What sort of mechanical performance are you looking for? Temperature resistance? Yield strength? Tensile strength? Impact strength? Stiffness? Wear? Garden variety PLA actually works pretty well for a lot of lower temp applications, especially where stiffness and yield strength are more important than impact strength or ultimate tensile strength.by LoboCNC - General
McMaster Carr carries Shore 40A two part silicone casting compound. Unfortunately, I've heard they only ship via UPS, which can be hideously expensive going to Canada.by LoboCNC - General
You don't really need a rigid structure if you are willing to turn your printer upside-down: UDIO Printer XY Drive This printer, which uses a modified H-bot configuration, has been my go-to printer for the last 2 years. It's been incredibly reliable. Unfortunately, I've been lazy about publishing any complete plans, but I'd be more than happy to share whatever details I've got with anyone inby LoboCNC - General
Quotedlc60 QuoteLoboCNC Kinda pricey - $40 for a 4 sided slide. Is a 2 or 3 sided assembly rigid enough to use stand-alone? Not compared to a good linear slide. A 3-sided set would work fine it seems for deltas. I really hate the linear bearings for polished rods, they seem to gum up and go bad pretty often, so I am wondering if these could replace those as well. Hmm DLC Plastic or steel rby LoboCNC - General
Kinda pricey - $40 for a 4 sided slide. Is a 2 or 3 sided assembly rigid enough to use stand-alone?by LoboCNC - General
You might want to check out the Alpha Wire EcoCable. The unshielded twisted-pair option looks ideal for this sort of application.by LoboCNC - General
And here's another online gear generator that I've used: http://hessmer.org/gears/InvoluteSpurGearBuilder.htmlby LoboCNC - General
Keep in mind that most of the 3D printed gears you see tend to be huge Duplo block versions of their normal metal, or even molded gear counterparts. While calibration prints may show your printer to be accurate when printing fairly smooth regular surfaces, the vagaries of squirting at dragging molten plastic along the convoluted pathway that forms a set of gear teeth are going to fundamentally lby LoboCNC - General
The thicker the plate, the less it will warp, and the flatter it is likely to be to begin with. If you can find a piece of rolled plate that is flat enough to begin with, for something like a 250x250mm plate, I'd imagine 6mm would be sufficient. I'm actually using an 1/8" thick rolled plate for my 350x350mm bed. It warps about 0.1mm out of level when heated to 70C, but that's OK for my needs.by LoboCNC - General
Quoteo_lampe At work we use very thin sheets to apply solder paste to PCBs. When I'm back from my holidays, I can take a closer look. I'm a bit confused about ( nonmagnetic?) spring steel on printbeds? Spring steel can either be stainless steel (most alloys non-magnetic) or regular carbon steel, which is always magnetic.by LoboCNC - General
Lots of places get really sloppy with their part designations. The GT refers to the tooth profile, and the number after it refers to which generation of the tooth profile. The original profile was designated GT, then GT2 and the newest is GT3. The number in front usually refers to to the pitch of the belt in mm. But because of the confusing terminology, most industrial supply companies wilby LoboCNC - General
I haven't used a flexible steel plate myself, but a 0.5mm should give you something with enough flex to pop a print loose. High-strength spring steel would be ideal. If you are using mild steel, though, you might want something a little thicker (0.8mm?) to keep from inadvertently putting a permanent bend in it.by LoboCNC - General
What type of questions are you looking to ask? If you are looking for specific recommendations (best pulley size, model of motor, etc), then you'll most likely get responses pulled straight from the BOMs of standard printer designs. If you are looking to build something different from the standard designs (to achieve some improvements or to meet some specific need) your questions, I suspect, wiby LoboCNC - General
QuoteDust I suspect the issue will be that the pressure changes during normal printing. Using that same pressure to change the size of the orifice may not be practical. Perhaps what is needed is a tiny silicone tire as a nozzle, having its own independent pressure system to adjust the orifice size. (probably liquid filled, as it doesn't compress) I agree, what actual nozzle diameter you get iby LoboCNC - General
Quoteetfrench I'm currently using a Teensy 3.5 (Arduino compatible) microprocessor with the TeensyStep library to do synchronized steppers. I'd be interested in your firmware. Here's a link to the TicStep firmware source and a Windows test utility program. PDF documentation for firmware is included with the firmware source code, and for the Windows test utility, I've included the C++ Builder (by LoboCNC - General
Anyway, back to the original thread topic, if anyone is interested in the coordinated multi-axis stepper control firmware I developed for the Tic T500, let me know.by LoboCNC - General
Oh, that's excellent! When I looked at the reprapfirmware wiki page, all I saw for, say G01, was the parameters X, Y, Z & E (and other misc parameters). Looking deeper I see that it does much more. (This capability is kind of buried in the documentation I was looking at - it might be worth making it higher profile.) I'd definitely keep this in mind for my next robot project, but for my cby LoboCNC - General
Quotedc42 QuoteLoboCNC I'd been searching for a while for stepper controllers that support tightly coordinated motion for greater than 4 axes. You can't have looked very hard then! RepRapFirmware on Duet WiFi/Ethernet has supported coordinated motion across up to 9 axes for well over a year. We only stopped at 9 because nobody has asked for more yet. Does the RepRap firmware coordinate motionby LoboCNC - General
I've developed alternate firmware for Pololu's new Tic T500 stepper controller that supports tightly coordinated motion across multiple axes for a 6-axis robot arm I am working on. If anyone is interested, I'm happy to post more details as well as the firmware source code and a Windows test utility. I'd been searching for a while for stepper controllers that support tightly coordinated motion fby LoboCNC - General
QuoteNumber_5 It's probably not worth trying to bind it to metal due to cost and also the dispensable nature of nozzles in general. It could be clamped to the hotend in various ways. Yeah, I think that's what I'm leaning towards - a small silicone disc (maybe 3mm dia, <1mm thick) clamped to a nozzle tip (drilled out to maybe 0.6mm) with a metal sleeve. And then poke a tiny hole in the silicoby LoboCNC - General
QuoteDust silicone doesn't stick to anything but silicone... (more or less) So it not going to adhere to a nozzle, not without some cleaver mechanical fastening system From what I understand, silicone overmolding with proper primers you can get very good adhesion to most metals. Acquiring non-industrial quantities of the proper primers and molding compound may be a bit of a challenge...by LoboCNC - General
QuoteOrigamib Biggest problem I see is nozzle wear. Brass already wears down quickly, how will silicone fair? Why not a silicone sock placed over a brass nozzle secured in place by a metal zip tie? I really like the silicone sock idea. I wonder if you overmolded silicone on to a brass nozzle if it would adhere we ll enough to not separate at the tip from the extrusion pressure.by LoboCNC - General
QuoteNumber_5 Here is what I was picturing when you mentioned this. Inside the nozzle is a cone. This cone is there to keep the tip of the nozzle from bulging out, it's thicker then the rest. The area around the cone is air, to give space for the cone to expand into. The bottom is corrugated. This may or may not be needed, but could make it easier to expand without pushing the silicone downwardby LoboCNC - General
QuoteSupraGuy This is a terrible idea from a control point of view. If you do this, the nozzle diameter is linked to extrusion pressure. Pressure is linked to extrusion speed, which is in turn linked to print head speed. therefore, you need to extrude faster in order to print faster, but you also need to take acceleration into account, so this means that your nozzle will be getting smaller closeby LoboCNC - General
QuoteMKSA QuoteLoboCNC A more accurate way to use stall detection for Z axis homing is to lower the Z axis in small increments and then move the nozzle back & forth in the X (or Y) direction with a very low current setting and detect the X (or Y) motor stall as the nozzle drags on the bed. This is what the MOD-t printer did, although it used servo motors and encoders rather than open-loop stby LoboCNC - General
A more accurate way to use stall detection for Z axis homing is to lower the Z axis in small increments and then move the nozzle back & forth in the X (or Y) direction with a very low current setting and detect the X (or Y) motor stall as the nozzle drags on the bed. This is what the MOD-t printer did, although it used servo motors and encoders rather than open-loop stepper drivers with stalby LoboCNC - General
Has anyone thought about or explored the use of a silicone rubber nozzle, or in particular, just the orifice area of the nozzle? I was thinking that you could start with a very small orifice (say 0.1mm) that could stretch to a wider diameter at higher extrusion rates, essentially giving you a variable diameter nozzle based on the flow rate. Of course, you'd have to figure out a geometry (and meby LoboCNC - General
QuotecharlieRC Sorry LoboCNC, didn't see your response before I posted above. At this point, I seem to be stuck with trial and error. Any suggestions about a controller? I was planning on using the eincy Rambo until someone said they don't provide enough power. I am now thinking about the Rambo Mini or just the regular Rambo, but not sure if that's any better. I am no loner sure what'sby LoboCNC - General
QuotecharlieRC QuoteLoboCNC If you want steppers to move faster, use as high a supply voltage as the driver chips and caps on your board will allow. (I think most ought to handle 24v at least.) Also, for a given size, try to choose a motor with the highest current rating your drivers can handle. These motors will have a correspondingly lower "rated" voltage, allowing them to be driven faster fby LoboCNC - General
If you want steppers to move faster, use as high a supply voltage as the driver chips and caps on your board will allow. (I think most ought to handle 24v at least.) Also, for a given size, try to choose a motor with the highest current rating your drivers can handle. These motors will have a correspondingly lower "rated" voltage, allowing them to be driven faster from, say, a 24v supply. Oneby LoboCNC - General