K'Tesh's OpenRocket Files...

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Well, it's taken a while, but I've been working on updating the Cherokee-D's files thanks to new information. However, the length of the post required that I do some shuffling to make things look smooth.



Thanks to Earl L. Cagel Jr. for his information on the earliest version of the Estes Astron Cherokee-D (K-47), it made other corrections possible.

Files are found in post 23 and 24.

Due to the need for the additional space for the Cherokee-D, the downscales of the Binder Design Velociraptor, and the Raptor got pushed to post 25 (the files were updated for better building and/or graphics) , and the Scrambler II (1908) was moved to post 22.

 
I would like OR files for Estes Expedition and V2. I have them in RS but doesn’t fully import into OR especially when attaching fins to an end transition. Mahalo.

For the V2, you need to create a phantom body tube in RS, then import it into OR and play with it.

For the Expedition? Thanks for the laugh! I needed that! You're looking at A MINIMUM of 300 internal body tubes PER INCH of the length of the taper. Good LUCK!!! (Don't even dream about doing the graphics, or getting valid flight info).
 
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For the V2, you need to create a phantom body tube in RS, then import it into OR and play with it.

For the Expedition? Thanks for the laugh! I needed that! You're looking at A MINIMUM of 300 internal body tubes PER INCH of the length of the taper. Good LUCK!!! (Don't even dream about doing the graphics, or getting valid flight info).
I imported the V2 RS file but OR removed the parts it didn’t like. I made a facsimile but not sure if the flight dynamics are accurate. Has anyone made an accurate ork file? I’ll try to upload the version I made.

So what you’re saying is that I need to integrate the derivative for the taper? The Expedition seemed to fly similar to the Honest John.

 
I imported the V2 RS file but OR removed the parts it didn’t like. I made a facsimile but not sure if the flight dynamics are accurate. Has anyone made an accurate ork file? I’ll try to upload the version I made.

I don't have one, and I don't know anyone who has. Please, do not upload the version you have to this thread. I'd recommend either uploading it to the "Scale" forum, or the appropriate forum for the motors used (LPR, MPR, HPR).

So what you’re saying is that I need to integrate the derivative for the taper? The Expedition seemed to fly similar to the Honest John.

Whoosh! Hear that sound? It's what I heard as that went right over my head. I don't know anything about that kit,other than it won't sim (or at least, won't sim easily, or accurately).
 
Today's additions are a new one from Vander-Burn Rocketry, the Cherokee-H, and a mod to make it an upscale of the Cherokee-D (1247)



The Cherokee-H is based on the Cherokee-E at a 3" diameter. It's really a nice kit. The measurements in this sim were taken from an actual sample that was provided to me. You'll also likely recognize some of the renders on the instructions from this thread (way back on the first page). Kit includes: laser cut fins and centering rings, an included baffle, slotted body tube, decals from Stickershock, 29mm motor retainer, 30" chute, 500 lb Kevlar shock cord, the required hardware for connecting up the recovery gear, and your choice of rail buttons or launch lugs (or both). Basically, except for finishing supplies, and glues, it's a pretty complete package. Rather than going with the black, blue, and white color scheme, Toby opted to go with black, red, and white to reflect the Cherokee-D's markings.



The sim has the marking's placements based on the Cherokee-E. So, don't blame me for the CP and CG markings being reversed... That's how they appeared on the "E's" instructions. For flight performance data, you'll need to delete the PBT with the "Air Fins". As the current version of OR doesn't support rail buttons, I opted to go with the launch lugs in "stock" locations.

Now for the mod to upscale it to a 3" version of the Cherokee-D (1247)



Now there's a couple of ways of upscaling, you can upscale by length or by diameter. I chose to sim the latter. The instructions state that you should remove 10" from the body tubes. For an upscale based on the diameter, I'd recommend trimming the longer (34") tube down to 30 ²⁵⁄₃₂" long, and the shorter (21.5") tube down to 10 ¹³⁄₆₄. This gives a correct length for an upscaled 18" long BT-55, and allows the bottom of the larger wrap to conceal the joint. The nosecone is not a perfect match to an upscaled PNC-55AC, but for this kit it's a good choice at 10.937" long. Those who want to make or commission an upscaled nosecone will need it to be 12.52" long. The fins are not an exact match to the Cherokee-D (as they were based on the slightly smaller Cherokee-E's fins), but again you get the right feeling with the supplied fins. The forward launch lug was placed just behind the joint in the body tubes, where I'd recommend splitting the rocket for a zipperless recovery system. Decal placement was based on the Cherokee-D (1247)'s markings.

In the near future, I'll be simming an upscale of the shorter K-47 version of the Cherokee-D. But for now, I can tell you that the combined length of the body tubes should be 37 ⁷⁄₃₂".

Thanks to Toby Vanderbeek!

Where do you find this upscale kit? Thanks
Bought the kit From Toby. Very excited to get back in the hobby.
 
Balsa Machining 3" diameter School Rocket. 29mm.
New addition to the list, recently purchased. I bought the long airframe and want to mod it a bit, so I created 17" and 34" versions to start with.
This is NC, BT, MMT and fins only.
View attachment 436323
Hi Alan,

While I appreciate your desire to help people with creating sims in OpenRocket. This thread is dedicated to the ones that I created myself. That is why I named the thread "K'Tesh's OpenRocket Files...", to keep my files separate from others.

I'm not trying to put down your efforts, but I have an extremely high level of detail that I incorporate into my sims, which assures the end user that every attempt to insure that the sims are faithful to the original, right down to the rounding of the nosecone, the exact shape of the fins, and occasionally to include the shape of the eye bolts. I did this as I found that sims from other people (especially on rocketreviews.com) are a haphazard mix of good and terrible.

I want to encourage you to continue making sims, and sharing them, but like the others who like to create new sims, please create your own thread to post them into. Feel free to critique my sims (the good, the bad, and the ugly) if you want here. However, please don't post sims here. We can do that elsewhere. Ok?

Thanks!
Jim
 
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Hey K'Tesh, speaking of sims, did you ever complete the D.O.M. design I pm'd you about? I'm itching to see your final take on it!
 
Hey K'Tesh, speaking of sims, did you ever complete the D.O.M. design I pm'd you about? I'm itching to see your final take on it!
Sorry... didn't see this message... No, I've been on a hold for sims for some time... but the dam is breaking.
 
K'Tesh,

May I please ask how you used OpenRocked to model the fin shroud in the Semroc Lil' Augie (in post #377). A less dramatic example is the fin shroud in the Estes Solar Flare (post #113).

Thank you for your consideration.

Stanley
 
Hi K'Tesh,

Thank you for your response.

Since you mentioned an externalized internal body tube, I will try that to see which provides greater stability. It is worth the experiment.

Stanley
 
Neither will do... Problem with these, which should be resolved in the next version of OR, is that they are internal components. While they add weight, they are excluded from the aerodynamic calculations.

In future versions of OR, we should get ring fin support.
 
Neither will do... Problem with these, which should be resolved in the next version of OR, is that they are internal components. While they add weight, they are excluded from the aerodynamic calculations.

In future versions of OR, we should get ring fin support.
I am not sure how accurately they sim in OR but I have used couplers to represent Ring Fins.
 
I am not sure how accurately they sim in OR but I have used couplers to represent Ring Fins.
Like neil_w said... They won't sim at all. B

This is because, like centering rings and externalized internal tubes, they're internal components. While their mass will be factored into the aerodynamic flight characteristics, their effect on drag and CP won't.

We need to wait for the next release of OR for ring fin support.
 
It’s a calculus joke but not a very good one.

I appreciate the info. I wondered if there was some trick to emulating unique rocket designs in OR.
If I remember right, integrate the derivative, is like squaring the square root type of statement.
 
Regrettably the forthcoming release still does not support ring fins. ;(
But you'll be able to sim it using pods, which will give you the body tube and its placement. I guess it'll not give accurate drag performance though.
 
Hi everyone,

I want to make sure that I am talking about the same thing that everyone else is.

I am referring to a fin shroud, which is the circular-shaped piece surrounding the fins. As I understand it, the fin shroud -- everyone is now saying fin ring, so perhaps that is the correct term -- is used to protect the fins, right? The fin shroud or fin ring does not provide flight support. That is, it does not contribute aerodynamically to the rocket's flight. Instead, it just protects the fins from damage caused by landing. Is that correct?

Thank you.

Stanley
 
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