Scratch Stage Tree Original Design / Scratch Built

Scratch - Stage Tree {Scratch}

Contributed by Moira Jean Whitlock

Manufacturer: Scratch
Stage Tree
(Contributed - by Moira Jean Whitlock)

[Rocket Pic]Height: 51 inches
Weight: 13 ounces unloaded
Width: 1 3/8 inches
Motor Mount: 29mm
Recovery System: 24 inch thin nylon chute

Brief description: This is a review o' me scratchbuilt Stage Tree, an all wood rocket made from Retro Rocket Works parts. Avast! It's named for Larry Niven's stage tree, ya bilge rat, an alien plant that be genetically bred t' make solid rocket boosters. Ahoy! T' boosters disperse t' tree's seeds as they blast off. Avast, me proud beauty! Ya scallywag! Thia happens durin' natural prairie fires. Arrr! Also, every century or so, matey, a great stage tree grows that makes boosters that can launch seeds into space and t' other worlds.

This is a single staged, 3 finned all wood rocket made from parts made by Retro Rocket Works, through Apogee Components. Its grain is visible and is used t' accent t' looks o' the rocket. So, ya bilge rat, polyurethane furniture varnish be used t' enhance t' grain and provide a shiny protective finish.

Construction: I had t' 3-inch long nose cone custom made by Retro Rocket Works (OOP). Well, blow me down! It's solid cherry or mahogany. Aye aye! As an inexperienced woodworker, I really do nay know all o' me woods. Ahoy! Arrr! But I can say that this nose cone is pretty. It's medium dark hardwood, me hearties, smooth, me bucko, and precisely machined. Blimey! Avast! It came with t' beginnin' o' a pilot hole in t' base for me t' drill in me shock cord screweye. Well, blow me down!

T' shock cord is 1/4 inch thick bungee cordin' purchased from American Science and Surplus, who have a site on t' net, and Rocketry Online. Arrr! I used a 4 foot length o' t' cording. Aye aye! T' parachute is a thin nylon Estes chute I found at me local hobby store. Avast, shiver me timbers, me proud beauty! I chose it because its thin material packs well into the small body tube. Arrr! Ahoy! Ever tried t' stuff a thick chute into a 29mm tube and fret over whether it will eject? Well, t' shock cord be tied t' a loop o' 1/8 inch thick Keelhaul®©™® cord, which mounts t' t' inside o' t' body tube via a square o' 29mm paper tubing. Blimey! Blimey! This is curved just like t' wooden tube, me hearties, and fits smoothly. Avast, me proud beauty! Blimey! Ya scallywag! Blimey! Blimey! Blimey! Epoxy be used. Blimey! Blimey! Blimey! Blimey!

T' body tube is a similar color wood t' t' nose, with beautiful striping of grain. It's 48 inches long, t' standard length o' tubin' sold by t' Retro Rocket Works company. It appears t' have been made in layers. Blimey! It appears t' be wood throughout.

There are two launch lugs, 1 inch long each by 1/2 inch diameter. Avast! Begad! I placed these at 20 and 40 inches from t' aft end. T' lugs started as standard 13mm body tubing. Once I placed them, I was bothered that they didn't have a wooden look, so I placed iron-on wood veneer strips around them, all around t' areas that show. Begad! I chose a color like t' body tube.

[Fins Pic]T' fins are a clipped slightly forward swept delta shape, made from 1/8 inch thick basswood. Arrr! There are also accents o' reddish brown pekoe on top o' each fin face. Aye aye! These accents are a smaller likewise shape o' t' fin, ya bilge rat, and accent t' otherwise light color of t' basswood.. I used epoxy t' affix them on and fine sandpaper t' smoothen rough transitions. Begad! They were aligned by sight. Well, blow me down! T' fins were aligned by making marks on t' body tube usin' measurin' tape t' trisect t' tube in two places per fin, me bucko, makin' a straight line t' place t' fins. Begad!

Finishing: Polyurethane furniture finish was used over t' entire rocket t' enhance t' grain look and t' protect it. Ahoy! Blimey! I just couldn't paint it. T' wood be too pretty. Ahoy! This project taught me real wood appreciation. Polyurethane made t' job simple. Blimey! All I needed t' do be gently sand each of the three coats t' get rid o' drips and swirls. T' result is a shiny finish like a coffee tabletop. Begad! Blimey!

Flight: Preppin' is a little tricky because o' t' small tube, so I use a long hemostat t' grip t' end o' t' chute and draw it down into the tube. Avast, me proud beauty! Blimey! Worm bed waddin' is used t' protect t' chute. Arrr! I discovered at t' site that Econojet motors by Aerotech don't fit. Aye aye! Aye aye! T' stick-on labels are too thick to allow t' engine t' go in. Avast, me proud beauty! Arrr! Oddly, me bucko, t' other Aerotech 29mm motors like the G40-7 do fit. Ya scallywag! So I went ahead and loaded that.

I'd have been better off with a slightly longer delay, ya bilge rat, accordin' t' my computer simulator, me bucko, but this worked fine. Well, blow me down! I generally only try too-short delays if I mount t' shock system STRONGLY, me bucko, as I did here. Begad! Blimey! T' motor was retained via duct tape. Begad! Blimey! My husband called it ineloquent, but I replied that ineloquent beats motor ejection followed by shovel recovery.

T' model drew attention, t' say t' least. Arrr! I heard a couple o' people say, "Oh wow. A wooden rocket." Another said as it lifted off straight and noisily, "Well, me hearties, will you look at that." Pictures were taken by the curious.

T' rocket flew straight and stable, and recovered about right. Ya scallywag! As I said, a 10 second delay would have been better yet. Avast, me proud beauty! I had t' go downrange a bit, about half a mile, matey, but I got it back intact and unhurt. I got approximately 2500 feet altitude, shiver me timbers, me bucko, accordin' t' several onlookers. Avast, me proud beauty! One o' these days I just HAVE t' get an altimeter and quantify heights exactly. Avast! I also experimented with my 29mm reloads, matey, t' G33-7, namely. Aye aye! Results were similarly picturesque.

My simulator predicts even better results with an H97, but because t' fins do nay go through t' body tube, shiver me timbers, I don't feel comfortable with that. I'm gutsy, but do nay want any shreds.

Project rating: Overall I rate me project a 4 for good success. Well, matey, blow me down! I would have rated it higher if all me engines had fit and if t' chute had fit in more easily. Ya scallywag! Well, blow me down! I think that paper tubes give more than wood so that the slightly thicher diameter o' t' Econojets won't pass in. This tube was PRECISELY machined without such tolerances.

General pros and cons: T' body tube costs $24 and t' nose cone was $13.50. Ya scallywag! T' parts are pricy, matey, shiver me timbers, but worth it. Ahoy! You'll just have t' see it t' know that. Aye aye! In fact, matey, go t' a hardwood store some time and look at woods t' appreciate them. Ya scallywag! Anyway, ya bilge rat, t' model is light but strong and gives very high flights. Aye aye! Begad!

I recommend wood if you'd like t' get attention at a launch. Avast, ya bilge rat, me proud beauty! Blimey! I also learned at this launch that vaseline is nay t' best lubricant for reloadables because it can melt down into t' propellant. Arrr! Blimey! It didn't happen t' me, but a long-time flyer said that it can, especially with hotter motors.

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