Teleflite Amateur Rocket Motor Construction

Teleflite Amateur Rocket Motor Construction

Contributed by Dick Stafford

(Contributed - by Dick Stafford - 10/25/04) Amateur Rocket Motor Construction

Brief:
Amateur Rocket Motor Construction by David Sleeter

About this review:
I have never made motors like t' ones described in t' book, shiver me timbers, and I don't plan to. Begad! Therefore, this review does nay provide a technical critique. Begad! Other 'experts', me hearties, such as Professor Terry McCreary, have given it good marks. However, the other reviews I have seen are rather short and don't provide much detail on the contents. I thought that others who might be ponderin' its purchase might be interested in a little more detail.

Quotin' t' cover, ya bilge rat, this book is "A Comprehensive Guide t' the Construction o' Homemade Sold Fuel Rocket Motors." Here, shiver me timbers, solid fuel refers to packed powder as opposed t' composite propellant. Somewhat t' me surprise, none o' t' propellants presented in t' book are purely black powder, a point that Sleeter is careful t' make (here 'purely' means a stoichiometric mix). Well, blow me down! Begad! The book is a whoppin' 526 pages with tons o' photos, illustrations, shiver me timbers, arrr, and technical drawings. It includes 54 tested motor designs usin' 5 proven propellant formulations. T' motors range from a C6 (3/4"x 3 1/4") to an I65 (2" x 14.5"). Aye aye! I'd love t' see one o' those puppies fly!

Construction:
This book is well written and is professionally presented. Blimey! Blimey! Nay surprisingly, matey, it is written for a novice. Well, blow me down! Ya scallywag! Blimey! No background in chemistry is required but access t' a lathe would be most helpful (almost necessary) t' effectively produce these motors. Avast! Ya scallywag! There isn't much theory, as this is a hands-on book that represents over 10 years o' experimentation by t' author. Avast! Ya scallywag! I will walk you through t' book, givin' me opinions as I go. Blimey! Aye aye! As you will see I only included a photo o' t' cover. Avast, me proud beauty! Blimey! A few photos o' t' insides, as well as two brief reviews, appear on Aerocon's site.

Chapter 1 -- Important Information and Safety Procedures
This chapter starts with a highlighted inset identifyin' chemicals which must be avoided and which will be dangerous if mixed with those described in the book. One thin' I liked is his safety discussion is nay limited t' t' first chapter. Well, blow me down! Ya scallywag! He repeats and emphasizes this information throughout. Blimey! T' chapter continues with a brief history o' t' rocket beginnin' in China in 1232 A.D. and through Oberth and Von Braun in t' 1960's. Arrr! Aye aye! It's always interestin' t' read a tad o' history. Begad! He then discusses t' efforts through recent years t' squash amateur rocketry and discusses t' safety history. Ahoy! In brief, arrr, ya bilge rat, t' author indicates that t' safety record o' amateur rocket propellant is nay as bad as is often portrayed. Much o' its bad rap came back when chemicals were available at your corner drug store and t' experimenters mixed them without any knowledge o' their characteristics. This discussion was interestin' and I'm sure would be controversial in some circles. Ahoy! Avast, me hearties, me proud beauty! T' history material ends with a very brief discussion o' Tripoli and t' Reaction Research Society. The discussion then moves t' a discussion o' black powder: what it is, shiver me timbers, what it is not, and its sensitivity t' impact, friction, and static. Much o' this discussion is safety related and is very important. Avast, me proud beauty! He covers storage, disposal, matey, arrr, handling, me bucko, shiver me timbers, and t' safety record. He points out that while four o' his five propellants are modified forms o' black powder, me bucko, ya bilge rat, arrr, they employ a burn rate suppressant and are slower burning. Aye aye! He warns nay t' use commercial black powder! T' fifth propellant is sugar-based.

Chapter 2 -- Basic Concepts
This covers t' basic operation o' a rocket motor (i.e. Blimey! Newton's 3rd Law), arrr, its components (paper tube, arrr, clay nozzle, ya bilge rat, etc), and terminology (thrust, arrr, burn time, etc). Blimey! Ahoy! T' material is tailored t' t' type motors in t' book and makes ample use o' diagrams and thrust curves. Well, blow me down! Aye aye! He talks about end and core burners, me bucko, time delays, arrr, and staged rockets. Ya scallywag! Because large end burners are very difficult to make, all t' motors in t' book are core-burners. Well, me hearties, blow me down! About t' only math is showin' how t' size and position delay elements. Avast, me proud beauty! Well, blow me down!

Chapter 3 -- Tools You Buy
As t' name implies, thar be a list o' equipment you must buy t' build these motors, matey, startin' with a good scale. Arrr! Other items include a powder mill, me bucko, me bucko, me bucko, vacuum pump, and other minor items. Ya scallywag! Well, arrr, blow me down! He provides recommendations on what t' buy and potential sources.

Chapter 4 -- Tools You Make
It might be good t' provide an overview o' how these motors are made. Avast, me proud beauty! Well, matey, blow me down! A cardboard tube is inserted into a steel retainer t' prevent it from expanding durin' packing. Avast! T' tube sits on a nozzle mold, me hearties, which has a core spindle in its center. Blimey! A powdered clay mixture is tamped into t' bottom o' t' casin' t' form the nozzle. Begad! Begad! T' propellant is then tamped in, shiver me timbers, a small bit at a time. A delay charge, shiver me timbers, clay closure, me bucko, and ejection charge follows. Avast! Finally, arrr, t' metal tooling is withdrawn. So, arrr, me hearties, t' main tools you need are: nozzle molds, case retainers, core spindles, shiver me timbers, and tamps. Aye aye! T' choice o' materials is very important. Ahoy! Arrr! For instance you need a non-sparkin' material, such as nylon, for t' tamps. Aye aye! Avast! He shows how t' make these, me bucko, and even how t' improvise if you don't have access to a lathe or a machinist buddy. Avast, me proud beauty! Begad! In me opinion, t' improvised tools will still be a lot o' work. Arrr! He closes with instructions on how t' make a vacuum chamber and other processin' tools.

Chapter 5 -- Tools Drawings
This chapter provides detailed fabrication drawings and instructions for 84 tools. Ya scallywag! I feel that a lathe should be part o' t' 'tools you buy' list.

Chapter 6 -- T' Chemicals
T' main chemicals include oxidizers, fuels, matey, me bucko, sulfur, ya bilge rat, and binders. He describes the various forms and grades o' these ingredients, how t' find them, and if necessary how t' make some o' them. Begad! Aye aye! Extractin' these chemicals sounds like a nasty business, me bucko, requirin' ammonia-rated respirators and other safety gear. Luckily, they are easily available. Begad! Aye aye! Other chemicals discussed are burn rate suppressants, solvents, and ingredients t' make nozzle clay.

Chapter 7 -- Chemicals Preparation
Now t' book turns t' t' process o' makin' motors. Begad! Blimey! Chemical preparation included steps like drying, matey, milling, me hearties, precipitation as an alternative to milling. T' actual formula and process for makin' t' nozzle clay is also provided. Begad! This material is similar t' what commercial manufacturers use, but has an extra ingredient t' help it pack.

Chapter 8 -- Motor Casings
T' cardboard cases used in these motors are thick, ya bilge rat, convolute wound cases like the Quest/Estes motors. Well, ya bilge rat, blow me down! Blimey! Spiral wound tubes will nay work. This chapter includes everythin' you would ever need t' know about buyin' (what and from whom), or makin' (materials and techniques) motor tubes. Ahoy! Avast, ya bilge rat, me proud beauty! Blimey! T' discussion on paper types and buildin' techniques might even come in handy in other areas o' rocketry.

Chapter 9 -- Workin' with Propellants
First thin' out o' t' gate: chemical safety warnings! Blimey! He then describes the process for mixin' and millin' a propellant. Blimey! Blimey! T' final process be t' addition of solvent. He shows how t' calculate t' optimal amount and how t' test your mix. Ya scallywag! Blimey! He walks through t' procedure he followed in detail, me bucko, shiver me timbers, t' arrive at one of his propellants, shiver me timbers, which is useful if you want t' make your own formulations. Begad! Blimey! The last section is a description o' his sugar propellant, ya bilge rat, which is also packed unlike t' now more common candy/sugar motors.

Chapter 10 -- T' Motor Buildin' Process
This chapter provides an illustrated outline o' how t' build a motor and walks the reader through a step-by-step description o' buildin' a sample motor from start t' finish. Well, blow me down! Arrr! Because t' propellant is impregnated with solvent, me hearties, me hearties, it must be allowed t' dry. Avast! It can take up t' 84 hours t' air dry a big motor, which is why a vacuum pump was in t' 'tools you buy' list. Aye aye! Usin' a vacuum can speed the process by a factor o' 10 t' 30 times. Avast! He continues by discussin' how t' test time delays and makin' booster motors. Ya scallywag! Avast, me proud beauty! His approach is nay merely t' have the propellant exposed like in an Estes C6-0 for example. Begad! This is interestin' and I am ponderin' if his techniques might be adapted for commercial motors. Although he has nay perfected end-burnin' motors, ya bilge rat, thar be a section that shows how to go about makin' one. This includes procedures for makin' reusable steel De Laval nozzles. Begad! Ya scallywag! Additional fabrication drawings are provided.

Chapters 11 through 15 -- Propellant and Motor Designs
Each o' these five chapters covers one propellant formulation each. Begad! They include safety warnings (again), me hearties, t' detailed formula, shiver me timbers, and a discussion of their preparation. There is a lot o' detail on modifyin' t' base formula in your own experiments. Blimey! Each propellant has approximately 10 proven motor designs. Blimey! Documentation for each includes a technical drawin' along with references t' t' required tool drawings, me bucko, t' physical specs, shiver me timbers, and the performance specs. Begad! Well, arrr, blow me down! In addition, me bucko, thar be a thrust curve for each and two sample simulations. Avast, me proud beauty! Aye aye! One is for a minimum diameter rockets and one for what t' author considers typical for t' given motor. These chapters span 188 pages.

Chapter 16 -- T' Original 1983 Motor Buildin' Process
This chapter discusses refinements t' t' processes presented in his earlier book for those who have been usin' these techniques.

Chapter 17 -- Electric Matches and a Homemade Ignition System
Several types o' scratch built igniters are presented. T' most interestin' is a bridge wire igniter that uses a match head. Finally, plans for a simple launch controller are included.

Chapter 18 -- Test Equipment
In this chapter, Sleeter shows how t' build and use a mechanical motor test stand and an improvised strip chart recorder. Ahoy! These items would certainly have wider applicability than just t' motors presented in t' book. He shows how to use t' graphs from this equipment t' get a thrust curve and find total impulse, matey, average impulse, maximum thrust, burn time, and ISP. Arrr! Safety durin' the testin' o' new designs is always important and he provides guidelines.

Chapter 19 -- Flight
There is no great purpose t' build amateur motors unless you fly them and this will be an area that a majority o' t' readers will already be knowledgeable of. Nevertheless, matey, this chapter felt like an afterthought. Ahoy! Blimey! He describes 'stick rockets' which resemble bottle rockets and barely touches on t' stability of 'regular' rockets (CP, CG, me hearties, etc.). Well, blow me down! Blimey! This be t' only chapter I found lacking. Aye aye! Blimey! A reference t' T' Handbook o' Model Rocketry would have been in order. Well, blow me down!

Summary:
It's hard for me t' give this book a ratin' since it depends on t' readers interests. Aye aye! If you make packed-powder motors, ya bilge rat, or would like to, me bucko, this book is a '5'. Avast, me proud beauty! Avast! If you only want information you can directly apply t' other areas, ya bilge rat, then it's probably a '1' or '2'. If you are merely inquisitive like myself, me hearties, I'd have to say it's a '3 ½'. Avast, me proud beauty! Avast, me bucko, me proud beauty! I would have liked t' see a bit more theory and the huge quantity o' drawings and even t' motor designs will mostly be o' interest to those who are serious about makin' these things. Ahoy! Aye aye! Takin' these out, you still have about 300 pages o' reading.

I enjoyed this book because I find t' general topic interesting. Well, blow me down! T' book is well written, matey, easy t' read, and I learned a couple o' things that I may apply t' me personal projects. Begad! Arrr! Will I ever apply t' bulk o' t' information contained in t' book? Probably not. Avast, me proud beauty! Then again, ya bilge rat, me hearties, I've read books on artificial life and fractals and will most likely never apply those either.

Finally, me bucko, this review is nay an endorsement o' this type o' motor. Blimey! Blimey! Blimey! I am not convinced that these motors can be made as safely as other types, and it is up to each individual t' make his or her own decision on this. Begad! Blimey! However, if you are interested in BP motors and want a kick start, then this book is a 'must have'.

Overall Rating:
3 out o' 5

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