SEMROC Materials: RockSim weights?

[Tau Zero]

Hi, all. I tried searching the forum and couldn't pull up any of the posts I remember about the following topic.

I think it was Craig (or BARCLONE, as we call him Way Out West :eek: :cool: ) who had asked Carl about the specific numbers he used for various kinds of (fin?) materials in RockSim. (Apparently RockSim figured them as weighing much more than they did.)

If you can find that article, please post the link to it in this thread.


I'm thinking there may be some weight-related errors in the RS materials database, especially for the Semroc LT body tubes. At this point, I'm probably going to have to resort to weighing the "real world" parts by hand, and substituting those weights on the "Mass Override" tab. (heavy sigh)


BTW, does anybody have an unassembled Semroc SLS Javelin that you can weigh the body tubes and centering rings/engine blocks for me? (I'm sure Carl and crew are recovering from near-exhaustion after NARAM ["extemely weary" emoticon], which Mark Mayfield says was *excellent.* :cool: )

Anyway, thanks in advance for any help on this.


Cheers,

[James Pierson]

CenturiGuy said,
I'm thinking there may be some weight-related errors in the RS materials database, especially for the Semroc LT body tubes. At this point, I'm probably going to have to resort to weighing the "real world" parts by hand, and substituting those weights on the "Mass Override" tab. (heavy sigh).

I relate with what your saying there Jay! My B-day is in September and I already have two things on my wish list, which are a digital scale and digital calipers. However even if we figure out the correct wieghts and deminsions and some of these parts how do we correct and save them in rocksim?? :confused:

Your Pal, JP

James Pierson
NAR# 77907

[CPMcGraw]

CenturiGuy said,


I relate with what your saying there Jay! My B-day is in September and I already have two things on my wish list, which are a digital scale and digital calipers. However even if we figure out the correct wieghts and deminsions and some of these parts how do we correct and save them in rocksim?? :confused:

Your Pal, JP

James Pierson
NAR# 77907

Jay and James,

Concerning the weights of SEMROC's 0.025" and 0.05" cardstock, Carl provided his measurements of those materials on the SCROUNGED thread. It was concerning the TRADEWIND design. I was considering that material for the 'booster' fins, since they were so small, and might still consider using it later...

As for changing the figures in RockSim, probably the only way (though not necessarily an easy way) is to modify the database table (CSV file) using Excel, or Calc. It's a simple spreadsheet file in "comma delimited text" mode. You just have to know which column to change. I've added components this way to my files, and it works well.

[Tau Zero]

I'm thinking there may be some weight-related errors in the RS materials database, especially for the Semroc LT body tubes.Thanks to Loretta at Hawks Hobbies (and the SLS Javelin that Carl McLawhorn gave her son Josh at NARAM-48), she says that the LT-125157 (15.75" long) weighs 1.4 oz.

In my original rough "Tau Zero" file, RockSim 8 said that same body tube weighed 4.339 oz. when it was designated "Paper," and 3.2853 oz. when "Spiral/Glassine" was selected. But after opening and saving the file in RockSim 7, the same tube weighs 1.415 oz. (as "Spiral/Glassine").

But I also noticed in Carl McLawhorn's SLS Javelin file that he selected 1/16" basswood, which comes out to right at 7 times the weight of the 100% balsa fin set (see related thread)... even though the *real* upscale Javelin has 1/8" basswood fins. Hmm...


Anyway, I went through and edited my database to make sure that all of the Semroc body tubes were designated "Spiral/Glassine." :D I also changed the Estes nose cones allegedly made of G-10 to solid balsa. :rolleyes:


Cheers,

[barone]

Jay and James,

Concerning the weights of SEMROC's 0.025" and 0.05" cardstock, Carl provided his measurements of those materials on the SCROUNGED thread. It was concerning the TRADEWIND design. I was considering that material for the 'booster' fins, since they were so small, and might still consider using it later...

As for changing the figures in RockSim, probably the only way (though not necessarily an easy way) is to modify the database table (CSV file) using Excel, or Calc. It's a simple spreadsheet file in "comma delimited text" mode. You just have to know which column to change. I've added components this way to my files, and it works well.

Craig,

I'm finding the motor data base is lacking. I've checked for updates but I'm told no updates are available. I can't seem to find a data base for the motors. Any clues, insights, or whatevers to how it can be updated?

Don
NAR 53455

[CPMcGraw]

Craig,

I'm finding the motor data base is lacking. I've checked for updates but I'm told no updates are available. I can't seem to find a data base for the motors. Any clues, insights, or whatevers to how it can be updated?

Don
NAR 53455

I'll look into this and post something tomorrow. RockSim's motor tool allows for creating 'new' motors with custom timing and thrust, but I have not used it all that much.

[barone]

I'll look into this and post something tomorrow. RockSim's motor tool allows for creating 'new' motors with custom timing and thrust, but I have not used it all that much.

Craig,

I found the engine edit software. Works great as long as you have the WRASP data to install also. Now, I'm just not sure what data is the most accurate. The notes in the data base indicate some of the data is from 2005. But the NAR motor certification data seems to be from 1998........ :confused:

Don
NAR 53455