update: first transformer wound

Last night I wound my first of two transformers for use in my home-built welder.  For the amount of time it took to recover a transformer from a microwave, purchase 10 gauge wire, pound out the secondary coil and replace it with the 10-gauge wire, I'm going to try and purchase the appropriate transformer for the next one.  My wiring job sucks and I'm definitely going to avoid doing that again!

I need a total of 40 volts to make this welder work- 20 V per transformer.  I hope I can find one that's perfect out of the box!


In other news, I made my first wafer of recycled plastic.  I used a hacksaw to cut a rectangle shape.  An initial look over the rectangle plate highlights some major issues.  This was made from plastic bags from the grocery store that I melted down in Crisco.  Initially I had melted it in water to form lumps of hard plastic, but when the sample I was preparing caught on fire in my kitchen I decided that using crisco would be a better idea.  It works pretty well, except that the plastic produced is covered in oily residue.

I suppose what needs to happen now is that I need to learn if it's possible to temper the existing plastic mold to get something harder.  But while I'm doing that I'm going to need to work out how to make the same thing with water without catching fire- the reason for that is that in lumpy form, the water-melted plastic seemed much harder than this stuff.  Perhaps a composite of the two will work out nicely.

The next thing I'll need to do is figure out how to mold multiple blanks into perfect copies of 3-d formed fan blades with proper fan shape.  Once I can do that, then I'll be able to install onto an axle, and for the main fan, I'll need to figure out a way to make the fan blades variable-pitch (although that's a much later and less important task).

To reiterate:
1) temper plastic mold
2) form fan blades
3) install onto axle
4) develop and install measurement apparatus
5) Convert all plastic to high temperature metals

Step 4 is the whole reason behind prototyping everything in plastic in the first place.  I hope to gain valuable fabrication experience with this process, and nail down the parts needed to get the device working as I get into step 5- working with metals.

Since I am limited in my workshop capabilities, melting down  bunch of plastic garbage bags to develop a breadboard seems like the cheapest solution, especially since 80% of the thrust is developed from the main fan in a turbofan engine, it seems like a good idea to find out how to reproduce the best parts of the best engines in the world today.

The F-15 ditches the stators in the medium and high pressure compression portions in favor of counter-rotating blades.  They also use variable-pitch blades to optimize airflow.  The engine used in the 747 also uses variable-pitch fan blades.   It seems as though that's what needs to happen in order to maximize the cold-air flow.

Once this done, then I can begin prototyping a turbofan, high-compression chamber, and begin work on the combustion chamber.  The problem with most home-builds is that the combustion chamber and the areas downstream get too hot and don't generate enough thrust to be anything but gas-guzzlers and incredibly loud. Apparently this is very, VERY far down the road as I must first complete a "working" breadboard with all the pieces worked out before I begin purchasing and fabricating parts from metal.

welding project

After viewing an instructible about a homemade arc welder I decided that the project looked so simple that I would try it out.  I needed 2 microwaves to take apart for their transformers.  Well I purchased one for $14 at the local value village and JUST when I'm about to get the coil out, I nick the side of the coil with the wire I DON'T want to damage.  That's about an hours' worth of work down the drain and I'm back to square one.


Well yesterday I picked up a new microwave off of freecycle.org, and then went to home depot and bough an 8 inch gutter nail to use as a drift, and a 24 oz ball-pein hammer (instead of my trusty waffle-faced framing hammer that's served me so well for my wood projects), as well as a 25 feet of 10 gauge wire, in anticipation of ACTUALLY WINDING THIS COIL!


Ideally I would package the welder with the plasma cutter (also on instructibles.com) and everything would be awesome, but right now I need to focus on finishing this project.  I think this will help get my teeth cut on some building.


Next time I will post pictures of the process of preparing the transformers.


Real Life Alert


I have midterms this upcoming week, so I will be unable to do much in the way of working on this project.  Differential equations, and discrete modeling... wish me luck!

what's needed

To get average joe into space, what's needed?

1. A spaceframe - what are the parameters of this spaceframe?
2. A propulsion system - how strong does it need to be?
3. The ability to not be destroyed by the extremes of heat and cold in outer space.
4. Re-entry heat shielding

Everything up there could stand to be improved upon, but to actually *get* a person or payload up into space, I think the propulsion system is the absolute most important part.

I know almost nothing about the technical details of rocketry and space flight, although I've been an enthusiastic watcher-from-the-sidelines for many years.  I think it's time to make a concerted, organized effort to get amateurs into space!

What's the big deal?

Why is it so damned difficult to get into space???  I think the sheer numbers of technical issues requiring specialized materials is something that's keeps us grounded.  When a payload moves up away from the earth, all of the variables are changing:  gravity, mass, radiation exposure, air pressure turns into vacuum, STP turns into BLOODY FREEZING, etc.  What needs to happen is some compensation for all of those changes at all heights.  It needs to be cheap enough to be able to be constructed by amateur teams, and needs to be cheap to re-use (non of this space-shuttle-esque expesive stuff!).

So what I plan on doing over the next few weeks, is posting some of what I think is important information in building a payload delivery system.

Project management

I'm thinking this is going to need to be a brainstorm-build-brainstorm-build approach, since I often get bogged down in the details of thinking about how to do things rather than actually doing them.

I suppose the first thing to do is collect data on high-altitude flight characteristics.  Wing designs, etc.  What would be totally awesome is a variable camber wing design that optimizes for different altitudes.  That would be the cheapest way to get us up into high altitudes.

From there I suppose we'd have to switch to a rocket-based propulsion and accelerate to escape velocity...  one question I've always had is, would it be cheap to skip ourselves off of the earth's atmosphere?  Or should we just shoot straight into space?

So my first build I'm thinking is going to be a model airplane...  something to get my feet wet.  I know!  I know it's nowhere near the awesomeness of model rocketry, but my thinking is, why use all that beautiful rocket fuel to get us away from 0 feet off the ground, when I could use that at tens of thousands of feet off the ground?  So the reason for the model airplane is going to be to test the idea of variable camber wing geometry.  I see no reason why a mechanical solution couldn't be found, and since the final project will be a large turbojet that moves very, very fast- I think the wings will ultimately become smaller in size.

So I suppose that my next project post will involve purchasing an RC airplace and familiarizing myself with flying it (fun!).  But the serious mental gymnastics will be done in my "lab" (read: living room) where I will be designing and building a variable-camber wing shape that will hopefully become a lifting body.  Once built I hope to install the RC airplane inside the new body.  (Of course I will probably have to design an RC chip that I can use to control the camber while in flight).

The next steps

If the variable-camber design works, then I will have to do some projections on when to change the camber of the wing shape for optimal up-thrust at different altitudes and velocities and angles of approach (I don't plan on using VTOL systems).  This will give me a flight plan to get us up to the maximum altitude using conventional atmospheric flight.  At that point all movement will have to be by rockets (unless somebody figures something awesome and cheap to do!).

Of course the next step in the propulsion cycle will have to be using jet technology.  This is going to be challenging!  Not only do I want a turbojet, but I also would like a cutoff valve to turn it into a rocket!

So now there's my layout.  I don't have a "project name" or anything fancy yet, but I have a goal in mind:  build a spaceframe that can handle high velocity and be optimized for travel at the highest altitudes, and build a rocket/jet hybrid that can be optimized for travel at every altitude.

Lets see where this takes us...