New upscale, Freefall XL

qquake2k · Aug 4, 2013

Okay, I give up. I can't stop building rockets. I must be psychotic. The latest I'm designing is an upscale of the Estes Freefall. I already have a generic GI Joe paratrooper, so this will be the perfect launch vehicle for him.

Freefall XL will be a 4" upscale. It won't be exact, because the body tube should be 37" long, and the LOC tubing is only 34" long. But it'll be close enough. The motor mount will be 38mm. I'm a little worried about the fins, though, because of the design. I'm afraid they'll break easily because they're narrow where they attach. I'm considering using 3/8" plywood. Overkill? Maybe. But I've never been accused of under kill!

View attachment Freefall XL.ork

cwbullet · Aug 4, 2013

Awesome idea for a build. Subscribed.

o1d_dude · Aug 4, 2013

You are the Rocket Building Machine.

fyrwrxz · Aug 4, 2013

38mm mount huh?? Joe must be into HALO jumps-LOL! Go for it!

cwbullet · Aug 4, 2013

I like it. I just upscaled it to 6 inches. You inspired me to build it dual deploy. Imagine a paratrooper from 5000 feet.

qquake2k · Aug 5, 2013

o1d_dude said:
You are the Rocket Building Machine.

More like the rocket building psycho.

qquake2k · Aug 5, 2013

fyrwrxz said:
38mm mount huh?? Joe must be into HALO jumps-LOL! Go for it!

Actually, it would be HAHO. His chute will deploy on exiting the vehicle.

qquake2k · Aug 5, 2013

cwbullet said:
I like it. I just upscaled it to 6 inches. You inspired me to build it dual deploy. Imagine a paratrooper from 5000 feet.

A 6 inch version will be very cool! You should have enough room for 3 or 4 Joe's!

If you're using my Open Rocket file for the 6" version, keep in mind the fins may not be exact. I used the largest photo of the Freefall I could find online, cut off one of the fins in Photoshop, and imported it into OR. When I upscale a current kit, I always order one of the kits. It seems more fair that way, since it's not my design. I'll scan the decal and trace the fin once I get the kit.

Target · Aug 5, 2013

Qquake could you maybe "beef up" in that area of the fins? An extra layer of paper? Possibly a thin layer of basswood glued/laminated and sanded to a taper? Just some ideas but you are the rocket machine who seems to cover all your bases. Looking forward to this rocket.

qquake2k · Aug 5, 2013

Target said:
Qquake could you maybe "beef up" in that area of the fins? An extra layer of paper? Possibly a thin layer of basswood glued/laminated and sanded to a taper? Just some ideas but you are the rocket machine who seems to cover all your bases. Looking forward to this rocket.

Well, I thought about fiberglassing the fins. But I've never done it before, and don't have the right epoxy for it. I also thought about 1/8" G10 for the fins, but working with it is problematic. The only time I've cut G10 fins, it was .092" and it ruined my bandsaw blade. I'll probably be lazy and just use 3/8" plywood. I do like thick fins.

cwbullet · Aug 5, 2013

Go with 1/4 balsa or plywood fiberglassed. I have a piece of each and the balsa with a layer of 6 oz and 3 oz is incredibly strong.

bradycros · Aug 5, 2013

I got this "Bail Out" kit a long time ago, back when we both were younger men.

It shares the same theam as your new build.

qquake2k · Aug 5, 2013

cwbullet said:
Go with 1/4 balsa or plywood fiberglassed. I have a piece of each and the balsa with a layer of 6 oz and 3 oz is incredibly strong.

Unfortunately, I'd have to buy the epoxy and cloth for it. I don't know that it's worth it to me.

qquake2k · Aug 5, 2013

bradycros said:
I got this "Bail Out" kit a long time ago, back when we both were younger men.

It shares the same theam as your new build.

Hey, I remember the Bailout! Is it a BT-60? Looks like the same fins.

qquake2k · Aug 10, 2013

I got the order from Hobbylinc. Thank goodness the 4" tube wasn't damaged this time. The Estes V2 kit is for my nephew.

qquake2k · Aug 10, 2013

This is the Estes Freefall kit. No painting required! LOL

I traced the fin and scanned it...

qquake2k · Aug 10, 2013

But no matter what I did, I couldn't get Open Rocket to import it. So finally, I took a photo of it against a piece of white card stock. As you can see, the actual fin (on the left) is quite a different shape than the one I originally came up with.

qquake2k · Aug 10, 2013

I finally got Open Rocket to import the fin. But there's something about the shape of the actual fin that OR doesn't like. With it, I have to add 30oz of nose weight to make it stable. And of course, that was a slippery slope. The more nose weight I added, the bigger the motor needed to be, which reduced the stability, so I had to add even more nose weight... Talk about a catch-22!

I really don't want to add nose weight, so I'll probably use the fin shape I came up with. I think it's close enough.

View attachment Freefall XL_2.ork

chadrog · Aug 10, 2013

Who wants to top this and toss out a mannequin?!?

qquake2k · Aug 10, 2013

I just can't figure this out. There's not that much difference between the two fins. And yet, Open Rocket says the fin on the left gives 1.78 caliber of stability. But the fin on the right gives -0.656 caliber. I don't think there should be such a huge difference, with everything else being equal.

View attachment Freefall XL 29mm.ork

View attachment Freefall XL 29mm_2.ork

qquake2k · Aug 10, 2013

This is so perplexing. I reshaped the fins in the first file I had made, so that the fins are closer to the kit. Everything else remains the same. And yet the stability increased to 2.11 calibers. Something's not right here. I'm concerned that the original file isn't as stable as OR says it is.

View attachment Freefall XL 29mm_2.ork

View attachment Freefall XL 29mm_3.ork

jazzviper1 · Aug 10, 2013

I have been wanting to do this for years.
I have dozens of GI joes with parachutes, I can't wait to see how yours works out.

qquake2k · Aug 10, 2013

Using my tried and true method, I got the centering rings cut out with a 4-1/4" hole saw, then sizing them on the lathe. The center holes were cut out with a 1-9/16" hole saw, and sized with a sanding drum in the Dremel.

rocketgeek101 · Aug 10, 2013

I'll be watching closely. Out of curiosity; how many rockets are in your fleet now? You should take a picture of all of them together and post it here for us to drool over...

qquake2k · Aug 10, 2013

rocketgeek101 said:
I'll be watching closely. Out of curiosity; how many rockets are in your fleet now? You should take a picture of all of them together and post it here for us to drool over...

Oh heck, 50 or 60? Maybe more? It would take me an hour just to set them all up for a group shot! Right now, I have rockets in my bedroom, garage, living room, computer room, they're all over the place. I have four brand new ones that haven't flown yet.

qquake2k · Aug 10, 2013

As discussed here, the weird stability issue is apparently due to a glitch or bug in Open Rocket. My gut tells me the design is stable, so I'm going for it. I've got two fin designs, the initial one and the more accurate one from the tracing. I've decided to use the initial fin design, even though it's not an exact upscale. The reason being, it's a little "meatier", and I think will be stronger. With the rockets the same colors, and the same decals, I think it'll be plenty close enough.

qquake2k · Aug 10, 2013

Got the blocks epoxied onto the centering rings for the tee nuts and rail buttons. Also got the rail button blocks sanded flush.

qquake2k · Aug 11, 2013

I printed the fin template on card stock and got it cut out. I printed the fin wrap on regular paper, but had to cut two and tape them together since it was longer than 11". As I've done in the past, I cut out "fin blanks" with the bandsaw. I love a bandsaw with a good fence!

qquake2k · Aug 11, 2013

I wanted to pin the blanks together to cut out and sand the fins together. Normally, I drill holes in the fin tabs for 1/4" wooden dowel pins. But in this case, I was afraid holes in the tabs might weaken them. So I drilled the holes on the perimeter.

qquake2k · Aug 11, 2013

When cutting out fins with the bandsaw, I like to use the fence wherever possible. I sanded what I could before making the final cut and removing the pins. You know, that little 1" belt sander from Harbor Freight has ended up being much more useful than I ever thought it would.

New upscale, Freefall XL

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