A vacuum engine

While having a tidy up today I came across an old Model Engineer plan for a vacuum engine. Designed by Jan Ridders of the Netherlands. It was free in issue 4323.

It looks relatively easy to machine, it's a nice small size and I've not made a vacuum engine before so I thought why not give it a go!

Has anyone made this model?

IanJ

Yes I’ve built one of Jan Ridders Vacuum engines. I think it was that one? I simplified the design a bit to make the build easier. Many people build these engines and never get them to run, so be warned! I’ve had mine running only twice for about 10 minutes each time. If I was to build another I’d try his vertical “”Marc” model as I suspect that may run better? I’ll try and find a picture of mine.

Edited By Vic on 24/09/2020 20:27:36

Lots of info on Jan’s engines.

Here

Thanks for the link Vic some interesting stuff there. That's a nice little engine, but only run for a few minutes! maybe that's why the plans were free? But I'll probably go with the plans I have and see how it goes.

IanJ

Ian if you get this made and it won't go on meths , then try a gas flame , I made a similar engine and turns out it will only run on gas but at least it runs, but hopefully yours will run on meths

I made two of these and got them both working , the problem I found is that it called for cast iron cylinder and piston. With the condensation caused in mine it stopped and when left rust deposits in the cylinder so would not work. I used a stainless steel liner and brass piston and worked for 10 seconds or so.

Bob

I admit to being a Jan Fan, but I doubt the trouble is with his plans. Jan's published many interesting engines, and some of them are difficult. For example, my first attempt at his Coffee-cup Stirling didn't work until I'd fixed all the tiny leaks and reduced friction at all points to the minimum. As built the engine didn't run, several hours later it did. Same design, same parts, but everything freed-up, flywheel balanced and the timing adjusted. Initially reluctant to start with run times in minutes, now it runs on an electric element for hours on end.

I noticed, in the failed state, that brass parts corroded, cause unknown, maybe heat, condensation and oil coupled with acid fumes from the sealant. The problem disappeared after the engine ran properly. Delicate engines may need repeated cleaning in the early stages: apart from debris due to machining and parts wearing in, if they're not working properly oil gums up, liquid collects etc etc.

Also a fan of Stewart Hart's Potty Mill engine. It's much less fussy and you can squirt high-pressure air into it. Provided the timing is right, and the parts turn freely, even a high-friction build will run. I found it a good balance of challenges. Made me think but none of it was too hard for this beginner.

Dave

Mmmm sounds like a challenge to make it go! But as usual we have some good advice on here thanks. I've not used meths for years, last time was in a Mamod engine, nearly burnt the kitchen down! So meths it is then!

I'll start by gathering together the metal, should have enough bits in the offcut bin.

I'll have a cup of tea, think of some ornate artistic design for the feet and plinth and fire up the KX1 (it's been idle for a while now) and see which parts I can make by CNC or manual machines. Should keep me occupied over winter.

IanJ

Ordinary methylated spirits doesn’t seem to burn hot enough but I was lucky enough to get a small bottle of 99% industrial methylated spirits from work. Glass fibre wicks seem to work best as well.

If you look online there are a number of build logs for vacuum engines including the Jan Ridders internal valve type. You may need to use “Flame Eater” or Flame Licker” in your search bar to find them though. Here’s a random one to start.

Flame Eater

" maybe that's why the plans were free? "

Think you'll find that many if not all of Jan's' plans are free, Look on his site to see most running.

Regards Ian.

Jan will normally send a maximum of 2 free plans if you email him. There were at some point more than a few legitimate copies of his plans available online so I collected some.

Video of my effort here. Runs quite well on simple meths burner. Adjustment of flame position is a bit finicky:-

John

Thanks John your video shows off the model nicely, and it works quite well, I didn't realise the wick needs to be so close to the cylinder.

IanJ

Basically the wick needs to touch the flat part of the cylinder next to the slot. The flame needs to be quite large. I think I made mine from an early drawing, I believe Jan has revised the drawing a little and made the cylinder bore larger. Worth getting the latest version from his site.

Good luck with the build.

John

There are some pretty snazzy spirit burner kits out there as well.

**LINK**

Interesting to see the position of the wick on Johns video, my plan had the wick straight up so a gap from wick to cylinder. I going to dig mine out of the shed in the morning and get it going. I remember I rubbed soft graphite pencil in the cylinder for lubrication.

Bob