Doc Cathode's Harebrained Flying Machine Project

In My Humble Opinion
41

Well, DougC, if you peeled the outer skin off a typical 2 or 4 seat general aviation airplane, say a 2003 model Cessna 172, it wouldn’t look any more substantial - and the skin on those things isn’t very thick.

I’ve flown ultralights even less substantial than that - I really like the MaxAir Drifter (although I didn’t own it, more’s the pity…) which is an 18 foot pole with a seat, wing, tail, and engine bolted on. Not for everyone, though.

And you really, really, really want to buy aircraft grade aluminum. I would NOT fly in an ultralight unless the hardware was aircraft grade.

As for the prop - I have no idea how to calculate the proper size prop for an airframe/engine combination, but you don’t have to be very off from the ideal to suffer considerable performance problems. And homemade props should stick to 2 blades - balancing is critical and that’s hard enough with two, much less more.

I agree with Sam - Getting into even the lowest level of aviation is going to cost you several thousand. If you can’t afford to sink 5K into a flying machine you can’t afford to fly - and even that would give you a very bare-bones machine.

Please don’t kill yourself trying to fly on the cheap.

What, exactly, is your motivation here? Do you want to fly? Then try to find a situation where you can exchange labor for flight lessons. Do you want to build a flying machine? Then go with model aircraft - although I know guys who spend more in a year on their models and radio control aircraft than I spend in a year on the full-size ones.

EVERYTHING that flies pays a high price for it - male birds, for instance, have only one testicle. At least as a human you have the option of losing money rather than one of your nuts.

42

Doc– my experiences in Rural Wisconsin as a boy convinced me that all do-it-your-self-er-ism is a species of madness. In Wisconsin, it was cabin fever after a long winter. Maybe elsewhere they get crazy with the heat, I dunno.

But no possible good can come of this.

I urge you as a friend to abandon this.

43

Bosda got it in one-madness.

Since having to drop out of college in '95, I’ve done nothing and gone nowhere. I’m on disability for chronic depression. My life h as gone from the stuff of dreams to garbage. I want to take garbage and turn it into the stuff of dreams. I can’t hold down a job or go back to school. But, I’ve been able to complete a few projects. They took much longer than they should have. I was only able to work on them erratically. But, I finished them.

If I can finish this project, I can have hope, a feeling of accomplishment, and a sense of self worth again.

It’s difficult to explain the why of it. But taking lessons or building an rc flying machine(which I’ve been planning to do for a while.) don’t fulfill the need. I know the risks of doing something this foolish. I know the long list of things that can go wrong. I don’t think any part of this will be fast or easy.

I never had some childish idea of going to the garage with duct tape and krazy glue and emerging  a few hours later with a working flying machine.

I’ve already abandoned a lot of designs or ideas as unworkable. Bike frames are out. I never intended to try a closed cabin design. Materiaks equal cost. The more parts there are, the more parts(and joints) can fail.

Right now, I’m thinking of a backpack engine and a parachute. It’s small and relatively simple. Plus, if depsite all precautions something does go wrong, I’m already wearing a parachute.

44
      • I can identify a bit–I kinda wanted to make a leg-powered flapping-wing thing too, ever since seeing the 80’s movie Condorman. It has been a mental exercise sort of thing, and it’s pretty much to the point where I have figured out basically how it all has to be put together. It was part of the reason I bought welding equipment, as I couldn’t imagine any way of doing it without being able to weld. That movie came out in 1981, so yea, I guess I am a bit serious about it. The materials cost isn’t the problem, really–it’s thinking of a plan that I have a fair amount of confidence in.
  • I think mine is a bit safer than a typical motorized-airplane though, as mine would be “testable” by starting out making short hops on level ground from a standstill, and doing progressively longer hops. So if it breaks or fails in the early stages, I won’t be far off the ground or moving very fast. I’ll just look really stupid…
    ~
45

Good lord, depression and flying can be a really bad combination.

Parachutes can fail. Just because you’re wearing one don’t imagine you’re perfectly safe.

Look, Doc - building a flying machine is going to cost some money. I dunno, maybe the need for that money and materials and what not can be the movitation to pull your life together - or maybe you’ll get halfway there and get yourself killed.

The problem - aside from you getting hurt - is twofold:

  1. Aviation accidents are not fun and not pretty. I don’t know where you intend to be doing all this but I hope it’s not in my neighborhood because the way you’re going about it you’re going to wind up in a heap. I’ve already helped haul a wreck off a runway and don’t care to do that again. (I also don’t like to hear grown men scream, plead, pray, or cry over the radio, either, but since you’re doing this on the very very cheap I guess you won’t be adding a radio to your equipment so it’s a bit of a moot point.)

  2. If one person dies in an aircraft it tends to reflect badly on everyone else who flies - sort of like the way the bad behavior of a few motorcycle riders smears the reputation of everyone else on a motorbike.

If you absolutely MUST be involved in building a flying machine of some sort will you consider joining a club and assisting other builders with their projects first so you can really see what you’re getting into? A successful build is a lot of work and effort, yet you say you’ve “gone nowhere and done nothing” since '95, and you can’t hold down a job. Are you able - mentally, physically, financially, and emotionally - to handle this sort of project?

46

I’m in sort of the same situation as Doc and I can say that a person really really needs something intellectally challenging that yields tangible results at times like that.

47

Keeping a job or staying in school requires consistency. You need to show up on time every day, do a certain amount of work, and be able to concentrate.

To complete a project, even one like this, you only need to function while working on the project. It doesn't matter if I spend the rest of the time in the fetal position, wearing clown make up, lying in a puddle of my own filth. If I can truly function for just the 2 hours, the hour, or the 10 minutes each week I work on this project, it will fly and it will be safe to fly. It may take years to finish. But, I will finish.
48

Agreed. I’ve cooked up more than one harebrained scheme on occassion simply to give myself a reason to keep going every day. Some times the only thing keeping me from taking to the rooftops with a sniper rifle is that I’ve got this project I’m working on, and I just have to see how it turns out.

49

Heck, if I had a decent workshop my backyard would look like a NASA testing ground.

50

Have you looked at taking continuing education classes? See, I take this shop class, and my instructor’s pretty cool about letting me use the toys for whatever I want, so I have gotten to work on a couple of neat projects. Don’t know how he’s going to react when I tell him going to be building a steam powered car in class.:cool:

51

You’d have to turn the LEDs off after dark, or you couldn’t see to drive. :eek:

52

You could just turn them way down so they only glow enough to be visible.
:smiley:

53

I have to disagree.

I can’t remember the exact details. But, in the late 70’s/early 80’s there was a man who fitted the exterior of his beetle with small, ovoid, chandelier bulbs. He did indeed have them set up to flash in various patterns. He did not have a problem with visibility. He did not have a problem with bulbs breaking. He did not have a problem with bulbs burning out quickly. The city, however, had a problem with all the extra flashing lights on a vehicle and made him stop.

54

Just build yourself a theramin and make music with it.

The posters responding in this thread have been more than gentle with you. If you can’t afford plans, you don’t have the resources to even begin to embark on a project so fraught with risk.

I’ve flown ultralights, with nice big Rotax motors on them, and I was still nervous as hell.

how about taking up gliding ? Its a Very inexpensive hobby compared to working towards a private pilot’s ticket. Get up in the air in a glider with someone experienced. It’s a blast, and easy to get the hang of.

if you proceed with this idea, we’re all going to be paying for your hospital stay, should you be so lucky to make it that far.

think theramin !@!!! Jimmy Page used one.

55
      • Assuming you are absolutely set on trying to fly around with, I don’t think this could really be done with found materials–at least not any materials I’ve ever found. If you can stand to part with a few dollars here and there, your possibilities expand a lot.
  • I would suggest looking at conventional hang-gliders for a design. They use very few materials and their efficiencies are very high, so it wouldn’t take a lot of engine to get them off the ground–I’d bet a 10-hp would do it, perhaps even a 5hp, but you’d want a horizontal-shaft engine, not a vertical as is common for push-mowers. The “controls” are largely instinctive. The frame consists mainly of only four main tubes, and they can be constructed to allow folding down very easily for storage in a small amount of space. The airfoil profile is controlled by battens inserted into sleeves in the fabric covering–so if you want to change the airfoil shape, all you need to do is make new battens. Mainly, take your time–expect to spend at least 90% of the total project time in the research/planning stage–find out as much as possible about current production hang-gliders, before even trying to plan out how you would do anything. You shouldn’t have to invent anything–the safest bet is to copy what already works.
  • I mentioined a WWI-style plane first, and I think now that would be wrong. A hang-glider is much more simpler. If I gave you the pieces for a delta kite and told you to assemble it without the instructions, you could probably do that. If I gave you all the pieces of a wood-frame airplane and no instructions, it would take you a lot longer, and you might have some leftover pieces.
  • As far as the powered parachute goes, I think you are greatly underestimating the amount of suitable materials and effort it would take to make such an aircraft. I’ve never seen anywhere that tells how to do that, and if it isn’t designed well, modifying it is darn-near impossible–you’re basically throwing the whole canopy-thing out and starting over, where with the hang-glider example above, it’s as easy as putting different-shaped battens in the sails. And of course, because of their high drag, you go from needing a commonly-discarded 10-hp lawnmower engine to something in the 40-hp range (like what manufactured examples use), and that means a motorcycle or snowmobile engine, something much less discarded and much more expensive to buy than a horizontal-shaft lawnmower motor. Being always attached to a deployed parachute is very safe, but you sacrifice a lot in the way of efficiency to accomplish that.
    …
  • It is true dabbling in homebuilt powered flight is not the safest hobby one can choose, but then again, I tend to take the view that a life without any risk is a life unlived.
    ~
56

What about a one-man hovercraft? if you have a decent lawnmower engine the rest is just basic woodwork and the ones I’ve seen on TV look pretty nifty to drive.

57

Maybe we should start a “Doperlabs” where we tackle design problems.

58

That would rule.
Heck let’s invent our own sci-fi universe too!