Help with designing and making a pneumatic tube transport system?

[dan_e]

So for YEARS I've been wanting to build a pneumatic tube system for my place of work. We have a 'need' to transport small fairly light packages from point A upstairs to point B downstairs (and back again). What we don't have is a budget! And besides, a huge part of the fun for me would be building it. Now for most sorts of things like this, like leatherwork, 3D printing, arduino stuff, there are communities online; forums and facebook groups that kind of thing where you can 'stand on the shoulders of giants' and ask questions, see builds, etc etc etc.
For this, besides the odd exception (German chaos computer club), (Lawless Hardware), (New-Mattic transport), (Tooth Fairy transport), (Pneumatic Beer Delivery), there's very little information online about how to actually go about building these. What works, what doesn't. What's needed. I also can't find any of the materials/products like the capsules themselves available to buy online here in the UK. I'd LOVE to use clear tubing like here but I suspect that's going to be out of my price range given the 68mm I.D. 75mm O.D tubing I've found online is a whopping £165 per 5m length!!!
I've approached a few of the commercial companies but understandably they've poured scorn on my idea to use "shop vacs" in the US parlance at either end of my point to point system, saying it "wont' work". However, clearly, they do. Given that the tooth fairy system above uses just one 'shop vac' (and valves) to accomplish what it does, and amazingly, the German system seems to do AMAZINGLY with just one vacuum. At least, I think it's a vacuum, the videos seem to either contradict each other or the system evolves between videos. Here for example it seems some sort of compressive air is used BEHIND the capsule whereas here it's a vacuum from obviously in FRONT of the capsule. I suppose they could be doing both for the longer runs. They seem to get astonishing results! Here, for example, the thing is going round the outside of a building at speed. There are other clips showing extremely long runs.
This kind of method of sending would be ideal but obviously it won't work for receiving as we don't want the capsules to just 'drop'...so a station like this seems more likely which seems to handle sending and receiving in one.
Any help much appreciated! I've tried reaching out to pretty much all the people in the videos above, and heard back from none, bar the commercial companies. Who are perfectly lovely people but want to sell their commercial offering which I can't afford. Plus I want to DIY this thing!
Thank you

[jboggs]

Since you're wanting to DIY this thing, and you're not sure what technology to use or even where to start, I would suggest you use the engineering approach. Try to identify the 3 or 4 main key issues that must be resolved, come up with a design approach for each of them that feels like it might work, and build a prototype to test it. The purpose of the prototype isn't to show what the larger system will look like. Its only purpose is to answer one basic question about one of the key issues. Example: How much air at what pressure will be required to move a capsule along a length of tube? How closely will the capsule have to fit the ID of the tube? How sharp a corner will it go around? I could go on and on, and you could build a prototype to answer each question.