Duplicator 4s dual extrusion woes

[Zak_Grigsby]

So my Duplicator 4s prints fine when only using one extruder. Hell, it prints FANTASTIC. But any time I try to print a two color part, I always get specks of plastic from one color deposited in the print of the other, and it doesn’t seem to matter which extruder I’m using. I print in abs at 221c on either side and I use makerbot software to slice (for the prime wall feature.)

[will_kostelecky]

What slicer are you using and does it generate a nozzle purge for each extruder at the start of each layer? If it does not then you need to find a way of doing one your self. You want the extruder to retract when it is done so it does not ooze on the extrusion of the next color then you want it flowing again for its next layer. You can do this by having a little sacrificial area where you lay down plastic. Simplify3D has built this functionality into V3 of their software. They call it an ooze shield and do it around the entire print area…which seems overkill but works.

[elmuchacho]

Hi Zak,

I got the Duplicator 4 too and it is well known to ooze when dual printing. My best advice is to reduce the temp as much as you can and increase the retraction length and speed in the slicer settings (unfortunately MakerWare is bit restricted unless you dive and create a profile and edit the file manually worth a look but reducing the temp work well).

Get that calibration object two colour calibration cubes by MakeALot - Thingiverse and try dual color print and reduce the temp until it still extrude and do not skip and produce less oozing. Bear in mind that each material viscosity mean you’ll need to do this for each material and find the lowest extrusion temp the material can be used.

MakeWare will automatically build the walls around the printed object and it will wipe and purge. But if it’s too hot the material expand in the extruder and slowly ooze.

Now if you have access to an other slicer like Simplify3D everything will change because since version 3 the support for dual color is really good as it allow you to set the temperature for the extruder individually and what I do is reduce the temp of the extruder not in use by 5 to 10 degree and increase the retraction length and speed slightly. Obviously that don’t replace the fact that you’ll need to find the minimal printing temp for the material.

Good Luck it’s really not easy to get the dual color working perfectly on a wanhao

[rspehr]

I have had the same experience with the Duplicator 4. I gave up on making duel prints. I have both extruders still in place, but use it as a mono machine. The dual print idea might work for the artsy crowd, but I need my prototype parts to be SHARP. The Wanhao Duplicator 4 machine was a great starter machine. I have now built a Mendel Prussa…Frigging fantastic prints! and I am now working on the new I3 Prussa. The home built machines can be tweaked easily. They also have a friendly group of users that will help you with a smile and a great attitude. It is nothing like what I ran into when working with the users for the Wanhao printers. You can find people that will help, but they are a grumpy pompus !$!@#5#$ group!

[Zak_Grigsby]

I just sprung for simplify 3d so I’ll recalibrate some more and give that a shot. I used a less than legit older version and I liked it, but didn’t spend the time with it. I’m going to actually try to get it to do right now that I have forum access on their website.

[will_kostelecky]

Good luck! I both love and hate Simplify3D. The slicing algorithms are fast, the way it generates support is great, the improvement to dual extruder use is great, and the level of detail that you can control is fab but there are times when the software quality simply drives me nuts. Its like they just don’t take the time to polish some details! I would still buy it but not without complaining!

I have gotten my Duplicator to work with both extruders but it is a challenge. Interesting comments from the person that moved to a Prusa I3. I did just the opposite and find the Duplicator to be a much more precise printer (though not as precise as my Ultimaker 2). It being a closed printer also helps a lot with printing ABS.

Obviously if you have not already done so the advice about finding the lowest possible extrusion temperature is critical for any quality prints!

Will

[krikey]

What software slicer are you using, some software offers a “wipe” function whereby the active extruder gets cleared off ready for the other. Theres also some customisation that can be applied to “suck” the filament back in when you swap. These functions are available in ReplicatorG and Skeinforge 50.

[ralphmc]

Hi Zak

I dual print a lot, and have spent 1000s of hours trying to get consistent perfect prints, I have come close but have never achieved consistent perfection. I have printed with a Duplicator 4s a Flashforge Pro and a Makerbot Replicator 2x and even a self built Delta Rostock with a 4 nozzle Kraken. I have used Makerware and simplify3d, they all exhibit this problem. I have used all sorts of material combinations and same material dual colour combinations, like you are doing.

The rags you are getting can be reduced, but not eradicated, believe me I have tried all the stuff other posters have tried ie increasing the retract value- in simplify 3d this is a setting, also by the way in the new Makerware this is now also a setting, the previous poster is right- in the older versions of Makerware you would edit the retract in the extruder profile which is quite a fiddle, but in the new version it is now a lot easier and can be done in settings.

Reducing the extruder temperature will reduce ooze, but really it would have to be done on the hoof to be effective and since it would take time to reduce the nozzle temp to below the materials melting temp and heat up again is impractical, and cannot be done in simplify 3d as the previous poster intimates. Also even with retract at extreme distances there is always a small amount of material smeared on the inside of the nozzle which will ooze as there is no negative pressure sucking it up during retract, gravity inevitably pulls it out, and I have noticed the longer the printing nozzle works the more oozing comes from the other nozzle which is what you would expect and is the root of the problem even keeping temperatures low fails because of this, this is why the pictures of the calibration cubes look clean, basically the material has not had time to ooze because the cubes are small, however bigger prints suffer badly, so to be of use you would have to print a calibration cube close to the size of the target print, but then you may as well just print the target anyway. I would say from observation as a rule the longer the time between nozzle swap over the more rags are produced.

Making small sacrificial areas does not work for obvious reasons. The purge walls help, but do not work 100%, it can still happen with all these tweaks, and even a couple of rags can spoil a print.

I fear us dual 3d printers will have to wait for the next generation of printing machines which are just around the corner these mechanically shut off the nozzle with a retracting pin, so stop ooze completely. So far I have seen only two machines like this the Arburg Freeformer (very expensive), and the soon to be released dual headed Celrobox to be shown next month at TCT in Birmingham UK, price not released but I believe around the £1000 mark. I am going to give it 6 months for this machine to be bedded in then sell my old tech and move to this new tech, however one question about this machine is while at the moment I know for certain the single head version uses this technology, I am unsure if the new twin version will, I assume it will but until I see it at TCT dont take my word for it please, but worth checking out Zak.