My first 3D printer

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Trnquill
Posts: 66
Joined: Fri Oct 05, 2012 10:01 am

Re: My first 3D printer

Post by Trnquill »

dognotdog wrote:Rigidity as in a Mill isn't required, as ideally no force is exerted by the print head onto the bed.
Yes, that is absolutely correct! What I'm actually worried about is the "deformation" of the frame when pushed about. In other words it's perfectly fine if things flex back and forth when put under abnormal stress but it would be nice if they always returned to the same exact position. Otherwise the calibration gets lost. Of course you should not put your printer under any abnormal stress but that's exactly what you do when for example removing prints from the bed or just accidentally bumping into build platform corners while changing filaments or whatever. I'm not overly concerned about this flex and give since people are getting excellent results with their Felixes! I know mine is capable of just as good prints. :)

Finished the wiring yesterday, no hassle there. The electronics box is laid out in kinda funny way because it basically forces you to route all the thick heating resistor wires over the board, blocking air flow and making closing the box lid hard. To me it would have seem a better solution to route those cables around (or under!) the RAMPS board rather than over it, but there's no space. If I route them around between RAMPS and the box fan, I'm disturbing the airflow really bad. And on the other side of the board there no space between the board and wall of the box. I didn't manage to do the wiring inside the box too nicely but everything outside the box is super tidy!

I did the finishing touches to the printer and ran into one more problem. The Z-axis endstop vane hits the optical port. The vane arm is just slightly too long. I'm not quite sure if I should file the vane a bit thinner or if I should move the optical port a hair further away. Maybe I move the port to make sure there's enough clearance between the port and the vane both ways.

aikx
Posts: 45
Joined: Sun May 13, 2012 1:14 pm
Location: Cologne, Germany

Post by aikx »

However, I do find the Z axis movement annoying, especially the Z axis slider. I cannot really tighten the bolts connecting the printed parts and the slider, as then it just binds up.
Use 2 or three washers under the bolts to avoid blocking.

Kjetilei
Posts: 334
Joined: Fri Mar 16, 2012 8:26 pm
Location: Stavanger, Norway

Post by Kjetilei »

As aikx said: use a couple of washers between each bolt and the printed base.

Trnquill: With the old Igus slider I used three small M4 washers. With the new Hiwin slider I use a M3 washer and a small M4 washer to really tighten it up.

I mounted the 1.5 electronics box on Wednesday and thought the same thing as you regarding wire layout. Maybe some sort of clip/clamp with sticky tape on the base could be used to secure the wires to the side (if such a clip/clamp exists). But a redesign would be a better solution (but I doubt I'll bother to change if that is made available).

PS: I would love to see photos of your printer :)

Trnquill
Posts: 66
Joined: Fri Oct 05, 2012 10:01 am

Post by Trnquill »

I'll do a photoshoot as soon as I get it printing! :)

But now I would need quick help! I have all the software up and running (finally, more on this later) and I tried calibrating the printer. The X-axis went to home OK but when I started moving it around it started doing odd things. The stepper works quite randomly, skipping huuuge amount of steps and making odd sounds. Usually when I click for example "move X +100mm" the X starts moving but in steps, pausing every 10mm or so. And if I push the extruder by hand there is very random resistance and the stepper screams and rattles quite strangely. What's up with that!?

I continued on by calibrating the Y-axis. No problems there until again I started to move the table in Y axis. First things looked OK but then the Y-stepper just stopped, made awful sounds and just vibrated back and forth in that very same place.

I calibrated the Z-axis and moved it around with no probelms.

Based on my knowledge and experience with a CNC router the behavior of X and Y stepper motors sound like there's broken wire somewhere. I know I was extra careful wiring the printer up and the solders were super clean so I'm a bit lost here. Any ideas?

Lioric
Posts: 116
Joined: Wed Aug 15, 2012 1:13 am

Post by Lioric »

Tune the stepper drivers, you need 400mA (between gnd and vref, if you do this, do it before attaching the heat sinks as they will cover the vref test pad. Or simply use the 25% turn)

See here for more details:

http://www.felixprinters.com/forum/view ... p=414#p414

I think we need to add a "Stepper Motors calibration" (or something like that) to the assembly manual, as it seems that this is a very common issue.

Trnquill
Posts: 66
Joined: Fri Oct 05, 2012 10:01 am

Post by Trnquill »

Lioric wrote:Tune the stepper drivers, you need 400mA (between gnd and vref, if you do this, do it before attaching the heat sinks as they will cover the vref test pad. Or simply use the 25% turn)
Ok, thanks! I did this for all the drivers and now at least the Y-axis is working fine. X-axis worked fine for a while but then it started to stutter again. Z-axis continues to work OK. I think I need to tune the X-driver more precise? I have the heatsinks installed, so I can't measure the Vref. Currently the X-axis moves in "periods" if I make it move greater distances. For shorter distances there is a noticeable "clack" sound after every movement. Some movements are replaced by this "clack" sound and no actual movement takes place. I try to post a video about this soon.

Trnquill
Posts: 66
Joined: Fri Oct 05, 2012 10:01 am

Post by Trnquill »

Here's the vid: http://www.youtube.com/watch?v=pxISzk9IwEY

But guess what? Now it works! It really puzzles me how on earth it suddenly started working, but I'm not complaining... :) I did follow the 25% rule earlier and made no adjustments to X-axis driver after that. First it didn't work and now it does. Or maybe I did adjust the pot at some point and just forgot... I tried the calibration print but right away noticed I didn't tune the extruder driver and had lousy extruding. But now that's sorted, too. My first print is in my hand! :)

Trnquill
Posts: 66
Joined: Fri Oct 05, 2012 10:01 am

Post by Trnquill »

I've been printing now for few days and no major problems have surfaced. Very nice! I have done filament roll mounting bracket and filament guide rings attached to vertical back beam of the printer and now she prints quite happily unattended. Yesterday I printed a 6 hour print without any intervention to filament supply or anything and it came out perfect.

Next thing I'll modify is the Z spindle. As I said during the build phase the threaded rod was slightly bent. When I run Z-axis back and forth at speed I can actually see the wobble on the rod and on the table. Also in the prints there's visible banding at roughly 1 millimeter intervals. I bought a new rod from local hardware store and it is dead straight. I'll install an aluminum coupling, too. Hope this helps!

Yesterday I ordered LCD/SD expansion module. Can't wait to install that and print without the PC!

Trnquill
Posts: 66
Joined: Fri Oct 05, 2012 10:01 am

Post by Trnquill »

Oh, I was a bit too quick on my comment of having no problems. :( Today I tried printing my first part after the yesterdays long 6 hour print. Nothing came out of the print head so I turned off the heat and disassembled it. There was some clogging in there and I removed all I could. I reassembled the hot end and print head and pushed some filament manually through the head. Nice flow again.

When I was ready to start the print again I tried homing the axis but nothing. No movement at all. Soon I noticed the hot end "cold side" fan had stopped. Also the fain in the electronics box had stalled. I tried plugging in and out the power cord but nothing. Seems like the power supply is dead. Is this common? What should I do?

EDIT: 15 minutes with power cord not connected and now she works again! :o Is this common?

aikx
Posts: 45
Joined: Sun May 13, 2012 1:14 pm
Location: Cologne, Germany

Post by aikx »

15 minutes with power cord not connected and now she works again! :o Is this common?
No! Never!
EDIT:
I tried plugging in and out the power cord but nothing.
Remove power cord AND USB cable to reset arduino.

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