Ok... Going Nutz here In China... NEED PVC Rocket Help!

[K'Tesh]

If the PVC is brittle and resistant to bending/flexing, how about simply cutting the pieces you need completely out? Meaning if you were doing it with 5 sections, cut those sections completely out, have the base slightly curved and glue everything in just as if you were making a nose cone and then join to bt with a coupler? Sorry if I missed anything.

The PVC flexes, and I can get the ogive(ish) shape, but I was really hoping to avoid having to deal with keeping 6 very long thin triangles aligned with each other.

I've come up with a slightly different possible design that is a Helluva lot easier to work out... and it uses the pieces I've already cut out. Not as sexy as some other rockets, but appropriate for the workplace.



This the JPL* Stubby PVC.: 4.375" OD, 54mm Powered, PVC body tube, Plexiglass fins. Mind you, the rail buttons would need to be put on stand-offs, but I didn't want to have to put in the phantom body tubes for them.

And the JPL* Stubbier PVC... Like the Stubby, just without the baffle, and forward body tube section



*JPL James Parsons Ltd.

 

[Cl(VII)]

That looks like a much more tractible design than an upscale Arapahoe, and it is decidely non threatening in appearance. A 4" upscale Arapahoe is not a trivial build even with all the materials we are spoiled with...I know of what I speak on this one.

 

[K'Tesh]

Yeah, I think it'd be easier to pull off... Presuming I can locate some kind of suitable ply for the CR's. The fins are a LOT smaller, and I suspect that the Plexiglass shapes should be easier to make. A mod I've thought up after posting the images (above) is that a good idea would be to build the fins such that they can be removed/replaced by unscrewing the aft CR/Thrust plate assembly. It'd add some weight, but should they be damaged (or even badly scratched), I could swap them out easily. Motor retention could be done with screws and washers, so no fancy (Read: nice looking) retainer would be needed to be glued into place.

 

[K'Tesh]

Update: Nothing to report.

My co-worker tried to find some plexiglass for me. However, somehow she managed to find some that looks to be about 3.5mm, and I asked for 5 or 6mm material. It's cheap, but I wouldn't trust it on something that is simming to be over mach 1.15.

No luck on the ply (and no $$ to buy it when I do at this time). Arriving here when I did has limited the number of hours I'm able to work (most kids were already in classes, I was just lucky when a teacher decided to return to USA to have his kid).

I could try cutting the details, but have been working on gifts for people back home (and here) (cut coins).

 

[Cabernut]

I just now noticed the "JPL" - nice.

Plexiglass as a fin material. Interesting. It has a shear modulus of 246ksi and a density of 1.19g/cm3 so it's pretty much half way between plywood and fiberglass.

I'll have to look into that.

 

[K'Tesh]

Ohhh... Shiny!!!! I was reading the English version of China Daily (the national newspaper), and I read about a new website for expats like myself. An English version of an online shopping site that will actually ship IN china! Oh, and they apparently have Birch Aviation Plywood. I'll need to show this to my coworker to verify the dimensions, but I *MIGHT* have a suitable material for CR's and bulkheads. I *MIGHT* be able to actually build something in the not to distant future.

Pointy Side Up!

 

[KenECoyote]

Hey Jim,

Sounds like despite the setbacks and slow going, you're getting closer. I admire your moxie and determination! :clap:

Additionally, while I love the Arapahoe, I think the Pencil rocket makes a lot more sense and also fits with the "Teaching in China" theme. The school officials and students should readily approve of that design since it just falls in line with school and education.

Have you considered making small/micro rockets in the meantime? There are vids out there on how to make small rockets and some are even non-combustible powered. Additionally, I love the small scale for scratch building since it's much easier to find parts, the strength of the parts aren't as critical (parts in small scale are often much stronger proportionally...you can use cardstock!) and it's much cheaper, quicker and easier to make. I'd just roll up some paper or cardstock for the bt, use a pen/marker cap for the nose and plenty of materials around for the fin stock. Once you do it small scale (and prove the design can fly), it's easier to then upscale. Just sayin'. :wink:


Here's some interesting vids for thought (albeit you may not be able to get all the parts). Also it's on you to make sure you don't violate any local laws.

Office Supplies rocket (Air Duster powered):
[video=youtube;b89secVPO5U]https://www.youtube.com/watch?v=b89secVPO5U[/video]
Making a minature rocket with Bickford fuse:
[video=youtube;qnXYmpmmxGM]https://www.youtube.com/watch?v=qnXYmpmmxGM[/video]
Mini match rocket:
[video=youtube;WFyKgmnCF-8]https://www.youtube.com/watch?v=WFyKgmnCF-8[/video]
Rocket from sparklers & soda can (looks more dangerous):
[video=youtube;wh2P1-u_Vsc]https://www.youtube.com/watch?v=wh2P1-u_Vsc&oref=https%3A%2F%2Fwww.youtube.com%2Fwatch%3 Fv%3Dwh2P1-u_Vsc&has_verified=1[/video]
Compressed air rocket from paper:
[video=youtube;jYKKknj_Shg]https://www.youtube.com/watch?v=jYKKknj_Shg[/video]Compressed Air rocket system (more elaborate):
[video=youtube;eNFfK5uo6D0]https://www.youtube.com/watch?v=eNFfK5uo6D0[/video]

 

[dhbarr]

Stomp Rocket are a 2litre bottle away, great for students.

 

[MaxQ]

Alright... I've been in China for 2.5(ish) months, and I haven't had a single rocket to build. I'm going a little bit nutz here.

I've found a thin wall 4"(ish) PVC pipe that I'm seriously thinking about making into a scratch built HPR rocket. Problem is, I've never made a PVC rocket before. Anybody got some build threads (actual builds) that I might be able to ponder over?

Thanks!
Jim

PVC rocket...makes me think of that guy that had the website for making sugar/ammonium nitrate fueled PVC rockets, back during the ATF hassles over AP.
https://www.space-rockets.com/newbook.html

Popular alternative for some folks.
All PVC and I think they had compressed kitty litter clay nozzles, drilled out.
(or maybe that was a guy on YouTube ?)
I always kinda thought PVC was a bit on the heavy side.

4 inch PVC...I'm thinking mandrel.
Start wrapping some of that fancy Chinese paper with wetted out wood glue.
I can see it now..The Chinese Paper Dragon Rocket.

[video=youtube;v5B4e79bmCs]https://www.youtube.com/watch?v=v5B4e79bmCs[/video]

 

[Salvage-1]

Yo there Jim. I find it incredibly ironic that we are in the US complaining that all the Estes parts, etc are made in China, and you are in China and cant find ANYTHING.

These are a chinese company made in china...
https://www.amazon.com/dp/B000WNYFHO/?tag=skimlinks_replacement-20
cant you even get these?

Ohhh... Shiny!!!! I was reading the English version of China Daily (the national newspaper), and I read about a new website for expats like myself. An English version of an online shopping site that will actually ship IN china! Oh, and they apparently have Birch Aviation Plywood. I'll need to show this to my coworker to verify the dimensions, but I *MIGHT* have a suitable material for CR's and bulkheads. I *MIGHT* be able to actually build something in the not to distant future.

Pointy Side Up!

 

[K'Tesh]

Yo there Jim. I find it incredibly ironic that we are in the US complaining that all the Estes parts, etc are made in China, and you are in China and cant find ANYTHING.

These are a chinese company made in china...
https://www.amazon.com/dp/B000WNYFHO/?tag=skimlinks_replacement-20
cant you even get these?

Yes, but having bought one in the US (from Apogee), I can say they are not a builder kit, and would be a momentary distraction rather than a satisfying full-on project.

As to the other projects:

If it involves fire, I want a commercial motor, I don't need kids trying this at home and getting themselves burned.

Stomp/compressed air/water rockets are an option if I can source the parts for them.

Still, I really want to build a HPR rocket that I can take to Thunder Down Under or post really cool photos of (for promotional materials).

 

[KenECoyote]

Still, I really want to build a HPR rocket that I can take to Thunder Down Under or post really cool photos of (for promotional materials).

Yeah, for that I wouldn't show up with matchstick and stomp rockets. :wink:

 

[dhbarr]

Stomp rockets only require PVC and 2L bottles, use any free paper plans for the kids.

Won't scratch the HPR itch, but if you -need- a distraction....

 

[KenECoyote]

Stomp rockets only require PVC and 2L bottles, use any free paper plans for the kids.

Won't scratch the HPR itch, but if you -need- a distraction....

+1

 

[midpower_madness]

You can build rockets in the PRC. Just ask - lots of hobby stores in Tianjin. Estes makes motors in China and local PRC companies sell these fireworks in specialty stores. Likely you'll find black powder types.

 

[Incongruent]

Hope I'm not too late.

A few pointers and some thoughts.
1) Don't heat it up (indoors)- above 70 Degrees Celsius, it starts degrading and releasing Hydrochloric acid.
2) Judging from your description (cracking), you have rigid PVC. There was a thread debating the use of PVC as a body tube for HPR, but I can't find it. There were mixed results and lots of mad people, but in the end it seems that they agreed: Not for newbies (the OP) but for experienced HP builders, sure. (It actually wasn't "sure", it was "whatever" and "you don't know anything PVC is awesome")
If you can find builders paper or flooring paper in China, I'd roll a tube with that. (I'm definitely not in any way an expert on this but my thoughts are that if Phenolic can get cracks from landing on a fin, PVC will too.)
There's an Apogee newsletter on custom tubes. (With copy paper) It says to cover the paper with white glue (since it has vinyl in it) and after it dries, iron it to fuse the paper together and smooth it out.
The flooring and builders paper is found in home improvement stores in the U.S., but I can't remember whether they have the stores or not in China. If they do, paper cones are a possibility too. You might be able to use some PVC as a shoulder on the nose cone if you used it as the mandrel. Rigid insulation foam makes *ok* ogive nose cones.
3) THIS IS JUST SPECULATION (mostly- 1 is from Wikipedia, but since it applies to safety, it's problably good practice to follow.)

and questions...
Is pvc all you have?
How about induction stabilizing the rocket? The ridges on the metal eraser holder can be replaced with bamboo skewers (plentiful) and the motor recessed into the tube. Might need extra nose weight or a shorter pencil though. Also ignition...
Or call it sky writer and just take off the fins. (Don't try this at home)
Are the students launching the rocket?
Is it a learning project, conversation piece/ decoration, or just to scratch the High Power itch?

If you want a time consuming build, try a scratch sport scale of one of the Chang Zheng rockets. (Further links on page)
I am a bit biased against pencil rockets though... I don't need any reminders on how I got poked by a really sharp pencil (or so it seemed) when I went to school in China.
The Chang Zheng 2E, 2F, 3, 3A, 3B, 4A, 4B, 4C, 5, and 7 have (small) fins, and the boosters on the 7, 3B, and 5 cause drag too. (Mostly from the change in cross sectional area. I think. Please correct me if not.) A scale model of these would problably not be threatening either, since the mission is scientific and discovery rather than war and explosions. And it's showing national pride (is that the right phrase?) and you can maybe use it to teach and it looks cool.
The nose cones are better made from balsa (or foam) than PVC or paper. A paper transition, maybe, but the tip should be carved.
I'm assuming you aren't interested in resin casting.

Also, if anyone knows, on the CZ-7, are the fan shaped corrugations stringers? If so, why not straight like on the other stringers?

In any case, good luck with your rocket however you build it.


-Tony

 

[K'Tesh]

Hope I'm not too late.

A few pointers and some thoughts.
1) Don't heat it up (indoors)- above 70 Degrees Celsius, it starts degrading and releasing Hydrochloric acid.
2) Judging from your description (cracking), you have rigid PVC. There was a thread debating the use of PVC as a body tube for HPR, but I can't find it. There were mixed results and lots of mad people, but in the end it seems that they agreed: Not for newbies (the OP) but for experienced HP builders, sure. (It actually wasn't "sure", it was "whatever" and "you don't know anything PVC is awesome")
If you can find builders paper or flooring paper in China, I'd roll a tube with that. (I'm definitely not in any way an expert on this but my thoughts are that if Phenolic can get cracks from landing on a fin, PVC will too.)
There's an Apogee newsletter on custom tubes. (With copy paper) It says to cover the paper with white glue (since it has vinyl in it) and after it dries, iron it to fuse the paper together and smooth it out.
The flooring and builders paper is found in home improvement stores in the U.S., but I can't remember whether they have the stores or not in China. If they do, paper cones are a possibility too. You might be able to use some PVC as a shoulder on the nose cone if you used it as the mandrel. Rigid insulation foam makes *ok* ogive nose cones.
3) THIS IS JUST SPECULATION (mostly- 1 is from Wikipedia, but since it applies to safety, it's problably good practice to follow.)

and questions...
Is pvc all you have?
How about induction stabilizing the rocket? The ridges on the metal eraser holder can be replaced with bamboo skewers (plentiful) and the motor recessed into the tube. Might need extra nose weight or a shorter pencil though. Also ignition...
Or call it sky writer and just take off the fins. (Don't try this at home)
Are the students launching the rocket?
Is it a learning project, conversation piece/ decoration, or just to scratch the High Power itch?

If you want a time consuming build, try a scratch sport scale of one of the Chang Zheng rockets. (Further links on page)
I am a bit biased against pencil rockets though... I don't need any reminders on how I got poked by a really sharp pencil (or so it seemed) when I went to school in China.
The Chang Zheng 2E, 2F, 3, 3A, 3B, 4A, 4B, 4C, 5, and 7 have (small) fins, and the boosters on the 7, 3B, and 5 cause drag too. (Mostly from the change in cross sectional area. I think. Please correct me if not.) A scale model of these would problably not be threatening either, since the mission is scientific and discovery rather than war and explosions. And it's showing national pride (is that the right phrase?) and you can maybe use it to teach and it looks cool.
The nose cones are better made from balsa (or foam) than PVC or paper. A paper transition, maybe, but the tip should be carved.
I'm assuming you aren't interested in resin casting.

Also, if anyone knows, on the CZ-7, are the fan shaped corrugations stringers? If so, why not straight like on the other stringers?

In any case, good luck with your rocket however you build it.


-Tony

Hi Tony,

Thanks for all the input. Sorry, I hadn't had time to respond earlier.

No, you're not too late. This stalled really quickly thanks to my former employer's ability to not deliver on her promises. I was told I'd get lots of hours, and there were weeks (two or three) where they'd materialize, only to dry up before the following month. No money, no way to play.

I still might do the pencil rocket, especially now that I've got a new school that is delivering as promised (8K RMB/month regardless of hours (so long as I work the shifts I'm assigned (and up to 15 hours / week))). Depending on the strength of the dollar, that's just under $1200/month (a livable wage here with plenty to spare after food)). I might want to re-think the PVC part though.

For the Omega/Cineroc upscale that I have planned, the body tube will be cardboard (I've already found it). The upscaled Cineroc will be PVC though.

Here in Yantai, there's nothing like the big box home improvement stores that I've been able to locate. I think my best chance is TaoBao, or BaoPals. However, there are tons of small "hole-in-the-wall" stores that sell some of the oddest stuff. I've avoided entering a number of them for that reason (or the owners are chain smoking)). Until now I haven't had the cash to shop online or in the small shops anyway.

The ambition is a combination of things. To give me something to build (scratch the itch), act as a conversation piece (on display at the school, and/or used at school functions), and hopefully be flown at something like Thunder Down Under in September 2018. Kids will not be able to launch these, and I will maintain ownership, unless the school wants to buy them from me.

I've thought about scale rockets. There's a number of scale paper models that I've seen that *could* be upscaled to meet my needs (and be flown), but how exactly I'm not 100%.

Also, today I reached out to Tripoli to see about what it would take to start a prefecture here in China (I've got an email address, but needed sleep before I could follow it up). I'm also thinking about the best place to launch. I'm thinking about going for the Gold(fish)(club). I am on the edge of the Yellow Sea, and it might solve certain issues I've thought of if I can get to the point of actually doing a launch here.

Xie Xie!
Jim

 

[Zebedee]

Just remember to use some kind of metallic paint so the shards show up on an xray...

 

[K'Tesh]

Just remember to use some kind of metallic paint so the shards show up on an xray...

[video=youtube;vypGPc2LVFo]https://www.youtube.com/watch?v=vypGPc2LVFo[/video]

 

[Incongruent]

Hi Tony,


Thanks for all the input. Sorry, I hadn't had time to respond earlier.

No, you're not too late. This stalled really quickly thanks to my former employer's ability to not deliver on her promises. I was told I'd get lots of hours, and there were weeks (two or three) where they'd materialize, only to dry up before the following month. No money, no way to play.

I still might do the pencil rocket, especially now that I've got a new school that is delivering as promised (8K RMB/month regardless of hours (so long as I work the shifts I'm assigned (and up to 15 hours / week))). Depending on the strength of the dollar, that's just under $1200/month (a livable wage here with plenty to spare after food)). I might want to re-think the PVC part though.

For the Omega/Cineroc upscale that I have planned, the body tube will be cardboard (I've already found it). The upscaled Cineroc will be PVC though.

Here in Yantai, there's nothing like the big box home improvement stores that I've been able to locate. I think my best chance is TaoBao, or BaoPals. However, there are tons of small "hole-in-the-wall" stores that sell some of the oddest stuff. I've avoided entering a number of them for that reason (or the owners are chain smoking)). Until now I haven't had the cash to shop online or in the small shops anyway.

The ambition is a combination of things. To give me something to build (scratch the itch), act as a conversation piece (on display at the school, and/or used at school functions), and hopefully be flown at something like Thunder Down Under in September 2018. Kids will not be able to launch these, and I will maintain ownership, unless the school wants to buy them from me.

I've thought about scale rockets. There's a number of scale paper models that I've seen that *could* be upscaled to meet my needs (and be flown), but how exactly I'm not 100%.

Also, today I reached out to Tripoli to see about what it would take to start a prefecture here in China (I've got an email address, but needed sleep before I could follow it up). I'm also thinking about the best place to launch. I'm thinking about going for the Gold(fish)(club). I am on the edge of the Yellow Sea, and it might solve certain issues I've thought of if I can get to the point of actually doing a launch here.

Xie Xie!
Jim

Hello.

Ummm... You're welcome! (I was going to put in pin yin for that, but I couldn't sound it out correctly - - I can only speak Chinese.)

I heard from my parents that Amazon was doing the Amazon Prime in China, they might have some kits, though problably mostly Aerotech, Quest, and Estes. Other supplies too, but chances are, way overpriced. (At least on less common items, baltic birch plywood, for example.
Accoording to Apogee, Chinese (18mm) motors are a tad bigger than our standard sizes, which is an issue in our standard tubed rocket.

Giant High Power upscale of Acme Spitfire is in order! (In addition to what you planned- what I call the "K'Tesh rocket". Sorry.)
Good demonstration rocket...
is a great excuse.
Scratch that itch!

So in central China there's "Sky Rocketry"
They make high power rockets too!
Just Kidding, those are for cloud seeding and stuff, but it's based in China and you might be able to get some stuff there. It might be bulk orders only though.
Even though it problably does work, "Forest Fire Extinguishing Rocket System" is worth a chuckle...
you'll have to read the stuff on their site since I can't.

So you've also seen the thread about water launches. (I believe you posted...) I've been to where I think you are, and I distinctly remember a bunch of barges and ships everywhere. High power rocket lands in/on one and you have a big problem. Especially if it's a failed deploy. Then there's recovery, not just from the ocean but before it gets run over by a boat too. Very hard to change shipping routes, cause it costs money.
There's picture on sky's home page with a rocket launching over what appears to be a body of water though. Problably not a model rocket. Problably not going to land in the water either, so maybe just for safety.

I also remember a very crowded city on the land, so you might be stuck in postage stamp fields. Or smaller.
Smooshed grain of rice fields...
Oddrocs maybe?

As for smoking shop owners, the problem and solution are remarkably similar to those of the boys restroom... hold ya breath. Except you could have to wait in line and stuff. In that case, I recommend paying a trip to the SCUBA shop first should you venture into the depths of these gas chambers.

Are there art shops or art sections? They might have some paper that could be useful, either in length/width size or thickness. A carded scale model would be cool. There are some free space model templates for download here, could be a good project even if not necessarily flyable.

Nose cones... If you find a mailing tube for the body, the end cap, sanded down a bit, could work for a shoulder (might need lengthening and needs a cone-ish shape.)
Book binding wire (and clothes hanger wire) makes usable engine hooks for LPR, if you can't locate spring steel (inside windshield wiper blade)
The book binding wire (or clothes hanger) also works for an eyelet for the nose cone, if you use layers on foam to make the nose cone.
Kites are popular, or so I think, so maybe you can check them out for Kevlar shock cords.
If CA is accessible, thin paper tubes wicked with it can be used as Launch Lugs.
Balsa and other fin wood might be hard to find locally, but there is copy paper "plywood" (stacked sheets of copy paper with perpendicular grain directions and glued together with thin CA or wood glue/ school glue (warp prevention needed)
I used it before, think of it as cardstock but less splitting between layers. The CA has to be wicked into every new layer though.
I think Bristol board is similar, a stronger cardstock made with different grain directions.


Sorry about out the lack of orginization and editing.

-Tony

 

[Titan II]

Just remember to use some kind of metallic paint so the shards show up on an xray...

PVC not showing up on an x-ray is a myth.

 

[Incongruent]

PVC not showing up on an x-ray is a myth.

PVC fracturing into sharp shrapnel isn't a myth.

I thought the problem was having to distinguish PVC from the surrounding flesh due to their similar densities.

It's always good to play it safe.

 

[K'Tesh]

Looks like I've got the manager's support to build the "Stubby"... Now with a plan on how to get the parts.

 

[K'Tesh]

Ok... Time to bump this again...

On Sunday, I found someone had tossed out some Styrofoam insulation, more than enough to do the job. I've been looking for some for quite some time, but despite all my inquiries, and searches, I couldn't locate a place that sells it. Took some time hauling it on my bicycle (uphill, into a head wind, during freezing temps, with large pieces of foam wanting to flop about while I'm weaving between pedestrians and cars), but I managed to do so. Then I tried to find my sim for it... Looks like it was one of the casualties of the 2016 computer meltdown. So... I re-did it.


It's not finalized, but I think my advances in techniques with OR are quite evident... I will need to find an appropriate piece of wood to form the tip of the nosecone, and its core, and some foam safe glue, but I don't think that will take 4 years.