Gary Lewis Posted May 28, 2020 Share Posted May 28, 2020 No, it isn't a Ford. But the vision was planted in my brain (thanks, Paul) right here on the forum, so what better place to record it? The plan is to make a rocket launcher, as shown in the link below, with my grandtwins. And then to make rockets and fire them. Here are the documents that would be good to read: Water Rocket Launcher Water Rockets All About Water Rockets Water Rocket Construction Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 28, 2020 Share Posted May 28, 2020 "Plugin not supported" sigh.... I hope your whole family can have fun with this Gary! Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 28, 2020 Author Share Posted May 28, 2020 "Plugin not supported" sigh.... I hope your whole family can have fun with this Gary! Yeah, my computer didn't like it either. But I do hope with you that the whole family can have fun with it. Thanks! As for what I did today towards that, I gathered the parts I have, bought most of the rest from the hardware store, and did some modification for the rest. The stoppers the parts store has are w/o hole. So I put the one I got in the lathe and drilled a hole in it, a bit smaller than the 1/4" of the barb that will connect it to the hose. And another thing the store didn't have was rubber bands. Not to fear, an old bicycle inner tube will suffice there. Last, I need some way to attach the new tire pump to the hose, and preferably with a Schrader valve. But, the store didn't have what I needed so I made one. I took a valve stem and cut the rubber off it and got down to the brass stem. That measured .234" when I got done. And I had a 1/4" hose barb fitting, which I drilled out to .231". I then coated the inside of the barb and the outside of the stem with blue Loctite and tapped them together. Looks like this: Now I have to find some plastic pieces for the fins. Any suggestions? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 28, 2020 Share Posted May 28, 2020 Yeah, my computer didn't like it either. But I do hope with you that the whole family can have fun with it. Thanks! As for what I did today towards that, I gathered the parts I have, bought most of the rest from the hardware store, and did some modification for the rest. The stoppers the parts store has are w/o hole. So I put the one I got in the lathe and drilled a hole in it, a bit smaller than the 1/4" of the barb that will connect it to the hose. And another thing the store didn't have was rubber bands. Not to fear, an old bicycle inner tube will suffice there. Last, I need some way to attach the new tire pump to the hose, and preferably with a Schrader valve. But, the store didn't have what I needed so I made one. I took a valve stem and cut the rubber off it and got down to the brass stem. That measured .234" when I got done. And I had a 1/4" hose barb fitting, which I drilled out to .231". I then coated the inside of the barb and the outside of the stem with blue Loctite and tapped them together. Looks like this: Now I have to find some plastic pieces for the fins. Any suggestions? Any Loctite primer? Don't these things take ferrous/ferric ions to catalyze? Foam from a butcher tray? You don't want thin, sharp plastic. obviously cardboard won't work if you think you're going to launch them off the boat. Swing test is good for empty stability but at launch, water is to the rear. Silly Putty or Plasticine may stick to the front of the bottle to add weight forward. You might try 3 v/s 4 fins. 4 fins will add 33% more correcting force for a given planform, but will add the frontal and surface area to drag as well. Maybe it's deep for a nine year old to understand TNSTAAFL. That there are always consequences along with advantages. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 29, 2020 Author Share Posted May 29, 2020 Any Loctite primer? Don't these things take ferrous/ferric ions to catalyze? Foam from a butcher tray? You don't want thin, sharp plastic. obviously cardboard won't work if you think you're going to launch them off the boat. Swing test is good for empty stability but at launch, water is to the rear. Silly Putty or Plasticine may stick to the front of the bottle to add weight forward. You might try 3 v/s 4 fins. 4 fins will add 33% more correcting force for a given planform, but will add the frontal and surface area to drag as well. Maybe it's deep for a nine year old to understand TNSTAAFL. That there are always consequences along with advantages. I don't have any Loctite primer. But the Loctite set up. How do I know? Because the first round I started to put the pieces together the wrong way 'round. Had them just barely started and realized that the hose barb was pointing the wrong way. But the barb didn't want to come off. It'd been maybe 3 minutes when I realized it, so I was sure it couldn't have set up. I got a drift and tapped them apart, which wasn't easy, and then had to scrape the hardened Loctite off of the parts. There's plenty of interference in the fit, so the Loctite is really just to ensure it seals. And it certainly did. I pulled a vacuum on it and it held. As for the fins, I've discovered that we have several 1 gallon water and milk bottles. And they have flat panels on the sides that will work nicely. Easily cut, thin but not brittle, and the hot-melt glue will probably adhere to them nicely. And, I'd planned on 3 fins. Hadn't thought about the weight, but Silly Putty would work nicely. Thanks! Link to comment Share on other sites More sharing options...
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