I have a similar issue - I've used an all metal hot end, however I fabricated parts myself, it doesn't seem to like any non-smoothness in the routing of filament, and mine would bind up after a few minutes printing - weird really, as when I first assembled it, I did spend some hours calibrating without any issue, and i think the problem developed after some time. I've now switched to the E3D allby majic79 - FoldaRap
I tried the wooz J-Head mount for my foldarap - there's a space constraint that prevents it from working with the E3D all metal hotend, so I did my own - this makes provision for an M5 Nut to be used to retain the standard pneumatic fittings that foldarap uses, however it would be trivial to remove the top and use the larger tube that E3D supplies with their hotend (ask and ye shall receive - beaby majic79 - FoldaRap
put a faraday cage around your electronics, ground the shield of the USB on the cage - that way if you do shock/short circuit, it won't interrupt anything.by majic79 - Controllers
well, first thoughts - it's a good idea, I'm looking at an NXP ARM device for a new board design, but I'll throw my criticisms in as well: Your cap's near the pins will affect your sample times on the analogue reads - as for thermistor sensor reading, they have a specific source current that should not be exceeded, this is usually a part of the design of the circuit that reads the thermistor Youby majic79 - Controllers
There's a bit more to the stepper drivers (logic, current control) than mosfets (although it's fairly certain that they use them in addition), I'm just coming up with ideas - you might be able to multiplex the signal bus to the stepper drivers (direction and step signals) a little easier instead of switching on/off power mosfet (or relay?) a lot cheaper (milliamp switching capacity, TTL logic)by majic79 - Controllers
I believe Marlin has a similar option also - I can't recall seeing a note in the circuit diagram explaining that they are handled in the IC - but having it in there (as an unpopulated option?) doesn't cause problems, and if a new version of a chip comes out without the pullup, it's still compatible (but I'm a lazy designer and I don't like to engineer things twice)by majic79 - Next Wave Electronics Working Group
Just a thought - why not multiplex the extruder control and switch on whichever extruder you require (you could feasibly do it with one extruder driver and just multiplex the output control with a couple of mosfets per channel) and use I2C to switch on/off the channel you want to drive. It could allow for relatively easy switching of multiple extruders. If you want to mix several colours at onceby majic79 - Controllers
You don't need to change the fuses (all the documentation I find says freq higher than 5Mhz, so 16Mhz or 20Mhz should both use same fuse) however you do need to specify in boards.txt the CPU frequency. I've soldered up a sanguinololu with a 20Mhz crystal and a couple of caps in place of the resonator (we were having problems) and it works well (had to change the fuses going from a resonator to thby majic79 - Sanguino(lolu)
Personally, I think the board should be designed to include the pullup, so that if the wire is accidentally removed/mistakenly not fitted, then the endstop is always seen as tripped - that means a change to the design, but could be done by adding a surface mounted resistor between signal and power on the board (or make it a pulldown and invert the logic in the firmware?) I put the resistor intoby majic79 - Next Wave Electronics Working Group
Ground connection shouldn't be a problem, unless it's at a different level to the other grounds on the board. I've isolated the 12V heater grounds from the rest of the board on my tweak of Gen7, but only so I could ensure a short, high current ground path. Your resistor will have a power rating, so long as you don't exceed that you'll be fineby majic79 - Next Wave Electronics Working Group
// Travel limits after homing #define X_MAX_POS 205 #define X_MIN_POS 0 #define Y_MAX_POS 205 #define Y_MIN_POS 0 #define Z_MAX_POS 200 #define Z_MIN_POS 0 That says how long your axis is (set the MAX_POS values to your real axis lengths) But also make sure these values are correct: // default settings #define DEFAULT_AXIS_STEPS_PER_UNIT {78.7402, 78.7402,200*8/3,760*1.1} // default stepby majic79 - Firmware - mainstream and related support
I etched my own heatbed (60W! I can hit 110 degrees in around 10 minutes in a 5 degree ambient - although I've got a smaller bed than most) using FR4 copper clad and I'm using the back of that covered in kapton (no glass). A friend of mine has a 250 silicone heater pad with a alu bed and glass plate on top (no kapton) both these scenarios workby majic79 - Next Wave Electronics Working Group
I'm printing ABS to a Kapton tape covered heatbed - it won't adhere unless temps are above 105c (I run it at 110c) - so I'd add kapton and double check your tempsby majic79 - Next Wave Electronics Working Group
I'd second Uncle_bobs suggestions - work out the mechanics first, then choose motors to drive it all (you'll be surprised what a single motor is capable of), a good mechanical design will not require masses of force/power to drive it all, especially as we're talking about moving a relatively light weight in what should be smooth straight motion (unless you're talking deltas, in which case, your mby majic79 - Controllers
I don't think driving two steppers will make it run any faster. Screw drives have backlash problems (play in the screw mechanisms) unless you go to adjustable nuts and funny screw threads (ACME etc) then you have servicing problems. Stepper speed is a frequency limiting factor governed by current in the coils (and microstepping won't make it quicker - you're still up against change in time to droby majic79 - Controllers
So first up - what endstop configuration are you using? You've got several ways of doing it, ultimately using builtin pullups or external pullups/pulldowns, with it either sitting high and going low on trigger, or sitting low and going high on trigger. "normal" is a low signal that goes high, if your electronics is rigged back to front, then you need change these lines: const bool X_ENDSTOPS_INby majic79 - Firmware - mainstream and related support
I'll finalise my KiCad layout (need to add the expansion ports in) and post it up on github at some point in the near future - I don't know gEda, but do know KiCad - I think KiCad is a little easier to work with for final manipulation, but you have to jump through a few hoops for the module definition and tying up the circuit diagram to real devices (once you get the workflow, it's a bit easier)by majic79 - Controllers
Mine's made out of ABS and I have no issues - I'd have thought it's a better material if you want a long term construction (the only advantage I can see to PLA is that it doesn't require a heated bed and has a lower melt/extrude point)by majic79 - FoldaRap
What speed are you trying to drive them at? There's a limit to how fast marlin can drive the motors (although I don't know what it is yet!) and you may be hitting that limitby majic79 - Firmware - mainstream and related support
I don't know if it helps, but when I first tried, I had some teething problems with my board (not communicating with the AVR due to incorrect TX/RX connections - a fault in my board design) and I tried swapping D+ and D- on the USB side, it then detected as a low speed USB device and failed to install the drivers - is it possible that this is the problem you are seeing? I wouldn't recommend doingby majic79 - Next Wave Electronics Working Group
Check the logic on your endstops, I'm using Marlin firmware, and the default for that inverts the logic of the endstops (so when it's untripped, it sees it as being tripped). I had a similar problem until I switched that around, then it worked. I'm using a mechanical endstop though, with pullups on the lines and the untripped endstop holding the line low (hitting the switch allows the line to goby majic79 - Next Wave Electronics Working Group
Well, have had a successful weekend calibrating and testing my machine - I'm now happily printing in plastics, I've made my own heatbed to go with it (had some serious trouble with your maths Traumflug, decided it was better to do my design without beer, then it worked!) this was plain copperclad FR4, I have a Seno Phenolac applicator that covers the board in a light sensitive chemical, I prinby majic79 - Next Wave Electronics Working Group
Well, this weekend I made the headbed Then had a go at a basic calibration print (been using this as a dry run test beforehand, so I've learnt the basics of the .stl->slice->print toolchain) Thought it looked pretty good, so did a test run (happy with it!) I did notice some oozing around the joints in the hot end when I did a longer run, so I've had some tweaking to do. Seriously consideby majic79 - FoldaRap
Works on mine - in fact I had to revert to my windows machine to configure the chip (so that the data lights flash) - not tried an actual print, but I've had communication with my AVR through it on my Gen7 boardby majic79 - Next Wave Electronics Working Group
I don't think duty cycle matters all that much, so long as the rate of rising edges stays consistent. your limiting factor for speed will be governed by the size of coils in the stepper motor (which is why driving them too fast will skip steps). there's an excellent calculator for working out max RPM of a stepper motor here: which will let you workout the minimum pulse interval (e.g. for a 4.3mHby majic79 - Firmware - mainstream and related support
Ahhh, ok, I'll add the extension board headers into my KiCad design and cut a new board - I think I have space on the board to hack something in temporarily (using a seven switch or similar) but this was attempt no1 and I've laid things out a little different (I think I'll put my KiCad design on github) trying to save as much space as possibleby majic79 - Next Wave Electronics Working Group
Motedis have a UK site (www.motedis.co.uk) and supplied 20mm T-Slot profile for my Foldarap at very reasonable prices (would definitely use them again)by majic79 - Extruded Aluminum Frames
Lincoln, United Kingdom - I didn't even know there was a map! Been doing my calcs, and I think I'm only running around 60W at the moment, the heated bed will add another ~45W or thereabouts (I'm doing my own PCB heatbed sized at 140x140mm so it fits the foldarap perfectly) Seen your designs for Foldarap2 - looks very interesting!by majic79 - FoldaRap
I'm only using the Arduino IDE to do my development, here's how I did it (assuming you have already got avrdude on your machine) Step 1) Download "Gen 7 Arduino IDE Support" (http://reprap.org/wiki/Gen7_Arduino_IDE_Support) and put it onto your PC Step 2) Extract contents of Gen 7 Arduino IDE Support and find the Gen7\bootloaders\Gen7 area - you're looking for a file called "bootloader-1284p-20mby majic79 - Next Wave Electronics Working Group
Quick question: Is there a reason for a lack of fan control pins? I'm thinking of adding it into my own customisation just so that I can turn on and and off a cooling fan on my hot end and perhaps add some cooling fans to my steppers (although I may just see if heatsinks alone will do) Starting to realise the benefit of this machine now, I may have to do a quick hack to the print head so that Iby majic79 - Next Wave Electronics Working Group