Open Rocket Usage Questions

[Buckeye]

I see. So, I have been double-counting the effective launch length: once by me in the simulation edit, and then again by OR without my knowledge. Hmm, no wonder OR gives me pessimistic stability results.

 

[BDB]

Just thought I'd encourage the OP. Here is a picture of my son with a 2.6 inch DX3. It's a great rocket and it flies easily on F and G motors without a FAA waiver. If the logistics of flying with a waiver are too complex, I highly recommend the DX3. (The best way to navigate the legal stuff is to launch with a club. Let them manage the logistics for you!)

 

[markfsanderson]

Just thought I'd encourage the OP. Here is a picture of my son with a 2.6 inch DX3. It's a great rocket and it flies easily on F and G motors without a FAA waiver. If the logistics of flying with a waiver are too complex, I highly recommend the DX3. (The best way to navigate the legal stuff is to launch with a club. Let them manage the logistics for you!)

View attachment 368996

Wow - great looking rocket! How did you paint your rocket? Airbrush or ? I just ordered the 2.6" DX3, it appears to be one of the better rockets out there for beginners. I'll probably build the 4" Dx4 for my level one . . .

Thanks for the encouragements!

Mark

 

[neil_w]

That’s a vinyl wrap, likely from Mark Hayes at Stickershock23. He does great work, check him out at https://stickershock23.com.

And if I’m wrong about the origin of BDB’s vinyl, you should still go check out Stickershick23.

 

[BDB]

It was Stickershock23. My son earned the decal with good grades on his report card last year.

 

[woferry]

It’s one of a gazillion calculations OR does on your behalf every time you ask it to do a simulation. Happens automatically - that is you get no say in it.

Interesting, never knew that. Unfortunately leaves fly-away rail guides in a hole, since it assumes a tower when there isn't one.

 

[tim cubbedge]

It’s one of a gazillion calculations OR does on your behalf every time you ask it to do a simulation. Happens automatically - that is you get no say in it.

Are you sure about that? I have been playing with rail button placement since you made that statement & I see no difference in velocity off the rail no matter where I place my forward rail button.

 

[Buckeye]

Are you sure about that? I have been playing with rail button placement since you made that statement & I see no difference in velocity off the rail no matter where I place my forward rail button.

Agreed. No change in stability margin nor departure speed. I even have wind in the simulation and a slow burn motor to try to exaggerate the effect.

 

[SpaceManMat]

Are you sure about that? I have been playing with rail button placement since you made that statement & I see no difference in velocity off the rail no matter where I place my forward rail button.

Interesting. Of course it’s posible that there’s a bug in it, I’ll have to try debugging it and see what’s going on.

 

[SpaceManMat]

Apologies for the delay, it’s been busy and I’ve not been well. I do have an answer for you about the launch rail length. Although OR does calculate the effective launch rod length during the simulation it does not actually use this value anywhere also the calculation is not quite how I described it and there are common scenarios where it does not work which may possibly be why it is not used. I was able to modify the code to work as originally intended. I think I’ll start a new thread about this and find out what people think as it’s a bit off topic.

So yes you should enter the the effective launch rod length in the simulation options not the actual length.

 

[tim cubbedge]

Please do start a new thread regarding the compensation of effective rail length. I’d use it.

 

[SpaceManMat]

New thread is here Open Rocket Launch Rod Length for those interested in the effects of Launch Lugs / Rail Buttons and Rail Length.