I figure someone here might know the answer. I think I know but I'm not sure . I'm tinkering with a small vacuum forming machine I built to make a few parts from various types of plastic. I've had some success with some parts using just a regular shop vac to pull the vacuum , but I'm wanting to ramp up the amount of vacuum I can pull. I know there are industrial pumps I can buy , but this is just a cheap project and I don't wanna dump a bunch of money into it. Would hooking up two shop vacs increase the vacuum I'm pulling or would the vacuum I'm pulling be limited to whatever vacuum level the biggest one could pull? I think it would just remove the air faster but it wouldn't double the force or anything . It would still be limited by the power of the biggest vacuum I'm using.
Your assumption is correct. It would just suck up the air faster. However, from my limited experience with vacuum forming plastic parts, the speed at which you can remove the air matters more than the actual pressure. Not sure what kind of parts you're making and out of what material, but the stuff I've worked with was making some dome-like parts that started out from clear plastic sheets (not sure on the actual polymer off the top of my head), which we heated up in an oven, then we quickly put them in the mold we made and formed it in place using a shop vac. Worked pretty well once we figured out the technique. But speed was key. Only had a few seconds from taking the sheets out of the oven to getting the part formed. Just make sure your mold is sealed as good as possible.
Thanks for the reply Right now I'm just playing around making some Mag holders and a competition holster for myself to use while shooting 3Gun. I've had success using Kydex , ABS and Lexan just playing around to see what I can do. I'm wanting more definition and somewhat sharper corners when I mold it. I realize there are limitations but ive seen parts vacuum formed that have way more definition than what I'm able to do.
All you need it a vacuum pump. https://www.harborfreight.com/25-cfm-vacuum-pump-98076.html And an air tank. https://www.harborfreight.com/5-gallon-portable-air-tank-65594.html Create a vacuum in the tank then use a ball valve to release it to the vacuum table when you have full vacuum on the tank. I've used this setup before with good success. You just have to time the release for when the plastic is draped over the mold and "has a seal."
If you have an air compressor you could use this to pull a vacuum instead of the electric one ^ https://www.harborfreight.com/air-vacuum-pump-with-r134a-and-r12-connectors-96677.html
