[ShelaVenna]

The level of suction is important but it’s not as important as a sensor. If your pump just pumps continuously, the pressure will increase continuously. Maybe there’s a theoretical maximum I don’t know about because I’m absolutely not a physicist or an engineer, but I know for a fact that any vacuum pump, no matter how weak, will eventually create pressure far outside the safe zone if it pumps continuously without releasing. You need a “smart” pump, meaning a pump with a sensor that will tell it to turn off when the pressure rises above the target range, and back on again when it drops below the target range. There are a few people who made their own programmable smart pumps, but I’ll be honest, I found them on penis pumping forums back when I tried looking into this a long, long, time ago. I don’t have a penis, but I figured that wasn’t relevant lol. I have no idea where to find those posts now, and I don’t think I ever found an actual guide about how to build one. I quickly realized it was probably too difficult a project for someone with absolutely no experience with building electronics. If you think you can figure out how to build one, there may be some kind of guide out there, probably buried deep in a penis pumping forum’s archives, so you’ll have to swim through a sea of dick pics to get to it. On the other hand, James98, who is already in this thread, has built at least 2 smart breast pumps. I have a feeling the reason he’s never posted a guide is because it’s very complicated and would lead to a flood of questions from people who have never even used a power tool. I don’t wanna speak for him though, let alone volunteer him to do anything he didn’t agree to. 

I forgot to mention that you can safely use a pump that has no sensor, as long as it continuously turns on and off in short bursts, and has a very low pressure setting. Nursing pumps work this way, but they’re not designed to run continuously for hours. There may be a way to get around that limitation and force a nursing pump to run for much longer periods, hopefully without causing the machine to seriously overheat, but I have no idea.

Btw, I’m assuming you already read that a wound vac can be used, and you’re just looking for a cheaper alternative. If not, go to the thread called “Evebra finally available”, and check out the wound vac mentioned there. Not all wound vacs will work for our purposes, but that one will, and it’s apparently a pretty damn sturdy workhorse. People who have used it seem to love it. It’s called the Deroyal Pro II, and there should be some available on Ebay. Don’t feel bad about haggling with the seller a little, within reason, and keep in mind that a lot of sellers will send you a discount if you wishlist an item but don’t immediately purchase. I haven’t tried the Deroyal pump myself because I already own an ancient Brava smartbox pump. They’re basically impossible to find nowadays. I lucked out and bought what was probably one of the last ones ever posted online. I personally wouldn’t even bother trying to find another, but I guess it wouldn’t hurt to try, just don’t hold your breath.