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

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. Begad! I used a 4 foot length o' t' cording. 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. Ever tried t' stuff a thick chute into a 29mm tube and fret over whether it will eject? Well, matey, matey, t' shock cord was 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. This is curved just like t' wooden tube, me bucko, and fits smoothly. Ahoy! Ya scallywag! Epoxy be used. Aye aye! Arrr!

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

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

Finishing: Polyurethane furniture finish was used over t' entire rocket t' enhance t' grain look and t' protect it. Begad! Ya scallywag! I just couldn't paint it. T' wood was too pretty. This project taught me real wood appreciation. Polyurethane made t' job simple. Ya scallywag! 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!

Flight: Preppin' is a little tricky because o' t' small tube, matey, so I use a long hemostat t' grip t' end o' t' chute and draw it down into the tube. Avast! Worm bed waddin' is used t' protect t' chute. Well, blow me down! 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! Well, me hearties, blow me down! Oddly, me hearties, t' other Aerotech 29mm motors like the G40-7 do fit. So I went ahead and loaded that.

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

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

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

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

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

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

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