It is good if you know which forces or imperfections exist at your printer. Then you can - solve print problems because you can find out where they come from (ringing etc.) - know where to spend your next dollar best to improve the printer if you want to You can decide to ignore those imperfections if they are small enough in your view. Regardless of this knowledge, the application of best pracby JoergS5 - CoreXY Machines
There are different requirements for a 3d printer: quality of print, speed, portability, cost, ease of usage, etc. etc. As different as those requirements are, so are the constructions. That's the salt in the soup... For me, I want a solid printer framed with concrete or granite to protect againts vibrations. BUT it is not as mobile as your printer ;-)by JoergS5 - CoreXY Machines
I understand. Bending force could be to the upper direction also, right? Like a heat bed which is fixed at 4 points and bending to top or down due to termal expansion. Edit: no, ok, I understand: upper surface upset, lower stretched, one direction - down.by JoergS5 - CoreXY Machines
I am not sure about your last graphic. The yellow arrow should be a vector addition of the other vectors. The blue and green ones don't have down direction. I think the blue and green arrows produce a torsion, the left ones counterclock and the right ones clockwise, and balance each other out.by JoergS5 - CoreXY Machines
So if you detach the extruder/hotend from the X guide, and it does not rotate, it means that the tensions of the belts are equal. This could be used to calibrate it. But if you move the steppers, the forces are different. So it's good if the tension forces are much higher than the forces of the movements. And the pulley diameters should be the same for the forces to be the same (if tension is eby JoergS5 - CoreXY Machines
piper3d, I found some interesting discussion in a cnc forum about stabilizing XY: #51 in the thread is especially good to understand the cable guidance. This is in some details an explanation why CoreXY stabilizes XY, depending on the belts. I don't understand all of the tread. I am searching some simulation freeware to get a good understanding, but did not find one yet.by JoergS5 - CoreXY Machines
Thanks for explanation. I read about your try. I am experimenting with worm and harmonic drives also to level the bed.by JoergS5 - CoreXY Machines
I didn't detect twists in your z axis belt solutions, which printer do you mean?by JoergS5 - CoreXY Machines
Thank you. But I will try avoiding to twist if possible, it feels wrong. I know this is not a good physical or mathematical argument...by JoergS5 - CoreXY Machines
Thank you piper3d for your image, now it is clear. I detected your video of the Piper 2 printer yesterday, I wish you very success with your nice project(s). Twisting the belts will have other disadvantages at the pulley, they would need to be tilted a bit. It is worth some thought however to bring the belts together at the extruder point. I hope that removing all torque will lead to the X blockby JoergS5 - CoreXY Machines
I will stop investigating now and take it the expense as experience... I bought some THK linear guides now and am very satisfied. I will build some jigs for woodworking, there I have usage for stuck linear guides (e. g. for a cross table). Thanks for your help!by JoergS5 - Mechanics
Thanks for adding the new aspect of Z torque ;-) You are right, it's more complicated than I thought. I have to think about how to optimize the arrangement of the linear guide again (e. g. horizontal or vertical). I expect this arrangement is important how torque and frictions have an impact. I did not understand your last sentence, unfortunately. Could you please provide a sample/image?by JoergS5 - CoreXY Machines
Hello, I am still building a CoreXY printer and a new question arose, please see images. The top two images are the normal two level construction: if the left stepper rotates, the forces at the hotend try to rotate left or right, will tend to stuck the hotend / linear X block and will have higher friction. The other hotend connections will lower this torque when they have high tension. But whyby JoergS5 - CoreXY Machines
Quotethe_digital_dentist The second generation of the mechanism is done Nice video, thank you for sharing.by JoergS5 - Look what I made!
The Hiwin guides I bought: I suspect the seller combined block and guides not fitting, i. e. the preloads are incorrect. I bought 3, one is ok, one high preload and one very high. I will try buying fitting block+guide in the future. In the meanwhile I bought THK and I am very satisfied with them. When I have time (when it is winter...) I will try recombine blocks and rails and exchange balls wby JoergS5 - CoreXY Machines
I found an explanation for 70 °C now: Unter bestimmten Belastungen und Temperaturen >70° C besteht jedoch die Gefahr von Spannungsrisskorrosion (SpRK). (translated: However, under certain loads and temperatures >70° C there is a risk of stress corrosion cracking.). I found at wikipedia that for corrosion cracking, you need 3 conditions: material, there must be tension stress, and there muby JoergS5 - Mechanics
Thank you for your information. I am more confused now after detecting the information of Stud54: Das eignet sich nicht. AlMgSi 0.5 oder 1 ist normales Alublech, gewalzt. Ich benutze nur Gussplatten, plangefräst aus Al Mg 4,5 Mn. ( translated: That's not appropriate. AlMgSi 0.5 or 1 is normal rolled aluminium sheet. I only use cast plates, face milled from Al Mg 4,5 Mn. ) This is the descrby JoergS5 - Mechanics
Hello, I bought an aluminium plate and wanted to use it as print bed,heated. It is AlMg4,5Mn0,7-O = EN AW 5083, W28 In the datasheet in the last line of is a strange comment, it shall not be used above 70 °C ????? So if I heat the bed to 100 °C, this makes trouble? I think it cannot be a typo for 700, because melting temp is 580-640. Does anyone know what this means? Is this important for mby JoergS5 - Mechanics
Thank you for the idea. I thought about something similar: running the carriages with a lapping / honing paste. After the correct preload is reached, exchange the balls and clean all. The guide is manufactured asymetrical: on one side it looks ok, on the other the form is different. I have nothing to loose... P.S. I will not burn it with the carriage, as it will destroy it when using paste. I wby JoergS5 - Mechanics
I bought some MGN12 linear guides and carriages. There are Hiwin compatible ones with ball diameter of 2.381 (1/8 inch) mm, and the other ones with 2.5 mm. You can see the difference at the form of the guide also. Putting one type of carriage on the guide is much too loose and otther round too solid. I have bought some used Hiwin guides now, and I am a bit disappointed, as they have imperfectionby JoergS5 - CoreXY Machines
Nice, long time since 2007, so you have a lot of experience!by JoergS5 - Look what I made!
You are right, no adhesion is bad for printing LOL Those fluids are very interesting, there are even some yt videos how to produce something similar. MICR Toner is interesting e. g. as a base. For use cases the properties should be regarded. I have some ideas like decelerate a linear guide faster, fix Z axis, make haptic AR/VR solutions, moulds for injection moulding and similar ideas. I wondeby JoergS5 - Look what I made!
Is it possible for one of both to use it as a layer between print bed and printed object? Magnetize while printing, then demagetize and remove object easily.by JoergS5 - Look what I made!
Thanks a lot you for sharing a lot of your experience about building a 3d printer. If I'd seen your blog earlier, I might not have a department store at home today I agree that thingiverse has very good, but very bad designs also. To value it, I often check the Makes and Comments of the thing and whether the author has designed other things also.by JoergS5 - CoreXY Machines
Welcome to this forum! I am building a corexy from scratch also. The best introduction to mechanical aspects I know is this blog with sub-blogs, it's a very good starting point to understand: Mark Rehorst is the_digital_dentist here. The blogs explains reasons for specific construction requirements, like xy frame, bed construction etc. For a big printer as you plan, a good stability to suppoby JoergS5 - CoreXY Machines
There are two rows with big gap on each side. One row presses at the upper corner, the other in the middle. They work together unfortunately. Maybe I try buying smaller balls. I double checked, they are 3.18 = 1/8 inch. I have a supplier, who offers 3.175 mm balls with good precision, G10.by JoergS5 - Mechanics
I know I should not buy linear guides from the far east - but I did it again. Now I have a MGR15 linear guide which is much too tight (two ball rows in the block). Has anyone an idea what I can do? The ball diameters are 3.14 mm. I bought two guides and 4 blocks. One of the guides is ok, so the second one is too big. Is it possible to hone or grind the guide or widen the block?by JoergS5 - Mechanics
I thouhgt about 3d printing the caps. I read somewhere to protect the rails by vaseline, thinned with isopropanol and let dry. The balls replaced by high precision balls (Hiwin 2.381 mm = 3/32 inch, clones 2.5 mm in most cases), then oiled.by JoergS5 - Mechanics
So we commented something that you do not plan ... So good luck with your construction, CoreXY is a very successful construction and you can achieve good printing results.by JoergS5 - Mechanics