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

[neotko 1,417]

Well so far the new magnets work nice, but it's a little pain in the butt to fit them, since the space it's small and they are 10x5,5x2mm magnets, this needs a tiny hand and patience but the Araldite crystal epoxy hold's them nice, one didn't stick because forgot to 'scratch it' (it helps a lot) but so far so good.

The fan area (not my new design but should happen the same) it's making really hard to print a large first layer with minimal fan, it flexes just enough to make it problematic. I had to place some blue tape to push it out but I'm not happy with the heat there, even with the heat shield (it's very thin), probably with wool heat shield would work, but it's too bulky. So...

This it's what I plan to order in aluminum (I'm waiting for the quote but I suppose that won't be cheap).

It's totally based on the um2 fan cap, but changed the inner area to make the air get symmetrically to my alu peek holder. Also I'll use also 30x30 fans, the good news (for me and maybe for @Ultiarjan it's that I found some cheap 30x30 fans that are 24v (um2 uses 12v in series and that's something I don't want to play with for 4 fans). Not sure if the holes will fit but that can be easily changed with some drilling or a printed part.

So for now I'll try to finish the new head and my 40x40 fans on my current setup but hopefully this fans should work.

I plan to attach the alu modded cap with a printed part. Also won't be using steel but aluminum, to improve heat dissipation.

[neotko 1,417]

Well some progress..

This is the fan cap I was using 1 week and a few days, printing the new (hopefully) final magnet head.

The upper and lower area was cover with heat shield, there's a slight deformation on the circle area that was near the ptfe coupler. But the mm and angle was intact. So the shield works, but could work better:

Check the circled area, that's where the ptfe coupler was. It has deformation from the heat of the ptfe coupler.

Ok..

Now the new fan cap, I'm really really happy with this design. Not only it prints really easy, also it's working like a charm on the heat department.

This design has bigger 'wings' that allowed me to place more heat shield on the wings (it's the area that got more deformation on my beta 1). So far the 15h of print, with the new magnets 150C and the slightly taller design, it's printing just like the stock head. Much better control now that I'm using the laser cut wood. The springs I bough where a hitandmiss, the ones from my pens are working much better.

This is the new assembly 3-6 minutes into the print, just finishing the first layers. Fan's where on minimal (my fans start at 174 and they where at 178+/-)

And this it's the heat almost 2h into the print.

Right now I think the design it's finished, but I wan't to test 2 or 3 ideas I have before giving up the idea of using the end of the machine. The Bowden does too much force when it’s there and the head it’s pushed down. I was able to make a hangar that did old the head, but then once it was inside it was stuck. Tryed using some lube and then it was so slypery that again was pushed down by the bowden.

If the hangars fail there are 2 options left.

- Change the extruders to the sides or to the front (not a beautifull idea).

- Since I use 1.75mm filament I could change the bowden to a smaller 2-4mm bowden setup to lower the force by ‘alot’ (in theory).

[ultiarjan 1,223]

Just saw these guys at 3dps London. They call it idex fff... independed dual extruder fff... I like the name. It's open source they share the design in December. I like there head setup. They use a wipe piece of rubber plus a prime tower . Quality looked good. I did not like there placement of filament and feeders... but that's easy to change. Could not really see there hotend setup but it looked like e3d.

[ultiarjan 1,223]

And in made a video of the machine. Upload it later when I have a good connection.

[neotko 1,417]

I'm finally very very happy with my mod

I was able to solve (a bit pure luck) the head z level by trying to fix other think.

After a gazillion different designs to make a solid hangar for this small head, I did this:

The little 'curve up' of entrance let's me ramp up the head a very safe 2mm. More than enough to solve most of the z errors from the 2 heads.

Check this small (boring) video. The heads on Z 0 go up when parking. This means that I could totally remove the springs and make a perfect z calibration by software. For my setup I'll leave them for now untill I do the first print. Hopefully I should be able to upload all the stls and assembly small tutorial in 2-3 days if there's no futher surprises. But so far, I'm soooo happy.

 

Edited May 24, 2015 by Guest

[neotko 1,417]

Well seems everything works. Hopefully soon I'll have more time to do a print. So far everything it's ready.

My head change sequence for Simplify3D

{IF NEWTOOL=0}G0 F8000 X4.8 Y50 ; Prepare to Park 1 on Left Hangar
{IF NEWTOOL=0}G0 F8000 X4.8 Y0 ; Park 0 on Left hangar
{IF NEWTOOL=0}G0 F8000 X177.2 Y0 ; Go Kiss Extruder 0 on Right Hangar
{IF NEWTOOL=0}G0 F8000 X177.2 Y50 ; Extruder 0 ready
{IF NEWTOOL=1}G0 F8000 X177.2 Y50 ; Prepare to park 0 on Right
{IF NEWTOOL=1}G0 F8000 X177.2 Y0 ; So long a thanks for all the fish.
{IF NEWTOOL=1}G0 F8000 X4.8 Y0 ; Searching Extruder 1 on Left Hangar
{IF NEWTOOL=1}G0 F8000 X4.8 Y50 ; Extruder 1 ready 

Also to make the 'home all axes' I had to change it, but I will have to write a proper parking on the end of gcode so there's no mix and I always know that the main clamp it's empty at the start.

I tryed to make some gcode files and run them via print from sd but they move weird, so I did the final movement tests via Printrun and it's loading/unloading nicely.

The 2 little blue tapes down the hangars are the parts that 'raise' the hangars 2mm, enough for the heads to never touch the bed.

Again a boring video. As soon I print something I'll put some music

Edited May 25, 2015 by Guest

[ultiarjan 1,223]

Cool! Looking good!

I improved my print quality. Now set the extra compensation in retraction during change to 0 mm. It caused filament grinding. Now the compensation for the dripping is 100% done by the priming tower.

@neotko if you want I can share a s3d factory file.

[neotko 1,417]

So far seems everything works nicely. No need for now for the fff file @ultiarjan Also my profile it's quite different since I'm using 1.75 and my retractions are 2.5mm. Also btw, don't use the extra compensation. Sometimes that (-) by default can make under extrusion because if there's too much retraction on the same area (and S3D love's retraction by default) because it's pulling more than what it's pushing.

Finally I measured the printing area for my mod and it's X 184mm Y 194mm for 1 head. And the area for Dual extrusion will be ... I'm not sure yet XD

The Metal Fans Cap I adapted from the UM2 design for my head (using 30mmx30mm 24v fans it's gonna cost a 30 GBP each (in orders of 4) and they are making it in stainless steel 0.5mm, just like the UM2 original (hopefully it will be a decent quality).

Also I posted some questions on Marlin subforum, noone answered but it seems that internally Marlin allows for M218 Z but with some tweaking, I'm not the best code editor but if I get some free time I'll try to edit some of that code to see if I can make Marlin apply a Z offset for the second extruder. Even now that the springs are working nicely (the laser cut wood fixes a lot of the problems of alignment) but I don't really like to have a spring there since it need's a bit more oversight that it should, and for better quality it should be better a Firmware Z offset than a manual adjustment that can (if not done properly) result on filament leakage.

Edited May 27, 2015 by Guest

[neotko 1,417]

Since I already placed a few questions on marlin and noone answered I'll try here...

Anyone knows if there's a way to temporally disable the z endstop? I googled and reprap marlins allow the command but isn't listed on ultimaker marlin. Without that I can't fix the z offset (doing relative positioning everytime the head changes it's easy to add this on the tool hange of s3d) but without disabling the endstop it won't be posible to do this without a full layer (raft or alike) at 0.2 at least with the lower extruder... so there's room to adjust the z. The springs well they work but I would really preffer a software fix. Atm I have 0.17 z difference from one to the other.

[jonnybischof 60]

The problem with mechanical limit switches is, you can't travel beyond the switches anyways - you'd run into the switch.

[neotko 1,417]

The problem with mechanical limit switches is, you can't travel beyond the switches anyways - you'd run into the switch.

Well I though about that but on my ulticontrol if I go to Prepare - Move Z, there I can move the Z passing the endstop, that's why I though this might be done. Also it's just a small 0.17 difference. I'm having a problem with the pen-springs I used because I had to cut them in half the cutted area tends to go though the washer/wood. Yesterday I ordered 4,4mm springs, (also more strong) hopefully this ones will work, I suppose I'll have to tune the springs so the cutted part stay flat against the washers.

Another problem I run into it's that because I have assembled and unassembled this like 15-20 times, the m3 holes on the aluminum peek holder have lost the 'screw' so I need to put a nut to fix the tension. I have 2 spare ones but it takes a good amount of time to prepare them (clean, use a file to clean the inner 11,1mm circle for the peek and then use a M3 tap to make the 2.5mm holes into a m3 screw).

[neotko 1,417]

@ultiarjan Hi.

 

Calibration;

You need to set the XY offset in the slicer you use. Start with a rough estimate, then print calibration pieces to refine.

I started with the D shape at 0.3 layers, and then went to the other one at 0.15 layers.

My curent ofset is: X 44,3  Y-0,9

Where do you set this?

I did set M218 at the start of the gcode

M218 T0 X0 Y0

M218 T1 X-34.83 Y0.15

And the first layer goes super (need's some tunning on the decimals) but.. When it parks extruder 1, it changes the X-Y so I can't reach the parking, because the 0 has change... Maybe I need to force a Toolchange before going to the park... ummm.

EDIT: Solved, just added T0 on the Simplify3D toolchange sequence so the X/Y stay the same for the movements and it's working

Now I need to make a prime tower and get a much better clamp x/y because after 6 layers it's making errors because it hits just a tinny bit. But works now just needs some software tunning and better alignment.

 

Edited May 28, 2015 by Guest

[ultiarjan 1,223]

in S3D you set it in the left bottom of the G-code tab of a process. only set it for one of the two processes, and make sure this is allocated to the correct head.

I only get the print order to work correctly when I combine the prime tower and the model in one STL (so 2 in total). I can't get it to work with 4 separate files (2 primetower, 2 model) and 4 processes. I would like this because I like to set the settings (flow, fill) separately for the primetowers. I mailed S3D support on this...

[neotko 1,417]

I'll try that too, so far the T0 before the tool code works.

Also I think that this works to make the prime tower to extruder first. Just assign 'Choose start point closest to specific location' and make that x/y point to an area close to the prime tower. I'm gonna be testing stuff all day and tomorrow.

[neotko 1,417]

Yay it's working! Woohooooo SOOO happpyyyy

 

I had a bit of x/y problem, I think the movement I catch Extruder 2 (on the left) sometimes the X it's a bit off when going from the side (maybe it's the magnets that move to the clamp and make a 'hit' because when getting it from upside it's just soo smooth).

Anyhow I solved this forever with a simple G28 X / G28 Y when I know that the X/Y it's near, so it's almost no time lost and works like a charm. In the long term (I just finished this today) I need to make a better X when going to pick extruder 2.

I'm going to dance a bit !

Btw, I have almost zero underextrusion from the extruder waiting, finally my 1.75 mod it's paying off, took a lot of time to make 1.75 mod work perfect but omg im sooo happpyyy lalalalalala

Thinks to do:

- Make S3D do the cleaning prime box first (yea that think I said before does not work) I think the only way for now it's to code the priming box, and that can be a pain in the.

- Make a spring holder so the extruders get a good wipe before going to print.

Hopefully this sunday I'll be able to sit down and short the stls + small tutorial to assemble it.

This is my toolchange sequence so far:

 

{IF NEWTOOL=0}T0 ; FORCE T0 so the it uses X0/Y0 as offsets{IF NEWTOOL=0}G0 F10000 X4.8{IF NEWTOOL=0}G28 X0{IF NEWTOOL=0}G0 F10000 X4.8 Y50 ; Prepare to Park 1 on Left Hangar{IF NEWTOOL=0}G0 F10000 X4.8 Y0 ; Park 0 on Left hangar{IF NEWTOOL=0}G28 Y0{IF NEWTOOL=0}G0 F10000 X177.2 Y0 ; Go Kiss Extruder 0 on Right Hangar{IF NEWTOOL=0}G0 F10000 X177.2 Y50 ; Extruder 0 ready{IF NEWTOOL=1}T0 ; FORCE T0 so the it uses X0/Y0 as offsets{IF NEWTOOL=1}G0 F10000 X177.2 Y50 ; Prepare to park 0 on Right{IF NEWTOOL=1}G0 F10000 X177.2 Y0 ; So long a thanks for all the fish.{IF NEWTOOL=1}G28 Y0{IF NEWTOOL=1}G0 F10000 X4.8 Y0 ; Searching Extruder 1 on Left Hangar{IF NEWTOOL=1}G0 F10000 X4.8 Y50 ; Extruder 1 ready{IF NEWTOOL=1}G28 X0

 

Edited May 28, 2015 by Guest

[neotko 1,417]

@ultiarjan I just found this, and on the gcode screen seems to work nice.

Just make 1 process print your part + 1 wipebox and the other process the other part + other wipebox.

I wasn't able to make it print first the box, but it's just so easy it's silly. Solution, place the boxes on a X bigger than the position of the object.

It's so silly I don't know why they don't document this on their web...

I need to test different objects, but it just seems to work. I have 'Optimize start points for fastest printing speed' and Print Islands sequentially without optimization.

I should play more with the stuff but I need to sleep. Try placing the wiping boxes there to see if works for you too.

[macua85 52]

Great work guys, looking really good. Out of interest, Foehnsturm, how did you fix the height adjusting problem of the print heads?

[ultiarjan 1,223]

@neotko. Nice! Think you deserve to dance a bit:)

Not sure I understand what you did differently in s3d than in the file I dropboxed you? Maybe dropbox me your latest factory file so I can compare? Thanks.

[neotko 1,417]

I didn't downloaded it yet. I didn't wanted add in the miz new settings to my config. I'll pass you mine when I get back.

What I did was place the prime box on a far x. S3d seems to make the order in a 'scan' way. First the items on the far x and then it scans down to x 0. It hard to explain for my in english buy I think yoy get the idea. I'll msg you latter with the file

[foehnsturm 969]

Great work guys, looking really good. Out of interest, Foehnsturm, how did you fix the height adjusting problem of the print heads?

Just turning the M10 PEEK a little within the aluminum mounting part (Merlin hotend). But as the nozzle tip is a little off center the x/y offset may change slightly due to that.

[macua85 52]

Hmm, interesting. Very simple way to do it, the e3d could probably adjust in a similary fashion, by turning the heat break. Do you find it needs adjusting regularly, or just initially?

[neotko 1,417]

This is what I mean by using the X s3d hierarchy to use it so it always do a wipe box before touching the print area. Check the image.

Tested with 3 different objects and the gcode preview says it works. I'll pm you the fff file

[neotko 1,417]

The trick does work perfectly.

 

Testing priming boxes. Works fine. Just had a small problem because Simplify3D doesn't take in account that the other process does exists, so it did drop some filament because he though that the area was 'empty'. Dual extruder really needs more intelligent slicers.

This to be really clean just need to change 2 thinks on the configuration.

- Remove the wiping boxes that go in last order

- Remove the tall brim/skirt because when going from skirt-to-skirt Simplify3D does not retract and it almost ruins the print (no biggie).

- I need to make a better X/Y sequence, there's one of the positons that isn't perfect and I had 1 layer that was displaced, but it was fixed with the homming I do between changes, only 1 fail on 67 layers, but that's just means that I need better X/Y sequence.

Enjoy the video and hopefully on sunday I'll upload everything.

Btw this was printed on 0.1 layer at 80-70mm/s (except the first layers ofc) PLA green and blue from formfutura (blue leaks more than green). Also there's a tiny little bit of understrusion on the first layer blue just because the priming boxes where waaaaay too small.

Edit: Printed this model and scaled it 0.5 https://www.youmagine.com/designs/stargate-dual-color-print

Edited May 29, 2015 by Guest

[ultiarjan 1,223]

I need to get used to the workflow as well, f.e. you can throw away the Gcode after use (save the S3D factory file) as you will re-calibrate XY often. This setup is lots of fun but also lots of extra work...

Changed the nozzles to test jet nozzles (@swordriff / 3dsolex.com) and the X was off about 0.7mm after change. Basically after a nozzle change you need to recalibrate Z and then XY.

Btw the jet nozzles leak a little more during a pauze than the E3D (as expected) so I'm now trying 0.5mm extra retraction compensation after tool change.

[swordriff 119]

The 3dSolex RSB nozzles are extremely slippery inside, and have a little longer "hot chamber" when used in an Olsson Block. Therefore you may have success with printing 5 deg lower temperature, especially when printing slowly.