Internal Grip Launchtube

[Blenderite]

Howdy!

I am in need of a good design for a internal grip launch tube. I saw one made by SaskAlex, and asked him for some more details, but he never has responded.

I need this for my space shuttle glider I am working, and it is getting very close to being ready, so hopefully someone has some ideas.

Thanks in advance!

[U.S. Water Rockets1]

Howdy!

I am in need of a good design for a internal grip launch tube. I saw one made by SaskAlex, and asked him for some more details, but he never has responded.

I need this for my space shuttle glider I am working, and it is getting very close to being ready, so hopefully someone has some ideas.

Thanks in advance!

Just out of curiosity, why does the launcher have to be an internal grip type? Is the bottle embedded inside the fuselage or something and you cannot get at the neck?

[arjan]

Howdy!

I am in need of a good design for a internal grip launch tube. I saw one made by SaskAlex, and asked him for some more details, but he never has responded.

The spreading cone launcher by SaskAlex looks promising.
What details are you looking for, maybe someone else can help you out?

[Blenderite]

Just out of curiosity, why does the launcher have to be an internal grip type? Is the bottle embedded inside the fuselage or something and you cannot get at the neck?

Exactly.

The spreading cone launcher by SaskAlex looks promising.
What details are you looking for, maybe someone else can help you out?

The part of that design I can't quite figure out is the way the lever is attached. Looks like there is a bolt going through the copper pipe, but I am not so sure that would work. Then I would have to use PLP or something on there to seal the bolt and the pipe. Any better ideas?

Spreading Cone Plan.avi

(1.75 MiB) Downloaded 331 times

[arjan]

Looks like there is a bolt going through the copper pipe

As far as I can see the bolt isn't going through the copper pipe. There's a piece of PVC around the copper pipe and there are two short bolts (one from each side) going into the pvc but not in the copper pipe.

Something like this.

[Blenderite]

Ah! Good idea!!! That does make perfect sense! Thanks!

[U.S. Water Rockets1]

Looks like there is a bolt going through the copper pipe

As far as I can see the bolt isn't going through the copper pipe. There's a piece of PVC around the copper pipe and there are two short bolts (one from each side) going into the pvc but not in the copper pipe.

Something like this.

What if you were to solder the copper pipe into a copper pipe fitting and then drill and tap the thick copper fitting clean through? The threaded copper would probably seal up nicely and if it didn't you could use a brass bolt and just solder the area where the bolt went through the copper fitting. Brass will take solder just as easily as copper.

[arjan]

Looks like there is a bolt going through the copper pipe

As far as I can see the bolt isn't going through the copper pipe. There's a piece of PVC around the copper pipe and there are two short bolts (one from each side) going into the pvc but not in the copper pipe.

Something like this.

What if you were to solder the copper pipe into a copper pipe fitting and then drill and tap the thick copper fitting clean through? The threaded copper would probably seal up nicely and if it didn't you could use a brass bolt and just solder the area where the bolt went through the copper fitting. Brass will take solder just as easily as copper.

I think that's an option but you won't be able to adjust the height of the lever, so you have to do it right the first time or find another way to adjust.

[U.S. Water Rockets1]

I think that's an option but you won't be able to adjust the height of the lever, so you have to do it right the first time or find another way to adjust.

Once you make one, you can document the position of the bolts and use the same measurements for successive builds. Even if you just take pictures as you go, that would be enough of a record to be able to get pretty good dimensions from.

[Blenderite]

I got my Grandpa to machine me the parts I needed. If only my camera battery wasn't dead I would post some pics

[U.S. Water Rockets1]

I got my Grandpa to machine me the parts I needed. If only my camera battery wasn't dead I would post some pics

That sounds interesting. Please post pix as soon as you can!

[Blenderite]

Here are some pictures.

IMG_0831.JPG (4.1 MiB) Viewed 61 times

IMG_0832.JPG (3.57 MiB) Viewed 61 times

So far I have pressurized it to 40 psi and it held very well. Can't wait to try it out with a rocket on it.

[U.S. Water Rockets1]

Here are some pictures.

IMG_0831.JPG

IMG_0832.JPG

So far I have pressurized it to 40 psi and it held very well. Can't wait to try it out with a rocket on it.

That looks really nicely built! Good luck with the design!

[Blenderite]

Thanks! Believe it or not, all the solder joints where done with a heat gun and regular solder sold for electronics. I am too cheap to get a propane torch and the thicker solder So far it seems to be holding very well.

[U.S. Water Rockets]

Thanks! Believe it or not, all the solder joints where done with a heat gun and regular solder sold for electronics. I am too cheap to get a propane torch and the thicker solder So far it seems to be holding very well.

That solder has a lot of lead in it (you probably did not get lead-free electronics solder) and so it is actually a lot easier to work with than the stuff they sell for pipes with no lead.