPSCARA not homing - 30 days ago
Maybe just a matter of bending the elbow by hand before sending the home command so the X switch will make contact first? I think MPSCARA needs QUICK_HOME enabled so both motors move together (keeps elbow angle constant until shoulder endstop makes contact), so make sure that's in your Configuration.h.by dekutree64 - Firmware - Marlin
Re: PLA creep - 2 months ago
Maybe. Rubbing two pieces of PETG together does have more of a stick-slip feel than PLA. But PLA should be fine if you enlarge the friction surfaces, and not have the annoying stick-slip feel when adjusting it. Surface finish also matters. Sand them flat for good surface contact, but leave sanding scratches for a bit of grippy texture. Around 120 grit is best, I think.by dekutree64 - General
Oversize bearing balls for rails and ball screws? - 11 months ago
My searching skills have failed me. Years ago I read that you can replace the balls in loose rail slider blocks with slightly oversize balls to get them running well again, but I can't find anywhere to actually buy them aside from Thomson Linear, which only sells big boxes for several hundred dollars. There they have a value called gauge, which is P05 for .0005" oversize and P10 for .001" oversizby dekutree64 - Mechanics
Re: Outrunner Schnekenstruder - 1 year ago
New idea: Mount the extruder on a single 17x23x4mm bearing, with a large gear integrated so it can be turned by a tiny motor off to the side, and have plenty of resolution even with hall sensors (around 150 steps/mm in this case). I wasn't able to get it to run closed loop (sensor placement trouble, I think), and I may need a larger motor, but I think the concept is viable. This motor is 1404 siby dekutree64 - Tech-Talk
Re: Possibly building 3D printer - seek a bit of advice ... - 1 year ago
Quoteevalon I will comment below but while I remember it: I noticed in the "screwstruder" thread that you had commented there: With this in mind - did you ever try out this extruder type yourself? And, if so, did you find it to be "excellent" - or did there appear to be maybe some "systematic" shortcomings? I may of course ask rq3 himself but since we are in contact now I thought I would ask youby dekutree64 - General New Machines Topics
Re: Possibly building 3D printer - seek a bit of advice ... - 1 year ago
I'd recommend against using ball screws on a 3D printer. The $20 Chinese ones are amazingly good for the price (about .001" backlash on my CNC), but they do have a bit of eccentricity, so you need a rigid frame and rails to prevent that from introducing wobble (not an issue on a mill since you need rigidity anyway), or something akin to an Oldham coupling to allow lateral movement (MirageC on youby dekutree64 - General New Machines Topics
Re: Possibly building 3D printer - seek a bit of advice ... - 1 year ago
3D printers are a lot easier than CNC mills, so I expect you'll have a good time whichever way you go. For heavy prints, something with a fixed bed would be ideal, but bed Z works too if it has good support like that Sapphire Plus. Bed Y may struggle with inertia toward the end of the print. For high temp filaments, you need a hotend that doesn't have PTFE tube in the melt zone. And probably anby dekutree64 - General New Machines Topics
Re: CNC vs 3D Print - 1 year ago
Initial printing tests are not looking good. Lots of underextrusion, especially at the start of each line. Retract moves were failing entirely (vibrating in place) until I lowered the max velocity to 3mm/s, and still sometimes failed to de-retract. 2mm/s doesn't visibly skip, but apparently is still missing some steps. It's also back to not following the helix after retracting, probably due to tby dekutree64 - Tech-Talk
Re: CNC vs 3D Print - 1 year ago
Ok, my NEMA11 is complete. I wanted to add a flat on the shaft, and thought it would be nice to shorten it by 3mm as well, so I decided to do both at once on the mill. I made some little clamping assist blocks, 14x8x6mm with a 4mm hole in the center, and then cut in half. Two of them hold the motor shaft square in the vise, and the other two hold a random piece of 4mm rod to support the other sby dekutree64 - Tech-Talk
Re: CNC vs 3D Print - 1 year ago
Quoterq3 I probably printed 100 prototypes in PLA, and they worked fine as long as the motor didn't get too warm. Yeah, regular PLA will certainly work. It just might need replaced periodically, whereas PLA+ with coarse threads will probably be trouble-free for many years. Quoterq3 135 degree, split point, 2mm diameter high speed steel bit I shall add that to my list of desired tools! I finallby dekutree64 - Tech-Talk
Re: CNC vs 3D Print - 1 year ago
I see no reason to use metal at all anymore. Tom Brazier's style of carrier with integrated hollow posts is a thing of beauty. With a bit of trial and error you can get it to print out ready to use, no cleanup needed (attachment Carrier.jpg). With a belt printer you could just put a bucket at the end and print more than you could ever sell Use PLA+ and coarse threaded screws. Grind the tip of oby dekutree64 - Tech-Talk
Re: Cartesian X weight reduction? - 2 years ago
Check out rq3's extruder threads in the tech-talk section. He's gotten as low as 42 grams including the motor. As for the X motor, it can at least be a shorter length NEMA17 than the Y axis. NEMA14 may work, but my guess is that you'd be better off enlarging the Y motor instead. The smaller motor would allow higher Y acceleration without print quality issues due to frame rigidity/vibration, butby dekutree64 - Extruded Aluminum Frames
Re: Building a CoreXY : machined or printed parts ? - 2 years ago
Quoteyet-another-average-joe The complicated one, that gives the best results, was demonstrated by Joe Pieckzinsky on his (amazing) YT channel. This extremely skilled toolmaker positioned the part vertically, attached to the table with a jig, and machined using the end of the tool. Needless to say he spent some time on tuning every detail ! He has an industrial CNC but did this operation on the Bby dekutree64 - Mechanics
Re: Edit Marlin for Polar Coordinates - 2 years ago
Probably easiest to modify the SCARA code, since that's already got angular coordinates involved. The forward and inverse kinematics for polar are much simpler than for SCARA. void forward_kinematics(const_float_t a, const_float_t b) { cartes.x = scara_offset.x + cos(RADIANS(a)) * b; cartes.y = scara_offset.y + sin(RADIANS(a)) * b; } void inverse_kinematics(const xyz_pos_t &raw) {by dekutree64 - Developers
Re: Pure Silver Heat Block - Beware - 2 years ago
Interesting. Time to add an iridium nozzle to your collection of exotic elements?by dekutree64 - Tech-Talk
Re: Life span of plastic parts? - 2 years ago
PLA cracks under continuous high tensile stress and softens with heat, but otherwise holds up just fine. Some parts on my CNC mill have been in use for 2 years now, and the only issues I've had are cracks from the outward pressure of set screws on GT2 pulleys and leadscrew shaft collars. I wrapped the pulley hubs with carbon fiber tow, and replaced the shaft collars with Taulman Tech-G, and bothby dekutree64 - CoreXY Machines
Re: Very Different Extruder in action - 2 years ago
Clever solution to the difficulty of grinding the underside of the flange, using two opposing single-ground bearings on different posts. And nice to see that the thin walled hollow posts are strong enough in plastic. That's how I wanted to eliminate the need for expensive shoulder screws, but I figured it would have to be made out of metal or they'd just break off. And you just left the spring waby dekutree64 - Tech-Talk
Re: Tb6560 + SKR 2 + Marlin => Z, r, angle 3D printer (≈R360+SCARA) - 2 years ago
I'd probably start with the latest Marlin and modify the SCARA code. Whatever way you go about it, Marlin is not well designed for adding unusual kinematics since it requires modifying several core files so you can't easily maintain a separate branch, and the code is already very cluttered so integrating more and more kinematics into the main branch is not such a good idea either. SCARA is not moby dekutree64 - General
Re: Quality Parts - 2 years ago
For the most part, consistent quality means expensive. Therefore, I prefer to find ways to work around inconsistent quality For linear motion, I think SBR rails are the safest bet. The set screws in the slider blocks allow you to adjust the tightness on the rails so you can get them just right without the need for high manufacturing precision. Chinese MGN rails are a crap shoot, but if you buyby dekutree64 - Mechanics
Re: Exoslide Core XY with "trough" down the middle of the bed? - 2 years ago
My guess is that it's due to the bowden extruder. It can't be the X/Y motion system or the previous layers would follow the same curved shape and wouldn't hit. If the 1/8" aluminum bed is mounted solidly to that 2020 extrusion carrier, heat expansion could cause it to bow. It needs to be mounted in a way that it can expand freely. But again, as long as the temperature remains stable throughout tby dekutree64 - Reprappers
Re: Maybe the World's Lightest Extruder - 2 years ago
Congratulations on a job well done How about a new BOM with sources for the extended race bearings and such?by dekutree64 - Tech-Talk
Re: How to cut model into parts to fit bed? - 2 years ago
Load it in your favorite 3D modeling program (I use Blender) and make some cubes and use boolean intersect.by dekutree64 - Printing
Re: Is this ringing? - What is causing this lines? - 2 years ago
What kind of printer? The inconsistent layers in the first photo are something I've always struggled with, and what made by far the biggest difference was changing from bowden to direct drive. Partial clogging may also be one cause, so putting a wiper on the filament between the spool and extruder is a good idea. The vertical lines in the second photo are strange though. The only place I've gottby dekutree64 - Mechanics
Re: Outrunner Schnekenstruder - 2 years ago
That may work if you have a motor with three screw holes (or drill and tap two more holes yourself spaced 120 degrees from the first). Otherwise the extruder roller screw holes overlap the motor mounting screw holes. But you would have to deal with the screw heads being in the way of the rollers. They could be counterbored, but that doesn't leave much material left around the roller screw holes.by dekutree64 - Tech-Talk
Re: IDEX for CoreXY - 2 years ago
Couldn't you use a belt path like this for the second X carriage? Y movement would be controlled by the first carriage's CoreXY belts (not shown), and then this one moves independently in the X direction while riding on the same Y gantry.by dekutree64 - CoreXY Machines
Re: Maybe the World's Lightest Extruder - 2 years ago
I've still only sharpened the flange on that one cheap 4x8x3mm bearing months ago, so the 9mm bearings are to go with that. I moved the posts 0.5mm closer to the center so the blade penetration depth is the same. As for the BLDC motor, they don't necessarily need high current. It depends on how many turns of wire per stator tooth. More turns = more torque for a given current, less turns = more sby dekutree64 - Tech-Talk
Re: Maybe the World's Lightest Extruder - 2 years ago
Quoterq3As noted above, one of the benefits of using shoulder screws is that you can very easily trim the shoulder diameter to adjust the bearing clearance. It's a one time thing during assembly. Wouldn't it be better to grind more off the cutter bearing flange? I'd rather have the bearings fit onto the posts without any wiggle room. Another way to do fine adjustment is to add shims under the cuby dekutree64 - Tech-Talk
Re: Maybe the World's Lightest Extruder - 2 years ago
Fabulous! But I still think the posts should be machined as part of the carrier with m3 screws into the top of them to retain the bearings, to eliminate the cost and almost all the weight of the shoulder screws. Unfortunately I still haven't come up with a machining strategy to make it with my current tools and skills, so I'll probably just stick with the NEMA14 and 3D printed carrier and leaveby dekutree64 - Tech-Talk
Re: Knocking sound from extruder stepper - 2 years ago
Hmm, perhaps it is indeed missing steps, but not due to filament pressure. I had some trouble with missed steps on retraction recently when trying out a new extruder design using a NEMA 14 stepper, and the solution ended up being to reduce the max extruder speed. I never did figure out exactly why that fixed it. I would have thought acceleration, jerk, and motor current would be the settings to aby dekutree64 - General
Re: Newbie / junkstrap - 2 years ago
Step 1. Buy Ender 3 Step 2. Convert to direct extrusion (very easy, and gives much better print quality) Step 3. Print parts for custom printer Step 4. Cannibalize Ender 3 for parts to complete custom printer I was a big fan of the SKR Mini when it cost $30, but it looks like the going price now is $50. Unless you really need any of the TMC2209 features like sensorless homing, I'd go with the Enby dekutree64 - General