Have you checked the endstop?by JamesK - Printing
I assume the servo pins are pwm. I haven't looked into it, but it seemed like an attractive place to connect an extra mosfet for some electronics cooling fans that I was thinking of adding.by JamesK - General
Excellent! Can we get a measurement of the pitch? 1mm would be a smoking gun I think (each side of the bearing, assuming out of phase and 2mm pitch belt).by JamesK - General
Quotethe center distance from the table changes with every tooth or gap ... this will be the same, but with much lower effect, when you bend a belt around a smooth bearing/cylinder and move it around Hmm, I can visualize the effect for one side of the bearing, but can't intuit how the two sides interact for different diameters. The maths looks marginally painful for a Friday evening (where's theby JamesK - General
How did you do that Donald? Handcrafted g-code?by JamesK - Printing
Quotedc42 QuoteJamesK I think most Deltas use ABL, not sure how that plays into the situation. Best practice on delta machines is to use the Z probe to perform delta calibration, but not to use ABL. People using ABL on deltas generally haven't calibrated them properly. Ah, thanks for the clarification - I hadn't appreciated the difference between auto-calibration and ABL.by JamesK - General
Mark's (digital dentist) build uses a ball screw on Y with very impressive results. He posted a writeup If you can't glean what you want to know from there I'm sure he'd be happy to answer questions.by JamesK - General
Um, so I don't want to seem argumentative, but a 1G acceleration equates to 9800mm/s2 - is that considered normal printing speed? I confess to a lack of knowledge, but that sounds on the high side to me. Your points about auto-levelling and the deltas are well made. I've often wondered what auto-levelling does to the "use full steps' line of reasoning. I guess it's one of those cases where the beby JamesK - General
QuoteThe difference in resolution between Z and X/Y is about 40 times. I agree that Z is different from X and Y, but not "40 times" different. The weight of my bed is more than 0.5kg and it relies on a belt to move horizontally. Please show me a printer that has a bed lighter than 0.5kg and something to move along Z that weights 40 times 0.5 kg = 20 kg. The weight of the bed isn't supported by tby JamesK - General
Quotedc42 On a delta printer, the Z axis drive relies on belts too. I have found this quite adequate down to layers heights of 0.1mm. I haven't tried lower. Good point. Deltas are really an ideal proof point of how well you can do with belt drives. It's such a cool design. Deltas are what got me excited about building a printer, even though I eventually opted to build a Prusa.by JamesK - General
Hi Jay, Welcome to the forum. You can add dual extruders to most cartesian printers fairly easily, and some CTC replicators come with them, e.g. (from ebay listing so image will probably disappear at some point) You can probably add a second extruder to your existing printer more easily than building from scratch, but maybe there are other things you want to achieve at the same time? Regaby JamesK - General
Given there are plenty of examples of good quality prints from belt driven printers, the answer would seem to be yes. It's an interesting question as to why though. Part of it is that micro-stepping works pretty much as advertised, provided that the torque requirements are still met. And even when the per-step torque requirements aren't met the errors are non-accumulating, so amount to a form ofby JamesK - General
QuoteUnless you want to be on the bleeding edge of development, now is a great time to get involved. Oh, that sounds like a cue for my 'old fart' rambling... When I got started with embedded microcontrollers back in the 90's I had to build my own programmer for the 16c84, solder my own circuit boards and do rs232 by bit banging in software. Now we can buy a mega2560 + ramps clone for $20 and havby JamesK - General
I don't know, this seems like a great time to get involved - there's just a fantastic amount of existing knowledge and robust designs to take advantage of, along with a ready supply of cheap components from China. Maybe we missed out on some of the white heat levels of excitement, but the opportunities are still very exciting.by JamesK - General
In hindsight, I overstated my case. It might not get into current limiting, depending on the vref setting on the a4988. If the voltage measured at the test point (or on the wiper of the pot) is 0.22V then that would match the current rating of the motor (with the /70% adjustment), and the 12V almost certainly wouldn't be enough to drive it. But if you went for about 1/2 that, say 0.1v then you'dby JamesK - Printing
That's one thing I don't remember having read about - how do you judge how much tension to put on the extruder? What constitutes too much tension?by JamesK - Printing
Hi Steve, exactly what happens when the filament fails to extrude? Does the extruder fail to turn (the stepper motor stalls & clicks, or maybe just stops without any noises) or does the motor keep turning and the filament slips? If you can push the filament through the blockage by hand then it suggests your extruder isn't producing enough force. If the motor stalls then you need to check theby JamesK - Printing
How are you connecting your power supplies? If you are using one for the bed and the other for everything else, then it's under powered. Expect the bed to draw roughly 11A, and spec the power supply for 15 to 20, depending on how well built you think it is. Now, if you are wiring the supplies in parallel it might work. Maybe. I would strongly suggest not doing that though. It's far safer to justby JamesK - Printing
It's very difficult to look at a 3d printer without thinking of adding a milling head for some cnc goodness, but really the requirements for milling and printing are so different I think it would be worth building two separate machines. Laser etching seems more compatible thoughby JamesK - Reprappers
Quotemanually set it to be on Sounds like you connected it to the 'fan' output of your controller board. That connector is intended for a print cooling fan(s) and isn't a great place to connect the hotend/coldend fan, even though it seems like the obvious thing to do with most Prusa kits only having one fan supplied and a big connector marked 'fan' begging to have something connected to it. Asby JamesK - Printing
Some of the new 2 part poly-urethanes are very impressive in terms of strength and machinability of the cured material. I've used Smooth-On Smooth-cast 300 and been very impressed. Making dimensionally accurate molds is pretty challenging though. A lot depends on the shape of the parts you want to make. Still, in terms of the potential quality of the finished parts, it's definitely a technique woby JamesK - General
Printing PLA? Looks like you need to add a print cooling fan to improve the overhangs.by JamesK - Printing
That's interesting. I actually meant the one you first linked to, with the magnified images. It seems to have deeper, thinner flutes than the second one. Those magnified images are the closest to perfection I think I've ever seen for FDM printing. Those edges look like a single filament looped out and back, and placed with remarkable reproducibility layer after layer. As an aside, I took your adby JamesK - Reprappers
Wow, that's a whole lot of functionality in there! Very impressive. I have a Taig lathe and I haven't even added thread cutting yet. The enclosure you've built is fantastic.by JamesK - General
Brilliant idea! That will really let us extract the maximum value out of the existing drivers.by JamesK - Next Wave Electronics Working Group
Sounds good. The duet seems like a nice controller, but I'm a little cautious about having the drivers soldered directly on the board. Perhaps with this new generation of spi configured drivers we can have the best of both worlds - software configurable current and modular/pluggable drivers. If the prices come down a bit I might look into using these with a cheap Due clone for my next build (thatby JamesK - Next Wave Electronics Working Group
I'm really liking the look of the new AMIS-30543 drivers. With the SPI based control for micro stepping and current limiting we could really have some fun with these. Has anyone looked at dropping the current on a motor when it's not moving, or dropping the micro-stepping during high speed moves? Not sure if that second one is going to fly - changing the micro-stepping while the axis is in motionby JamesK - Next Wave Electronics Working Group
Very impressive print (the vase).by JamesK - Reprappers
Quote I watched the YouTube video you linked to above: amazing! Isn't it! I can't imagine the forces that are acting on that thing, or the cost of the motors & drivers that are operating it.by JamesK - General