Make a Toy Piston: Find Solution to Inner Can Size Issue

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Discussion Overview

The discussion revolves around the construction of a simple piston using cans, focusing on the size requirements for the inner can to ensure proper sliding. Participants explore the purpose of the piston, potential materials, and the mechanics of creating a vacuum within the piston assembly.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification, Debate/contested

Main Points Raised

  • One participant proposes using two cans, emphasizing that the inner can must be significantly smaller in diameter than the outer can for effective sliding.
  • Another participant questions the choice of using standard coke cans due to their lack of strength and suggests considering narrower cans for better rigidity.
  • There is a discussion about the purpose of the piston, which is to demonstrate the creation of a vacuum when the top can is sealed, and how pulling down on the piston affects air pressure.
  • One participant clarifies that the vacuum is created in the space between the top of the sliding piston and the top of the bore, not inside the piston itself.
  • A question is raised about the terminology, specifically whether "cylinder" and "bore" refer to the same concept in this context.

Areas of Agreement / Disagreement

Participants express differing views on the materials and design of the piston, indicating that multiple competing ideas remain unresolved regarding the best approach to achieve the desired functionality.

Contextual Notes

There are assumptions about the strength and rigidity of different can types, as well as the definitions of terms like "cylinder" and "bore," which remain unclear and may affect the discussion.

Who May Find This Useful

Individuals interested in DIY projects, physics demonstrations, or those exploring vacuum mechanics may find this discussion relevant.

Althepump
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I would like to make a simple piston from cans. Two cans. The problem is the inner can has to be thousands of an inch smaller (diameter) from the exterior for better sliding. Solution? Add a ring would not help much unless both are within a fraction of an inch.
 
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When you say cans, do you mean normal coke cans? What the purpose behind making the piston? Normal coke cans don't have much strength.

If you could use a narrower can like one of the coffee drinks or something like that, those cans I think might give you a bit more rigidity for the cylinder. The piston itself could be molded from epoxy putty. Look for a video on youtube about using epoxy putty to make pistons.
 
The purpose of making a piston is to demonstrate that it can create vacuum inside piston when pulling down providing its top can is Sealed. Also, show If not sealed, pulling will be no problem because of surrounding air pressure around it is in equilibrium.

I will look for epoxy putty on a video. I hope it can show the demo.
 
Vacuum inside piston?
You mean a cylinder with sliding piston, maybe?
 
Between the top of cylinder (piston) and the top of the bore. As the piston slides down, the space creates between the top of the sliding piston and the top of bore. It cannot be inside the piston; all solid like epoxy putty. I just saw the video.
 
Is cylinder a bore?
 

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