RU speaking of something like this?by tgit23 - Developers
QuoteWhat controller do want to use? An 8bit Arduino would have a hard time driving the steppers fast enough Is that why I can't get any torque out of these 28BYJ's past a feed rate of 100? I kind of figured it was the magnetic s in correlation with the step-down gears in the 28BYJ. I was planning on shifting to the Mega2560 once I had some good success with the UNO & GRBL. QuoteI currentby tgit23 - Developers
Hi boylucky, I had ran across the magnetic rod ends for delta printers and found it quite a fascinating replacement for ball joints. I'm not really sure how the model above will turn out; general motion so far works good but I have my worries about precision especially on the Y-Gantry getting torqued from Z-pressures. So far its only been a $16 adventure without having a hot-end or extruder oby tgit23 - Developers
Quotedc42how to mount the stepper motors in such a way that they can swing with the leadscrews.but resist rotation. I was thinking exactly the way the hexapod cnc did it - looks like it has a swivel 'L' link to the tool fitting and U-Center axis Motor holders. There was also this project here which was a delta with a movable bed. http://www.diyouware.com/ Found it most interesting for tool chaby tgit23 - Mechanics
In case anyone else is interested it appear the modification in the "https://github.com/ruizivo/GRBL-28byj-48-Servo" GRBL firmware was made in stepper.c file as shown below.. I've added 28BYJ routine to the Z-Axis; Project is at Also the picture above project can be found at: if (st.counter_x > st.exec_block->step_event_count) { st.step_outbits |= (1<step_event_count; if (sby tgit23 - Developers
Quotedc42 You can't have the beck ends of the leadscrews sticking out like you can in your diagram 4 posts up (unless you stand the printer on a table with holes cut into it!). Wonder if instead of pushing the bed up from the floor or table top if it couldn't hang the bed from the top - allowing the same setup as diagrammed above?? It would be nice to have the stewart platform control just theby tgit23 - Mechanics
Quotedc42 It's not a Stewart platform Looking at that design; I couldn't help but think a 6-axis bed with a solid top extruder wouldn't have been easier to develop. This of course leads into the thinking that perhaps a Stewart Platform linked directly to the bed like the image 'hexapod' might not only be a little simpler but offer the option of bed tilt. Throw in some cheap 28BYJ stepper motorby tgit23 - Mechanics
I like it; but I'm doubting it'll gain much success across development teams of various firmware's or worse case scenario they'd use the same variable name to represent a value that isn't "exactly" represented the same in their specific brand of firmware. I've actually ran across that quite a bit with abbreviations and standards when trying to merge two pieces of software. If someone wanted toby tgit23 - Developers
Wouldn't copying the 'configuration.h' Marlin file be the same thing? I'm really a newbie and don't understand much; but that was my thought when I read your post.by tgit23 - Developers
I've also started working on the same situation but using a Cartesian Design. Have there been any new/updated advances to firmware that supports the 28BYJ uni-polar stepper motors since the forum was active? After digging around a while it seems there are a few routes to get a solution - 1) Turning it into bi-polar as shown 2) There is one Arduino motor shield that would create a uni-polar coby tgit23 - Developers
Yes, yes.... Thank you so much for this answer. I always wondered why delta printers didn't "tip" the head/bed when moving side to side until you made this statement. Then I noticed all delta printers have 6-links and its not just for extra strength .. Googling stewart platforms actually found about the design I was speaking of - except of course I didn't realize it'd take 6-connections toby tgit23 - Mechanics
I just had a thought and wanted to share it with developers for some feedback on viability and whether or not its already been attempted. Perhaps if it sounds okay; I'll find time to play with it. How about a Delta Printer that uses the lead-screws as the connecting joints instead of trying to stick them in the three corners of a triangle? 1) The bed (i.e. Plate) could have over-sized holes driby tgit23 - Mechanics