This is for my new (still planned) printer and one of the objectives is to make it as future proof as possible. With that in mind, I've discounted thermistors as I may want to print at elevated temperatures at some point in the future. Thermocouples seem to be potentially problematic with wiring and insulation. Which leaves me with PT100. Initially, the printer will be using a Diamond hot end (alby deckingman - Duet
Thanks again. Voltage will be 24 V (as per your recommendation in answer to one of my earlier questions). Electronics will be Duet (naturally) Print bed will be 400mm x 400mm but printable area is looking like 320 x 340 max. The diagonal therefore is 467mm. Assuming our earlier stab at acceleration to be correct(ish) we had something like 3,400 mm/sec^2. Which would give us sqrt(2*3400*467by deckingman - Duet
Yes could be a bit overkill. From memory of the pics that DC42 posted, I think the daughter boards only have 2 terminals per sensor so probably only support 2 wire PT100s but an accuracy of +/- 1 degree would be plenty good enough for the hot end and bed I'd have thought. Edit. Just looked again and it looks like there are indeed 4 terminals per sensor, not 2.by deckingman - Duet
As we will have the choice (with daughter boards) of using thermistors, thermocouples, or PT100 probes what do you experts recommend for a largish printer with potentially longish leads (say 1 to 2 metres)? Accuracy and reliability being more important than low cost. Thanks in advance.by deckingman - Duet
Thanks yet again. Of course this leads me to the inevitable question - what is a good number to use and/or what determines the ideal setting for that number?by deckingman - Duet
Thanks DC42, I knew I could rely on you to point me in the right direction. I knew about the reduction in torque due to speed (that was where my 50% fudge factor came from) but not the other things. Somewhere in the order of 3,500 sounds much more realistic than 66,000. So what about settings for M201 speed (M210 was typo in the title)?by deckingman - Duet
As title really. The Wiki is unclear. It states that M566 is a workaround for an algorithm limitation on some firmwares but goes on to say: "Recent versions of RepRapFirmware don't have the limitation, but instead they use this parameter to determine the maximum allowable speed change of each motor when cornering."by deckingman - Duet
Is the following a valid method for determining the maximum acceleration capability? Going back to schoolboy maths (long forgotten) Force=Mass x Acceleration. Therefore acceleration is Force / Mass. Looking at the spec for high torque stepper motors I can see that the holding torque can be 40N.cm. When in motion though, that torque drops off depending on the speed that the motor is stepping at. Tby deckingman - Duet
Quotecozmicray Do you know of any work by the timing belt manufacturers for back and forth applications in CNC, 3D printing etc. I think for 3D printer the tension device should fix initial tension of the belt, then just let it run Tweeked every once in a while, to take out stretch and other slack No (about timing belt manufacturers for CNC, 3d printing etc), and my automotive knowledge datby deckingman - CoreXY Machines
Quotecozmicray you can't use a spring tensioner if the belt turns in one direction, like the belt on auto engine. Please advise the auto engineer designers Quotethe_digital_dentist Um, if the belt turns in one direction you can't use a spring tensioner because it will run into the pulleys. Er, actually as an ex automotive engineer, this is something I do know about and you both right andby deckingman - CoreXY Machines
Just checked the link you posted - those screws look like the dogs' danglies.by deckingman - Mechanics
Yes I think 0.05mm is a good place to set the bar with a view to potentially printing at 0.1mm (although personally, I do most things at 0.3mm and rarely bother with less). But you never know what you might want to do at some point in the future........... When you think about it, if the lead screws are only lifting the bed and not being used in any way to provide any sort of lateral stabilityby deckingman - Mechanics
Quotelkcl there's also the fact that the ID of the bowden tube cannot ever be the same as the OD of the filament (otherwise it wouldn't move freely, even if it is PTFE): as a result the filament buckles (in unpredictable ways) a bit like a microwave down a wave guide, it bounces off the inside, but far less predictably. this and the other factors you mentioned is why you have to do 4 to 5mm retby deckingman - CoreXY Machines
Quotedbeck002 Thank you for the input GroupB. How do I get in touch with DC42 and the reprap firmware community? I will be needing a lot of support if I wish to convert all my machines to Duet on 24v. If you could point me in the best direction it would be very helpful thank you again. There is a whole section on these forums dedicated to all things Duet. DC42 is a regular contributor.by deckingman - Printing
What type of thermocouple(s) is/are supported with the daughter board?by deckingman - Duet
QuoteJamesK QuoteDust Normal cause for that sort of thing is that the thermistor is escaping from the hot end, a very small gap and the temperature reading lowers a lot. Wouldn't that cause the actual hotend temperature to be higher than intended? A breakdown in insulation would cause the thermistor to over-read and result in lower than expected hotend temps. When the printer has been unused forby deckingman - Printing
QuoteDust Normal cause for that sort of thing is that the thermistor is escaping from the hot end, a very small gap and the temperature reading lowers a lot. Cheers - I'll check that.by deckingman - Printing
For some reason I'm having to increase the hot end temperaure and print slower than I'm used to, otherwise I get severe under extrusion and the extruder chewing up the filament. I was thinking it was a bad reel of filament but have tried a part used reel that I know was good and get the same issues. So, I can no longer print PLA at 190 or 205 deg C. I have to use at least 220 and 235 deg C is betby deckingman - Printing
Quotehobbymods I wont be twisting belts or having them run hard against flanges. I will extend the shaft on each stepper so that the drive pulley will be on the correct plane for each of the 2 circuits, and do some sort of pedestal bearing mount to support that extension. I've got toothed idlers coming for where it turns on the toothed side and plain idlers for the other, I'm not going to all tby deckingman - CoreXY Machines
I don't think there is a definitve right and wrong way. 4mm pitch with 2:1 gearing will do exactly the same as 2mm pitch and no gearing. 4mm pitch with no gearing would probably work too. It would give you 5 full steps per 0.1mm but my gut instinct tells me that may be a bit too course. I still think 16mm is much larger than is necessary but I guess it won't have any negative impact. Can you getby deckingman - Mechanics
I was just perusing the list of G code commands (as you do), and I came across the M201 maximum acceleration settings and M203 maximum feed rates (which I assume to mean speed for the axes). I've never played around with these on the assumption that I have a RRP Mendel so the default RRP values ought to be about right. However, the machine I'm planning will be a completely different beast so howby deckingman - Duet
Another little tip. If you are planning to fix this stuff together by tapping the ends and using bolts in the slots, Screwfix sell M5x16mm socket button head A2 stainless bolts for £2.59 for a pack of 50. M5 A2 stainless washers are 99p for a pack of 100. They also do a limited section of Cap head screws. e.g. M5 x 20 A2 cap head @£3.77 for a pack of 50.by deckingman - Extruded Aluminum Frames
Man, you are a star! Don't suppose you have that as an stl do you? No worries if you don't - I can cobble something together in OpenScad. Thanks for taking the time. I really think this, or something very like it, is going to work. Compared to my existing Mendel, my planned printer could end with 60% bigger X and Y, 500% bigger Z but with 30 to 50% shorter bowden tubes. Brill !!by deckingman - CoreXY Machines
Quotehobbymods I must have got it wrong about the 1mm pitch being the norm....thought I'd done my homework. I'm looking again at the Hiwin range: And if I'm using a Duet which seems likely, I'd probably be looking at 0.9 deg steppers? The simple/standard internal recirculating screws they have seem to come in a range with all sorts of pitches starting at 1mm, so maybe 4mm with 2:1 pulley ratby deckingman - Mechanics
I've only been able to find 2 suppliers of Open Builds V slot in the UK. Ooznest and RoboCutters. I've ordered a few bits and pieces and both offer excellent service. However..... I was about to order a pile of stuff so shopped around on the interweb thingy and found RatRig in Portugal. They claim their very own extrusion made in Portugal to the exact Open Builds spec and dimensions . Comparingby deckingman - Extruded Aluminum Frames
What you have in mind is exactly what I'm proposing to do with a couple of minor differences. I've got (designed) 2 linear rails on the sides but at the front, two lead screws at the same position and a single one in the centre of the back. My bed will be 400x 400 (about 330 x 340 printable area) but a lot taller (about 800mm Z movement). As the bed will be constrained by the linear rails (I'm pby deckingman - Mechanics
Quoteaussiephil I have some thoughts on this based on my flying extruder setup on the delta that should work if your prepared to have some vertical height above the printer. I have around 200mm of Bowden length with 580mm diameter coverage withe the extruder suspended centrally about 300mm below the central retaining point 500mm above the hot end. The central point is then pulley counterweightedby deckingman - CoreXY Machines
I too have wired but not wireless where I want to use the printer. Cat 5e cable, Gigabit ethernet, POE too but no wifi. It won't put me entirely off buying the Duet for my new planned printer but it's a shame that I'll also have to go out a buy some sort of dongle thing and cease to use a perfectly serviceable cable/wired connection.by deckingman - Duet
Quotethe_digital_dentist Quotedeckingman The thing is, I need to mount the extruders somewhere so if I can figure out a way that will keep the bowden tubes as short as possible, it'll be a bonus. The shorter the tubes get, the stiffer they get. With 3 of them connecting the extruder gantry to the hot end carriage they'll be pulling the extruder gantry around as if it is all one piece. Unless yby deckingman - CoreXY Machines
Quotethe_digital_dentist You can get high temperature silicone from an auto parts store, print a mold, and mold a part to fit the block. You might be able to find two-part silicone that can handle high temperatures which would be easier than squeezing stuff from a tube. That's an idea. Might work better than buying silicone baking sheets and cutting them up. Hmmmm........by deckingman - Mechanics