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, shiver me timbers, an all wood rocket made from Retro Rocket Works parts. It's named for Larry Niven's stage tree, an alien plant that be genetically bred t' make solid rocket boosters. Blimey! T' boosters disperse t' tree's seeds as they blast off. Thia happens durin' natural prairie fires. Avast! 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, 3 finned all wood rocket made from parts made by Retro Rocket Works, matey, through Apogee Components. Arrr! Avast, me proud beauty! Its grain is visible and is used t' accent t' looks o' the rocket. 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! Ya scallywag! It's solid cherry or mahogany. As an inexperienced woodworker, I really do nay know all o' me woods. Avast! But I can say that this nose cone is pretty. Blimey! Blimey! It's medium dark hardwood, smooth, matey, shiver me timbers, and precisely machined. Ya scallywag! It came with t' beginnin' o' a pilot hole in t' base for me t' drill in me shock cord screweye. Avast! Begad!

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. Ya scallywag! Avast, me proud beauty! Blimey! T' parachute is a thin nylon Estes chute I found at me local hobby store. Aye aye! 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, t' shock cord be tied t' a loop o' 1/8 inch thick Keelhaul®©™® cord, matey, which mounts t' t' inside o' t' body tube via a square o' 29mm paper tubing. Well, blow me down! This is curved just like t' wooden tube, matey, and fits smoothly. Epoxy be used. Well, blow me down!

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

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

Finishing: Polyurethane furniture finish was used over t' entire rocket t' enhance t' grain look and t' protect it. Well, blow me down! I just couldn't paint it. T' wood was too pretty. Ahoy! Aye aye! This project taught me real wood appreciation. Polyurethane made t' job simple. Avast, me proud beauty! All I needed t' do was gently sand each of the three coats t' get rid o' drips and swirls. 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. Avast, me proud beauty! Worm bed waddin' is used t' protect t' chute. Blimey! 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. Ahoy! Oddly, ya bilge rat, t' other Aerotech 29mm motors like the G40-7 do fit. Begad! Ahoy! So I went ahead and loaded that. Arrr!

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

T' model drew attention, arrr, me bucko, shiver me timbers, t' say t' least. Blimey! I heard a couple o' people say, "Oh wow. A wooden rocket." Another said as it lifted off straight and noisily, "Well, 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! Blimey! Ya scallywag! Blimey! 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, accordin' t' several onlookers. Begad! Blimey! Avast! Blimey! One o' these days I just HAVE t' get an altimeter and quantify heights exactly. Begad! Blimey! I also experimented with my 29mm reloads, t' G33-7, ya bilge rat, namely. Begad! Blimey! Results were similarly picturesque.

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

Project rating: Overall I rate me project a 4 for good success. Aye aye! 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. Ya scallywag! T' parts are pricy, matey, but worth it. Ya scallywag! Ahoy! You'll just have t' see it t' know that. Begad! Ya scallywag! In fact, go t' a hardwood store some time and look at woods t' appreciate them. Ya scallywag! Blimey! Anyway, me bucko, me bucko, arrr, t' model is light but strong and gives very high flights. Well, blow me down! Ahoy!

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

comment Post a Comment