Auto pump plans

[FLAK2187]

Anyone have diy plans for an automatic pump? Preferably one that can cycle pressures.

[AndyJ]

Well, frack! I was searching "electric pump" on this subforum, not the ball forum. I'll head over there. Got any favorite threads to point us to?

I sketched out an Arduino-based pump controller a couple of months ago and ordered all the parts; everything showed up but the electrically-controlled valve. I've ordered two more valves from different sources, but one went to back order and the other is coming from overseas by rowboat, I guess.

You can use a controlled air leak instead of a valve, but I figured if I half-assed the project I'd never get around to re-doing it the right way.

I'm doing my own because I want a cycle that varies from very low to low vacuum to avoid circulation problems with long pumping times, and that will automatically turn off after a preset time, so I can just put it on and go to sleep. I'm trying to stretch some tight scars out; despite the claims, scar tissue *will* stretch, it's just painful and time-consuming. I'm making very good progress with the hand pump, but it's really boring...

[AndyJ]

I have an Arduino Uno and a relay board; the pump is 12v and the valves are 3, 5, or 12v, depending on which one comes in first. I have a box with a 25-year collection of wall warts, so whatever voltages I need, I'm pretty sure I have a wall wart to match. Might have to dedicate a power strip to them, though. A BMP280 pressure sensor and an I2C digital display so I can scroll through the programs. You run out of IO pins real quick!

Sounds like we're working from the same basic parts; I expect our devices will be similar. I hope yours turns out excellent so I can steal all your good ideas. <grin>

I'll check out the threads, thanks.

The Plan So Far is to create pumping files on the desktop; high and low pressures, ramp rate, frequency, and length of session, and download those to the Arduino. Then scroll through with the display to pick one. One button for Cycle Start, one for manual run (to get the cylinder comfortably fit; I have trouble with that sometimes), one for vacuum bleed. (with a needle valve in the dump line to control the dump rate) One button for Trim; hold that down, hit Cycle Start or Bleed to trim the whole program for higher or lower vacuum. Use the power strip switch to turn the rig on and off, so all the wall warts go offline too.

[AndyJ]

I'm a software guy, not a hardware guy. I had no idea about current draw, etc. Plus the relay board was cheap and the wall warts were free. Someone with even a rudimentary knowledge of electronics can surely do a better job of things. I'll get it to work even if it gives the EEs the twitchies.

[FLAK2187]

I found my wife's breast pump and just gave it a try; It might work if i can figure out a way to modify it some. I tried it with a glass vase and my usual tubing. It created a suck, although not a strong one, but it doesn't build up pressure so it just releases all pressure. I think it might work if I can use my hand gauge to create pressure then attach the breast pump to cycle already at the desired pressure; this means I can only do cock and not full package though.

[AndyJ]

Tee in a hand pump so you can get enough vacuum to make the seal, then turn the breast pump on?

[SFBallpumper]

I use a breast pump, but I added a check valve to it. It’s made for aquariums. It was around $4. The Top Fin brand has been more durable than others. The check valve made all the difference for me. Just make sure that the end that’s labeled “out” is pointed towards the tubing that goes into the pump.

[AndyJ]

it must be a conspiracy, because the solenoid valves are what is taking forever

I'm getting impatient. What do you think about using a fixed air bleed and PWMing the pump, or just blipping it on and off to keep the vacuum within a narrow range?

You couldn't do vacuum dumps, and the pump would run a lot, but the solenoid valve could be added later.

[AndyJ]

If your valves showed up, mine might be coming soon! Probably all in the same shipment...

edit: nope, nothing new on the tracking pages. I ordered a "US inventory" one that's supposed to be here on the 17th. We'll see...

[AndyJ]

The "US inventory" valve still hasn't shown up, but one of the Chinese ones did. The vendor apparently didn't know the difference between "tube" (measured on the outside) and "pipe" (measured on the inside). The nipples on the valve are about 3mm, and the bore looks to be about .75mm. While it would technically work, it would be more of a controlled leak than what I wanted.

I ordered a Parker "fast response" 1/4 NPT valve, 12v. It'll probably sound like maracas when doing stepped pulls...