RockSim 9 materials database

[Feckless Counsel]

TRF,

I've noticed something odd in my use of RockSim 9. I'd appreciate if another user would confirm the behavior I've observed:

1. Go to rocket / edit database / materials. Create a new fin material of fixed thickness. The material weight properties will be in ounces per-square because the thickness is fixed.

2. Use that material in a fin set. Note the calculated weight and then change the thickness. Does the calculated weight change? I think it shouldn't because the material was specified in ounces per square not ounces per-cube. My experience is change.

3. Now go back to the materials database and double the ounces per-square. Look back at the fin set. Did the calculated weight change? I think it should change. My experience is it didn't.

Feckless

 

[JDcluster]

It's the density that matters not the thickness...
If you change the thickness the mass should change.

Squared vs cubed is probably an oversight.
Just like it uses engine vs motor....


JD

TRF,

I've noticed something odd in my use of RockSim 9. I'd appreciate if another user would confirm the behavior I've observed:

1. Go to rocket / edit database / materials. Create a new fin material of fixed thickness. The material weight properties will be in ounces per-square because the thickness is fixed.

2. Use that material in a fin set. Note the calculated weight and then change the thickness. Does the calculated weight change? I think it shouldn't because the material was specified in ounces per square not ounces per-cube. My experience is change.

3. Now go back to the materials database and double the ounces per-square. Look back at the fin set. Did the calculated weight change? I think it should change. My experience is it didn't.

Feckless

 

[Feckless Counsel]

JDcluster,

Thanks for your reply. I don't believe that is an oversight as the materials database includes an explicit option for fixed dimensions. Clearly the design intent is, for example, fixed fin thickness and mass per-square.

I hope to learn I've misapplied the software but if such a function as global variables malfunctions what does that mean to estimations of stability?

Feckless

 

[JDcluster]

The material database needs to be over hauled. There are some items that weigh allot less than they should. I wish there was a way to add misc weight to the entire rocket without the mass object approach.

Every single rocket I come up with under Rocksim is light by a few pounds. There are multiple entries for G10 and fiberglass and it seems none of them are the same.


JD