STEMFIE Infinity Gears

STEMFIE Infinity Gears

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Print Profile(3)

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A1 mini
P1S
P1P
X1
X1 Carbon
X1E
A1

0.2mm layer, 2 walls, 15% infill
0.2mm layer, 2 walls, 15% infill
Designer
9 h
5 plates

0.2mm layer, 2 walls, 15% infill
0.2mm layer, 2 walls, 15% infill
Designer
9.2 h
5 plates

0.2mm layer, 2 walls, 15% infill
0.2mm layer, 2 walls, 15% infill
Designer
8.1 h
5 plates

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Released

Description

The STEMFIE Infinity Gears project is not just a playset but an educational tool that illuminates the mechanical principle of gear reduction through six steps. Each module features two gears on one axle: the small gear with 17 teeth and the large gear with 58, resulting in a 3.41 gear reduction.

 

This means that for each complete turn of the initial 17-tooth gear in the motor axle, the corresponding 58-tooth gear in the sixth last stage turns about 0.0634% of a full rotation, significantly reducing the speed and increasing the torque at the output of the final stage compared to the input at the first stage.

 

The TT motor turns at roughly 60 rotations per minute. As the gear wheels transfer rotation through each step, the last axle seems almost to remain motionless.

 

This educational toy is made of STEMFIE components; therefore, it is modular and can be expanded. If you 3D-print more parts, how many more gear wheel reductions can you make by extending the main beam?

 

⚠️ Please be cautious when using this toy with mechanical gearwheels, as there is a risk of pinching fingers or catching clothes and hair in the mechanism. Ensure you can quickly disconnect the USB power to the motor if necessary.

Tools for assembly

For assembling this project, you need an H1.5 mm Allen key for screwing the BT2 screws securing the tip of the TT Motor and the printed part on the TT Motor's axle. You will also need the STEMFIE nut and screwdriver, which you can download and print in 3D using this link.

Blender scene file

To facilitate the assembly of this project, please download the provided Blender scene file. With it, you can navigate and easily view this project in 3D. Blender is an open-source 3D software you can download from Blender.org.

Video


Documentation (1)

Other Files (1)
Project - SPS-000006 - Infinity Gears (stemfie.org)_f0d0ce22-7e8a-4b0b-b573-6fe6f55fb74e.pdf

Bill of Materials

List other parts
An H1.5 mm Allen key for screwing the BT2 screws securing the tip of the TT Motor and the printed part on the TT Motor's axle.

Purchase from Bambu Store

Comment & Rating (5)

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Nice project. I had a couple of small issues. Firstly, the shoulder bolt holding the long beam onto the motor bracket seems to be a size too long and ended up stopping before fully screwed in. I'm not sure if it was being blocked by the motor or if the thread was bottoming out on the shoulder. Secondly there is one less of the taller spacers in the 3MF than shown in the PDF. I just left the spacer off the third reduction gear shaft so it matches the final gear shaft. Will probably print two more so they all look fully dressed ;p. Also the description mentions a Blender scene, but I presume it means the PDF rendered from the Blender scene.
The designer has replied
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Hi @carl.olsson :) I'm delighted that you enjoy this STEMFIE project! 😃 Thank you for posting the image and for your valuable feedback. The shoulder screw should measure two block units in length, which means that it should pass through two beams, and then, roughly 5 mm of thread should extend outside. It could be so that the internal thread of the motor bracket is a bit blocked. Sometimes I work the threads a few times before it gets easier to screw it the full length of the screw. I have updated the 3MF file now. Thank you for noticing the missing spacer. It is not clear where to find the Blender file. Click the green "Download or print" button and choose "Download STL" to find the Blender file. BTW, I love the motion blur effect in your STEMFIE Infinity Gears project photo. :-) Cheers, Paulo
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Replying to @Stemfie3D :
Another thought: I managed to painfully pinch my fingers while trying to manually back drive the gears. I figure a little bit of a bevel on the gear edges could reduce the chances of that (given it's intended for children, not just childish adults :p) and could also reduce the likelihood of close stacked gears interfering.
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Replying to @carl.olsson :
Thank you for this feedback, Carl. :) I have also noticed this issue and will improve the shape of the STEMFIE gearwheels. I have experienced similar pinching issues while playing with LEGO Technic. I will immediately make a note about this in the model description.
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