QuoteAndrewBCN To get that more critical view and better judgment, imo it is essential to actually build a first 3D printer from an existing design, then if possible design your own and built it with some small theoretical improvements and prove that these theoretical improvements actually translate into real improvements in practice. This takes time, but it gives you a proper valuable backgroundby JamesK - General
That gave me a good laugh, it has the undeniable ring of truth to it. Still, if we meet every new member with a wall of negativity we risk missing out on the enthusiasm, experience and new viewpoints that they might bring. In my case that would be mostly the 'enthusiasm' category, but nasone did indicate in his first post that he has relevant experience and access to facilities that most of us onby JamesK - General
That's a pretty nice looking set of parts I went for the opto endstops instead of mechanical. They're not a whole lot more expensive and I'm hoping to mount them so that they can't be contacted even if the cpu goes nuts and keeps on driving past them. That should avoid broken mounts and having to readjust them. I'd hope (but don't know) that they would have a more reproducible switch point thanby JamesK - General
Ah, finally a delta with a decent amount of bracing. I thought I was never going to see one The mill looks very fine too.by JamesK - General
Hi, I'm going through the same process right now. I got most of my parts through aliexpress where the prices are better. I was expecting some rejects but so far everything has come good, if a little slowly in some cases. The ramps board in particular was better quality than expected, and the smooth rods, bearings and lead screws all seem reasonably good. I used this vendor for the electronics pby JamesK - General
What voltage do you run your stepper drivers at? The datasheet specs that as a 12V motor (hence the low 0.4A current rating). The stepper drivers can't microstep accurately unless they get into the current limiting regime, which with that motor it won't unless you are using substantially more than 12V drive voltage.by JamesK - Printing
So the only thing you changed was to swap over the motors? If so, and that changed the amount of vibration, then yes it must be the motor that is the source of the problem. I don't know enough about stepper motors to know why that might be. As far as tightening the belt goes, I would think that with the belt loose it was absorbing some of the vibration, and when you tightened it up it transmittedby JamesK - Printing
"I wish to develop a reprap made to push the limits of speed and acceleration" That seems to me to be a perfectly valid and interesting thing to want to explore, just for it's own sake. It seems like we have identified two main categories of problems - dealing with the physical forces resulting from rapid acceleration and getting enough filament through the extruder. Dealing with the forces invoby JamesK - General
Shame - it would have been an impressive beast to see. I suspect any printer you make at this scale is going to come out pretty heavy though! Core-xy vs H-bot is going to be an interesting conversation. I was interested to see 691175002's assertion that core-xy was inferior, previously I'd only seen favourable comments about core-xy. Your point about belt length seems valid, but a H-bot still neby JamesK - General
I haven't built a coreXY (yet!), but it looks to me like 2 belts each of roughly 2*x+y - call it 3m+ for the target 1m^2 area. I suspect that's doable with fairly standard belts, especially as coreXY keeps the moving mass fairly low and we're not aiming for absolute highest speed. But definitely something to keep an eye on. Those filament volume & weight estimates are awesome. Designing forby JamesK - General
Ah, looks like the Melzi has the micro-step signals wired up by default, so it's less likely that your problem is anything to do with that.by JamesK - Printing
Very clever design!by JamesK - Delta Machines
I can't wait to see where you go with this - it should be fascinating (and possibly a little scary!). I was reminded of this video - can we add an extruder and call it good?by JamesK - General
The details depend on what electronics board you are using. If it's a mega 2560/ramps combo, then the microsteps are set by jumpers that go on the pins under each stepper driver module. If there aren't any jumpers on the pins then you get full steps and lots of vibration. Your firmware has to be configured to match the micro-steps setting on the board. There is lots of configuration in the firmwaby JamesK - Printing
Looks interesting. I'm sure you could make it work with enough $$$, but I'm not sure how fast it would go. My biggest concern would be the amount of moving mass on your x-axis, and the twisting moments applied when the head is at the top front position. I keep finding myself drawn towards core-xy with a Z-bed. The forces all look much more manageable in that layout (but I'm just a clueless beginnby JamesK - General
It's difficult to get accurate temperature measurements of small objects with an IR thermometer. If you're uncertain of the accuracy of your thermistor, why not take it out of the hot end and use it to measure a couple of knowns, like melting ice and boiling water. If it can report those accurately then you can assume it's giving you a good value for the interior of the hot end. Or you can get aby JamesK - Printing
QuoteOlaf you´d use an adapterboard between driver and RAMPS That's a nice idea. You could probably connect straight into the existing driver sockets to pick up the ground and control lines and then put suitable voltage rated decoupling capacitors on the adapter board, leaving the rest of the RAMPS circuitry unchanged. With the adapter only having to deal with the stepper drivers it should be eaby JamesK - General
They have higher resistance coils, so take a greater voltage to drive the 1A. Work is VI, so the laws of physics remain unbroken. I'd expect the DRV8825 to drive them fine, but you'd probably need 24 to 36V to get good step rates and that would present a challenge if you host the drivers on a RAMPS board. a good quality RAMPS will have 35V capacitors, so it should be possible to run it to 24V. Waby JamesK - General
QuoteggherbazThis is exactly the reason why it is in between two glass sheets. If any of the sides acts differently, there will be deformation and stresses that could lead to separation of the sheets or cracks in the glass. Sounds good - look forward to hearing how it goes!by JamesK - General
Quotethe_digital_dentistWhat are you trying to achieve by combining all this stuff? Putting multiple thin layers of different materials together, each with different expansion and warp behaviors over temperature, is a sure fire way to never get the thing flat. An aluminum plate is simple, inexpensive, and works without any screwing around. My 12" x 12.5" x 1/4" plate cost about $30. Are you gby JamesK - General
Very nicely done - I remember looking at pics of your build. Out of interest, do you have a total cost that went into that?by JamesK - General
That 1/4" plate sounds nice, but it will add a lot of mass to a moving print bed design. The simplicity of the Prusa layout is very appealing, but I keep finding myself drawn to a core-xy layout with the bed motion confined to Z. Maybe next time. I was wondering about epoxying some pieces of aluminum U channel to the heat bed to increase flatness and rigidity, but I have my doubts about how theby JamesK - General
QuotecdruAre you talking about being flat, or being level? There's a difference and it's the latter that's usually the bigger issue. Interesting. It's certainly being level that is more talked about, but being level without being flat seems both ill defined and not particularly useful. My MK2 bed is decidedly non-flat and I've been worrying about how I'm going to deal with that. I was wondering iby JamesK - General
You can check the voltage at the pins on the stepper driver. Are you using A4988s? If so, MS1, 2 and 3 should all be high for 16x microstepping (according to ). If MS3 is low that will explain the factor of 2 you are seeing. If all three are high then maybe it's a faulty driver - you could try swapping them around and see if the problem migrates to a different axis. If you are using 8825s then iby JamesK - Printing
QuoteThe z axis rise is not making the noise now with the 2031 setting but it did before with the 4000 setting. With the mismatched steps/mm setting the Z axis would have been trying to work with double the configured max velocity and acceleration settings, so maybe that was too much for the motors. Glad to hear that they are sending you a replacement - sounds like things are headed in a generalby JamesK - Printing
That doesn't sound good, and definitely needs fixing. Assuming that the Z axis is free moving with the threaded rods out, checking the Vref has to be top priority. Info here: You'll need to know the driver type and the current rating of the stepper motors. I should probably 'fess up that this is entirely theoretical for me, I'm still working on my first build. Hopefully someone with more expby JamesK - Printing
Hi Ralphy, ABL is auto bed levelling where the printer uses a probe to measure the height of the bed at various points and then compensates for any tilt by moving the head in Z during each layer. It's very convenient and makes great sense for delta style printers where all three axis are in motion all the time. I'm not so sure it's the best approach for printers like the Prusa i3 which were builby JamesK - Printing
That's really cool - the printer has placed the filament with twice the vertical displacement that was intended, yet you still have a nearly intact print. Good keepsakeby JamesK - Printing
That's an interesting object. What materiel are you printing with? In the second photo it looks like filament has pulled away from the complete width of the the 3 perimeter inner cylinder. Is it possible that the thin walled radials are cooling more quickly than the thicker inner and outer walls, shrinking and pulling away? If so, you might need a heated chamber to control the cooling more evenlyby JamesK - Printing