Using flexures and camshafts for some homemade hydroponics valves

[@crispychicken7933]

Great video, thanks for keeping it dense and not drawing it out to a 20 minute like everyone else

[@TheGlitchyCorgi]

I'd recommend switching to a groove cam disk. You're flexures will be spending the bulk of their time in the pre-load configuration so you'll be getting creep over time. You can leave the rest of the design almost exactly the same and just make the cam disk sit all the way over the bearings and even take advantage of the too-small range of motion as you'll want a dead-position where no cam followers are being depressed to make assembly easier.

[@wildgophers91]

This is awesome! I'd love to see more about your hydroponics projects!

[@matthewmcconnell9011]

Really nice. Might have to use something like this when I get my hydro garden up

[@Personnenenparle]

I made something similar last year, and then i found some small selenoid valves that work perfectly for that. They are pretty cheap and should work great for nutrients. On aliexpress they are called "DC 4.5V 6V 12V 24V Small Mini Water Valve Electromagnetic Solenoid Valve Normally Closed N/C Water Flow Control Valve" Pretty cheap and plugged in the right directio, you wont have any leak. Also, the valve chamber is all plastic, so no corrosion

[@ІгорАлієв]

Great work. I saw syringe+screw+stepper combination for dosing liquids. Add 2 checkvalves and 1 endswitch for initial position and you have ready product. Washing machine solenoids or solenoid valves from ali as suggested by someone in comments are also an option. It is price and reliability, that determine the best option.

[@user-vi8br8dk2r]

You should consider a sailing winch servo. These servos have 720 degrees but are simpler to operate as a stepper motor

[@vornamenachname8001]

I 3d printed something very similiar and decided to have one central cam disk with the hoses arranged in a circle around the disk (the hoses are parallel to the axis of rotation) this way the forces of the squished hoses cancel each other out. I use 8mm OD silicone hose with 1mm wall thickness and a nema 17 stepper motor the whole assembly for 8 hoses has a radius of 75mm and a height of 65mm with the stepper motor included. the stepper motor has plenty of torque and a "pancake" stepper motor could propably be used. instead of flextures i use "pins" that just slide radially between the cam and the hoses and are otherwise constrained. the hose end of the pins is shaped so that the hose is piched only on a small section of 1mm. the only hardware used are 12 M3 screws and 8 heatstake inserts, the stepper motor and a 16 tooth gt2 belt pulley that ise used as an interface between the cam and the motor shaft.

[@BenKoren]

Very cool.

[@tylermiller9356]

Great idea, simple and effective. Just a thought if you use negative materials and keep the same geometry on the area where the value contacts the hose it would allow the supply flow to be supplied or restrictive better while using less force on your components.

[@MiTheMer]

Really fascinating!

[@HMBM-7777th]

Nice!

[@TheEngineerC]

Don't use a stepper motor, use a dc motor with worm gear (eliminates backdriveability and adds a lot of torque at low cost), also add a potentiometer to the cam. The driver board can be a simple h bridge with a microcontroller that reads the potentiometer position. (Also BTW a stepper motor driver can also be used to drive DC motors). Next setup a simple protocol to control the device via serial. something like a ;;. This will allow you to connect all your valves and pumps to a single serial bus (daisychain wiring). This will give you a near identical setup to one of those serial smart servos like dynamixel.

[@stefanguiton]

Great video!

[@PhantomUnboxing]

Yo this is amazing

[@KarlMiller]

Great work... I haven't seen your other videos, so I am not getting the reason for this design over a bank of small solenoid valves? Don't you get leakage from all the channels between the starting and selected channel when actuating the servo?... or is the pump turned off when changing channels?