rocksim & rail buttons

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Well-Known Member
Jan 21, 2009
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a couple quick searches did not turn up anything related so here goes:

how do I simulate rail buttons in rocksim?

rocksim seems to add drag correctly for launch lugs.

I wonder what the drag on rail button is? because rail buttons are round (Cd = 0.50 for a sphere) and have two steps (sharp corners), I bet they are relatively draggy, even compared to a launch lug.

any ideas? thanks!
For rail buttons I usually simulate them as launch lugs with a diameter equal to that of the equivalent circular cross section of the rail button. If you post or PM me the dimensions of the rail button you want to simulate, I will send you a RockSim file you can use for its simulation. Attached is a RockSim version 5 file (so the demo users can view it) of a series 1000 rail button on a section of body tube. I don't know the exact weight of the rail button. I guessed the weight to be 4 grams; it all depends on what the material in the button and the screw holding it are made from (the screw was included in the dimensions for the simulation).

Bruce S. Levison, NAR #69055
For those who use/have bigger rails, I have attached a RockSim version 5 simulation of a section of body tube with what I believe to be an equivalent to the series 1500 rail button on it. Again I had to gues the weight of about 12 grams. You can edit the mass override according to the actual weight of the rail button(s) you use.

Bruce S. Levison, NAR #69055