The original discovery goes to Core Storage 's wife, and what a brilliant discovery ! She was annoyed by the fumes of aceton and who can blame her. I tried it with some reluctance on PLA. I used store bought lemon juice on glass . and the parts sticked so well, I got to lower the temperature of the heatbed (to 50-55C) . From then on, I never went back to lemonless surface. You really have tby waste - Printing
I have to report on the marvels of lemon juice. We have to give kudos to the girlfriend of the guy who suggested it For PLA , no kapton tape or anything, just lemon juice on glass, it sticks so hard you have to use leverage to force it out of the glass. The lemon juice lasts for 3-4prints and then you re-apply. no bad solvents, no nasty smell no anything. bed temperature at around 55-60C Foby waste - Printing
thanks nophead I will try to change the j head. scad to fit my preferances . you saved me a lot of time and trouble Im currently building a A3 laser cutter based on your Mendel90 design, basically everything apart the z axis parts. Laser cutter is a bit of an overstatement as Im only using a 1,5W blue diode. more likely a stencil cutter wood engraver As I was building the parts for the laserby waste - Mendel90
I know its a newbie question but I have busted my head trying to find it and it seems I cant Im trying to set the parameters for the 10mm hotend (rep-fab type) extruder in the scad files but I cant nophead here said that its in the wade.scad but i cant find what i need to change can someone help me pointing me where i change the parameters for the extruder? And a second small question regaby waste - Mendel90
thanks konwiddak I already use 35% of regular (27mm/s) speed on first layer. your sugar suggestion seems nice. I used a slightly more expensive one, ie the lemon approach discribed in previous posts and YES i can attest it works wonders. even the biggest print stick to the bed very hard. probably the sugars in the lemon juice (i bought readymade lemon juice) have the same effect as the suggaryby waste - Printing
lemon could be a quite good idea and chemically not so offensive. lemon juice has sugars inside so by heating it up you probably create a nice gluey caramel that sticks to PLA as you can see in the picture I also have problems with sticking PLA on the heated glass. I also have problems of infill popping up during the first layer as you can also see. my settings are hotend 205C (first layer, sby waste - Printing
I have the same problem with abs melting but not completely dissolving in acetone I left it 24 hours, some of it is melt as the acetone is now thicker, but a big sludgy stuff is on the bottom. i stirred it a bit and left it a bit more but the sludgy stuff doesnt dissolve. in your experience how many hours did the ABS took to dissolve and did it dissolve completely??by waste - Reprappers
but viktor by forcing the laser through the glass fiber, you get a nice 0.1 focusing range which is great considering that most 445nm focus around 0.4mm with the g2 lenses. so you suggest using a glass fiber as a solution? does it consume power from the laser?by waste - Laser Cutter Working Group
thanks for the info and the nice pics. I have some questions though a) where did you get the focusing lens b) how did you drive the on/off of the laser? (both electrically and from the g-code command) c) what firmware are you working with and what tweaks have you done?by waste - Laser Cutter Working Group
Im really sorry I never mentioned that I already have a driver based on these nice AMC7135 chips. Those chips are really wonderful as the require minimum electronics and provide 350mA each . So this board that has 4 of them gives out 1400mA. The only problem, (and thats why Im switching to 5V input) is that these chips have top input voltage of 6V . One can make a nice driver out of a PT1415 Iby waste - Laser Cutter Working Group
Hey traumflug, after playing around with my new MOSFET i think we should make some small addition to the very informative page you pointed me to. In your conclusions you write that there is not one right solution as PMW makes all MOSFET (even "big ones") go hot. And thats true. Nevertheless, on the heat bed side of things, most of the times a MOSFET is full on, or full off, probably because theby waste - Next Wave Electronics Working Group
focusing lens slourp but i ll settle with what i have now and see how it goes. back in the controlling the laser discussion, as we use small diodes (1,5W) to do the job, couldnt we use the hot-end mosfet in controlling the on/off switching of the laser? in my GEN7 electronics board I have I though I can cut the 12V line which goes at the hot-end and provide it with a 5V one, so the mosfet woby waste - Laser Cutter Working Group
thanks VXD, the lens you used is focusing lens, or collimating? either way i will try to set it up first and then see how it goesby waste - Laser Cutter Working Group
Back to the heat bed MOSFET problems I just changed the MOSFET to an IRF3703 and kept the resistor to 10Ohm as suggested by traumflug, now the heatbed consumes around 200W now and the MOSFET keeps around 35-40C with a very small heatsink and no additional airflow. It seems the low RDS(on) of IRF3703 really helps it keep cool in the initial stage of heating where the PMW is full on. So i defiby waste - Next Wave Electronics Working Group
Well M140 diodes from this guy with the small marking on their barcode can be driven up to 1400mA with no real problems apparently Im going to use a 4 AMC7135 led driver for that purpose (1400mA) with a heatsinkby waste - Laser Cutter Working Group
cool Im on the same path, building a Mendel 90 look alike with just XY for small (1,5W 445nm) laser cutting projects as stencils for example. I also have a Gen7 1.2 board laying around that will do the actual driving with 2 pololus . I d love to see yours working it would be a great encouragement My 445nm laser diode (the usual M140) , has a quite "big" beam even with the g2 optics I use. woulby waste - Laser Cutter Working Group
with the heatbed not connected I get 12V on the output with the heatbed connected I get 4 that goes up slowly to 7V the I tried something else I connected the heatbed to the hotend mosfet and the hotend to the heatbed mosfet. when I turn on the heatbed (it warms up the hotend now) I get a stable 11V when I turn on the hotend (it warms up the heatbed now) I get a 9V that stabilizes nearly to 11Vby waste - Next Wave Electronics Working Group
Oh Iv seen that you changed 1KΩ to 10Ω in gen7 1.4.1 (I have your 1.3 version) The only thing I changed was the older MOSFET that probably died from overheating and stopped working completely . The firmware is definately the same Voltage is stable at 5.03 at both ends of the resistor R11/R12. I will replace them with 10Ω and report back , well now with the new resistor the voltage stabilizesby waste - Next Wave Electronics Working Group
thanks Traumflug for your answer, I had a IRFZ44N that stoped working, I replaced it with the same. Now it works but i get only 3V on the heat bed which over the next 2-3minutes rise to 6-6,3V tops. And the heat bed temperature rises very slow now. In order to compare it I take measurements from the second mosfet that its working flowlessly when I measure the hotend mosfet I get 11,6V I alsoby waste - Next Wave Electronics Working Group
I measured voltage between the two ends of the diode near the mosfets. The mosfet working correctly (hot-end) reads 0V. the diode near the heatbed reads around 6V. is this an indicator of a destroyed diode as well?by waste - Next Wave Electronics Working Group
I replaced the MOSFET with a new one of the same type. now the heated bed works. BUT a) the delay is still there b) the heated bed now heats up considerably slower. Investigating the second I found out that the heated bed takes only 5V-6 form the board. To be precise it starts around 3V and stabilizes around 6 after 2-3 minutes. If i disconnect the heat bed the voltage on the heat bed pins isby waste - Next Wave Electronics Working Group
Hey, I was using the 3d printer without any problems, but the MOSFET attached to the heating bed was getting really hot. So hot I couldnt even touch the heatsink surface. I could read temperatures of over 70C with an infrared thermometer. So i decided to change the heatsink with something bigger. I attached the new heatsink the temperatures went up again but somewhat lower and some what moreby waste - Next Wave Electronics Working Group
I managed to measure the pot, it was working corectly and the values were ok. so this doesnt really make sense. Its definately the stepstick, as I tried the same stepstick in different positions on my board and in all positions the pot was not responding the stepsticks powers the motors, it just powers it an a very low value is there any way to test anything??by waste - Controllers
Hi Traumflug, Im using arduino IDE .023 and I found the boards.txt in one of your files about gen7 board probably I got the Atmega from you ready with the bootloader, so I dont know exactly which was the right speed, and the chip doesnt really understand anything other than 57600 both in the serial monitor of IDE and of repetier. So in the beggining 57600 didnt strike me as odd, apart fromby waste - Next Wave Electronics Working Group
I have 2 thermistors one for the bed and one for the extruder both are of the 100K type But I have this strange thing. The one gives me a 23C reading (pretty close to the 20C I measure with my thermometer) and the other one gives me a 357C reading. At first I thought the second one needed a custom table, but it didnt really work So I made this experiment. I set them both as type 1 in my repetby waste - Controllers
for future reference to other people while my chip (644@20MHz) according to the boards.txt has Gen7-644-20.upload.speed=57600 I had to change that to Gen7-644-20.upload.speed=115200 in order to get arduino .023 to upload the firmware the serial monitor still communicates at 57600 and also the repetierHost communicates at the same speedby waste - Next Wave Electronics Working Group
Hi, Im using gen7 v1.31 with repetier firmware but I have I very difficult time uploading new firmware. It can be done at some point after dozens of retrys but I cannot consistently repeat it. the connection with the board is ok, I can see the messages in the serial monitor alright at 57600baud in arduino .23 (and i can communicate with the machine from repetierhost), but when I press upload anby waste - Next Wave Electronics Working Group
I have a stepstick that its trimpot doesnt seem to respond when I turn it. the motor turns but the current doesnt increase. It seems like its in a minimum is this a broken trimpot, a broken stepstick or just something that im doing wrong??by waste - Controllers
well you were right, the pins on the e-go board were wrong and I found the transmit pin in another place now the arduino says Expected signature for ATMEGA644P is 1E 96 0A Double check chip, or use -F to override this check. I have selected 644P@20MHz and the chip you have provided says 644-20PU so I assumed this is the right one, so I use -F ???? It worked correctly with 644@20MHz (no P)by waste - Next Wave Electronics Working Group
yes the device is recognized (dev/ttyUSB0) , thanks, I ll try your method with the TxD pinby waste - Next Wave Electronics Working Group