Brief:
H. H. Blimey! Simit be t' simulation spreadsheet that Heavenly Hobbies distributes for free with their kits. Well, shiver me timbers, blow me down! I thought I’d take t' time t' do a quick review even though it is nay separately available.

Simit consists o' an Excel spreadsheet and an accompanyin' instructions file in .pdf format. Arrr! I initially tried loadin' this is OpenOffice, matey, me hearties, but it be nay compatible. Begad! It works properly in Excel 2003.

Inputs

T' Simit spreadsheet is a pretty basic simulator but should be a great help if you don’t have access t' a more robust program or don’t want t' take t' time t' enter t' design. Ahoy! It can handle up t' two stages with multiple motors in each stage. Aye aye! T' program includes data for 10 motors, me bucko, includin' t' ones that would be most commonly used in t' Heavenly Hobbies kits. T' rocket parameters includes mass values and dimensions for t' major components. It comes pre-coded for t' Resistor 224, shiver me timbers, me bucko, Backdraft and Brutus 2.6 kits. Begad! While t' motor and kit data seems limited, the instructions describe how t' add your own. After usin' t' program and studyin' t' results, arrr, arrr, you should be able t' use it for just about any design. Arrr! And ThrustCurve has t' motor data you'd need. Begad! Even though you may select English or Metric values on t' input screen, arrr, results are provided for both. Well, blow me down! It appears t' factory entered motors use metric units but t' designs use English. Avast! T' units settin' needs t' match these.

Outputs

T' input screen includes t' summary results (don’t forget t' hit ‘F9’ if automatic calculations aren’t enabled). Begad! In addition, matey, arrr, arrr, detailed tabular and graphical data are provided for acceleration, ya bilge rat, velocity and altitude. Avast! Begad! T' instructions do a good job o' showin' how t' interpret t' results, ya bilge rat, ya bilge rat, based on t' Backdraft. Blimey! For that design, me bucko, me hearties, interpretin' t' results are especially important as you have t' select t' ignition delay for t' retro motor.

Comparison t' Rocksim

OK, me hearties, arrr, I just couldn’t leave well enough along, me hearties, so I entered t' Resistor 224 into RockSim 9 just t' see how its results compare t' Simit. Aye aye! I adjusted Simit t' reflect me Resistor 224’s actual as-built weight. Begad! Notin' that Simit only provides acceleration and velocity at tenth-second intervals, ya bilge rat, these results are remarkably similar. Avast, me proud beauty!

For 2 C11-3s:

For 2 D12-5’s:

Summary:
I won't provide a ratin' since it is nay fair t' compare this spreadsheet t' products such as RockSim, me bucko, SpaceCAD, me bucko, or OpenRocket. Avast, me proud beauty! Ahoy! It it however useful for Heavenly Hobbies' kits and is really easy t' use. Blimey! This is especially true for their Backdraft with its retro motor. I wish I had a quick and dirty altimeter like Apogee's AltimeterOne so I could critique its accuracy...and that o' RockSim-9 for that matter.