Shopsmith Forums

[quote="dgale"]But calculus should have taught you that you can only get infinitely closer and closer without ever getting perfectly square. Besides, I bet your square would look a lot better than mine ]

GREAT point, about getting square without ever getting to square. It's sort of like "integration by parts" in a way I suppose--solving the problem without actually solving the problem!

As for being an MD and a Rocket Scientist in the same lifetime, it's only a "model" rocket scientist at this point. Although, one of the projects my company is working on involves the lab of a PhD Physiologist friend (and his lab) at the Kennedy Space Center. So although we don't actually work on the rockets, I have driven by them several times! Seriously though, the technology is very suitable for supporting long-term human spaceflight...it just isn't as much fun as this high-powered model rocket stuff!

My son and I have built a couple rockets and flown them. It is pretty fun! I had a Space Shuttle Columbia model rocket as a kid but never got to fly it. I don't know what happened to it, but I did find the remains of the launches pad on a recent trip to my parents.

[quote="tcbetka"]

I bet you'd find it easier than you might think. I haven't done much R/C aircraft flying, but I do have that "RealFlight" simulation program with a controller, and it's pretty slick! And you don't have to fix anything when you crash--just hit "restart."

Ha, the first time I flew my first Model RC I told the guys at the flying club that I didn't need instructions because I was a real pilot and had my own airplane, how hard could it be Well, as I was picking up the pieces of what was left over shortly after takeoff, I asked where I could find an instructor.

heathicus wrote:My son and I have built a couple rockets and flown them. It is pretty fun! I had a Space Shuttle Columbia model rocket as a kid but never got to fly it. I don't know what happened to it, but I did find the remains of the launches pad on a recent trip to my parents.

What a great activity for a kid... Model rocketry can teach someone a LOT about fundamental principles, like the law of gravity, Newton's laws, etc. All you have to do is care enough to do a little research.

But if you like building, testing and experimenting with stuff, then model rocketry is especially great. Where else can you design something quite quickly, and then build it for only a few dollars--and then go see it in action flying hundreds or thousands of feet? And if you've got something like a SS unit in the workshop, then it just makes the job that much easier.

Thanks for the post.

fredsheldon wrote:

tcbetka wrote:
I bet you'd find it easier than you might think. I haven't done much R/C aircraft flying, but I do have that "RealFlight" simulation program with a controller, and it's pretty slick! And you don't have to fix anything when you crash--just hit "restart."

Ha, the first time I flew my first Model RC I told the guys at the flying club that I didn't need instructions because I was a real pilot and had my own airplane, how hard could it be Well, as I was picking up the pieces of what was left over shortly after takeoff, I asked where I could find an instructor.

Yup. After nearly 3500 hours in "real" aircraft, I can honestly say that I crash the models on a regular basis. I've seen guys with hundreds and hundreds of hours flying R/C aircraft, go from a beautiful model to a steaming and twisted pile of scrap in about 3 seconds, LOL. It's quite intimidating, to say the least!

But that RealFlight app is a GREAT money-saver, and it's loads of fun as well...well worth the money it costs.

tcbetka wrote: . . .
I am not interested in buying a new unit right now, although that might happen a year or two down the road. But I am quite interested in talking to them about what accessories I might be able to buy from them to use with the Greenie. Then, if I did decide to go with a new(er) unit, I could also use those SPTs with that as well. That was my first thought anyway, although as has been pointed out, it might not work out as well as I'd like. Before I stick any more money into this Greenie, I want to find out how feasible it would be to add SPTs--because if it is, then I'll likely just restore this one and starting adding them. If it isn't, then I may just clean this one up a bit, use it for a year and then upgrade. I don't think it is really going to lose much value from what I paid for it--I certainly haven't seen them any cheaper anywhere.

All the SPT's will fit both the old greenie Mark 5 and the newer models. There are some 'accessories' that are model dependent however.

JPG40504 wrote:All the SPT's will fit both the old greenie Mark 5 and the newer models. There are some 'accessories' that are model dependent however.

Very nice. I thought so--I found the online PDF catalog, and have been looking through it a bit tonight. There are potentially some very nice upgrades that a guy could do...especially if you need a new power head.

Thanks for the post!

Ahh Estes Rockets. When the rockets all crashed we lit the engines alone for fun. Never had great luck, but I did learn a bunch of lessons from them.

#1 - Don't overcorrect for wind. We tilted the pad to counter the wind and never saw the first rocket I launched ever again.

#2 - Don't speed the process with a glue gun. Built one of the small rockets with basicaly popsicle stick fins and a body tube that was big enough to hold the engine. It went 100 feet and the fins melted and it crashed.

#3 - If it can hit anything it will. My buddy Tom traded for a completed rocket. Launch #2 the rocket went up, the parachute didn't come out and it did a nose dive into the street.

#4 Secure the parachute well. I chased a rocket a 1/4 mile through a soybean field only to find it was just to nose cone and parachute. The rest of the body went somewhere else. Without the weight the parachute just kept floating with the wind.

It's a good fun hobby and even the bad launches are fun.

Now multiply the power of the engine by 50 or 100, and the weight of the rocket by 50...and rinse and repeat. Some of those rockets go supersonic within about 2-3 seconds. Obviously if they go up and reach apogee before going into lawn dart mode, they won't be going as fast when they hit the ground. But if the rocket is under-powered and arcs over under power, LOOK OUT! It will accelerate all the way into the ground again, and at 50-100 pounds (or heavier), it can be lethal.

This is why you need to be certified.

letterk wrote:Ahh Estes Rockets. When the rockets all crashed we lit the engines alone for fun. Never had great luck, but I did learn a bunch of lessons from them.

#1 - Don't overcorrect for wind. We tilted the pad to counter the wind and never saw the first rocket I launched ever again.

#2 - Don't speed the process with a glue gun. Built one of the small rockets with basicaly popsicle stick fins and a body tube that was big enough to hold the engine. It went 100 feet and the fins melted and it crashed.

#3 - If it can hit anything it will. My buddy Tom traded for a completed rocket. Launch #2 the rocket went up, the parachute didn't come out and it did a nose dive into the street.

#4 Secure the parachute well. I chased a rocket a 1/4 mile through a soybean field only to find it was just to nose cone and parachute. The rest of the body went somewhere else. Without the weight the parachute just kept floating with the wind.

It's a good fun hobby and even the bad launches are fun.

#5 model rocket theory of distance. Look in the direction it appears to land, and take the estimated distance and add 1 full city block. (it's always farther out than you thought). Then get on your Schwin Stingray and peddle after it.