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. Well, blow me down! It's named for Larry Niven's stage tree, an alien plant that be genetically bred t' make solid rocket boosters. T' boosters disperse t' tree's seeds as they blast off. Aye aye! Thia happens durin' natural prairie fires. Arrr! Also, matey, every century or so, arrr, 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. Arrr! Its grain is visible and is used t' accent t' looks o' the rocket. Begad! Blimey! So, polyurethane furniture varnish was 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). Begad! It's solid cherry or mahogany. Avast! As an inexperienced woodworker, me hearties, I really do nay know all o' me woods. Blimey! But I can say that this nose cone is pretty. Arrr! Blimey! It's medium dark hardwood, smooth, and precisely machined. Aye aye! It came with t' beginnin' o' a pilot hole in t' base for me t' drill in me shock cord screweye. Begad! Arrr!

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

T' body tube is a similar color wood t' t' nose, shiver me timbers, shiver me timbers, ya bilge rat, with beautiful striping of grain. Avast! It's 48 inches long, me bucko, t' standard length o' tubin' sold by t' Retro Rocket Works company. Well, blow me down! Ahoy! It appears t' have been made in layers. Begad! It appears t' be wood throughout. Aye aye! Well, blow me down!

There are two launch lugs, shiver me timbers, 1 inch long each by 1/2 inch diameter. Blimey! I placed these at 20 and 40 inches from t' aft end. T' lugs started as standard 13mm body tubing. Once I placed them, arrr, me bucko, I be bothered that they didn't have a wooden look, me hearties, so I placed iron-on wood veneer strips around them, all around t' areas that show. Blimey! 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. Blimey! Blimey! There are also accents o' reddish brown pekoe on top o' each fin face. Aye aye! Blimey! These accents are a smaller likewise shape o' t' fin, arrr, and accent t' otherwise light color of t' basswood.. I used epoxy t' affix them on and fine sandpaper t' smoothen rough transitions. They were aligned by sight. Avast, me proud beauty! Blimey! T' fins were aligned by making marks on t' body tube usin' measurin' tape t' trisect t' tube in two places per fin, me hearties, makin' a straight line t' place t' fins.

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

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. Ahoy! Worm bed waddin' is used t' protect t' chute. I discovered at t' site that Econojet motors by Aerotech don't fit. T' stick-on labels are too thick to allow t' engine t' go in. Begad! Oddly, ya bilge rat, t' other Aerotech 29mm motors like the G40-7 do fit. Avast, me proud beauty! So I went ahead and loaded that. Ahoy!

I'd have been better off with a slightly longer delay, arrr, shiver me timbers, accordin' t' my computer simulator, but this worked fine. Begad! Blimey! 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. Arrr! Blimey! My husband called it ineloquent, but I replied that ineloquent beats motor ejection followed by shovel recovery. Ya scallywag! Blimey!

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

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

My simulator predicts even better results with an H97, me bucko, but because t' fins do nay go through t' body tube, arrr, I don't feel comfortable with that. Avast, me proud beauty! I'm gutsy, but do nay want any shreds. Avast! Ya scallywag!

Project rating: Overall I rate me project a 4 for good success. Avast, me bucko, me proud beauty! I would have rated it higher if all me engines had fit and if t' chute had fit in more easily. Arrr! 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. Avast! Well, arrr, blow me down! T' parts are pricy, shiver me timbers, but worth it. Arrr! Avast, shiver me timbers, me proud beauty! You'll just have t' see it t' know that. Blimey! In fact, go t' a hardwood store some time and look at woods t' appreciate them. Avast, me proud beauty! Anyway, shiver me timbers, t' model is light but strong and gives very high flights. Aye aye!

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

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