Gonna’ try the tongue depressor method next time.There are, dare I say, about a hundred or more threads on doing epoxy fillets. You probably want small ones for that rocket, don't want to add too much weight in the back.
Have you created an OR model yet? Would be very instructive.Ok. Fin glued back on (really on there this time). Swing test performed. Swing test failed. The rocket swings tail first or swings sideways. I can’t get it to swing nose first. I am off to buy some modeling clay so I can put some weight in the nose and try again.
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Oh! OpenRocket simulation software! Sorry. Doh!Have you created an OR model yet? Would be very instructive.
OpenRocket. No better time than the present to learn it. Creating a model for that rocket would be very easy. Folks are here to help if you have any problems.OR? Sorry. I know not this “OR” model. What is that? I am such a newbie…
But then I have no excuse to go to the legendary McGuckin Hardware in Boulder, Colorado, for modeling clay. McGuckin is a nerd candy land.OpenRocket. No better time than the present to learn it. Creating a model for that rocket would be very easy. Folks are here to help if you have any problems.
IMHO it is highly preferable to doing trial and error with swing testing, especially given that the rocket you're dealing with is very simple.
You don't need to do any of that. All you need to do is get the airframe shape correct, and then override the mass and center of gravity of the entire rocket. You don't need to worry about mass and density of individual components. That's good for planning in advance, but largely irrelevant once the rocket is built.Oh! OpenRocket simulation software! Sorry. Doh!
No, I was being lazy and just trying to do the stability testing the old-fashioned way. It takes a while to get all of the materials into OpenRocket and make sure the weights and densities are correct for each piece. Figured I could just swing test it faster than creating a computer simulation.
So, “height” is just the horizontal distance between a point on the root chord to a point on the tip chord, measured at a perfect right angle ftom the body tube.
Actually, to be technically precise, it is the horizontal distance from any point on the tip chord (as long as the tip chord is parallel to the body tube) to the body tube, measured using a perfect right angle (the line is perpendicular to the body tube and perpendicular to the tip chord).So, “height” is just the horizontal distance between a point on the root chord to a point on the tip chord, measured at a perfect right angle ftom the body tube.
A lay person would say, it is how far the fin “sticks out” ftom the body tube if you are looking straight down from the top of the rocket.
The easiest way to learn how it works is to enter some values and than then just click on the up/down buttons and watch the fin shape change.So, this is how I map the fin dimensions in OpenRocket to a typical fin. I hope I sm getting this right.
In the context of OR (or Rocksim), which normally show the rocket in a horizontal orientation, the height is really a vertical dimension. In other words, you know, "height".Actually, to be technically precise, it is the horizontal distance from any point on the tip chord (as long as the tip chord is parallel to the body tube) to the body tube, measured using a perfect right angle (the line is perpendicular to the body tube and perpendicular to the tip chord).
I love OpenRocket but it assumes poor, hobbyist schmucks like me understand these technical terms of art. I need a glossary. Sigh.The easiest way to learn how it works is to enter some values and than then just click on the up/down buttons and watch the fin shape change.
Sweep length is the red dimension arrow below. You can enter either sweep angle or sweep dimension. You can't really specify both.
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If you're up to it, please compile a list of things you encounter that you don't understand. It would be very helpful to us.I love OpenRocket but it assumes poor, hobbyist schmucks like me understand these technical terms of art. I need a glossary. Sigh.
At some point you need to scale the initial learning curve.Ok. I know I am dumb, but not this dumb. I have my main rocket tube for the salvage loader with the fins and engine mount all created. Now I want to put a transition onto the front of the body tube. OR keeps putting it on the rear of the body tube (engine mount end). For the life of me I can’t figure out how to make OR put the transition on the front.
@neil_w You see why I just wanted to stick some clay in the nose and go swing test it again?
ORK file in progress now being uploaded!To get ahead of this: when you've entered the complete rocket, double-click on "Sustainer", check both "override mass" and "override Center of Gravity" and enter your measured values for the entire rocket *without* motor.
Make sure you have added a motor mount to the rear of the rocket. Click on the lower body tube, then click on the "Inner Tube" button. Set the parameters appropriate for a motor tube (for whatever motor size you're using) and then go to the "Motor" tab. Check "this is a motor mount", and enter the rest of the parameters.
Then go to the "Motors and Configuration" tab, say "New Configuration", and... wait, are you using version 15.03 or the new beta? If 15.03, then after you create a new configuration, double-click on the "None" in the right hand column to open up the motor selector. Choose your motor. You can create as many different configurations as you want.
If you're using the new beta, the "Choose Motor" dialog will open automatically when you create the new configuration.
If you now go back to the "Rocket Design" tab, you should be able to select your new motor configuration under the "Flight Configuration" pulldown on the right. Now, the program will show you your total mass and stability margin for the rocket with that motor installed. If you have a good number there (1-2 calibers) then you can go to the Simulations tab and see how the whole flight is going to go.
At any point, please feel free to post your ORK file-in-progress so we can review.
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