Linear Actuator

[seandepagnier]

Any particular reason your using a 24v clutch?

Price, I can get one of these for $25 on eBay. Using a boost converter right now. It draws about 7.5 watts engaged including the boost converter.

7.5 watts is a huge amount of power just for a clutch.   The pi zero uses about 1 watt, and often the average motor consumption is less than this.    What about using a resistor and capacitor in series with the clutch?   This can limit the power it consumes (to hold) but still allow a larger current to lock.  The usual clutch current of raymarine drive is also around 6 watts so this is really a lot of power consumption.

If you are using a motor which can actually be driven from the L298N: "2) Large output current, the instantaneous peak current can be up to 3A"   it isn't enough for the motor.

Why do you have toothed pulleys and belts if you are using planetary gears?

Also, the cheap ballscrews on amazon may work but are usually 400 grade stainless which means they will rust a lot more than normal stainless.   I am not sure where to find 316 ballscrews, or other alloys though.   I think these ballscrews may work well if there is enough grease and they can stay covered.

I am still not sure which tillerpilot you want to replace...   The belowdecks units such as raymarine type 1 and 2 linear drives using ballscrews have a much larger brushed dc motor than what you selected.     This is a much more powerful and efficient motor.   It uses something like a 3.5:1 reduction from this motor using a toothed belt to the ballscrew and magnetic clutch.   In raymarine units,  these toothed pulleys wear out especially if the autopilot is stressed a lot and eventually this belt skips which acclerates the wear of the toothed pulleys.   I would consider this and either use hdt5m belts at least 15mm wide, gearbox which is rated for 4x the torque you will ever drive it, or have the magnetic or other clutch capable to slip before the the gearbox or belt would.