A different multi-extrusion approach - UM tool / printhead changer

[macua85 52]

The reason for using the back is there is a large area where the head can't print there. Its much of a muchness really I guess, but the heads will be stored above unusable build plate area.

Yup dual v6's. I had a problem with them blocking before, but hoping that was down to cooling and this new design fixes it.

[neotko 1,417]

Back of the machine it's nice if you don't use bowden (or you move the extruders to sides/front). The preassure from the bowden on the back push the parked head and it's almost impossible to have it steady from the bowden and the 'shakes' when printing fast small areas. If you use direct drive it should be fine adjusting the hangar I think.

I did loose a lot of time trying to place them there and tryed almost everything (with bowden ofc).

[ultiarjan 1,223]

Yup dual v6's. I had a problem with them blocking before, but hoping that was down to cooling and this new design fixes it.

 

Curious about your result... been thinking myself to go for a combination of a UM2 head and a V6, to be more flexible with higher temperatures on PET/XT, but I started with just the UM2 head setup in order not to change to much at a time..

[macua85 52]

Yea the biggest attraction for the v6 is the temperature range. I've got some nylon i'd like to try printing with. Also goes for direct drive so think making a chamber could really help with printing these exotic materials too.

Neotko, know what you mean about the bowden issue. I'll give it a go, if it doesn't work out I can always turn the main carriage around and have them stored at the front. Either way, i lose around 30-40mm of print area. I'd really like to reduce that, but to be honest I seldom print anything that uses the full bed. Maybe we need to work on a mechanism that somehow lifts the parked heads out of the way, or swing them to the side or something...complicated though. I'd better get it working as standard first really!

[neotko 1,417]

Filament wiper addon. I need to improve it so it's easier to remove without compromising how steady it is.

[Titus 170]

Nice one! Although it sounds like a pinball machine

[ultiarjan 1,223]

Looks like a little less needed force would be nice, but it seems the idea will work

Could not resit playing with it myself a bit, made this based on the ReprapBCN-sigma idea, in itself it's not so bad as the space mid-front is lost anyhow. You do lose Z depending on how high you make this thing, but thats not my main concern, the constant Z distance needed is more anoying imho.

Basically I like the idea of wipers on the side better..... Now I'm just thinking if I dare to drill holes in my UM2 side panels :( maybe it's better to glue a mount inside ..

[neotko 1,417]

The force it's easy to make it lower just using other material. Taking the metal from a metal brush. Also the wire I'm using it's 0.4mm. I wanted to teat how was the feedback and how easy/hard was to attach and remove. It's firm but it needs less strength on the wire or just using a 0.02 metal from a feeler gauge (it's easy to cut that with scissors). I will do more test with different materials.

[neotko 1,417]

You could try something like this for um2, I just downloaded the step files, and it's easy to do. Like on my design since the wiper only uses x/y forces, you could clamp it on the front.

I do this in two parts and join it with screws, it holds very steady and it's easy place firmly at any z.

[ultiarjan 1,223]

Yeah, that's probably better than drilling. . . . . just need to work around the LED strips, the're glued to the front panel, but I can make something to fit over them.

[ultiarjan 1,223]

My first Flex + PLA combination.

@Makerpoint flex45 at 240c + PLA at 205c.

The MPflex45 was a big surprise as it almost didn't drip when the head was pauzed (kept it at 240c). I used slow printing & retraction speeds of 15mm/s on the (semi)flex.

I'm a little afraid for the 240celsius printing with the PLA head, Think I'll soon try to print a new one in XT or PET.

[Dim3nsioneer 557]

 

@ultiarjan: What did you slice the print with? I guess it wasn't Cura due to its lack of specifying retraction and speed for individual extruders...

[ultiarjan 1,223]

I use simplify3D (more info on page 27). In this case 15mm/s for the flex and 35mm/s for the PLA. You can see some underextrusion on the PLA (I need to "atomic" more often..). I notice these tiny prints are more difficult. The tricky part on the dual head print is the retraction on tool change. I reduced this now to 10mm.

I started with 20 mm retraction, but I think this kills the teflon, and it caused huge underextrusion, 15mm works ok, 10 mm also works ok but there's a bit more dripping on the parked head. When you use large prime towers al works fine, I'm still finetuning the size of the towers, when I compensate by extruding a little extra after toolchange the towers can be smaller (I now use 0.2 mm) but when you compensate to much you'll grind the fillament at the feeder.

Would be nice if someone had any scientific correlation between retraction distance and temperature creeping up into the teflon (using the olsson block). Basically I need to know the maximum safe retraction distance, at 205 celsius printing (my PLA default).

My main wish for S3D would be to set infill separately on the primetowers, so I can use small towers at 100% fill even when the print item has lower infill and I get more stable results independent of the used fill%. Unfortunately if I use a separate proces on the primetowers in simplify the printorder gets messed up. I can only control this correctly when I put tower A and Item A in one .STL ands tower B and Item B in the other .STL. I then control printorder by assigning a starting point (closed to a set coordinate).

[neotko 1,417]

After a week making stuff for a customer I finally was able to finish the calibration and print something interesting. Dual extruded skateboard with wheels working.

Done in Cura, without wipe or ooze shield. The walls did work perfectly but Cura uses a different hierarchy on the order, so on one extruder the order when super on the other didn't, anyway the walls did the job. I like s3d but I love how Cura prints.

Now I'm gonna change filaments and go with the final version on Colorfabb fluorescent and black.

Cheappla 16€/kilo 205C 1.75mm 55mm/s 0.2 layer

[ultiarjan 1,223]

nice! I like these "no assembly needed" prints.

Setting print order would indeed be nice, i'll mention it for sure this monday at the ultiEvening with the Cura developers.

[ultiarjan 1,223]

Just tried a retraction heavy thing, I need to get a bit more overlap between the colors but S3D has an "outline overlap %" on infill but I didn't find out jet how to increase overlap between materials.... (anyone ???)

[neotko 1,417]

That's exactly why I have stop using s3d for dual for now. With complex designs since it's working with 2 process each process does not know that an objects exists on the other process. They don't know each other existence so they can't communicate where the holes are or where they touch. Cura understands the objects as a whole not 2 process with different ideas. The 2 process think it's cool, but sometimes it isn't.

I just finished understanding what makes Cura print one or other object first after each tool change. Was so easy with the gcode preview of s3d. Each extruder stl must have it's cleaning tower positioned on a x/y lower than where the object it's. Also the prime-wipe tower must be bolean as one object.

Like this. The s3d preview print animated shows it's printing first the wall/prime before going to do the real print, on all the 250 layers (more or less I don't remember now XD).

Btw the new cura has the dual extrusion removed :(why? Now that I finally have it! @daid please pretty pretty please, super pretty pretty pleassse, add it pleaseee. Btw just saw the cool supports on 15.06! nice beta! Please? Pretty pretty please?... I don't need it improved, just as it it's right now...

Edited June 13, 2015 by Guest

[Dim3nsioneer 557]

@neotko: Dual extrusion will be in the new Cura. But not at the beginning. Maybe somewhen in autumn. It's a question of manpower. Not only for the developpers (Daid is by far not the only one working on the new Cura right now) but also for the beta testers. Being one of them I can assure you everything is done to make the new Cura a success. But that means that certain feature have to be postponed, dual extrusion being one of them as Ultimaker has no non-experimental dual extrusion atm (I know, the truth hurts sometimes).

But you may have seen people talking about legacy Cura. That's the Cura we all know (and as someone just wrote today on Github 'love and hate') and which was created by Daid. This legacy Cura still sees bugfixes. Afaik this bugfix period will run along with the introduction period of the new Cura. I guess there will be more information about this after the Ulti-evening comming Monday.

[neotko 1,417]

thanks @dim3nsioneer btw some stuff on the beta look soo neat. great job #curadevelopers

[ultiarjan 1,223]

Each extruder stl must have it's cleaning tower positioned on a x/y lower than where the object it's.

@neotko maybe I'm just dumb buy I don't get what you mean by this... would any of these options work?

[ultiarjan 1,223]

hmmm, or do you perhaps mean towers closest to the 0 position (left front ?)

[neotko 1,417]

After each tool change, Cura try to prints first the object that's more close to the x/y 0, that's why I use on the screen above that strange walls.

[neotko 1,417]

This is the print finished, the one from the cura preview.

Colorfabb leaks more than my cheappla, I need to adjust a bit the retractions, but so far so good, the shield did the job and the whipetower worked flawlessly layer after layer, this time 2h print I left it totally unattended (except the first 5mins to remove the blops of filament from the head and be sure that everything was going ok). Really happy to fell that I can leave the printer 2h without touching it.

Edited June 13, 2015 by Guest

[ultiarjan 1,223]

@neotko so basically the options are (please add or comment);

Cura;

- manual replacing the tool change into the Gcode , basically just 2x a find & replace.

- no options to use different settings for the parts of the print item, let alone for the towers.

- fixed position for primetowers close to X0 Y0 not very logical in our setup.

+ free & opensource

S3D;

+ Easy workflow with toolchange code in the scripting option

+ Separate process/settings for the parts, not for the towers

+ Specific retraction settings for the tool change and per material (different speed for flex)

+ freedom to place primetowers where you want as you can set the "start close to" coordinates for every process

- issue with to less overlap (not on horizontal, only on vertical connections; can be solved in CAD with own design, and maybe by over extruding the outer shell in some cases.

+ Superior layer viewer with tool movement simulation.

For sure I fully trust Cura will get better in the end, and the "toolchange G-code insert" should be a fairly simple plugin but I think i'll be using S3D mostly for now. Basically cura will need to be able to assign processes to different parts of the print and I have no clue if this is currently on the roadmap .. (is there any roadmap ??)

I also tried the New Cura (version june 3) and it looks promising but it also looks like there is still a huge amount of work to do .. the whole GUI is still rudimentary, i'm very curious to see the developers presentation on Monday.

[neotko 1,417]

@neotko so basically the options are (please add or comment);

Cura;

- manual replacing the tool change into the Gcode , basically just 2x a find & replace.

- no options to use different settings for the parts of the print item, let alone for the towers.

- fixed position for primetowers close to X0 Y0 not very logical in our setup.

+ free & opensource

S3D;

+ Easy workflow with toolchange code in the scripting option

+ Separate process/settings for the parts, not for the towers

+ Specific retraction settings for the tool change and per material (different speed for flex)

+ freedom to place primetowers where you want as you can set the "start close to" coordinates for every process

- issue with to less overlap (not on horizontal, only on vertical connections; can be solved in CAD with own design, and maybe by over extruding the outer shell in some cases.

+ Superior layer viewer with tool movement simulation.

For sure I fully trust Cura will get better in the end, and the "toolchange G-code insert" should be a fairly simple plugin but I think i'll be using S3D mostly for now. Basically cura will need to be able to assign processes to different parts  of the print and I have no clue if this is currently on the roadmap .. (is there any roadmap ??)

I also tried the New Cura (version june 3) and it looks promising but it also looks like there is still a huge amount of work to do .. the whole GUI is still rudimentary, i'm very curious to see the developers presentation on Monday.

 

I totally agree with you. The two main thinks I like of cura for this it's that he process the object as one object not 2 separate thinks. This if one print needs big 'brims' can be a bit frustrating, or if the object has too mane open areas with no circular form. Also the Cura ooze wipe works quite nice. Also sometimes with the first layer s3d tries to print it as each object in the stl is, not as a block. Other think I like of cura vs s3d it's that you can feed it with almost any fast stl without worrying much about objects intersecting. S3d it's really far on the stl fix department. For me cura would work just perfectly if the stupid wipe tower would be 2 towers, not just 1 with mixed materials that even with glue it always falls down.

So my main points (btw I totally agree with your points)

Cura:

Good:

- Fast stl process since you can make the stl with almost no need to think about objects intersecting.

- Merge the stls as one object and process it as an object.

- Dual extrusion overlap

- Easyer to think on speed/mm3/s so one can adjust the temperatures with some numbers base (this S3D does it very poorly)

Bad:

- Bad first layer with lines. Retraction while combing it's a must to make quality first layer and even with that sometimes isn't enough.

S3D:

Good:

Everything you said

- Superb quality on first layers.

Bad:

- Also on first layers sometimes the way it prints the brim/skirt can ruin them if you don't use glue.

- Crappy stl repair, very very crappy. Netfabb cloud it's a must when doing fast stl.

- It's a mess to 'move' one dual extrusion object, even worse to align it, when scaling 2 parts sometimes it changes the central point and you need to start over.

- The way to input the print speed and first layer height it's really crap. It need's a pure dimensions input, % isn't good at all. At least for me