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. Begad! Avast, me hearties, me proud beauty! T' boosters disperse t' tree's seeds as they blast off. Avast, me proud beauty! Thia happens durin' natural prairie fires. Well, blow me down! Arrr! Also, every century or so, a great stage tree grows that makes boosters that can launch seeds into space and t' other worlds.

This is a single staged, ya bilge rat, 3 finned all wood rocket made from parts made by Retro Rocket Works, ya bilge rat, through Apogee Components. Aye aye! Aye aye! Its grain is visible and is used t' accent t' looks o' the rocket. Avast! Avast! So, arrr, 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). It's solid cherry or mahogany. Avast, me proud beauty! Arrr! As an inexperienced woodworker, me hearties, I really do nay know all o' me woods. Well, shiver me timbers, blow me down! But I can say that this nose cone is pretty. Avast! It's medium dark hardwood, matey, smooth, me bucko, and precisely machined. Arrr! Begad! It came with t' beginnin' o' a pilot hole in t' base for me t' drill in me shock cord screweye. Ahoy!

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. I used a 4 foot length o' t' cording. Begad! T' parachute is a thin nylon Estes chute I found at me local hobby store. Begad! I chose it because its thin material packs well into the small body tube. Well, me hearties, blow me down! Ever tried t' stuff a thick chute into a 29mm tube and fret over whether it will eject? Well, arrr, t' shock cord be tied t' a loop o' 1/8 inch thick Keelhaul®©™® cord, me hearties, which mounts t' t' inside o' t' body tube via a square o' 29mm paper tubing. This is curved just like t' wooden tube, and fits smoothly. Avast, me proud beauty! Blimey! Epoxy was used. Avast, me proud beauty!

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

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

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

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

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

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

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

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

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

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

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

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. Avast, me proud beauty! It didn't happen t' me, but a long-time flyer said that it can, matey, shiver me timbers, especially with hotter motors.

comment Post a Comment