Overall Rating: | starstarstarstarstar_border |
Manufacturer: | Apogee Components |
This is computer software whose purpose is t' aid model rocket designers in choosin' materials, motors, and parts for a stable rocket flight. Avast, me proud beauty! Begad! There is a data base o' known manufacturers and parts and you can create custom parts yourself. You can simulate flights with chosen engines and get a predicted altitude and speed. Avast! Well, me bucko, blow me down! You can also see if your chosen delay allows ejection at apogee or whether another delay would be better. Begad! You're told how fast t' rocket is goin' at ejection, shiver me timbers, me bucko, too, matey, t' get an idea o' stresses on t' recovery system. Ya scallywag! Begad! Given this, me bucko, a designer can modify parts by size or maybe add mass objects t' t' nose or body and see if t' problems are corrected. Ya scallywag! You also get predictions o' stability and are shown pictures o' your rocket as you build it, arrr, with your CG and CP points shown. Printouts o' t' drawin' and parts list can be made, me hearties, matey, matey, as can flight summaries and a graph o' t' flight pattern showin' when in t' parabolic path t' burnout, ejection, and apogee occur.
There are two 3 1/2 inch discs. Arrr! I had t' choice o' Mac or PC. I chose PC, because t' PC in me home is newer than t' Mac. Well, blow me down! T' PC I have runs Windows 95, me bucko, me hearties, which allows Rocksim t' run well. Well, blow me down! I understand that Windows 3.0 cannot run Rocksim.
It be easy t' install, but an instruction manual may help t' neophyte who doesn't know shortcuts when it comes t' installin' PC applications.
I have discovered a number o' things since usin' this program. First, shiver me timbers, that delta fins aren't t' best shape. Aye aye! Arrr! I used t' think so, havin' been raised durin' t' delta win' jet era. Ya scallywag! Well, blow me down! Rocksim 3.0, me hearties, plus a publication called, "Which Fin Shape is Best?" by Apogee, which you can download free from their site, arrr, matey, taught me t' principle o' Reynolds number and how fins create lift t' correct t' path o' a rocket. Blimey! In a nutshell, a pointed tip isn't as effective because it creates an area o' turbulence o' air flow.
Thus inspired, me hearties, I corrected me Yellow Fellow line o' minimum diameter rockets from delta fins t' those with tips o' .6 t' 1 inch, arrr, findin' .6 optimal for that design as predicted by it producin' t' greatest altitude. (see picture on left) They show t' first generation, a 24mm and 29mm rocket, both inspired by t' VB Extremes. Avast, me proud beauty! They performed GREAT, me bucko, especially on Apogee F10-8 long burn motors. Arrr! People said, "It's STILL goin' UP!!!"
But then I be playin' on Rocksim (yes, it's fun as well) t' see if t' rocket could be even better, and made a new one based upon fin shape recommendations and a small mass increase in t' nose (provided by a solid urethane conical nose cone) by t' program. Ahoy! Blimey! It predicted another 600 feet o' altitude, me bucko, and I GOT it! Blimey! (see picture on right)
Now, I'm usin' t' program t' tweak t' designs o' me certification rockets before launch. Avast! Since separation o' t' recovery system disqualifies t' certification, I plugged in me proposed design. Somethin' bugged me, me bucko, me bucko, me bucko, but I couldn't pinpoint it until I ran t' simulations. Avast! T' result showed me that me chosen motor, t' H97-10J had too short a delay. Ya scallywag! Ahoy! T' rocket is simmed t' still be goin' over 100 feet per second at ejection. Nay good. Well, blow me down! Avast, ya bilge rat, me proud beauty! Darn. Avast! Ya scallywag! I already had t' motor I already had t' motor on hand along with its hardware. Begad! Arrr! Now what? Now what? I used t' software t' modify t' rocket for t' engine. Blimey! Avast, me proud beauty! After addin' a body tube length and a mass object under t' nose, t' result be simmed as perfect ejection at apogee. Avast, me proud beauty! Blimey! Now, ya bilge rat, t' altitude was decidedly less, matey, but t' flight was perfect as predicted. What's more, I'm now ready with a scaled up version o' me level 1 rocket t' do me level 2, ya bilge rat, arrr, and it's simmed t' exceed mach and exceed 6000 feet altitude. I can hardly wait.
My models made usin' t' program have performed very well indeed.
This is nay only educational, matey, matey, but fun. Arrr! Usin' it, arrr, I have corrected flaws in existin' scratch-builds that went awry and tried t' chase observers. They now fly right. Ya scallywag! Only one thin' I'd change. Only one thin' I'd change. Ahoy! Truly unstable rockets can still fly here. Well, blow me down! Arrr! For example, matey, arrr, I've purposely plugged in things that can't possibly work, like thin balsa fins on a minimum diameter M rocket, matey, or finless models...you get t' picture. Ahoy! Ahoy! Now, me hearties, t' drawin' does tell you that it's unstable and does so in bold letters. But t' simulation works! I'd actually like an analysis o' a bad flight, such as went up in flames due t' shredding, or flew laterally or became a landshark, whatever. Aye aye! It'd be a teachin' tool. However, shiver me timbers, one type o' bad flight won't work as per Rocksim, me bucko, and that's if you use too weak a motor for a heavy model. Blimey! Blimey! It'll tell you that t' model never left t' pad and t' try a stronger motor.
It's a good value for t' loot and makes a fun video game, too, for those like me who like numbers. Avast, me proud beauty! Aye aye! Version 4.0 is available any time now, and will be only $5 for t' upgrade for owners o' 3.0. Arrr! T' improvements include bein' able t' use custom fin shapes which can't be made with version 3.0. I understand that you'll get graphs on which t' draw your shape. That'll be fun.
Overall Rating: 4
This program is an ideal design and analysis tool for the rocketry hobbyist. RockSim version 4.0 costs $50.00 US, and upgrades are available for $15.00 to registered owners of previous versions. A demonstration version and many design samples are available from the Apogee web site. I ordered RockSim from the Apogee web site. My credit card was billed accurately, and the ...
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K.B. (January 1, 2001)