I just started to work on a shredder that has been built by my predecessor and has some serious design flaws. I’m doing my swiss civil service in indonesia on a organic farm/education center for organic agriculture. There are plans to implement a recycling strategy to put all the plastic waste (which is abundant in indonesia) to new use. My background is civil engineering so I don’t really have the knowledge to build machines but I hope with a little bit of help of you and some research it will be enough to get the shredder working. (We also have a finished compression oven which is working and waiting for shredded plastic)
So basically there is no money available for the project. Everything had to be as cheap as possible. However they did spend money on the motor and the laser cut parts. What they didn’t really plan through was the gear box/speed remover. The Motor has 1.5hp and 1450 rpm. They put in two v-belts each with a 1:5 ratio resulting in a 1:25 reduction. Now the problem is pretty obvious. While the v-belt reduces the speed to the right rpm it does not deliver any torque. It’s just enough to shred though some soft pet. But it clogs right away once it reaches harder parts like the top of the bottle. The small wheel of the speed reducer is spinning through since the friction of the v-belt is just not enough.
Now I was thinking about how to fix this. The most important thing is cost. I could buy a WPA 80 1:20 gearbox in Jakarta for 1Mio RP (ca. 60 euro) but this is already considered really expensive and also I would have to make a lot of changes to the current design of the frame. So I was thinking about maybe exchanging the two v-belts with motorcycle chains. These should be readily available and fairly cheap around here. I’m not sure if I find the right size of sprockets around here and how to attack them to the motor and shredder but I’m sure I could wing this somehow.
Does anyone of you have experience with something like that? Do you think it could work or is it just a waste of time and money and we should just invest in the more expensive gearbox?
Here are some pictures of the shredder: