Nozzle changer

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Harjit Singh

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Apr 6, 2026, 6:13:28 PMApr 6
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Toby, can you share the design files for your nozzle changer, please?



Thanks in advance.

Toby Dickenson

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Apr 6, 2026, 7:06:07 PMApr 6
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Harjit Singh

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Apr 6, 2026, 7:13:17 PMApr 6
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Wonderful. Thank you.

The last line in the Readme is:  Put a pillar nearby to carry the vertical force when loading a nozzle tip, to avoid causing the build plate to bend.

I don't understand, and didn't notice one in the video. Can you please elaborate?

Toby Dickenson

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Apr 7, 2026, 6:03:42 AMApr 7
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This advice is for assembly onto the lumenpnp, and is specific to that
type of machine. The rigidity of the build plate on the lumpnpnp is
lower than typical for a pick and place machine. It is sufficiently
rigid for normal picking and placing loads, but the force of loading a
tip can cause the plate to flex. Opulo mitigated this with their stock
design by recommending super-slow tool changes.

The lumenpnp uses a pillar in the middle of a secondary build plate to
prevent the whole plate drooping in the middle. Search for "build
plate foot" on this page:
https://docs.opulo.io/semi-assembly-4-0/frame

I recommend using the same part directly underneath the toolchanger to
prevent flexing from fast changes.

Toby
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Jacob Christ

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Apr 7, 2026, 9:56:24 PMApr 7
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Harjit,

I know this is not what your looking for but it might be of interest as well.

I've merged the Richard Klinger version so that it can be printed in a single go in PLA here:


I've had pretty good luck with this version vs the Opulo version that comes with the Lumen.  The multi material ones look like they would probably work better than the single material version and one day I hope to switch over to them to hopefully lower the amount of tool change crash I have.

Both these multi piece versions look amazing but I want to get some more nozzles before I start experimenting with printing in different material because I've had problems in the past mixing materials in my nozzles.

Jacob

Toby Dickenson

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Apr 8, 2026, 3:53:53 AMApr 8
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Hi Jacob,

That is an interesting variant. Which orientation do you print that? On its back I assume?.

> The multi material ones look like....

Maybe I am overlooking something, but of course all those designs using different color filaments will be equally functional in a single color with the same filament. I swap colors just to make the photos clearer.


> I hope to switch over to them to hopefully lower the amount of tool change crash I have.

Can I draw attention to this difference in the models. The surfaces painted red cradle the main shaft of the nozzle tip. More cradling = better vertical alignment = smoother changes.

image.pngimage.png

I have added an (untested!) all-in-one stl to github if you want to try that.


Harjit Singh

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Apr 8, 2026, 5:29:36 PMApr 8
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You guys blow me away with how quickly you are able to create new designs. 

Toby, a couple of questions:
1. Can you make a single holder? I want to print one to make sure the scaling, and feel is correct, and then if I have to, make adjustments to the model, and print the entire bank.
2. if you have a few minutes, how did you convert the multiple layer design into the all in one?

Jacob, thanks for the design. I poked around the other items you have, and I'm definitely going to use the "Printed Board Holder"! I was thinking of making what Richard had but I like these better because the provide support, and the "long" tail provides stability, and adjustability. Thanks for sharing this.

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cdh...@gmail.com

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Apr 8, 2026, 5:46:44 PMApr 8
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Harjit,

 

I use Prusa Slicer for printing, and it can take an STL and ‘slice’ it at any point with a cutting plane (intended primarily for cutting a large object into printable pieces).

 

Using this method, you can ‘slice off’ one holder for testing without altering the STL and then print the whole thing later.

 

Regards,

 

Chuck Hackett

UP Northern 844, Mitch-Cal Shay #2

Owner MiniRail Solutions, LLC (http://MiniRailSolutions.com)

“By the work, one knows the workman”

 

 

 

From: ope...@googlegroups.com <ope...@googlegroups.com> On Behalf Of Harjit Singh
Sent: Wednesday, April 8, 2026 5:29 PM
To: ope...@googlegroups.com
Subject: Re: [OpenPnP] Re: Nozzle changer

 

You guys blow me away with how quickly you are able to create new designs. 

Toby, a couple of questions:

1. Can you make a single holder? I want to print one to make sure the scaling, and feel is correct, and then if I have to, make adjustments to the model, and print the entire bank.

…..

Mike Menci

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Apr 9, 2026, 1:15:35 AMApr 9
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It look like #green" part is other material more flexible to work like the spring - than printing all in one is not a good choice!? 

Toby Dickenson

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Apr 9, 2026, 4:29:02 AMApr 9
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On Thu, 9 Apr 2026 at 06:15, Mike Menci <mike....@gmail.com> wrote:
> It look like #green" part is other material more flexible to work like the spring - than printing all in one is not a good choice!?

I think all the parts here would work well printed in either PLA or PETG.


>> From: Harjit Singh
>> 2. if you have a few minutes, how did you convert the multiple layer design into the all in one?

This model is in OpenSCAD, linked in github above. OpenSCAD is a scripting language for 3d solid shapes. In my experience this is intuitive for anyone with a background in programming or mathematics, but maybe not for someone with a background in conventional CAD or machining. If you can make a 2d web page by nesting divs in html&css, then you should be able to make a 3d solid shape in openscad. If you are new to openscad then start with a nightly build (rather than the ancient stable release) and set the "manifold" rendering engine https://gist.github.com/ochafik/95587ff653ecb708cbf9a735723b1478

The models are primarily created in script, but OpenSCAD shows a gui editor for any top-level numeric and boolean variables. In this model there is only one — offset — which is the gap between the exploded parts in the 3d view:
image.png
Setting that to zero closes the gap:
image.png
That view is not computing the complete 3D geometry; it uses some rendering trickery for speed. The next steps are the menu Design/Render (F6) then File/Export/STL (F7) to produce an STL of the complete toolchanger with no gaps. The model contains 4 separate parts but that detail is lost in the STL export so you get the complete toolchanger in one stl file.

The top-level Tool_Changer.scad file includes other files which describe the geometry of each part. My normal export process is to open those files one at a time, and export a single part to STL.

> On Wednesday, 8 April 2026 at 23:46:44 UTC+2 Chuck Hackett wrote:
>> I use Prusa Slicer for printing, and it can take an STL and ‘slice’ it at any point with a cutting plane
>> 1. Can you make a single holder? I want to print one to make sure the scaling, and feel is correct, and then if I have to, make adjustments to the model, and print the entire bank.

Another option is to edit the file Dimensions.scad (using your favourite text editor) and change the line nozzles=7 to nozzles=1. OpeSCAD updates the rendered view when you change any source code file.
image.png
Toby


Jacob Christ

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Apr 9, 2026, 2:37:59 PMApr 9
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I don't remember, I think I printed it in base down like it would be mounted on the machine.  I had to break the springs away after the print but I think I just had to push the nozzel in by had with a little bit of force do do this.  I think the other motivation was not having the proper hardware to assemble the stack of prints.  I have that hardware now and I might try just printing the layers all with PLA and assembling.

Jacob

Jacob Christ

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Apr 9, 2026, 2:43:06 PMApr 9
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Harjit,

I use the board holders with a corner piece that I'm not quite sure where I got it from (but probably from the Opulo 3rd party web page).  You can see a picture of it in this image:


Jacob
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