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Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc.
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
So a quick FEA of the three beams (300 mm span, 300 g carriage weight, 3000 mm/s^2 acceleration), with the torsional load included gives the following results (URES Displacement): I beam: 91.42 grams. 2.81 microns max deflection. Box Beam: 116.64 grams. 1.33 microns max deflection. 2020: 136.12 grams. 1.50 microns max deflection. So from worst to bby Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
Quotemcdanlj My chiwin rails ran better (smoother, less resistance, more consistent) after I attached them to 2020 (using a very tight jig to make sure they were parallel all along the length) than they did unsupported, for what it's worth. That's useful to know, i guess there isn't much room in the carriages to account for deflection. Quotemcdanlj Hardware store aluminum in my experience is usby Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
Quotethe_digital_dentist I'm not sure what numbers it would take to prove it, but I suspect that square tubing is both lighter and stiffer than an equivalent size t-slot, and you can pick it up at your local hardware store. You can quite quickly compare stiffness of beams of similar material by comparing second moment of inertia. From the 8020 website (because im not working it out manually forby Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
QuoteMKSA Would it be possible also to move this in the correct topic, CoreXY, eventually in a sub category "in progress" for follow up. So many similar projects that get buried in the "general" discussion. I have no objection to that - but also no idea how to do it. I've made some changes to the design to incorporate what people have been saying. Will post renders when I finish up some bits.by Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
QuoteSupraGuy In any case, I was asking what ADVANTAGES, not what differences. I understand well the appeal of designing something different. Other design features were copied and emulated as closely as I was able from known good and working designs, as I felt no need to re-invent parts of the design which already existed and were perfectly adequate. Does it have to have any advantages? If I waby Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
QuoteSupraGuy In general, I like it. Thanks! QuoteSupraGuy I'm a little unsure however what advantages it offers over something like the Railcore. It seems to me that if I'm going to be buying linear guides, extrusion and all of the plates, for a CoreXY build, there's already an existing solution out there that does all that that's already been debugged, and issues identified. So theres a fewby Ed3D - General
Re: SoM Y axis rebuild - 5 years ago
Quotedc42 Quotethe_digital_dentist You're referring to the Maxwell type kinematic mount. Those are effective, too, but harder (for me) to make. You have to be able to mill the slots in the plate at accurate 120 degree angles. If the angles are not exactly 120 degrees then I believe the Maxwell mount will still work, however there will be a slight rotation of the bed when the temperature differeby Ed3D - Mechanics
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
Quoteo_lampe Guiding the belt like you showed for the Z motor requires a very long belt. A simple triangle with some extra wrap around the stepper pulley will do. It's not pictured but the belt basically runs around the PSU and control board so its defined by them. There's not enough space in the centre to fit the PSU if you just make a triangle! QuoteMKSA Seeing this, I experience "deja vu"by Ed3D - General
Re: Antibacklash Nuts - Best practice for mounting? - 5 years ago
QuoteWesBrooks Had flatspots on my Delrin V-Slot wheels on a build for a previous employer. Granted the wheels - in error - were too tight against the rail, but the ease at which the aluminium extrusion wore a flat in the wheel in its extrusion direction doesn't give me confidence in its durability. I agree - the wear on these plastic style ones will be massive.by Ed3D - General
Re: SoM Y axis rebuild - 5 years ago
Have you looked at Kinematic couplings? It might be interesting to try spacing the three mounts around a PCD so the slots all point inwards. Currently I think you're slightly over-constraining the bed still so it may be beneficial to switch to three sets of rollers / grooves rather than what you have at the moment. Edit: Nah you're good.by Ed3D - Mechanics
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
So thinking about the 4 Z rails I see now how silly that is - it's completely over-constrained when you actually consider your 6 DOF (XYZ ABC). With 4 rails you're seeing XY constraint at 4 places and 6 lots of axis C constraint. The three screws then provide AB and Z constraint. With 2 rails you're still over constrained in XY but now only with two points and you only have 1 constraint for C.by Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
Thanks a lot - some great help here! Quotethe_digital_dentist Print head: covering the ugly hot-end with fans and plastic shrouds, etc. makes it look "professional", but tends to make it a PITA to service, and the extruder is going to be the least reliable thing in your printer- you will have to service it from time to time. Make sure you can take it apart and get it back together easily. Thinby Ed3D - General
Re: Looking for suggestions for 0.9 Nema17 stepper - 5 years ago
Im really interested in the whole 0.9 vs 1.8 steppers for XY and Z. Would be interested to hear peoples thoughts. It seems to me the main gain is vibration damping.by Ed3D - General
Re: Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
Thanks a lot! In terms of the points you raise: - I absolutely agree that 4 rails is going to be a challenge to prevent binding and I spent quite a long time going back and forth on it. In one iteration I had 3 rails aligned with the leadscrews. I settled on 4 because I think it will give the absolute best stability but have put a couple of things in place to help align them. First the bed extby Ed3D - General
Re: Antibacklash Nuts - Best practice for mounting? - 5 years ago
I personally believe that you want to mount them upside-down in the case of a printer Z axis otherwise the platform is resting on the spring not the threads (if that makes sense) Effectively you want to view it as a normal nut that is being pushed by a spring into engagement at all times. So you want the spring to push the nut down into engagement (working with gravity) so that the weight of thby Ed3D - General
Design Review! Looking for comments / critiques and ideas for my new printer build. - 5 years ago
I think this is going to be quite a lengthy post so please bear with it! I’ve been working on this design for a printer for a couple of months now and I think I’m almost finished (famous last words) and ready to start ordering parts and building! What I’m looking for some thoughts on the designs and any ideas you can think of to improve the design before I build prototype one! The basic spec forby Ed3D - General
Re: Best Auto level sensor & Extruder? - 5 years ago
Anyway..... the_digital_dentist I like your bed You did manage to link the same picture before though.by Ed3D - General
Re: Best Auto level sensor & Extruder? - 5 years ago
QuoteWesBrooks With regards the original post I've tried the standard ormerod and mendel extruders, E3D titan, and Bondtech.the printed extruders worked well but didn't last well. I never got along with the Titan. Found it fiddly to set up, lacked power and ground filament when there were loads of retracts. That said it was consistant once setup. The bondtech is my favourite but I don't think itby Ed3D - General
Re: Best Auto level sensor & Extruder? - 5 years ago
QuoteMKSA QuoteEd3D QuoteMKSA If you look here, you can see that the very few correctly built cartesian printers don't use ABL because they don't need it. If you need ABL, you made a clunker and no "sensor" will be good enough as it will stay a clunker. Of course a Delta, SCARA or similar it is a must in order to define the origins. I would be using ABL to compensate for thermal expansion / wonby Ed3D - General
Re: Best Auto level sensor & Extruder? - 5 years ago
QuoteMKSA If you look here, you can see that the very few correctly built cartesian printers don't use ABL because they don't need it. If you need ABL, you made a clunker and no "sensor" will be good enough as it will stay a clunker. Of course a Delta, SCARA or similar it is a must in order to define the origins. I would be using ABL to compensate for thermal expansion / wonkey bed mounting. Suby Ed3D - General
Re: Best Auto level sensor? - 5 years ago
QuoteDust The word best is a big red flag!! those here that make a sensor will say theirs is best. those that have a sensor will say the one they are using is best. best is the one you personally like the best. For what ever reason that may be. Absolutely agree! Its a very loaded question. I just wanted to hear peoples thoughts / experiences with different sensors.by Ed3D - General
Best Auto level sensor & Extruder? - 5 years ago
(Probably a repeat thread so apologies if it is!) Im working on a new printer build and wanted to get some ideas what you all thought on some parts. What do you think is the best auto-level sensor is in terms of ease of use, repeatability, package size, bed material options, etc. Currently I'm looking at the BLTouch so I can use a glass bed but if its worth not having glass so I can use a PINDAby Ed3D - General
Re: New arm design? Would love feedback - 5 years ago
I can appreciate both sides of what you two are saying. No the deflection isn’t great, neither is repeatability and it could easily be much much better using machined Al but then its no longer this cheap to build. I think this poises itself in a certain price to quality level that many might find appealing / fun.by Ed3D - General
Re: New arm design? Would love feedback - 5 years ago
QuoteDaGameFace Anything specific you have in mind for the arm? Nope, just a really cool project. Im sure I can find some kind of use for it though! Perhaps an auto print remover? What are you planning to use it for?by Ed3D - General
Re: New Printer Design - Could do with some feedback / thoughts on spec! - 5 years ago
QuoteIf you use 3 Z leadscrews/motors instead of 2 (1 in the center back and 1 in each front corner) and you use a probe on the hotend, you can take advantage of auto bed levelling. gtj If you use 3 Z leadscrews/motors instead of 2 (1 in the center back and 1 in each front corner) and you use a probe on the hotend, you can take advantage of auto bed levelling. I agree with MKSA - the 3 point leby Ed3D - General
Re: New arm design? Would love feedback - 5 years ago
I would recommend switching out the lead screws for ball screws. You can get them cheap from china (link) Second im not sure those couplers are good - switch them out for some of the more rigid style ones not the sprung ones. Im really interested in this project - any plans to make it available to other people?by Ed3D - General
Re: New Printer Design - Could do with some feedback / thoughts on spec! - 5 years ago
Ive been looking at the Voron quite a lot recently and its an interesting machine - seems to go against what some of you are saying though. What do you think of the design?by Ed3D - General
Re: New arm design? - 5 years ago
Nice! Whats the speed / rigidity like? how about repeatability?by Ed3D - General
Re: New Printer Design - Could do with some feedback / thoughts on spec! - 5 years ago
Replying to a few people here in one go (not sure what the forums policy on multiple replies is) QuoteCoreXY is fine, but moving the whole thing? No thanks. Moving the bed in the Z axis would be so much better. Lifting the CoreXY 8n the Z axis defeats the whole purpose of not having the motors moving. It doesn't remove the benefit at all - when the head is moving X and Y the motors are stationaby Ed3D - General
Re: An open source kiln as part fo the RepRap project? - 5 years ago
What temperature are you aiming for?by Ed3D - General