Monty3DP
Posts: 27
Joined: Sat Apr 26, 2014 3:15 pm

Purge Wall for dual prints

Fri Jul 18, 2014 12:59 pm

Hi,

For dual extrusion prints, is there a purge wall option to basically wipe the nozzle. This is required if not, there's pretty much no point doing a dual extrusion print as the two colours will contaminate eachother due to leakage

Thanks

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KeyboardWarrior
Posts: 480
Joined: Thu Jun 19, 2014 5:02 pm

Re: Purge Wall for dual prints

Fri Jul 18, 2014 3:59 pm

I was gonna type this out, but then I didn't. This isn't a purge wall, but works just as well. Pic should be self explanatory, if not just post and I can clarify any questions. I use this method for making prints so that they don't leak. The idea is that those two pillars on the side will grab any ooze and keep the extruders busy when they otherwise wouldn't be.


Image

Edit 8/7: Order of processes was messed up
Last edited by KeyboardWarrior on Thu Aug 07, 2014 1:14 pm, edited 1 time in total.

dennisjm
Posts: 342
Joined: Wed May 07, 2014 9:51 pm

Re: Purge Wall for dual prints

Tue Jul 22, 2014 6:50 pm

Adding objects manually sort of works, but the real magic in the makerbot slicer is the purge wall specific retraction settings. So basically when you're done using nozzle one and switching to nozzle two, you retract nozzle one a whole bunch. Then when ready to use nozzle one again, you purge some additional material into the bucket part of the wall to ensure it's ready to print. It works much better than simply adding manual objects.

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TenKOhms
Posts: 172
Joined: Wed May 14, 2014 3:04 pm

Re: Purge Wall for dual prints

Tue Jul 22, 2014 8:24 pm

dennisjm wrote:Adding objects manually sort of works, but the real magic in the makerbot slicer is the purge wall specific retraction settings. So basically when you're done using nozzle one and switching to nozzle two, you retract nozzle one a whole bunch. Then when ready to use nozzle one again, you purge some additional material into the bucket part of the wall to ensure it's ready to print. It works much better than simply adding manual objects.
This seems like it can be implemented in the tool head change scripts, you would just have to get the right G-Code coordinates for your printer.

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KeyboardWarrior
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Re: Purge Wall for dual prints

Tue Jul 22, 2014 11:34 pm

dennisjm wrote:Adding objects manually sort of works, but the real magic in the makerbot slicer is the purge wall specific retraction settings. So basically when you're done using nozzle one and switching to nozzle two, you retract nozzle one a whole bunch. Then when ready to use nozzle one again, you purge some additional material into the bucket part of the wall to ensure it's ready to print. It works much better than simply adding manual objects.
I would argue there is very little magic going on in the Makerbot slicer. Adding a wall to be printed isn't something miraculus by anymeans, you could even do this in Simplify3D by adding in per-layer G-code commands in the scripts tab.

dennisjm
Posts: 342
Joined: Wed May 07, 2014 9:51 pm

Re: Purge Wall for dual prints

Wed Jul 23, 2014 12:42 am

I've tried messing with this. It doesn't work quite right. There is another thread discussing the issues.
http://www.forum.simplify3d.com/viewtop ... 2&start=10

dennisjm
Posts: 342
Joined: Wed May 07, 2014 9:51 pm

Re: Purge Wall for dual prints

Wed Aug 06, 2014 7:13 pm

Here is an example of what happens to me when I do duel extrusion prints with S3D. Normally, I print with the same color support material as main plastic but in this case it's what was in the printer and this wasn't an important print, more just tinkering around with stuff.

So..
IMG_3371.jpg
This is pretty much why everyone says they still use Makerware for duel prints. I printed this one with S3D because I wanted to customize the supports though. Unfortunate Neither software has all the features.

Hoping S3D comes out with purge walls TOMORROW. :)

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TenKOhms
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Re: Purge Wall for dual prints

Wed Aug 06, 2014 8:26 pm

dennisjm wrote: This is pretty much why everyone says they still use Makerware for duel prints. I printed this one with S3D because I wanted to customize the supports though. Unfortunate Neither software has all the features.

Hoping S3D comes out with purge walls TOMORROW. :)
why not just add retraction && purge to the tool head changes for each process? Shouldn't be too difficult since the purge G-Code is already available in the starting script.

dennisjm
Posts: 342
Joined: Wed May 07, 2014 9:51 pm

Re: Purge Wall for dual prints

Wed Aug 06, 2014 8:32 pm

TenKOhms wrote:why not just add retraction && purge to the tool head changes for each process? Shouldn't be too difficult since the purge G-Code is already available in the starting script.
This might be possible but both tools would purge on the same spot since there isn't any way to customize the tool change script depending on which tool your changing to. So you might be able to do something like a variable height purge object and purge in the middle of it but it's just not a very good solution.

At best I think you could do something like retract the [old_tool] and extract [new_tool] with a bigger amount than your standard retract settings and then add two custom objects with different processes. I haven't tried that. It may come close to a purge wall feature. It's on my list to try actually.

The point is that all that is a pain when instead I could just open up Makerware and export with that instead. Much less work.. unless of course I have an object tha t needs some special support consideration in which case I get motivated to come post here again so that we can get purge walls in S3D soon :)

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TenKOhms
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Re: Purge Wall for dual prints

Wed Aug 06, 2014 8:43 pm

dennisjm wrote:
TenKOhms wrote:why not just add retraction && purge to the tool head changes for each process? Shouldn't be too difficult since the purge G-Code is already available in the starting script.
This might be possible but both tools would purge on the same spot since there isn't any way to customize the tool change script depending on which tool your changing to. So you might be able to do something like a variable height purge object and purge in the middle of it but it's just not a very good solution.

At best I think you could do something like retract the [old_tool] and extract [new_tool] with a bigger amount than your standard retract settings and then add two custom objects with different processes. I haven't tried that. It may come close to a purge wall feature. It's on my list to try actually.

The point is that all that is a pain when instead I could just open up Makerware and export with that instead. Much less work.. unless of course I have an object tha t needs some special support consideration in which case I get motivated to come post here again so that we can get purge walls in S3D soon :)
Well you already have two processes, one per extruder, so you would have two very similar tool change scripts, one per process. The only difference is the extruder being selected would be different, and then you could change the position the tool goes to to purge & wipe, although purge and wiping on the edge of the bed i don't think it would be an issue if they did it at the same edge spot, but if it does, like i said just move it slightly to a slightly different Y position. May seem like a bit of work, but after you get the gcode correct, it's kind of a one time setup and then you'll have it for future dual extrusion prints.

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