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Mechanical engineering uni project (slrpnk.net)

submitted 1 month ago by [email protected] to c/[email protected]

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I'm a mechanical engineering student with a fairly open brief for a short project. Have to draw a 3D cad model of a mechanism and do some motion analysis. So i thought i'd ask the fine folk of slrpnk if they had any projects that need a bit of ironing out.

Probably best suited if you have an idea and want see how the parts might move in 3 dimensions. I'd be able to tell you stuff like how much force/torque is in a particular part, letting you know how strong bits need to be.

Has to be a mechanism of some sort that i draw from scratch - let me know what dimensions i need to accomodate. And i have to present it to the class.

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[–] [email protected] 3 points 1 month ago (3 children)

For work in Malawi I am thinking of introducing a bricket press to make brickets from biomass. One person must pull a lever and a piston is pressing biomass into a cylinder and compresses it. The end of the stroke should be stronger and less fast. And with returning of the lever the pressed bricket or pellet is pushed out and new biomass is inserted. It can be an interesting design from scratch and nice context? It would be challenging to make it convenient for the person while large pressing forces are reached (5000n)

[–] [email protected] 2 points 1 month ago (2 children)

I think I'll see what I can do with this, Does something like this look suitable? From my back-of-envelope calculations, this gives 17000N force (about 1750kg-force like they've said).

And then the challenge is to release the pellet, and refill from a hopper containing more biomass material. Can you tell me what biomass material you would be using?

[–] [email protected] 2 points 1 month ago

A cool. That is a known wide spread design. This is a very high force, I'm impressed. But it will come at a cost of displacement correct? We aim to make brickets for cooking fuels and we have a lot of groundnut shells. These groundnut or peanut shells have a a lot lignin so it is possible with wetted mass (softening)and perhaps heating with fire (lignine becomes like a glue at 200degC). After that the brickets are sundried. The bricket shape could be like icehocky pucks or at least the shape to cook with.

I think the wooden design is not that interesting to generate, but with a pellet release and refilling in one lever go (or two steps). That would be an interesting puzzle, yes?

[–] [email protected] 1 points 1 month ago

Only I would expect the design would not be 3 dimensions as you asked but mostly all forces in one plane 😁