Need help with spool rocket idea

[ljwilley]

I want to build a HPR spool rocket, and I thought that maybe I could use some empty 3d printing spools for the upper and lower rings. Just wanted to ask if anyone sees anything wrong with the idea, as I am new to spool rockets.

Thanks in advance!

 

[jqavins]

I'm not sure what you mean by that? There's usually just one spool, even if it's built up from separate parts, two discs and a tube. I'm no expert on this, but a filament spool seems pretty small for an HPR spool; I'm sure you could stick an 18 or 24 mm MMT in one and fly it LPR.

 

[ljwilley]

See I told you I have no experience with spool rockets. The 3d printing filament spools are too heavy for 18mm-- maybe 24 or 29mm. The spools are also too short to use only one. I was planning to put one on each end and a tube in the middle. Thanks anyway.

 

[jqavins]

How heavy are the spools? Something like a Q-Jet 18 mm D16 or D20 could lift a decent amount, I should think. Anyway, if a 24 mm fits then that gives you lots of options.

The beautiful thing about spool rockets is their simplicity. Just shove an engine into the hole*, figure out something for recovery, and off you go.

* Get your minds out of the gutter, people.

 

[ljwilley]

Each spool is 250 grams. I am also planning on 3d printing some parts to adapt the spools to the body tube. (they aren't the perfect size) And there also will be a tube, and a motor mount. The motor mount is because the tube that fits in the spools is 38mm and now that I think about it I don't really want to do high power rocket motors on it.

 

[kuririn]

See I told you I have no experience with spool rockets. The 3d printing filament spools are too heavy for 18mm-- maybe 24 or 29mm. The spools are also too short to use only one. I was planning to put one on each end and a tube in the middle. Thanks anyway.

I think you can use just one. If models like the Newway Square in the Air and the Squirrel Works Pie in the Sky can fly stable then I don't see why a single 3D filament spool cannot.
You will have to rig recovery gear, because tumble recovery is not an option with something this heavy.
You can extend the motor tube below the spool and leave enough room in front for a chute. Doesn't need to be fully contained.
The Loc Cool Spool has the chute sticking out the front.
Since this cannot be simmed, the acid test will be an actual heads up flight.
BTW here's a spooler I'm working on from a 3D filament spool a friend donated to me.


29mm motor mount, parachute recovery.
Good luck with yours!

 

[ljwilley]

I'm basically doing the same thing as you- same hatchbox spool.

 

[jqavins]

I haven't done a spool, but my thinking is that when I do, I'll just leave enough room in the MMT for some dog barf, then stich the folded 'chute on top with some tape. Tie a shock cord to a hole in the top plate near the edge (already present on that Hatchbox spool, for example). Bing bang boom done.

 

[Sooner Boomer]

I used a Carris (brand) plastic spool. I put a 29mm mount in the bottom end (just long enough to hold a short 29mm motor), and cut a hole in the top end to fit a BT-55 coupler. Flew great. As with all spools, it stops flying when the motor burns out, so short delays are called for! I stopped flying it when the kevar recovery harness broke inside the body. By this point, it was more Gorilla Tape and hot glue than original plastic.

 

[mproctor13]

Bad Boy Rocketry on ebay sells a kit for which is 29mm mmt, a couple of centering rings, 1/4" tube, and an esun spool. Supposed to fly on Estes E16 and F15, with tumble recovery.

https://www.ebay.com/itm/326055624703

 

[ljwilley]

Yes, I have seen that. Might have to get one some time!

 

[Sooner Boomer]

The Spool family
https://www.rocketryforum.com/threads/rocket-family-pictures.167694/#post-2166690

 

[mikeyd]

I went to Atwoods farm and tractor supply, and found some empty spools that used to hold the bulk rope for sale, and asked what they did with the old spools and if I could buy them. They gave them to me. The come apart and the inside just fit a 29/38 adapter. I fly it on G64-4 reloads.

 

[kuririn]

I went to Atwoods farm and tractor supply, and found some empty spools that used to hold the bulk rope for sale, and asked what they did with the old spools and if I could buy them. They gave them to me. The come apart and the inside just fit a 29/38 adapter.

Kit 'em and start a new rocket company.
Call it Fools' Spools.

 

[cwbullet]

I'm basically doing the same thing as you- same hatchbox spool.

They work but tend to break when coming down. Add a large chute if you want that not to happen.

 

[ljwilley]

Yeah. I wouldn't have guessed that, as it seems pretty durable. I was going to put a big chute in it though, as it would not be good if it landed on a person/car with a small chute.