Shredder Drive

Calculations

• Largest force comparison- 15,000 in lb or 173 kg m. (1730 Nm) for the 45.6 Cu In Hydraulic Motor that we use in LifeTrac

Shredding Rate

• Precious plastic shredder - what is shredding rate of precious plastic shredder? 3kw, 50kg/hr. [1]
• By comparison, we have 5W steppers. Minebea_Stepper_Motor_Specs
• This allows us for 3000/5=600x less throughput. This means that for 12 hour run time, we get 1 kg of shred.
• This is minimal, but doable for production or 2 filament spools/day. This means. $1200 revenue/month if selling spools at $20/spool.
• This is a mere 5W. Use 100W - and get 10x-20x the production rate - of 20-40 spools/day. That is a potential business.

First Order Shaft Torque Calculations

• 1" shafts made of mild steel would break at 3000 ft lb of torque (ref?)
• Minimum torque requirement 200 ft lb, or 28 kg m. This is 1/6 the strongest motor.
• Precious Plastic Shredder calls for 3 kg m from [[Lyman_Filament_Maker_Calculations#More]. But that is old - and apparently not enough. The PP Pro shredder calls for 100 kg-m torque.

Motor Torque

• Motor Torque Calculator says about 1 kg m for 3000 rpm with 3kW drive as in Treadmill Motor. Compare to 173 kg m for strongest torque relevant to tractor drive as in 15000 In Lb Motors.
• Our goal is in between for now, 30 kg m. Reduction of only 30x to 100 RPM.

Geardown

Belt Geardown

• Serpentine belt on D=1.3" shaft of Treadmill Motor

Gears

Planetary Gears

• Planetary Gearbox

Motor Choices

Try a treadmill motor (3kW) and a drill motor (100W).

• Brushed motor is 75-80% efficient. [2]
• We can try a small DC motor, 30W. This yields a theoretical 12 kg per 12 hour day grind rate, which is just about correct. [3]
• Ex. JYCRS390H - [4]. Not 30W. Appears to be 5W - [5]

See Motor Selection Criteria

Internal Links

• Precious Plastic Shredder
• Open Source Shredder