Traveling Rocket thread

[MikeyDSlagle]

"Not Cleveland...No, Say it's not Cleveland" lol. Anyone guess the movie without "googling"?

Welcome aboard. I'll get the list updated.

 

[Tractionengines]

One of the baseball movies... I was going to say Major League...but that's not right....

 

[jqavins]

A League of Their Own?

 

[Tractionengines]

"Mr Baseball".... right? Haven't seen that in years, but I think that's the name of it.

 

[MikeyDSlagle]

Yep
Mr Baseball with Tom Selleck
Good movie.

 

[Sooner Boomer]

I think if you go with a design that requires a composite motor, or anything that needs a motor bigger than 24mm, you'll be excluding a lot of folks like myself. It's not terribly hard to design/build a tough, good flying rocket that goes up on BP. Or maybe there should be two rockets, one high power, one for us mundanes.

 

[DeepOvertone]

I think if you go with a design that requires a composite motor, or anything that needs a motor bigger than 24mm, you'll be excluding a lot of folks like myself. It's not terribly hard to design/build a tough, good flying rocket that goes up on BP. Or maybe there should be two rockets, one high power, one for us mundanes.

I’m pretty sure he said it’ll fly really well on a D12. That motor is pretty much ubiquitous.

 

[MikeyDSlagle]

I think if you go with a design that requires a composite motor, or anything that needs a motor bigger than 24mm, you'll be excluding a lot of folks like myself. It's not terribly hard to design/build a tough, good flying rocket that goes up on BP. Or maybe there should be two rockets, one high power, one for us mundanes.

We have been brainstorming since early December. I ultimately settled on 24mm. It will be limited to about 70 mm to prevent anyone from loading an Estes 24mm E into it. It will fly on some Q-Jets up through E composites.
You haven't signed up so the only one excluding yourself is .... yourself. If you want in send me a PM with you address and I will gladly add you to the list.

 

[Sooner Boomer]

Sorry, I must have confused threads in my mind. OR says it should hit just under 600' on a BP D.

What kind of chute/streamer does/will it have? Chute protector?

I think you're underestimating the durability of cardboard and balsa, but that's not meant to start an argument.

 

[Sooner Boomer]

We have been brainstorming since early December. I ultimately settled on 24mm. It will be limited to about 70 mm to prevent anyone from loading an Estes 24mm E into it. It will fly on some Q-Jets up through E composites.
You haven't signed up so the only one excluding yourself is .... yourself. If you want in send me a PM with you address and I will gladly add you to the list.

I'm open to try it. PM sent.

 

[MikeyDSlagle]

We had one drop out but two more signed up. Eleven - now it's thirteen - different states, counting me here in Louisiana, two from Oklahoma. Hopefully more will trickle in.

1. shawn_rocket ---- Missouri
2. jbrracer ---- Indiana
3. Wally Ferrer ---- Virginia
4. Tobor ---- Illinois
5. bobbyg23 ---- South Dakota
6. dhbarr ---- Oklahoma
7. jqavins ---- New York
8. CPUTommy ---- Massachusetts
9. rdbrown ---- Kansas
10. Tractionengines ---- Ohio
11. Sooner Boomer ---- Oklahoma
12. tsmith1315 ---- Georgia
13. TheTank ------ Connecticut

 

[dhbarr]

We had one drop out but two more signed up. Eleven different states, counting me here in Louisiana, two from Oklahoma. Hopefully more will trickle in.

1. shawn_rocket ---- Missouri
2. jbrracer ---- Indiana
3. Wally Ferrer ---- Virginia
4. Tobor ---- Illinois
5. bobbyg23 ---- South Dakota
6. dhbarr ---- Oklahoma
7. jqavins ---- New York
8. CPUTommy ---- Massachusetts
9. rdbrown ---- Kansas
10. Tractionengines ---- Ohio
11. Sooner Boomer ---- Oklahoma

Could I trade with @Tractionengines ? That would dramatically shorten the overall waiting time

 

[MikeyDSlagle]

The motor tube and rings arrived yesterday afternoon. I hope to have the tube cut down and most of it assembled tonight. Thanks to @shawn_rocket for the parts.

Sorry, I must have confused threads in my mind. OR says it should hit just under 600' on a BP D.

What kind of chute/streamer does/will it have? Chute protector?

I think you're underestimating the durability of cardboard and balsa, but that's not meant to start an argument.

No worries.
It's not so much the durability of the materials as it is the conditions this rocket may experience that could otherwise wreck a paper/balsa model.
Rambunctious toddlers
Damp grass
Mysteriously appearing mud puddles
And let's not forget the carrier. It will run a gauntlet from state to state. Fiberglass will handle more abuse.

Wally tossed in an 18" Roto-foil from Bama Chutes. Looks like a flat chute with squares cut out. We'll use that. And a Topflight chute protector. I'll put in a bag of dog barf as well.

Any upgrades along the way are welcome. I will include the remaining airframe and will try to design and print a coupler with A/V bay in the event someone wants to do dual deploy with larger motors. Shouldn't be too difficult to design. I'll look into it.

I am installing the engine block to limit it to 24/40, 24mm C and D and 18mm Q-JETS with included adapter. Smaller 24mm single use should fit as well, and some of those are Fs, so it may can get some good altitude if a flyer has the means to track it.

I'm open to try it. PM sent.

Got ya, thanks.

 

[MikeyDSlagle]

Could I trade with @Tractionengines ? That would dramatically shorten the overall waiting time

If he agrees then sure, no problem at all.

 

[jqavins]

You could get carried away optimizing the route. But don't.

 

[MikeyDSlagle]

You could get carried away optimizing the route. But don't.

Lol
Not even gonna try. It's better to let it wander around. But if Dh wants to trade, he be moving down the roster, it's fine. I'm not going to actively optimize the route.

 

[neil_w]

If I may make a couple of comments on the "final" ORK file that was posted yesterday.

1. OR shows stability margin quite a bit below 1 with most motors.
2. In the simulations, launch rod length is set to 30", which results in extremely low speed off the rod for most motors. Even after changing to 48", many of the motors in the file have unacceptably low speed off the rod.

Am I missing something?

 

[jqavins]

Oy. Adding nose weight to fix number one only exacerbates number two. Looks like I'll be buying some Q-Jet D20s.

 

[jbrracer]

If I may make a couple of comments on the "final" ORK file that was posted yesterday.

1. OR shows stability margin quite a bit below 1 with most motors.
2. In the simulations, launch rod length is set to 30", which results in extremely low speed off the rod for most motors. Even after changing to 48", many of the motors in the file have unacceptably low speed off the rod.

Am I missing something?

Short and big fins, my guess it will be fine due to base drag. Someone can do the math if they want.
As for the speed off rod that's a good question some are slower than I shoot for off the rod. And I don't see anything in the sim that indicates a mistake.

 

[neil_w]

Short and big fins, my guess it will be fine due to base drag. Someone can do the math if they want.

The big fins are already accounted for in the OR calculations. As for base drag... this rocket is 9:1 aspect ratio, I don't think it really qualifies for much of a base drag correction.

As for the speed off rod that's a good question some are slower than I shoot for off the rod. And I don't see anything in the sim that indicates a mistake.

It's simply a very heavy rocket for its size, due to materials choice.

 

[jbrracer]

The big fins are already accounted for in the OR calculations. As for base drag... this rocket is 9:1 aspect ratio, I don't think it really qualifies for much of a base drag correction.

It's simply a very heavy rocket for its size, due to materials choice.

You are right, I'm not used to small fiberglass rockets and have never sim'd a rocket of this size.
most of my fins are longer and wider than this rocket itself.

 

[jbrracer]

The big fins are already accounted for in the OR calculations. As for base drag... this rocket is 9:1 aspect ratio, I don't think it really qualifies for much of a base drag correction.

It's simply a very heavy rocket for its size, due to materials choice.

Heck the rocket I'm building now has four times the weight of this rocket just in the nose.

 

[neil_w]

These are the motors that seem to work, although two (C11 and D20W) are marginal. I don't know why it's showing higher rod speed for the C18 vs. the D20.

Stability margin ranges from .46 to .78 for the motors on this list.

There are all manner of reloads that are possible as well, of course; this is just a pruned list from the ORK file, and I threw in the E30 as well.

 

[DeepOvertone]

Im working with mike on the simulation right now to see if there are any optimizations or minor errors. We are discussing cutting the fins down a bit. I've messed with the file and found a little stability there.

 

[neil_w]

Adding a couple of inches to the body tube would help quite a bit as well, although the added weight would further marginalize the D20W and C11.

Edit: actually it looks like 1 more inch on the body tube and a cut-back on the fins would do it. Just under 1 caliber with the E20.

 

[DeepOvertone]

I think he already cut the body tube down so we are stuck with that length. May just have to add lead to the nose and optimize fins. I'm also seeing that the motor retainer is not fitted in the sim.... So I'm looking to see if an aero pack would be lighter than the estes one. I find the estes ones to be a little bit chunky.

 

[DeepOvertone]

So I'm looking to see if an aero pack would be lighter than the estes one. I find the estes ones to be a little bit chunky.

An Aeropack is only a few tenths of a gram lighter so its not worth the additional expense. Darn

 

[neil_w]

An Aeropack is only a few tenths of a gram lighter so its not worth the additional expense. Darn

A motor hook is lightest of all.

 

[MikeyDSlagle]

Long post and kinda jumbled.
I'm at work, in and out of meetings prepping for some classes, so bear with me. I'm on my phone with no access to OR.

First file I posted was mid December and received zero input. Now everyone wants to jump in with ideas and suggestions.
Where were yall last month when we were trying to decide what to fly? LOL.

This ORK file was my latest design idea and now it is getting the comments and participation that I have been looking for. It will be tweaked, I only just now received all the parts. And it can be changed. I am open to ALL suggestions for airframe length and fin shape. I can cut the fins down but I can't add to them of course, but once they're mounted that will be it.

Airframe is cut at 9", the cutoff is 9" as well, more than willing to take it down to 6 or 7. I can lighten the rings and take some out of the fin tabs to shave some weight.

@neil_w
You haven't missed anything. I was only assuming most folks had at their disposal a shorter rod so I set that purposely short. Some of those motors are unacceptable and they are not recommendations but simply showing what I have simmed. But having them in there has opened up a line of communication that will help finalize the design. When it's built and ready to fly the sim will be finalized with weights and stability then I can recommend motors.
NAR requires only .5 CAL. I fly many well below that, albeit short stubbies. But for a rocket at 9:1, I have no problem flying it between .5 and 1 CAL.
Thank you for working on the sim. I'm at work and getting stuff ready for some classes with no access to OR.
I found anomalies when I added one inch to the airframe. Stability went up but altitudes went way down, some even returning large angles of attack.

@jqavins
Therein is the dilemma of this project. Keep it light for small motors and reduced shipping, but built with fiberglass, and can't go too high on readily available motors, oh yeah, it has to be stable.

@jbrracer
I'm there with ya. Most of the motors I fly are bigger than this rocket.

@DeepOvertone flies with me here in Louisiana and we have been texting back and forth. He is looking at the file since I can't while at work. Sweeping the fins appears to help quite a bit.

 

[neil_w]

First file I posted was mid December and received zero input. Now everyone wants to jump in with ideas and suggestions.
Where were yall last month when we were trying to decide what to fly? LOL.

Speaking for myself, I won't be participating so I only check this thread occasionally. Saw a "final" ORK and was curious to check it out.

Regarding the rocket: I certainly wouldn't shorten it. It'll reduce weight a bit but also reduce stability, which is already marginal.

Regarding the motors: it would useful IMHO, when truly "final", to include only motors/delays in the ORK that are believed to work well. That is most useful info for the flyer.

Regarding the launch rod: Personally I wouldn't fly this rocket on less than a 48" long 3/16" rod. To get a decent rod speed with 36" rod, you need a much higher thrust motor, which is likely to be a bad choice for that very same flyer who lacks a proper launch rod.