New Creative DIY MIA Trike-A-Sail (TM) Prototype using Steel Telescopic Square Tubing and Tyvek

This is the start of my DIY full scale MIA Trike-A-Sail(TM). It is a creative build, first full size prototype, using steel perforated telescopic square tubing for the frame and Tyvek house wrap for the sail. These are materials I had readily, at hand, from other projects, and decided to use them to prototype the build. What is great about the perforated square telescopic tubing is that I can bolt easily brackets and make distance adjustments easily. Eventually, I will refine both the trike and sail and will be making a new trike, welded, and a new sail with Dacron, Mylar and Rip Stop.

The trike is, what I am calling, a micro trike, because of the wheel diameter size and compact design. It is pretty straight forward a T base with tubing for triangulation bracing for the axle to base and mast sections. The wheels are from Harbor Freight here in the USA, Arizona. Rear ones are 10" diameter and the front one is 8" diameter, they are the ones with the galvanized shiny rims and the only way HF sells these in these sizes and finish are as "Caster" assemblies for about $13 each. I removed the caster brackets for the rear ones, which are rigid, but left the front wheel with the swivel caster intact and that is how it shows in my photos and videos. I figured the front wheel swivel caster has the angled forward bracket already and it minimizes assembly. I don't know yet how long the front swivel wheel will last, but it looks promissing. I reused the two 5/8" Diameter hex bolt axles from the rear casters and attached to the front swivel caster bracket for foot rest extensions, after drilling two 5/8" diameter holes on the swivel bracket sides.

The first photo shows an RC Poly MIA Trike-a-Sail(TM) that I normally fool around with in the backyard, during lunch hours when it is windy. I thought I start this project with this photo for prespective.

On the sail, I may need to remove the lower 2ft length, as it looks a bit tall. Or maybe just leave it as is and run it in lighter winds. The sail is 14 ft tall at the Luff by 5ft at the Foot. All reinforcements for the mast pocket, perimeter edging and batten pockets are done also from the same tyvek material, 4 ply (2 ply folded in half) double stuck to the sail with tape and will be sewn for added strength. I did not want to get to elaborate with the sail shape and so for this prototype I kept it basic to speed up the process.

I designed the pulleys for the RC Model in the photo, the green parts, as 3D Printed parts and refined them and enlarged them for the full scale version. These will use sakeboard bearings for smoothness. The sail test mast on the last photo is an swimming pool skimmer telescopic FG 1.5" OD Boom 15 ft fully extended. OK for the trial test, but I will need to purchase 2 of these at $40 each to use the wider tubes for the mast. It is still quite cheaper than purchasing a real Sail mast , and I I will have a couple booms.

Here is the video Part 1 of the build.

I thought I show a photo of the pulleys in the MIA Poly RC Land Yach for reference, in case someone is wondering ... The ones in green, were done originally but I modified the brackets as in the previous post video, for easy of attaching to the pulley bracket itself without the need for extra hardware.

A bit more about the wheels I am using. From basic physics larger wheels grab easier more distance and will move objects faster, I do have other larger wheel barrel size as well as small bicycle wheels that I can swap, but I really wanted to use these smaller rather attractive galvanized hub wheels for compactness. Here they are, in a closer view.

We can see how nice the front swivel caster bracket looks and if the swivel bearing does not fail too soon, I think this makes a nice quick option for front steering wheel. Also the caster bracket angle is a bit more swept forward than a regular smaller swivel caster and this really caught my eye. Plenty room on the sides to attacht direct foot rests or extensions for control.

The price for these are peanuts! It still boggles my mind how some are able to sustain a profit at these price levels even with mass manufactruring. But hey, more power to the consumer. For a project like this, it is OK, a DIY project (for fun) and not for competition. I am not trying to design a product for sale either, so Im not looking for the highest in quality but things that make sense and are more practical and affordable for the DIY.

With all due respect to all manufacturers of great products, I know the amount of effort, time and money that is required to produce something worhtwhile (I am one of them when it comes to Unique RC Models) and I hope this project is not seeing as a competition or trying to undermine the cost and efforts of the real things. If this thought has cross anyone's mind, understand this is just for fun and for anyone who wants to take a bit of risk into making your own with basic off the shelf inexpensive materials and hardware. Also there are so many ways to skin a cat so to speak, but this is one of my ways. I am still not sure if it will work as I hope it will, but good to document it as it is built, so changes can be made and refined with that reference.

For the triangulated bracing geometry of the trike. I am using Galvanized 1/2" conduit, but I will need to purchase a 1/2"conduit bender to make the seat and other parts that require precise angle bends. The beauty about the $3 counduit tube is not only the price and good amount of length (10ft) but it is easy to flaten the end in a vice to create direct mounting tabs. Simply drill a 1/4" hole to be used with galvanized 1/4-20 hardware. This tubing is not extruded but wraped formed and thus has a hairline joint along the length of the tubing, good to take note when making tabs to flatten parallel with the seam or at 90 degrees to it, if you want to be precise.

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Hiko said..
Very interesting stuff you are doing there. Just a thought on your steering setup As landyachts have a lot of sideforce from the sail the conventional approach is to have the steering pivot axis meet the ground directly under the tyre footprint to balance the steering and make the yacht easier to sail Look forward to your results.
Your microlite trike does indeed fly well!
Cheers Hiko

Thanks Hiko. As far as the steering, do you mean like in the attached photos?, I do that on my RC Land Yacht models and will do that on the refined version. I finished the sail and gave it a rather pseudo test run and the steering without the extension links or foot rest was interesting with the swivel wheel. Also I don't think the swivel bearings will last with the side forces anyway, so I think after a couple fun runs I will replace it with the proper angled steering fork. Another thing is that the trike sits hight at the front and this goes against my design criteria on my rc models both from an aesthetical and functional point of view. But I just wanted to get the trike quickly assembled (sort of) with off the shelf parts so that I can test the fit with the sail. It would not be hard to tilt the swivel front wheel a bit with a couple brackets so to obtain the steeering axis in line with the wheel to gnd contact.

OK it is late and can't work on the trike right now but here is what I envisioned this thing will look like after some details are added.



I did this preliminary study in CAD a while back. I had to transfer all dimensions of the tubing, wheels etc, to cad to get a rough idea of this thing, but with precise part dimensions, so that I can easily modify and create or bring any other CAD part into view in scale.

Hiko, :) no problem, sometimes it takes a few photos or paragraphs to see the other person's direction.

This whole project is also a sort of an excercise of whether I could manufacture quickly a full size sail with basic materials and tools. The sewing part was a bit tricky, as I had to roll the sail to get it to fit on my sewing machine, and even though I was careful not to crumble the Tyvek, as I was sewing it, it was inpossible when I sewed the batten pockets, it crumbled but that made it actually a bit more manageable. But the process is no different than that of which I already employ in my RC model sails. So when I make the nicer full size sail, I will at least have and idea of what to expect and have a better plan of process.

Have you ever wondered what happens when you throw a hard core industrial machinist into a scale model shop and vice versa, a model shop machinist into an industrial shop, not that they could not do each other's job, being that they are both machnists, but when you are acustomed to working at a certain scale, it takes a bit of time to readjust the senses for the other. It happens to me from time to time. I had to adjust my thinking also when I went from making miniature helicopter carbon frame and CNC aluminum part kits and upgrade kits for palm size helis for 18 years to making 5 foot and larger ultralights with sewn sails.

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sn said..
Be wary of those cheap stamped steel, split wheels,

Under load they tend to tear the hub out of the rims, which would be a little disconcerting if you happen to be drifting sideways across a salt lake, concrete or bitumen carpark when a wheel collapses.

I was lucky - the one that failed for me did so on a grassed football field, and I wasn't going all that fast at the time.

Was the one that failed on you from HF? Mine look pretty sturdy but under heavy side loads I have yet to find out. I have a few options for wheels, I have solid plastic hub ones with solid rubber tires, non inflatable, but I was concerned those would fail, at the plastic hub, sooner than steel.

I love your Micro flight ultralight.
Really cool how he turns his head while flying.
You have fantastic computer skills to produce these items. Well done.

I have seral designs of my own for full scale land yachts, but one of them is really tempting me, every time I see it, it is similar to this RC model and it would have to be made from plywood, also similar to the rc model... of course It would be strictly for dry lakes, no beaches, but, hey!, boats are still made from wood and coated to protect them from moisture.

Here is a refined trike structure study drawing, which has the bracing for the seat and a more typical LY front steering wheel.
I prefer a fulll back and head rest support as it feels more comfortable. I also like the seat braces the way I show in the drawing, because they provide triangulation support also to the seat back rest. I simply don't trust, too much, a back rest that rests only on a couple small brackets, near the hinge point. My next video segment will explain this in more detail.

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TrikeASailor said..

sn said..
Be wary of those cheap stamped steel, split wheels,

Was the one that failed on you from HF? Mine look pretty sturdy but under heavy side loads I have yet to find out. I have a few options for wheels, I have solid plastic hub ones with solid rubber tires, non inflatable, but I was concerned those would fail, at the plastic hub, sooner than steel.

No such thing as Harbour Freight here in Western Australia, nearest would most likely be Bunnings - our local home grown hardware store.

The stamped 2 piece steel wheels you have look identical to those sold with cheap bag trolleys - made in China.

The "FALLSHAW" style plastic wheels that most of us here in Australia have adopted, are known to be extremely well made and robust.
Decent 20mm or 3/4" bearings are easy to fit, and the wheels are good for over 100Km/hour.

SAFETY

I have been pondering on this subject while, waiting for my mast tubes to arrive, and checking this site and the web to see how others are adressing this topic with respect to the typical open frame wind sailer or blow karts. Not much in terms of what I would consider a safe vehicle, they are all open frames. Unless you submerge yourself in a coffin style wind sailer there is really no protecion other than the design of the kart itself. For this reason I have invested a bit more time into my final design and have made some improvements to the more typical and familiar land sailer open structure most people go with. I will post a CAD of it when I have finalize it. There are still a few things I am tweaking and it will probably need to be a welded structure to keep it simple and clean.

Thanks so much for taking the time to point out those items. About the tires, my experience designing rc model land yachts has shown me that tires are probably the second or most important thing in a high perfomance land yacht, besides the sail, and structure. My best running RC Land Yachts have round smooth and thinner profile tires than a typical rc buggy wheel, larger diameter also. The logic behind this is that they have less resistance on ground and are able to move easier and faster. Of course, this all ties to other things that are also important and part of the specific design, bearings, how level and straight they are, tire material, gripping ability to hold while in a turn or acceleration, etc. There is a lot one can learn and do it a lot easier and faster in a model, which yields great info that is quite transferable to full scale. However, the best experience is the one you get by operating the real thing. Really appreciate the suggestions. Still waiting for my tubes, but I have gotten busy again with the RC Microlight and Ultralight orders. I also just shipped another RC Trike-A-Sail Pantera RC Land Yacht Kit to Spain. I hope the gent who bought it will do a nice video and post it. I am tired of posting my own videos... :)

Its been a while and I got busy with work, but hopefully soon I will resum the build of the Land sailer.

Meanwhile this may be of interest to some of you, if you are into parasails. I explain how I arrived at this design in the video.