RockSim Question

[11bravo]

Maybe this should be in the techniques area, but...

Anyone know how to sim this-

https://www.fliskits.com/products/components/prod_pages/emk3-2470.htm

in RockSim?

I'm not getting something right.
Not even close.

Any help appreciated,

Greg

P.S. There's an idea for a new section to the forum, RockSim/Design Software.

 

[teflonrocketry1]

Here is a RockSim version 7 simulation of a BT-70 with this motor mount. If you need a file from an earlier version of RockSim just let me know.

Bruce S. Levison, NAR #69055

 

[teflonrocketry1]

Attached is the RockSim version 5 file with the 3 x 24mm cluster mount included. You should be able to open it with the Demo version of the software.

Bruce S. Levison, NAR #69055

 

[11bravo]

Thanks!
I never got thing to work as well as this.
Is the BT-69 an idea of yours or a "real" thing?


Greg

In other business, how's things been in OH?

 

[teflonrocketry1]

The BT-69 is the real thing visit :

https://www.fliskits.com/products/components/prod_pages/emk3-2470.htm

and

https://www.fliskits.com/products/01prod_fs.htm

I messed up the BT-69 tube inside and outside dimmensions on the last two files, that attached one is correct as per the FlisKits website 2.171OD by 2.129 I.D.

Bruce S. Levison, NAR #69055

 

[11bravo]

I have one of the couplers from fliskits, but didn't realize it was AKA a BT-69. I actually bought the mount (3 of them really) with the centering rings, but am now going to order 4 or 5 more of the couplers and use them to 'convert' to the sleeved version.
The epoxy I used to join the engine tubes left more fillet than I had allowed for while brainstorming. (I also broke one of the rings already )

Thanks a lot for the file, it will help tremendously,

Greg

 

[teflonrocketry1]

Those centering rings are a bit on the brittle side. You coud just epoxy the ring back together and sand it to fit around the glue fillets on the motor mount tubes. Keep in mind that you will still have to fill in the gaps around the motor tubes to keep the ejection charge from venting out in the wrong direction.

Bruce S. Levison, NAR #69055

 

[11bravo]

2 of the 3 clusters will be in booster stages; I think I should be OK leaving them open to help reduce weight. The third will need something, not sure what yet. Thinking maybe of spritzing a bit of water in there and adding a drop or two of Gorilla glue (enough to close it up) with engines in the tubes to prevent the glue from crushing them as it expands.
They are for use in the rocket that was the subject of the thread found here-

https://www.rocketryforum.com/showthread.php?s=&threadid=10348

The .rkt file you will find there has not yet been modified to show the sleeves/couplers.

Greg

 

[teflonrocketry1]

The design looks good; nice and stable. I am interested in seeing how you are going to couple the stages together with the sleeves. How are you going to keep the motors aligned? A lot of hard work, money and paperwork for this flight; I hope all the motors ignite and stage properly!

Bruce S. Levison, NAR #69055

 

[11bravo]

I'll have to get back to you with the specifics.
Have them in my head, but at this hour things don't usually come out in a coherant form.
I know how it's going to work, just have to put it together (this would be a good time to glance down at my sig line ).

Greg