Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
The Regular Stuff: Chat, Buy, Sell, Off Topic, etc. => General Discussion - Model & Toy Steam Engines – Stirling Cycle – Flame Lickers – Small Antique Originals => Topic started by: SimpleyMake on July 13, 2022, 10:20:11 am
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A week before I was thinking of adding a new model to my 3d printed Stirling engine collection. Then I thought why don't we create a "Stirling engine car" with alpha mode configuration. Then I was like, no there are already many different stirling car models with alpha config. I was running Walking beam Stirling engine to pass time, that is when I got an idea of three things,
- The new model must be moving type
- Lot of moving/oscillating parts
- Should look different/weird/confusing/attractive to hobbyist as well as general public. Also must look big...
The below image is just the under development model, still lot more changes to be made. Final design will be updated once done. For now you can see the run video of developing model "Double beam Stirling car".
How long it took me to build this?
- 2 days of imaginary drawings
- 2 days of real time CAD drawing
- 2 days of 3d printing time
- 1 day to assemble/test/creative video of current model
Total it took me a week to build this. This build was interesting, challenging, scary (feared whether model can push itself or not) and thrilling.
What are the pending developments in this model?
- All the metal pins will be replaced with 3d printed plastic shaft
- Heat shield to cold junction
- Smooth out few frictional places
- Long connecting rods design will be changed
- Color combination is white, black and orange
Current model dimensions are: 22cm length * 10cm width * 33cm height
I hope you all like my new design and have a great time watching the run video below...
Run video (https://youtu.be/eHUH11DXMwc)
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An update on the model evolution:
So after trying out the first model in different surfaces, I thought of making few design modifications in the model.
- Initially the gear ratio was approx 1:2 but now I have increased the ratio to approx 1:11. This modification is made to make the model move more stable on uneven surfaces.
- Double beam reduced to singe beam. The long connecting rod with addition of beam for power piston looks visually good but the losses due to moving parts are notably big.
- Proper flywheel weight distribution design.
See the results in below video..
Only thing left is to add the heat shield which has been fabricated. It just needs to be attached.
https://youtu.be/y6AMk2llYzw
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A fun machine..!!!
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I rather liked the look of the double beam model, but function definitely takes precedent over appearance.
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I rather liked the look of the double beam model, but function definitely takes precedent over appearance.
Yeah even I liked the double beam configuration but due to some constraints on friction and length of connecting rod I was forced to change it.
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Another update on the development process.
Thought of creating a simple yet effective flame shield to prevent the flame exposure directly to plastic components,
For now,
- The Flame shield prevents approx 70% of the heat directly reaching plastic
- planned to flare the bottom end of shield for about 6 to 7mm so that 95% of flame heat can be trapped and also improves the hot junction thermal efficiency.
- Flame shield can be easily stretched and squeezed to match the displacer cylinder diameter. This makes easy for users to fit and remove it easily.
- Also the flame shield covers 10% of the spirit lamp head. In this way it may as well act as wind shield for the flame.
Now with the current flame shield I was able to run the model for more than 15 minutes without any damage to nearby plastic parts and also the water in the cold junction did not get hot at all, the temperature change in water was minimal. Good idication that the flame shield is executing its purpose...
Please take a look at below ijmages and video...
https://youtu.be/Cmh1cXYAgCM