Need help on school project

[Kaleb Lindley]

So we are doing a project in physics and it's the balloon powered car project. If you are unfamiliar you are to build a car, that is powered by a balloon, out of household objects. I asked if I may make my car out of wood and Mrs. Teacher said sure. So the problem is that I only have a hand saw, drill, and dremel. So I made my first car and brought it to school and realized once I got there that my drill holes are not straight. I need a way to drill my holes very straight and extremely precisely. I would also like to make straight cuts but that is fairly hard to do with a hand saw. If anyone can help me to make a cutting guide for it that would be awesome. So to sum it all up I would like some recommendations on maybe a drill guide as in how to make one out of 2x4, or just drill precise holes with a poorman's workshop, as well as a cutting guide for the hand saw. Another note to take is I have the poorest of poor man's workshops. I have no; bench vice, table saw, chop saw, drill press, etc. Any advice on designs would be happily accepted as well. Thanks in advance.

[andy bessette]

In the absence of a drill press, use the square corner of a box or drawer, etc, as a V-block to align an extra long drill bit for drilling a pilot hole into a thick block of wood, which can then be used as a guide. The pilot holes can be opened up to any larger size.

[Yonak Hawkins]

Kaleb, a lot depends on what resources you have available. If you have an uncle (or the wood or metal shop in your local technical school) who has a drill press he could make a drill guide for you .. actually, he could drill the holes for you but that would be cheating. Otherwise, do you have a way to cut a 2X4 square .. chop saw, miter saw ? If not, using a guide that you know is square, draw two lines on adjoining edges of a 2X4, 3" from the end, prop that 2X4 on top of another 2X4 and have your sister stand on it. That will hold it firm enough for you to saw it without it moving. Saw slowly and evenly, following the line, being careful that the end of saw doesn't poke into anything laying around, such as your dad's car. Now cut another piece that is 2" wide. Hold the two pieces of wood so that they form an "L". Tape these pieces in place with duct tape and use the inside corner as your drill guide. Everything takes patience and care. Good luck.

[Chris Schoenthal]

Kaleb, not to rain on your parade, but I have experience building a balloon powered car that I did with my grandson last year, and I do have all the tools.
I got the lightest wood possible (balsa), hollowed out the middle of it, made sure that the wheels would spin freely and yet never could get the balloon to push it along. The car was too heavy.
We finally got a cardboard box, cut and taped it up and it worked great.

[John K Jordan]

Kaleb, not to rain on your parade, but I have experience building a balloon powered car that I did with my grandson last year, and I do have all the tools.
I got the lightest wood possible (balsa), hollowed out the middle of it, made sure that the wheels would spin freely and yet never could get the balloon to push it along. The car was too heavy.
We finally got a cardboard box, cut and taped it up and it worked great.

What about the light weight balsa and tissue paper construction that used to be used for RC model airplanes?

JKJ

[Kaleb Lindley]

so take a 3" piece and a 2" piece and make an l shape out of them? I have a hammer and nails or screws I could use should I use those over duct tape?

[Van Huskey]

Kaleb, not to rain on your parade, but I have experience building a balloon powered car that I did with my grandson last year, and I do have all the tools.
I got the lightest wood possible (balsa), hollowed out the middle of it, made sure that the wheels would spin freely and yet never could get the balloon to push it along. The car was too heavy.
We finally got a cardboard box, cut and taped it up and it worked great.

+1 I hate to say it but wood (even balsa) it not the way to go IF you want to well in this challenge. Helping one of the neighbor's kids last year I did some research and cars like below seemed to be the way to go. Given it is a physics class understanding the mass of a wooden car is just too high for the forces involved seems quite important.

Balloon-Car-2013-Vista-136-qpq247.jpg

Styrofoam take out boxes also seemed to be popular for the body.

[Matt Day]

CD wheels? Nice. I look forward to doing I mean helping my kids with these kinds of things one day.

[John K Jordan]

CD wheels? Nice. I look forward to doing I mean helping my kids with these kinds of things one day.

Ha! Reminds me of a science fair project I did in 7th grade which involved some electrons. When I told my dad I was accused of having him build the thing he just laughed - there was no way he could have built it! At my school science fairs were the highlight of the year for what I now realize was a surprising number of kids. The "geek" population usually started on the next year's project as soon as the fair was over.

When I was a science fair judge we got to meet and ask questions of each finalist. The number of brilliant high school students was encouraging. Gave me hope for our country.

JKJ

[Yonak Hawkins]

Hammer and nails or screws are too cumbersome and you'll likely split the wood. Use duct tape .. wrap it all the way around, then set the corner of the "L", where the two pieces meet, where you want your hole drilled. Use the inside corner of the "L" as your drill guide. Practice on scrap before you drill in your finished piece. Practicing is always a good practice.

[Nick Decker]

Ha! Reminds me of a science fair project I did in 7th grade which involved some electrons. When I told my dad I was accused of having him build the thing he just laughed - there was no way he could have built it! At my school science fairs were the highlight of the year for what I now realize was a surprising number of kids. The "geek" population usually started on the next year's project as soon as the fair was over.

When I was a science fair judge we got to meet and ask questions of each finalist. The number of brilliant high school students was encouraging. Gave me hope for our country.

JKJ

My one memory of science fairs was when I built a volcano out of clay. You would put some kind of flammable powder in the "crater" and light it to create the "eruption." It was quite a hit, except that the ash got all over everything, including the other kids' projects, so they shut me down.

Today I'd probably be arrested as a terrorist.

[rudy de haas]

1) you can use your school geometry set to draw the lines on the wood where you want to cut it. however.. it takes years of practice before you can cut a 2 x 4 nearly square with a hand-saw. I've tried for many years and never yet succeeded. it's one reason I love power tools: straight every time! The same is true of drilling - you can make a drill guide easily enough but holding a hand drill straight is possible only for people who have used the tool many many times.

2) if none of your friends have dads with the right tools, I'd suggest changing your design to accommodate what tools and materials you do have. For example, if your car is to be reaction powered (? - i.e. you attach a blown up balloon and the reaction as the rubber pushes the air out moves the car) then weight is a big issue so I'd suggest two axles attached to the bottom of the thinnest piece of material you can find that will still be rigid - and whether the edges are cut straight won't matter.

[John K Jordan]

My one memory of science fairs was when I built a volcano out of clay....
Today I'd probably be arrested as a terrorist.

I've seen some of those. What a mess! These days they use baking soda or something.

With a year to plan and no cell phones and internet for distractions (mid 60s) it was amazing what some people came up with. My friend Julius scraped phosphor from the inside of B&W TV CRT tubes and with the help of a powerful vacuum pump and a high voltage power supply he built a working electron microscope - pretty dim, but hey. Another guy did some glass blowing and made a C02 gas laser from scratch (dangerous with an invisible beam!) One guy, lying low after a run-in with the humorless FCC over a home-made television broadcast station, invented a hold circuit for household phones and got a job offer from Ma Bell. Another guy put everyone out of running one year - he designed and built a continuously operating cloud chamber. He got money and a job with Westinghouse out of it. My efforts were a little more reserved, such as a kymograph for recording the physical response of electrical stimulus to the gastrocnemious muscle of a frog (just try to find live frogs in Pittsburgh in the middle of the winter!) and a centrifuge with a chamber to hold a mouse for testing the effect of G-forces on memory, coordination, and balance. My mother was unhappy when she discovered I had cut a 3" section of stainless steel tubing from her vacuum cleaner. Hey, it was research....

The things many of us did with fire and explosions (home made nitroglycerin, mercury fulminate, C4, etc.) would these days get a quick visit from homeland security. Two friends built a fake cardboard flying saucer complete with flashing lights and noise makers and ran it down a set of guide wires stretched down the hill and crashed it into a pit at the bottom. They had filled the pit with every flammable liquid and gas they could find and set it off with a blasting cap. This was timed to coincide with a big country club gala on the next hill. Made a huge fireball which not only got the attention of the people at the country club but also the local TV news and the county law enforcement. Good clean fun.

JKJ

[Roger Feeley]

If you want to drill holes straight, consider a horizontal boring machine. Mount your drill on a piece of plywood that has a straight edge so that the bit would stick out over the edge. Try to mount the drill so that the bit would be parallel with one edge of the plywood. Now, shim the plywood so that the drill bit would be parallel with a tabletop. The tabletop gives you a usable plane in one axis. Clamp a straightedge to the tabletop to slide the plywood againse and that gives you a usable plane in the second axis.

By experimenting and shimming the bottom of the plywood and the edge, you should be able to get to a place where the bit is parallel to your two reference planes. Now you have a horizontal boring machine. you can add spacers under the plywood or the piece to be drilled to adjust the height off of the table. You can mount another board perpendicular to your guide board to hold your work piece at the right angle.