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Dual Extruder Issues

Posted: Tue Oct 18, 2016 11:03 pm
by cwdesignsvs
Hello Everyone. I recently purchased the dual extruder upgrade, I installed it with no issues, I leveled it following jules guide for same material extruding, but once I started printing I've run into an issue. In the images I have attached it seems that internally there are bits of material stuck, even with ooze shield being used. Does anyone have a leveling tool that I could buy? or anything that would be useful to level my heads? I would appreciate any help from the community, I really love this 3D printer and I understand that dual extruding has a steep learning curve but any help would be great.

Thank you,
Christian Garcia

Re: Dual Extruder Issues

Posted: Wed Oct 19, 2016 3:06 am
by Jules
Unfortunately, you're always going to have trouble with tiny dripped bits on that particular shape, because it has such a large open area in the center where the shields at the outside aren't going to help you.

One thing that might help, is to increase the cooling by as much as you possibly can. That means buying a small desk fan and pointing it at the nozzle that is farthest away from the bed fan. You might try increasing the retraction a bit, and lowering the printing temp.

You can try speeding it up too (particularly if you are using one of the slowed down profiles that I posted) ....I would speed that up for that kind of print. Take it up to 100%. Less time for drips to form and fall off on the print.

As a last resort....You can make the colors less contrasting to help, white and dark blue are always going to show every little drip starkly.

Re: Dual Extruder Issues

Posted: Wed Oct 19, 2016 4:46 pm
by cwdesignsvs
Jules, I'm sorry it wasn't drip. The nozzle barely scratched the surface of the blue print. I can see I wasn't very clear, is there any way I can level it correctly and not run into any issues. I didn't have drip from the PLA. I will be changing my nozzles to stainless steel so I would like to get the leveling right this time.

Re: Dual Extruder Issues

Posted: Thu Oct 20, 2016 3:21 am
by Tim
Honestly. . . you are better off doing this without the dual extruder. Take a look at these fantastic designs, done by being very clever with swapping out one color filament for another at the right time:

viewtopic.php?f=6&t=3278

Click on the link in the first post. I think what Vicky does is exactly the sort of effect you're trying to achieve here.

(Note that the dual extruder can make life a bit easier by having the 2nd color available without having to swap out spools, or feed cleaning filament through the nozzle to get rid of the last color.)

Re: Dual Extruder Issues

Posted: Thu Oct 20, 2016 3:49 pm
by cwdesignsvs
Tim, so I shouldn't have bought the dual extruder? I purchased it because I honestly thought it would make life easier.

Re: Dual Extruder Issues

Posted: Fri Oct 21, 2016 2:29 pm
by Jules
My ISP is down, so in brief, duals r great, but take extra fiddling. Can try using a small hop on retraction.

Re: Dual Extruder Issues

Posted: Mon Oct 24, 2016 5:30 pm
by Tim
cwdesignsvs wrote:Tim, so I shouldn't have bought the dual extruder? I purchased it because I honestly thought it would make life easier.
I wouldn't necessarily say that, but the dual extruder configuration has its limitations, and it's a huge extra learning curve. One must take care not to use the wrong tool for the job. . . just because something has two colors doesn't mean that it must be done with a dual extruder. If the two colors are blended throughout, then it's definitely a job for a dual extruder. If the colors can be separated into layers along the Z axis, then it will probably be easier to run one color at a time.

If the plastic is PLA, then you have a much better chance of getting good results with more retraction to reduce dripping. PLA doesn't drip much when it's configured correctly.

But if you look at two-color designs posted on Thingiverse and so forth, most of them are compact and work well with a drip shield around them. When there's a lot of exposed detail inside, or large flat top surfaces that will be passed over by both nozzles, then you are exascerbating the problems endemic to the dual extruder. In short: There's no way to put a drip shield around your design, since it's large, flat, and viewed from the top.

P.S.---A drip shield inside the cut-out areas of your design might work well, but I'm not sure if Simplify3D will do that (you can always try). In some ways, the dual extruder is hardware that is far advanced relative to the software that is needed to use it properly. We've all been waiting for the software to catch up, but it hasn't been happening.

Re: Dual Extruder Issues

Posted: Mon Oct 24, 2016 5:40 pm
by Jules
It's not really a drip that's a problem with that....it's ooze. The inactive nozzle is always oozing while the other one is working, and you've got a large open surface area there, giving it more time to ooze, and the tip of the inactive nozzle is brushing against the interior ledge in a couple of places.

Here's an idea....put in a sacrificial wall. Mimic the inside edge where it is brushing, only about a half mm closer to the dog shape. Atttach it to the actual wall with tabs in a couple of places, then just cut it off when you are done. With luck, the wipe will happen on the inside wall, and spare your print.

Re: Dual Extruder Issues

Posted: Wed Oct 26, 2016 12:36 am
by Tim
Jules wrote:Here's an idea ...put in a sacrificial wall. Mimic the inside edge where it is brushing, only about a half mm closer to the dog shape. Attach it to the actual wall with tabs in a couple of places, then just cut it off when you are done. With luck, the wipe will happen on the inside wall, and spare your print.
Well, that's true. . . you don't have to wait for Simplify3D to build a wall for you. In fact, theirs have attachment problems from the way the base of the wall is made that make them rather too easy to pop off.