An "R"-powered rocket build

[Theory]

use a flap sanding disk on a rod with a drill. Still mark it so you know where you are sanding. Don’t need to sand the whole thing, just the spots where you are glueing.

I second this idea, though I believe the entire area will need to be sanded as the inside of the main airframe will receive coupler assemblies that will run the entire length.

I wonder of you could fab up a sanding flapper with a long dowel and some 220grit. say cut a slit in the end and slide the paper in that then secure the other end to your drill via a hole bored down the center that is filled with a piece of steel rod. doesn't need to win a beauty contest, jut needs to work

 

[Rockyt]

Wiping all the tubes down with lacquer thinner to remove any release and other contaminants.

Also worked on the centering rings to get them to perfectly fit in the tubes. With a belt sander it's quick work.

View attachment 376962 View attachment 376963

I saw this posting start with 'wiping'...

then had to ask myself... "Is bottom thrust plate a new term for 'toilet seat?"

true story, no ill will intended. Truly

 

[Rail Dawg]

I like the flap sanding disk idea. Learn something new every day!

Chuck C.

 

[djs]

Don't you have a small child you can give a dust mask and some sand paper to?

I just do the "sand paper taped to a stick" method, although that sucks...

 

[Rail Dawg]

I second this idea, though I believe the entire area will need to be sanded as the inside of the main airframe will receive coupler assemblies that will run the entire length.

I wonder of you could fab up a sanding flapper with a long dowel and some 220grit. say cut a slit in the end and slide the paper in that then secure the other end to your drill via a hole bored down the center that is filled with a piece of steel rod. doesn't need to win a beauty contest, jut needs to work

This idea could work too. A dowel would fit nicely into a drill chuck.

The main thing is being able to get a little pressure on the sandpaper. It doesn’t have to work perfectly as there is plenty of surface area on the roughened-up coupler/tube interface.

Thanks!

Chuck C.

 

[GalantVR41062]

https://www.amazon.com/US-General-Engine-Cylinder-Adjustable/dp/B002ZKUPAS

https://goo.gl/images/hVHoxv

I wonder if they make a cylinder hone for a 12" bore, or modify one of these to work in the tube, and extend it to work the length of the tube.

~John

 

[Ez2cDave]

Ok guys put on your rocket thinking caps.

I’ve got to sand the inside of 5’ G12 tubes to make it better for the epoxy.

Going to use an orbital sander but of course can only reach a couple of feet in. Been considering ideas like sandpaper on a stick or duct-taping an extension to the sander.

Thought maybe you guys could come up with an even better idea lol. Got to be a way I can get a little bit of elbow grease onto the sandpaper.

Thanks.

Chuck C.

Chuck,

Make a "hone" . . .

Remember than piece of Blue Tube coupler you had laying around ?

Peel ( if you can) the outside layer ( sand it down, if you can't peel it ), so that you can attached a sheet of 220 sandpaper ( double-sided tape ? ) . . . Put a bulkplate in each end with a hole in the center for 3/8" - 1/2" All-Thread ( secure with double-nuts ) . . . Chuck in up in a drill ( preferably a 1/2" variable-speed drill . . . Spin it up and start "honing" !




Dave F.

 

[Pyropetepete]

Ok guys put on your rocket thinking caps.

I’ve got to sand the inside of 5’ G12 tubes to make it better for the epoxy.

Going to use an orbital sander but of course can only reach a couple of feet in. Been considering ideas like sandpaper on a stick or duct-taping an extension to the sander.

Thought maybe you guys could come up with an even better idea lol. Got to be a way I can get a little bit of elbow grease onto the sandpaper.

Thanks.

Chuck C.

Small child.

 

[MClark]

I have a friend's daughter peel the waxy layer from a 12 foot length of 16" sonotube.
When she was in the middle I started rolling it.

 

[rcktnut]

https://www.bing.com/videos/search?...1DB5C3925C60742FF29A1DB5C3925C60&&FORM=VRDGAR

Build up outside of wheel to right dia. and put sandpaper on!!

 

[Rail Dawg]

I have a friend's daughter peel the waxy layer from a 12 foot length of 16" sonotube.
When she was in the middle I started rolling it.

Of course you did lol!

Chuck C.

 

[Ez2cDave]

https://www.bing.com/videos/search?...1DB5C3925C60742FF29A1DB5C3925C60&&FORM=VRDGAR

Build up outside of wheel to right dia. and put sandpaper on!!

Man, that little guy is really bookin' !

Dave F.

 

[warnerr]

i really love hones! This company has them in micro to giant: 12” does nice work: https://www.brushresearch.com/pdf/FlexHone_Resource_Guide_For_Customer.pdf

 

[TonyL]

Chuck,

by the time you have fabricated a deluxe sanding stick/wheel/etc or fancy custom honing cylinder you could have been done already with an orbital sander taped to a broom handle. Heck by the time you get done reading all this discussion you could have been done already. I would suggest just mark the depth on the handle and have at. Always remember to change your paper often

br/

Tony

 

[Wallace]

Chuck,

by the time you have fabricated a deluxe sanding stick/wheel/etc or fancy custom honing cylinder you could have been done already with an orbital sander taped to a broom handle. Heck by the time you get done reading all this discussion you could have been done already. I would suggest just mark the depth on the handle and have at. Always remember to change your paper often

br/

Tony

Agreed, don't overthink it. A simple stick or rod with a slot cut in it in a drill will happily hold a piece of sandpaper or scuff pad. Ball hones are perfect (and pricey) if you actually need 'em,and cylinder hones even more, but almost always end up being single use unless you're into production since they're somewhat size specific.You only really need a hone if you're attempting to true the I.D. I've got dozens of simple home made and they always work.

 

[Wallace]

Example.

 

[Wallace]

Those 3 stone hones are great in concept but suck to use. I've had way better results with Flex (ball type) hones. But...That's been for automotive motorcycle applications where shooting for improved surface/I.D.'s. If you want to spend the dough, this'd be your friend. Just remember that you'll likely never need it again so 300 bucks for single use. Clear as mud right?https://www.amazon.com/305MM-Flex-H...+hone+12+inch&qid=1552831435&s=gateway&sr=8-3

 

[Rail Dawg]

Those 3 stone hones are great in concept but suck to use. I've had way better results with Flex (ball type) hones. But...That's been for automotive motorcycle applications where shooting for improved surface/I.D.'s. If you want to spend the dough, this'd be your friend. Just remember that you'll likely never need it again so 300 bucks for single use. Clear as mud right?https://www.amazon.com/305MM-Flex-H...+hone+12+inch&qid=1552831435&s=gateway&sr=8-3

Definitely the way to go but like you said for single-use hard to justify. Am thinking of getting a dowel that will fit into the drill chuck and cut a slit in it. See if that will do the trick.

Got a couple days here where I can do some build will find out if it works.

Chuck C.

 

[Wallace]

Yup, pretty stiff price for something that just ends up taking up space. Maybe try a broom handle cut down at the shank to fit in a drill? A centering ring or 2 as a guide. Shouldn't be overly difficult to make it work. Oh, and thanks for sharing since all of us would love to attempt this type of project but probably never will.

 

[rcktnut]

I know it's manual labor but they do make these: https://www.walmart.com/ip/Allway-Tools-UPS-Universal-Pole-Sander/19866130

Might work good as is or you could build up the center of the pad to get a bit of curvature to match the tube.

 

[Rail Dawg]

Yup, pretty stiff price for something that just ends up taking up space. Maybe try a broom handle cut down at the shank to fit in a drill? A centering ring or 2 as a guide. Shouldn't be overly difficult to make it work. Oh, and thanks for sharing since all of us would love to attempt this type of project but probably never will.

It goes both ways on the sharing because I pick up ideas I hadn't thought about.

I've got to cut a coupler down to 24" today or tomorrow. Haven't had to cut G12 before because I always used tubes that were pre-cut. However some good ideas were posted to this thread so it should go smoothly.

I've got a diamond blade on the table saw and will use a block of wood as a brace. Should be able to make a good clean cut.

After sanding the inside of the coupler I'll start putting in the vertical stringers. Those will then be carbon-fibered in place. Should make for a very strong assembly. The motor is going to put out upwards of 3 tons of thrust so you have to provide strength all the way up the rocket. Any weak area will crush like an aluminum can.

Since we're not going for altitude there's more leeway to overbuild the insides. This will be the proving grounds for the 16" "S" rocket that is being planned for next year.

I'm always learning and this is a big project. It's fun to share the journey. I'll post more pics soon.

Chuck C.

 

[Rail Dawg]

I know it's manual labor but they do make these: https://www.walmart.com/ip/Allway-Tools-UPS-Universal-Pole-Sander/19866130

Might work good as is or you could build up the center of the pad to get a bit of curvature to match the tube.

Lowes has these in stock! That's a great idea. It's worth a shot. I want to be able to get some oomph into the sanding and am not sure the spinning paddle idea will do enough. There's only 2-3 feet in the middle I can't reach but want to make sure it has a good bonding surface area.

Chuck C.

 

[rcktnut]

Lowes has these in stock! That's a great idea. It's worth a shot. I want to be able to get some oomph into the sanding and am not sure the spinning paddle idea will do enough. There's only 2-3 feet in the middle I can't reach but want to make sure it has a good bonding surface area.Chuck C.

Why sure! I was thinking a sponge under the paper could be shaped a bit or just tighten the sandpaper enough to get a bit of curvature. You could sand it vertically or lay the tube down,(work bench height) secure it somehow or have someone hold it and sand it horizontally.

 

[Wallace]

The pole sanders with U joint actually work fairly well, bit hard to control at times though. You can also get pole sander heads with just a right angle.The sponge is a good idea too. The "stiffer" you can get the backer the better off you'll be. I suspect you'll revert to power tools rather quickly though..

 

[Rail Dawg]

I might go to power tools quickly. There’s only 3 of the 5 ft tubes to get in the middle of so maybe after the appropriate amount of cussing and swearing with the manual paper I’ll be done.

The first couple of feet in each tube will be done with a disc sander.

Chuck C.

 

[blackjack2564]

I have 2 12inch tubes sitting out back.....to sand interior I just bit the bullet and reached inside with folded sandpaper and did it all by hand. Wet sanded and hose by my side. Went quick...wet sand it.
Some times the easiest way is right there all along. I can reach past 1/2 way from each end.

It's a cylinder within a cylinder, once glued, nothings going anywhere. I really believe you are overthinking this. lol

 

[Rail Dawg]

I have 2 12inch tubes sitting out back.....to sand interior I just bit the bullet and reached inside with folded sandpaper and did it all by hand. Wet sanded and hose by my side. Went quick...wet sand it.
Some times the easiest way is right there all along. I can reach past 1/2 way from each end.

It's a cylinder within a cylinder, once glued, nothings going anywhere. I really believe you are overthinking this. lol

I think you're right lol.

Chuck C.

 

[blackjack2564]

Some ideas for Av-bay; we did this "floating" bay to cut down interior space needed to pressurize ejection charges.
Jig for cutting tubes on my ancient table saw. You probably have a nice large table so spacing will be easy.
Set blade so it barely extends out of cut and rotate slowly.
Insert bay where you want it....use shoplight or flashlight to illuminate interior.
We bolt in place for easy prep and removal as a unit.
Mark and drill first hole.Insert bolt to hold in place, then continue around exterior. we used 8 -1/4in. bolts staggered.
4- 5/16th tie rods holding everything together and 5/16 U-bolts with 2in. seatbelt harness for Y-harness on each side extending out end of tube.[ hopefully prevent zippering lol]
Recovery attached to these.
Nutz epoxied in place with JB Weld.
Charge Holders curtesy of Rocket Junkies..they made custom 16 gram holders for us. We only ended up using 8 grams per side with 6 number 6 shear-pins.

 

[Rail Dawg]

That's really nice work Jim. And a good explanation too.

It's appreciated.

Chuck C.

 

[Rail Dawg]

Cut my first 24" coupler tube on the table saw using a diamond blade.

Using the fence and simply taking my time it came out perfectly.

Woo hoo! This is fun.

Chuck C.