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Joined: Thu Apr 23, 2020 11:41 am

Swap filaments during print?

Thu Apr 23, 2020 11:45 am


I want to swap from PLA to TPU half way through a print. Does Simplify allow this? I know that it's going to take a lot of fiddling with the TPU settings, but I want to give it a try if I can.

Any help appreciated...

Posts: 38
Joined: Tue May 15, 2018 2:49 pm

Re: Swap filaments during print?

Fri Apr 24, 2020 2:57 pm

I think saying does S3D allow this then No BUT I would setup process for each material and at the given layer insert the gcode manually for change filament and try that cant see why it wouldn't work if you have everything setup like temps and feed

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Location: Philadelphia PA Area

Re: Swap filaments during print?

Fri Apr 24, 2020 4:01 pm

you may want to see if tpu will stick to pla.. I expect not.. to do that create a square model say 25 x 25 x 3mm tall. load this into the slicer and set up your pla settings. Now load a second copy and adjust the height of the second model to so it is 3mm above the first and create a second process for TPU. Make sure only the first model is selected in the first process, and that only the second model is selected in the second. Prepare to print the first one only, print it and leave it on the bed. Manually change your filament flush the extruder of PLA, Load the TPU and now prepare to print using the second process.. see if the TPU will bond to PLA..

Attached a square model for you to use
square 3mm tall.stl
(28.79 KiB) Downloaded 78 times

Posts: 178
Joined: Mon Mar 02, 2015 1:23 pm

Re: Swap filaments during print?

Sat Apr 25, 2020 2:35 pm

Options to consider...

This will depend on your Printer (Brand, Type, Firmware...).

I use these options as needed and, which one, depends on what I need and the printer I’m using...

Things you’ll need to know:
Does your printer respond to a Gcode ‘Pause’ command?
Which commands for your printer (M0, M117, M322)?
Does the printer have a 'Broken Filament Trip Switch'?

This will Pause at Layer 3. It goes into the Scripts panel:
{REPLACE “; layer 3,” “M322 Z3.0\n; layer 3,”}

This will Pause at Layer 3 and wait for Button Press to resume
M0 Z3.0
G1 Z3.0

This will Pause upon Broken Filament (if machine is equipped with a trip switch):
When ‘tripped’ the Extruder should move to front of machine and wait for Resume/Button Press.
Setup two process (for PLA and TPU) and When at the desired Layer/Z-height, manually trip the switch.
Change the filament and Resume.
With a Second Process set to take over at that same Layer, printing will continue. HOWEVER, since Temps will be different, you can add Gcode to scripts telling pinter to Wait until at desired temperatures are reached..

My Favorite method is 'Tripping the Switch', that frees me from being locked into specific layers and allows me to control it in Real-Time (especially when adding threaded inserts and nuts into pockets before the top layers are processed.

It will take some practice and I’ve found it to be a valuable addition to my skills... Learn where and how to implement Scripts. Look at other Posts about implementing them and check into your printer's compatibility and Gcodes...
3D Print Parts

Posts: 3
Joined: Thu Apr 23, 2020 11:41 am

Re: Swap filaments during print?

Sat Apr 25, 2020 9:47 pm

Thanks for the ideas, greybeard.

It's a Prusa i3 MK3S, latest firmware. I'll take a look at the gcode to see if it supports the options you mention.

I'll report back.

Posts: 3
Joined: Thu Apr 23, 2020 11:41 am

Re: Swap filaments during print?

Sun Apr 26, 2020 9:22 pm


Thanks for your advice - it's really helpful. I have a Prusa i3 MK3S.

I literally just discovered a way to do this in S3d:

Will give this a go, and report back!

Posts: 9
Joined: Mon Apr 20, 2020 8:44 am

Re: Swap filaments during print?

Wed Apr 29, 2020 11:28 am

The video basically shows the procedure suggested by airscapes, which is the easiest way to operate directly in S3D.

Did TPU stick to PLA?

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