mmm, if the PSU is a true PWM PSU, the current returns are independant. they are suppose to be floated. you can try and measure for connectivity between the +/- pin to L, N and E. there should be more than 1M ohm resistance. each will sink its own amt of return current. also, u can try the circuit with 0.5ohm (r1 r2) ... pump them into a bare heater bed and measure the voltage across R1 and r2 tby redreprap - Controllers
first of all, are you informed about the Rsense value on ur stepsticks? with that value on hand, u need a voltmeter to "see" the Vsense ... and u need a small trimmer screwdriver I_TripMax= Vref/(8*Rs) ---> for A4988 if ur Rsense = 0.05ohm 2.5 = v / (8x 0.05) v = 2.5 x 8 x 0.05 = 1v with some light fingers and a steady hand, adjust the mini trim pot so that it reads 1volt ref to ground.by redreprap - Controllers
if you are good at electronics, you can put in a rectifier on each supply, that could prevent voltage difference problems, but load wise will be tricky, to passively induce load balancing, you can try a small value (but high power resistance, wastes some power) ... maybe 0.5ohm 20w? ... but for simplicity, no resistor is ok, some laptop PSU are current limiting, it just stops at its max supply.by redreprap - Controllers
wow, its good to have friends that can do nice metal works ! any youtube?by redreprap - CNC Routers, Mills, and Hybrid RepRapping
i wonder, is there a similar chemical to do this for PLA? ok nvm, tried googling, some results are carcinogenic !!by redreprap - Reprappers
if you know the parameters of your steppers, u could prolly change some things on the drivers to improve certain performance issues (maybe something like this mods ...) looking at what you described ... MOD that Rsense!!! i even tried 0.68 ohms lol (very low current steppers)by redreprap - Reprappers
mmm ok i get wad u mean. unless, the nozzle also is scaled up. that would be interesting to see Dirty Steve Wrote: ------------------------------------------------------- > No. > > If you are extruding a width of .5mm, a 1mm wall > would be two nozzle passes to fill, If scaled to > 2mm, your gcode would still only contain the > original two passes to fill at 1mm. So scaled bby redreprap - Reprappers
maybe its a contact, those pins etc. can u measure the resistance of the thermister from the pin on the ramps? if cant, see if u can solder 2 probe wires on the board, clip that 2 a meter. turn everything on, monitor that (direct soldered on).by redreprap - Reprappers
ive always been a fan of PLA ... but this really changes alot of things lol its weally sooo shineeeee !!! waitaki Wrote: ------------------------------------------------------- > I've seen several others but not that one.by redreprap - Reprappers
cool ! >< i suppose this is the 1 http://youtu.be/bcXLJRIKGuQ hmmm btw i googled and acetone boiling pt is only 56degree C, so prolly a boiler @ 100degree is quite high ?by redreprap - Reprappers
WOW that is really very nice price !by redreprap - Stepper Motors, Servo Motors, DC Motors
isit because ULN drives at full step? and i noticed the sample controller, is not logic buffered, does it affect? benjamin.w Wrote: ------------------------------------------------------- > i just finished making the instructables and it > works well. like you said the encoder hasnt got > enough steps for my desired control and i now need > an encoder that has more like 64 steps. i'vby redreprap - Stepper Motors, Servo Motors, DC Motors
anybody saw this? and is trying something printee on it lol?by redreprap - Developers
HA ! well said, is it worth their fight, if they fight you, they will want to know if they will get MONEEYYYYYY out of you, the lawyers probe your existance first, if they discover you are a multi-millionaire JUST because of the machines you make ... hmmmm ... otherwise, you must be related to steve jobs, you have his same genes and they DO NOT WANT you to take over the world with your new machby redreprap - General
haha yes i remember, acrylic overheats and starts to blister .... ohhhh nooooo !by redreprap - Developers
well i really dont know simba, i have been putting my hands in and out of experimenting stuffs related to this for a few months now. TBH, i have yet to get to the parts that command the whole printer, i have been unable to put my whole brains into this as something else distracts me. atm, my mods are simply, take a ramps, multiply it by using ramps as a master board, extract un-used pins, pull oby redreprap - Developers
woot looks like scaling problem is now solved with a nice vectorizing software (magic tracer). so the workflow from KiCad to Gcode is solved on the software coding side it seems (http://3roomlabs.blogspot.sg/2013/03/022-further-experiments-with-magic.html). the flexible scaling option enables any size convertible to scale (limited to your screen resolution, cos the PCB trace is first obtained thby redreprap - CNC Routers, Mills, and Hybrid RepRapping
so, then it is possible to carry out a scaling adjustment at hardware level? yes? jbernardis Wrote: ------------------------------------------------------- > As you scale, you need to worry about extrusion > width (or in the case of milling, the cutter > width). It would also have to scale accordingly.by redreprap - Reprappers
looks like no choice, to try eagle 2 gerber ... o my .. layer 254 = cooling !by redreprap - CNC Routers, Mills, and Hybrid RepRapping
lets say the gcode is already done to scale, and its not a sliced item (like PCB milling) do we change the steps/mm for XYZ?by redreprap - Reprappers
is there a overiding function on a firmware to affect over all printing scale? if say you calibrated a printer to be X steps per mm travel. is there an additional function on the firmware to quickly change the master scaling of the print to 2x, 1.5x etc ?by redreprap - Reprappers
yea true ... this "ramps" is not a full ramps... since its 10 stepsticks ... decastepsticker?by redreprap - Developers
wooot .... i have just tested a few standard lengths and found the ratio of KiCad to Gcode scaling. 1mm = 72pixels. KiCad has its own standard internal scaling to components as a standard. the internal scale if printing from PDFcreator can be adjusted. in this case, in the metric(inch) usage, Kicad printing via PDFcreator can be set to a DPI of 1829dpi per inch (it is actually exacly 1828.8, cby redreprap - CNC Routers, Mills, and Hybrid RepRapping
if anyone have a really huge PCB layout in kicad, im willing to have a go at rendering it to gcode for fun.by redreprap - CNC Routers, Mills, and Hybrid RepRapping
arrrgh error error error ... lol cant open itby redreprap - Developers
ahhh soft pins. so these soft pins are permanent arduino.h standardized or its only special to ramps or marlin or etc ? the colorful diagram is really good. but is there a table somewhere that maps the soft pin to hard pins? bobc Wrote: ------------------------------------------------------- > Yes, the Arduino pin numbers are software numbers. > There are mapping tables for each Arduinoby redreprap - RAMPS Electronics
yes i think u missed the point about current sense Mr Simba. also ... each stepstick as it is ... is not designed to be in "bridged mode" like a stereo amplifier to get 2x the power. for your "bridge mode" stepstick to work, you need to re-design the stepstick into a new type of "pairing" capable stepstick. it will prolly involve a daughter board that sense the drive frequency of 2 stepsticks.by redreprap - Developers
wunderbar !by redreprap - Developers
alo folks out there ... just diggin around was trying to figure out the relation of pins between arduino n ramps, and yes there is this list in the wiki : // For RAMPS 1.4 #define X_STEP_PIN 54 #define X_DIR_PIN 55 #define X_ENABLE_PIN 38 #define X_MIN_PIN 3 #define X_MAX_PIN 2 #define Y_STEP_PIN 60 #define Y_DIR_PIN 61 #define Y_ENABLby redreprap - RAMPS Electronics
yea i saw gEDA, didnt try it ... yet. it does gcode to the actual scale internally? or there is a need to calibrate that scale for first run? i think i am getting it. do have a read (KiCad to Gcode) and most importantly, im not sure if the Gcode is legit since i dont have any machine to try it lol.by redreprap - CNC Routers, Mills, and Hybrid RepRapping