Dual Extruder Upgrade - Limited Availability

[jimc]

haha jin...good ol comcast can you believe they charged me 3000 bucks to run that crap down my driveway. uh dont get me started.

on another note, thanks for the pic. i see the block does look pretty short and i see a heat break of some sort in the feed tube above the block. its really good to have that short melt zone. you have better control of the filament. cool, looks promising and a little less "off the shelf" than other extruders. i like it!

[sprior]

First test print, blue shell, red infill.

[sprior]

I stopped the cube after it was about a quarter done because if I let it finish you wouldn't see the infill was different. Things I noticed using Simplify3D:

1. The left extruder no longer moves all the way off the bed so when it does that initial prime extrude it does so over the glass. We'll have to move that off to the left hand side.

2. There was no prime for the right extruder.

3. There was no wipe for color changes and since they had some plastic left in the nozzle it would leak out when the other extruder was being used. You can see the blue fuzz on the left from that. Didn't happen as much with the red because the middle layers used just a little blue compared to the red.

[jimc]

from what i gather s3d doesnt have the wiper wall feature as of yet so there isnt alot you can do about the drooling...atleast that i know of. i know nothing of dual extrusion so i am just passing along info that i have read on the s3d board. some people model thier own wiper walls but there is no guarantee that the correct extruder will wipe at the right time. i think some people have set up a tool change gcode that will retract the filament completely out of the hot zone then a positive extrude on return. your going to have to dig into the tuning issues concerned with it. maybe josh or rick will have some tips once these get going.

[jsc]

I had the same issue with the extrusion direction being reversed. The RAMBO connector isn't too directional, so you can just reverse it, but I think it should work in the correct direction.

[jsc]

The PID parameters are not perfect. I'm getting an oscillation of 2 degrees both ways at 210.

[jsc]

My first dual extrusion test. I can see that there will need to be some work done on tuning my procedures for dual extrusion already. I'm using the sample tool change gcode from the wiki. The straightforward way has the double side effect of sometimes leaving a streak from over extrusion on reset from wherever the new tool happened to be to the point where it starts getting used (black), and also missed lines at the start of a tool change from under extrusion on reset (white).

What ideally should happen is that the old tool should retract, the new tool should move into position and extrude to reset. But that doesn't seem to be straightforward using Simplify3D.

Also, starting up is a bit tricky now, since you need to prime both extruders. Here's my first stab at it:

Code: Select all

M201 X1000 Y1000
G28
T1
G1 X50 Z0.3 F9600
G92 E0
G1 E10 F225
G92 E0
G1 E-6 F3000
T0
G92 E0
G1 E10 F225
G92 E0
G1 Y50 Z0.3 F9600

WARNING: don't use this if you have a binder clip on the front edge!

That homes, moves both extruders to the front edge of the bed, extrudes 10mm with each, then does a rapid move into the bed in the Y axis to strip off the blob. I'm sure this could be improved. The right extruder gets primed first, then retracted 6mm. The left extruder just gets primed and starts printing immediately.

An alternative would be a modification to the common extrude-and-wipe sequence, where the left extruder gets wiped on the left edge and the right extruder gets wiped on the right.

[jsc]

Most printers appear to define tool 0 to be the right extruder and tool 1 to be the left. Maybe the firmware should be changed to follow this convention, or does it not matter? Maybe it is better to leave it as it currently is, since the left extruder can span the whole bed, but the right one cannot get down to X=0.

[willnewton]

from what i gather s3d doesnt have the wiper wall feature as of yet so there isnt alot you can do about the drooling...atleast that i know of.

I don't know if Makergear has any influence over at S3D, but perhaps this would be a feature request with some weight behind it, especially if it came directly from a printer manufacturer.

Thanks for posting up your pics and info guys. It's good inspiration for the future.

[Josh]

For anyone who notices that this topic has been moved - we've created a new M2 Dual Extruder subforum, in which all dual upgrade discussion can be collected. Please post future topics (configuration and installation troubleshooting, etc.) not directly related to the release announcement, there.