Steven Mosbrucker

i will have to run calculations on the internal stresses involved with plastic blades and if they will survive the abuse. With let alone shredding plastic bottles.

Yea the best weight would be to use a pipe of some kind. One of my side passions is cars. I have been thinking about making a inertia dyno where you detect the rpm of the rollers and the change of rpm and the duration. Knowing these nad the polar moment of inertia of the whole system will tell you the cars hp.

Anyways at my local metal supplier…[Read more]

woops read months and day backwards so it was less than 2 years ago.

o man i talk about this 2.5 years ago. i will look back at the calculations.

Check out my calculations for shredder section.

I made a acrylic shredder concept of my metal shredder. It was glued together. I could shred like 1 sheet of newspaper with 2 n shreds it would pop the glue off the sides.

naw thats fine ppboys i look at cad drawings all day at work. It is good enough to make a rough estimate but usually you need both “blades” in the case of this design it uses stationary blades. It would be nice to see where those blades are relative to the rotating blades in the assembly.

Well for the hell of it lets say you have a 28mm cross section circular bar of HDPE that fits exactly in that scoop of the blade. That fits in that hook of that blade. First determine that area .014m * .014m * 3.14 = .00061544 m^3. ok and again lets say we are shredding HDPE. Lets say the 3500 PSI for HDPE Shear Stress just like i said in first…[Read more]

ok i will perform calculations tomorrow morning. I go through forms once a week. so sorry about the wait.

I have a couple ways of calculating the torque needed on my calculation post.

I am working on my V2 of my filament extruder dubbed the FilaFactory. But i need to go to market with my shredder in a couple weeks first before i can continue working on it

2Hp at 30RPM should be more than enough to tear apart any 3d printed parts.

Hopefully you dont get to the point of taking a plastic to its melting point where heat of fusion comes into play. Basically what heat of fusion is is at this point the plastic does not change temperature but changes state from solid to liquid. You just want to find the temperature that with a specific extrusion speed will take the plastic right…[Read more]

Ok so i had one question asked. How do you calculate the area for a bottle. i have a image that i made for that there is a average amount for calculation. basically you want to take this length that is in black which is where the blades pinch and the furthest down a water bottle can go (i suggest crushing bottles before putting them into…[Read more]

https://youtu.be/LJ9OspwEA5A
Above is the video i made about shear stress hopefully that helps.

I replied inside my original post that you read the calculations required for shredder. I will make a video to explain but the blade thickness has nothing to do with the calculations. Check out my reply ask me any questions you have.

Hey guys I have been in and out of the forum. I am going to try to be around more often as I am trying to move into this space and away from my day job hopefully soon. So in shear mode of failure the thickness of blades makes no difference in the determination of the cut area. The thickness of the blades determines if the blades will survive the…[Read more]

Badass project guys.

So basicly these cross section are regardless of blade thickness. The cross section is with respect to the parrallel contact of the blade the cross section goes top to bottom not along material. Where blade thickness comes into play is the resistance to torsion at the hex/square shaft input.
My perticualr and precious plastics design has only 1…[Read more]

This is the correct link.
As long as you get it small enough it is not that much different. I will probubly have a different hopper as shavings dont really roll as well into barrel compared to the virgin resins. as the current hopper design is for pellets.