Homemade Vacuum Cylinder

Years ago I ordered a one size fits all pumpset which turned out had an even bigger cylinder than described. It required a rubber sleeve at the bottom to get a seal without sucking my balls in. The handpump that came with it was lousy and was the first to go. I switched to mouth suction and added a valve from a hand soap dispenser. I hooked up a big vacuum meter which made the whole setup even clumsier.

I just wanted a simple practical setup so 2 years ago I bought a plexiglass cylinder and some flat offcuts. Last week I finally put it together which was actually even easier than I thought.

Materials used:
Tubing (carshop)
Plexiglass cylinder 60x56mm 50cm (€10.96 @ plastic shop)
Plexiglass offcuts 1kg (€8.33 @ plastic shop)
2-part epoxyglue (DIY shop)
Valve (bicycle inner tire)

I cut the plexiglass disc with a scrollsaw using a jigsaw blade, drilled a hole through it and expanded the hole to fit the valve with sandpaper rolled around a drill bit. I cut the cylinder to size with a saw (Ryoba), lapped both ends and beveled the bottom rim. Then I sanded the bottom of the disc to give the epoxy a bitter grip, glued in the valve and glued the disc with valve ontop of the cylinder.

It works great although I may have made it a bit too long, but I can always shorten it if I want to.

P.s. the plastic shop actually gave me about 2kg of offcuts and I’ve used half of it for other little projects :)

Interesting. How thick is the wall of the cylinder?

Very nice. You could go into the cylinder making business. The end that seals against your body looks a little sharp though. Maybe you could cut out a flared end piece and glue that on.

The wall is 2mm thick. After lapping the end was pretty sharp but after sanding the edges of the rim with 150grit and 240 grit it was left smooth enough. I may round the entire rim to make it a bit a smoother.

Perhaps adding 2mm would make it more comfortable without losing much of the seal which is great at the moment, no need for lubricant. It’s just fine as it is but I’ll think about it.

I have thought of making some for friends but I would need a cheap source for good valves.

That’s a great setup, you might think of picking up “plastic dip” from a hardware store, this is the rubberized stuff you see on tools, I used it on my tube, dipped it three times and it’s a nice finish

Warm the bottom up and bend it into a flare.

Yeah the plastic dip works very well, especially if the tube is a little big, keeps the skin from getting sucked up too.

That is a good idea, but the technique might require some practice on some spare tubing before trying it out on your finished cylinder.

True.

Thank you Piet for your interesting and informative post. The part about using the valve from a hand soap dispenser grabbed my attention. Could you please tell us some more details about that too, thanks.

Here are old pictures of the dispenser valve and my previous setup. The dispenser valve leaked a little bit so I used a rubber lid to close off the tubing.

This time around I’m trying to prevent red dots which requires me to keep the vacuum low. Hence I’m not missing the meter, but it’s there if I need it.

Thankyou Piet, I see now what part of the valve and how you had used it.

What did you think was the cause of the small leak from this valve?

Do you think lubricating the valve with something like silicone grease or similar would reduce leakage?

The bicycle valve has to be much better, I would imagine.

The soap dispenser valve is plastic on plastic and meant for soap, it’s not air tight. It only leaked at a slow pace though, there was plenty of time to put on the lid, some kind of plug would work too. Lubrication might keep it air tight during a session.

The bicycle valve works perfect especially in combination with the tubing used. I should look for a source for these valves. Not all bicycle valves work, I have a couple that require depressing by a bicycle pump mouth piece before they allow airflow. That end would be inside the cylinder which makes those valves useless. The valve used is called a Dutch Valve (Hollands Ventiel).

It’s a pity the valve from the soap dispenser is not better at holding air.

I had this funny idea that, on rubbish collection day, you could just walk up and down the street and pick out various “bits” from all the recyclable waste. Then you’d come back with most all the parts needed for a basic disposable pumping setup. The valve from the soap dispenser could have been an important component, had it been better sealing. Oh well…

You could step into a bicycle repair shop and ask for valves from old tires. They’re also called Dunlop valve, Woods valve and English valve.

I shortened my cylinder a bit and it’s still working great.