RepRap Noob. Working on first printer.

I started building my first raprap a couple of days ago. I wanted to show off my progress a bit while I take a break.

I opted to build an Prusa Mendel i2 as the parts seemed readily available. I'm also integrating a Raspberry Pi into the printer for control. I think other than some wire clean up and rerouting, I'm down to the software aspect of the build; which is probably the most frustrating part of the build. Anyways I wanted to share from photos and some personal milestones. I wanted to kind of list this stuff in a public forums to get a handle on what is left and perhaps get some critiques or ideas on improvements.

Hardware Milestones:
Frame built, measured and tightened.
Wires Connected, sheathed, and secured.
Got all 3 axes moving and responding to end stops.
All secondary hardware (monitor, raspi, lights) mounted.
All hardware connected to single powersupply (one 120VAC line)
Got heatbed and extruder to heat up and report temps.
Got extruder to squirt black goo.

Software Milestones:
Got Raspberry Pi to respond to bluetooth keyboard.
Got Raspi to connect to wifi.
Got Raspi to connect to SSH.
Got Raspi to connect to VNC.
Got Raspi to do the above through the internet too.
Got Raspi to display Pronterface window.
Got Raspi to recognize arduino.
Got Arduino uploaded with firmware.

Hardware to do list:
Figure out why leds wont turn off with remote. (goes to green, possible grounding short)
Get leds to respond to commands from either arduino or raspi.
Figure out how to get battery monitor off of lilliput screen.
Figure out how to get lilliput screen to power on with PSU.
Create an on/off switch for PSU.
Neuter the PSU's excess wires.
Print new endstop switch mounts (cracked)
Print Spool holder for 1kg spool of PLA.
Clean up some of the wiring.
Reroute some wires that are dangerously close to moving hardware.
Get a smaller friggin HDMI cable.

Software to do list:
Get Raspbian's Pronterface to connect to printer.
Get printer calibrated properly. (hard)
Get Repetier-Server to recognize printer.

Are the motors and hot end wired up using CAT5?

No, the stepper motors are wired up using their stock harnesses from the factory, and the hot end is wired up with a relatively thick single strand copper wire.

Ah, you have some kind of braid or plastic conduit around them. If it's plastic conduit, where did you source that?

It's computer wire sleeving used in computer modding. Plastic, fairly heat tolerant, you ignite it and it generally extinguishes itself. I covered all the wires in it to both combine strands and add protection against abrasion from the threaded rod. It's available in electronics stores here in Texas, but you can get it online at places like amazon.

Plastic conduit would be nice, but I've only seen it in black and I find it's fairly heavy for smaller wires. I have some here, I was thinking about using it to cover the thread rods as it's easy to remove, but I haven't gotten there yet.

Well, I figured I would make a new update today. There's quite a lot of trials and tribulations associated with this project. I suppose I should start by addressing the previous to do list and see what's been accomplished and what hasn't, then move on to new issues.

Hardware to do list:
Figure out why leds wont turn off with remote. (goes to green, possible grounding short)
Solved, it was solder short, removed till I can address the issue.
Get leds to respond to commands from either arduino or raspi.
Not yet complete, I want to use the IR receiver input that came with the LEDs. I need to capture the signals from the remote and figure them out, then I should be able to output them back to the controller.
Figure out how to get battery monitor off of lilliput screen.
May not be possible, it's quite annoying. I haven't found info on it yet. It seems silly considering how advanced the OSD is.
Figure out how to get lilliput screen to power on with PSU.
Right now I would settle for the screen's built in battery not running the PSU's fan when it's off.
Create an on/off switch for PSU.
Complete, I just added a simple for now, I plan on a machine mounted one. At least now I can somewhat soft power off the PSU
Neuter the PSU's excess wires.
Tied back for now, I may ditch this PSU, I want it intact for future projects.
Print new endstop switch mounts (cracked).
Not yet there yet.
Print Spool holder for 1kg spool of PLA.
Not yet there yet.
Clean up some of the wiring.
Started, waiting on some parts.
Reroute some wires that are dangerously close to moving hardware.
Started, caused some issues that need repair.
Get a smaller friggin HDMI cable.
Complete, got a thin 1 ft cable, much nicer.

Software to do list:
Get Raspbian's Pronterface to connect to printer.
Complete! It was a baud rate issue.
Get printer calibrated properly. (hard)
X and Y axis done mostly, Z-axis continues to be a problem
Get Repetier-Server to recognize printer.
Haven't figured it out yet.

Powersupply Issue.
Okay, so I'm not a hundred percent sure yet, but I think my power supply is lacking. It's a 300w ATX powersupply, and maybe it would be fine if it was just running the reprap, but it's also running a 12v monitor, the Raspi, a usb hub, a wifi/bluetooth dongle and some LEDs. I think with all that extra crap, it's too much for the power supply. I find it's hard to initialize it's power sometimes, sometimes the heated bed wont heat, and the z-axis motors are unreliable at best. I pulled the voltage on the 12 volt leads and they are reading at about 11.70v with a moderate draw. I'm going to do some further testing on this issue. My desktop computer has an 800w modular powersupply, I'm going to run some leads to the printer and test it out later on.

Parts, parts, parts.
So electronic parts are rather hard to come by in El Paso. While I was rerouting wires my thermistor split on the hot end. Fine, whatever, get another one. That's rather hard here. Online they are slow to get here, about a weeks time, I ordered a few from a couple of places, but in the mean time I tried to find quicker substitutes. Radioshack? Useless, I found one thermistor and it's hard to identify and huge. TigerDirect store? Nope. I got a bag of 10k thermistors from amazon, mine are accurate with the right table, but past 110C they screw up. So I'm stuck waiting on parts, hopefully the 100k thermistors I ordered will work fine. I also got lots of PTFE tubing in today.

Other Hotend Issues
I had another issue with the hotend before I cracked the thermistor, the solder melted between the heated resistor and the wiring to it. I repaired this using a pair of crimp connectors. They are quite secure and shouldn't melt in the future. During this repair I also practiced dismounting the x-carriage and will make adjustments to make it easier in the future for hotend cleaning and repairs.

Software Stuff
I successfully got the Raspi to talk to the reprap today and issue commands. It's great. My next task will be to make it easier to deal with arduino software changes. I'm going to learn about the various code repositories and see if I can update stuff using "the cloud".



Here's my first print. A crappy cube.


Obviously there are some issues with this print. First, the y axis was 2mm off, I think I've fixed that. Second, the printer stopped and melted the top towards the end. I think this maybe a power supply issue, I'm not sure. I'll do more testing when an effective thermistor gets in. Then there was a temp issue with the material, which I think I figured out, then there is the z-axis, which is screwed and I think is a PSU issue.

Here's the PSU switch I added.


Simple but effective, I'll do something more extravagant when I figure out the power issues.

Edited 3 time(s). Last edit at 08/22/2013 09:30PM by Snarky.

I would look into this one first. I experienced may of the issue you are talking about (including the printing ones) until I added a 2nd PSU to my setup. It's on the 11Amp power connector of my RAMPS which just powers the heat bed. This solved all kinds of issues with my prints. The one supply was over loaded. The stepper motor drivers rely on percise control of current in tiny increments to do micro stepping. Your thermistors for your hot end and bed heaters read tiny voltage changes to determine difference in temperature. That said any minor fluctuations in the supply voltage or current will make both stepping and temperature reading inaccurate, which in the end will wreak havoc on your prints.

I have graduated from PLA to ABS and keeping that hot end at 230 for ABS instead of 180 for PLA seems to be taxing the main supply again. I'm looking to upgrade to a quality high watt name brand supply for this one. That said, you might or might not get away with running the screen, PI, and lights off of the one supply while printing PLA, but you will probably defiantly run into issue when you go to ABS. Could you find a regular DC power adapter big enough to power the screen, PI, lights, and anything else that is part of the functions of just the printer it's self?

I wouldn't recommend trying to run your PC and the printer off the same PSU. Too many issues to go into here.

On the prints, be sure to take the time to go though properly set the X, Y, Z, and E step (especially E) settings in your firmware before trying to do too much printing. I didn't pay enough attention to this when I started and wasted a bunch of time dealing with mixed step and printer hardware issues. Had I gotten the step issues out of the way first the hardware issues would have been much more evident.

Edit: Oh, and thank you for taking the time to so thoroughly document your build and trouble shooting. Hopefully future first time builders will stumble onto this thread and find it helpful or maybe even better it will wind up as a permanent link somewhere.


Snarky Wrote:
-------------------------------------------------------
> Powersupply Issue.
> Okay, so I'm not a hundred percent sure yet, but I
> think my power supply is lacking. It's a 300w ATX
> powersupply, and maybe it would be fine if it was
> just running the reprap, but it's also running a
> 12v monitor, the Raspi, a usb hub, a
> wifi/bluetooth dongle and some LEDs. I think with
> all that extra crap, it's too much for the power
> supply. I find it's hard to initialize it's power
> sometimes, sometimes the heated bed wont heat, and
> the z-axis motors are unreliable at best. I
> pulled the voltage on the 12 volt leads and they
> are reading at about 11.70v with a moderate draw.
> I'm going to do some further testing on this
> issue. My desktop computer has an 800w modular
> powersupply, I'm going to run some leads to the
> printer and test it out later on.

Edited 1 time(s). Last edit at 08/23/2013 11:17AM by appdev007.

I wanted to post about a few things I've figured out with my Reprap.

Z-Axis problems
Previously I had thought that issues I was experiencing with the z-axis were related to various things. Possibly the power supply, possibly the fact that my motors are wired in parallel instead of series, maybe in stepper driver voltage. Nope.

I'm using RAMPS 1.4 with an Arduino Mega. I bought it preassembled with all drivers in place and such. I found that under the drivers, that none of the jumpers were installed to change the stepping. So, you "could" change the calibration and driver voltage to fix the problem, however shorting out all the pins brought almost ever axis close to the default settings for calibration, and the z-axis now works superb. .50 cents of jumpers solves all my problems.


PSU Problems after all.
Of course, there are other issues. My power supply quit functioning. I think it have more to do with the fact it's a 6$ powersupply than any thing. I ordered a nice new 500 watt unit, that is modular. It will have the by product of making the reprap and psu more easily separating. One plug instead of 3 molex.

Heatend thermistor issues
The is the biggest issue I've having now. Thermistors I've tried don't seem to be particularly good. I've got some named brand ones coming, but they are all the slow boat from china. Others that I've been able to acquire: suck. I ordered a fancier hotend, with a built in thermistor which is coming. In the meantime, I'm trying to get the one I have working. I vaguely remember resistance calculations from Fields and Waves. The probably I have is that the resistance values are operating tempuratures are too close together and too close to zero, I might try adding another resistor in series in the meantime to try to solve my issues, however, psu issues have me waiting on parts again...

Other stuff
I don't know why I decided every zip tie needed to be red. I'm almost out, the amount of times I change reroute wires eats them up. I've finally got the entire x-carriage wire set bundled. Annoyingly though the manner in which I wired it hits the x-axis homing switch. I could switch that in the software and move the switch, especially since there is a fan there, but I might also just move the fan and wire bundle to the otherside of the carriage. I haven't decided yet. Also I'm reminded that I need to get on with my lighting system. Lighting is really helpful when trying to determine various issues, especially with the filament speed.

New updates.

X,Y,Z axes all working properly. Hotend and Heated bed functioning properly. Raspi remote controller functioning properly. Still can't print.

Latest problem is relatively easy. My heated bed glass is warped like crazy. It's tempered glass. I'm not sure if it came warped or has just warped since I got it. But I tested it with a straight edge, it's way out of whack. I can probably get some fairly small prints to work in the middle with some tweaks. However I recently ordered a borosilicate glass plate to replace my tempered one. Should be here eventually. Hope it's flat.

I would print on my heatbed pcb, but it is also not flat, and that piece I know came that way. I think once I get a new piece of glass, I'll clip it on all four sides, and it should be fine.

I might try to flatten this piece of glass on the stove. We have flat ceramic cook top and the worst that could happen is the glass shatters into a billion pieces. I might also try to just force a stick with a glued surface till the new piece comes. I could also try a new piece of glass or mirror from hobby lobby as an interim.

Don't try to flatten the glass.....It will shatter and melt your floor, or break your cooktop. Get a picture frame or mirror from the dollar store and cut it to size.

I got the warp out of the glass today. Brought it up to about 800 degrees slowly, and of course contained incase it grenaded. It's silly to think it would crack a cooktop, it's not a bomb, just a potential source of hot shrapnel. I managed to get it where there wasn't a 1-2mm bow in the middle. It's still not perfect, so I'm still waiting on a chunk of pyrex that'll hopefully be a little flatter. But it's good enough right now to where it's actually a surface you can print on.

wow thats cool, i had no idea you could bend the glass, i guess 800c would do it?

I dont think i have anything in my house that would go anywhere near that high, my cook tops max out at 300c

Wow! 800° C on a cooktop! Was it fun?