CRC Mid Power Rocket builds

[CRC]

Thanks, all this patriot needs is for someone to yell MERICA!!!! when it's being launched :rofl: I This ones name is going to be.... Patriot E

 

[nute]

That turned out nicely!
An E12 will have that thing scooting!!
When I get home I'll run a sim.
How heavy did it end up being?
You know...
CTI makes a G65 white long burn that fits in there...
If you can, Try to take a video of the flight when she does fly!

 

[CRC]

lol, you sound like my buddy....put a g in it lol I just ordered my first G this weekend from online.
it is 106g without a chute, cause I ordered a 12" nylon chute I'm using instead of the stock 12" plastic chute......so what 110g-112g
Oh dont you worry, I'll be trying to get a vid of it.
Thanks Nate, I'll be waiting to see the sim results, I bet it goes at least 1000' I wish I remembered what kit that nosecone I used was from.

My next E build has been delayed, cause I got a buggered up kit, I've contacted estes & hope they can replace the part so I can continue building it.

 

[nute]

lol, you sound like my buddy....put a g in it lol I just ordered my first G this weekend from online.
it is 106g without a chute, cause I ordered a 12" nylon chute I'm using instead of the stock 12" plastic chute......so what 110g-112g
Oh dont you worry, I'll be trying to get a vid of it.
Thanks Nate, I'll be waiting to see the sim results, I bet it goes at least 1000' I wish I remembered what kit that nosecone I used was from.

My next E build has been delayed, cause I got a buggered up kit, I've contacted estes & hope they can replace the part so I can continue building it.

OpenRocket is saying about 1500 feet with an E12!

with that kind of altitude, I would really recommend a mylar or similar streamer over a parachute- that is if you ever want to see it again, LOL

Yesterday I flew a slightly smaller rocket to that same altitude, and using a streamer I was able to recover it relatively easily.

Nate

 

[rocketgeek101]

...I just ordered my first G this weekend from online.

Hymmmm good for you! Which one?

 

[CRC]

Muhahahah 1500' awesome, thanks again Nate!!!! Hmmm mylar streamer.....Ok I admit I know nothing about streamers.
Maybe you guys can answer this or point me in the direction of a site,page,thread with streamer info.
Things like, what size do I use on my rocket? do I go by the size of the rocket, the weight, how fast I want it to fall? What the pro's & cons of nylon & mylar. How fire resistant is it? how long does it last? what is too fast of a decent rate? I want them to come down quickly, but I don't want damage. I've only ever had a streamer in my first rocket that was a A3T, 8" tall toy. How do you keep it attached to rocket?, tape dont seem very strong.
Like I said I dont know nothing about streamers nor have I came across any info about them while I've been learning about rockets.
thanks guys, James

 

[CRC]

Hymmmm good for you! Which one?

Aerotech G77-7R

 

[rocketgeek101]

Aerotech G77-7R

Cool! I flew that exact motor in my Estes Nike Smoke. The red flame is just plain awesome

 

[nute]

Aerotech G77-7R

Excellent choice!!
my first G motor was the reloadable version of that motor, the G71R!
I'm quite partial to that Redline propellant; It's my personal favorite!
That motor will not disappoint!!

 

[CRC]

Some mail came.....Giggity.

 

[CRC]

Well lately I've had a few builds on the go at the same time so forgive me if I go back & forth between showing you guys them, I've held off on my estes magician till I see what estes sends me(i contacted them about a broken part) but for right now I've gotten a bunch of loose parts to design my own rocket.
This will be my first scratch build as in I'm winging it completely with my design, I will need some help as I've downloaded openrocket, but I cant figure out how to design my rocket on it, let along sim a flight. Anyway here is a pic of some of the parts I'll be using.
So far I used 2xbt60 tubes that were 18" long. I cut one at 7.5"
I made a rough bulkhead with 1/2" poplar wood, now I just got to sand it down for the perfect fit.
I'm making this rocket an E-powered rocket, so I made a motor mount & made my own centering ring out of the 1/2" poplar, I wont be doing that again as it took me 3 trys cause the first two broke Buying centering rings, here I come. Hrs later of sanding I got one
I also got cooling mesh as you see, & a coupler, next update I'll have some more parts I'll be using.

 

[Rex R]

I've made centering rings from 3mm Depron & cardstock. OR: well one generally starts with the nose cone and work toward the aft end, bt60 is 1.637 o.d., 1.595 i.d., bt50 is .976 & .950(measurements are in inches). so which end gets the 7.5" piece of tube? and where are you putting the baffle?
rex

 

[CRC]

Well where would the suspense be if I told you that Rex? lol I will say the cooling mesh will go right above the MM :wink: I hope to make some progress onit later today.

 

[CRC]

Ok I did get to work on it a little, I got my bulkhead sanded to a near perfect circle, I then tacked in onto a coupler, then used wood glue to get a nice ring inside, now let it dry. I also dug out a few more parts I'll be using, like 1/4" LL and a 15" nylon chute, swivel, 6'x.5" shockcoard

 

[nute]

This is looking to be an interesting build- I have yet to try my hand at a baffle but look forward to giving it a try soon!

 

[CRC]

So I got some mail today, with my nose cone It's translusant...oow, ahh. I aslo got the shock coard attached to one end. Now it's time to glue my baffle together. More pics to follow.

 

[CRC]

Ok I gota bunch more done but I'll post pics & details later, right now I need to figure out how big my fins should be. I was hoping to get some thoughts on how wide & long I should make the fins, I dont want to give away shape yet, but I dont want an unstable rocket. I can say it is 41" long, about 6-7oz(without motor) & will be flown on a e motor. Is there a difference(stability wise) of 3 or 4 fins? Is one generaly more stable then other??

 

[nute]

Ok I gota bunch more done but I'll post pics & details later, right now I need to figure out how big my fins should be. I was hoping to get some thoughts on how wide & long I should make the fins, I dont want to give away shape yet, but I dont want an unstable rocket. I can say it is 41" long, about 6-7oz(without motor) & will be flown on a e motor. Is there a difference(stability wise) of 3 or 4 fins? Is one generaly more stable then other??

4 fins will bring the CP (Center of Pressure as you may know) further back in relation to the rest of the rocket and CG. Just for comparison, the Estes STM 012 is a three fin, 41" BT-60 kit and it has fins with a root cord of 6in, tip cord of 1.4", height of 3in, and sweep angle of 54 degrees. It is plenty stable (about 1.5 calibers) even with an E12 loaded, and I have flown it quite successfully on Aerotech E11J reloads (although you may never see it again after it crests 1300 ft LOL!) My own version of this kit turned out lighter than you are describing, but an E should have plenty of power. Also, this kit has forward, canard fins that bring the CP forward. Without these the rocket has over 3 calibers of stability. I wouldn't worry about 3 vs. 4 fins, and most size fins would likely be fine, but YMMV depending on CG location.

Nate

 

[CRC]

great info, funny thing is just 3 days ago my buddy bought the estes stm012(beat me to it as I was going to buy it after christmas) So it a great example. I knew bigger fins brought the cp back, but I never thought about # of fins, but that makes sense now I hear it. I was planning on just using my estes kits as a guide for possible fin sizes, but really I dont know much about how diff fin shapes affect flight. I was just going to make something that looks like it belongs on the rocket, hopefully keeping the cp between 1-3 calibers, but honestly I'd be guessing quit a bit.
Calibers.... Teach me more please Nate, is it just a measurement of bt diameter widths between cg & cp? or am I missing something.
I know you dont want too much, like say 5 calibers, not do you want less then 1. I also have intentions of buying/trying a 24mm F to put in this unnamed badboy, so I was thinking bigger fins better then smaller fins.

 

[Rex R]

for a comparatively simple rocket (no pods, or winglets) open rocket is a great help, it lets you 'play' with fins to find a size/shape that works for you. for a rocket in the 1.5" diameter and larger size you probably don't want to go below 125% of the body tube diameter for the fin width(semi-span), likewise for the root chord(that bit that glues onto the body). hth
Rex

 

[CRC]

for a comparatively simple rocket (no pods, or winglets) open rocket is a great help, it lets you 'play' with fins to find a size/shape that works for you. for a rocket in the 1.5" diameter and larger size you probably don't want to go below 125% of the body tube diameter for the fin width(semi-span), likewise for the root chord(that bit that glues onto the body). hth
Rex

Thanks Rex, also great info, I'm locking that fact away in my memory(dont go less then 125% of the bt diameter for fin width or root chord), now is there a too big percentage, say like 700%(7x) the bt diameter? I imagine at some point bigger is not better....I'm guessing when you bring cp & cg out of wack.
I'll post some progress pics in a few min.

 

[nute]

great info, funny thing is just 3 days ago my buddy bought the estes stm012(beat me to it as I was going to buy it after christmas) So it a great example. I knew bigger fins brought the cp back, but I never thought about # of fins, but that makes sense now I hear it. I was planning on just using my estes kits as a guide for possible fin sizes, but really I dont know much about how diff fin shapes affect flight. I was just going to make something that looks like it belongs on the rocket, hopefully keeping the cp between 1-3 calibers, but honestly I'd be guessing quit a bit.
Calibers.... Teach me more please Nate, is it just a measurement of bt diameter widths between cg & cp? or am I missing something.
I know you dont want too much, like say 5 calibers, not do you want less then 1. I also have intentions of buying/trying a 24mm F to put in this unnamed badboy, so I was thinking bigger fins better then smaller fins.

I have limited knnowledge in the area of how fin shape effects overall stability, but I can tell you that, as you may have figured out, rearward swept fins will move the CP back, whereas forward swept fins will move the CP more forward.
As far as calipers go, you nailed it! One caliber is equal to to the BT diameter, and 1-2 caliber a of stability is gene really optimal for most rockets. However short fat rockets are often successful with less than one, and tall skinny rockets often need well over two. Also, you are correct about not wanting too much stability (overstable) as this can, if I recall correctly magnify any weather cocking.
In general, Estes rockets are well designed Nd if your fins are modeled after theirs on a similar rocket you should be fine

Also, I agree entirely with Rex that learning how to use Openrocket is a good skill to have. IMHO it is a great step in the hobby and will allow you to mess around with fin shapes, sizes And locations until it looks and performs how you like
Then you can print out a template of he fins ( how I designed my L1 rocket)

( please excuse my poor typin, as this is from my iPod's teeny tiny keyboard )

BTW, as for putting an F In a BT-60, you're a braver man than I!

Nate

 

[CRC]

However short fat rockets are often successful with less than one, and tall skinny rockets often need well over two.good info, makes sense Also, you are correct about not wanting too much stability (overstable) as this can, if I recall correctly magnify any weather cocking. Yes that makes sense too
In general, Estes rockets are well designed Nd if your fins are modeled after theirs on a similar rocket you should be fine

Also, I agree entirely with Rex that learning how to use Openrocket is a good skill to have. IMHO it is a great step in the hobby and will allow you to mess around with fin shapes, sizes And locations until it looks and performs how you like
Then you can print out a template of he fins ( how I designed my L1 rocket)
didnt know you could print out a fin template, I tried mucking with it a few times but I cant figure out some things & it fustrates me till I shut her down & just grad the glue or exacto & go at it.

BTW, as for putting an F In a BT-60, you're a braver man than I!

Nate

Well we did put an 29mmf-50-4 in the shortend magician(bt55)....he did lose it though....but it was really cool & I think I'm smarter then him so I think I can pull this off with a 24mm E30(sorry I thought there was a 24mm F) since I care more about things like delay,chute size ect. Which I am recreating his one he lost, slightly diff though & will SUCCESSFULLY launch AND retrieve it.( I feel you lurking Ryan:dark lol he has not joined TRF but I told him about it. But that build is for another day/thread, first back to my(think I got a name for it) current rocket.

I got my baffle glued up & fillets applied
I got my MM installed & made & 3rd ring/endcap with a notch out of it so the engine hook can flex
I made it out on 1/8" picture matting.

 

[nute]

Looking very good!
Especially the baffle!!
Actually, aerotech does make. Couple 24mm Fs, the F32 comes to mind.
When you do let her rip on an F a small chute and large fillets applied beforehand will both be your friends as well as a lot of tracking powder, perhaps a reflective Mylar streamer, and, depending on where you fly, a sonic alarm
These wi all increase your chances of successfully recovery.

 

[Rex R]

for the 24/40 RMS motor there are F12, F24, F39 re-loads . I used an F52 in a bt80 bird w/o damage.
Rex

 

[CRC]

Great to know Rex & Nate, This rocket has a date with a 24mm F(I thought i saw 1 somewhere, but site I went to didnt so I assumed I was dreaming)
So I got the bt together, I used the baffle as a coupler, the 7.5" piece is a payload bay.
I also made the shape of my fins, yes there is 3, not 4. I did this mostly to keep weight down. The fins are approx. 5.5" long(root edge) & 3" wide(fin semi span) I made/cut the leading edge @ 46deg, the outside tip edge @ 3deg & the trailing edge @ 10deg. I made the fins with 3/16" ply
I got one leading edge sanded, after work I'll sand some more, also I'll prob glue 1 fin on.

 

[nute]

Great to know Rex & Nate, This rocket has a date with a 24mm F(I thought i saw 1 somewhere, but site I went to didnt so I assumed I was dreaming)
So I got the bt together, I used the baffle as a coupler, the 7.5" piece is a payload bay.
I also made the shape of my fins, yes there is 3, not 4. I did this mostly to keep weight down. The fins are approx. 5.5" long(root edge) & 3" wide(fin semi span) I made/cut the leading edge @ 46deg, the outside tip edge @ 3deg & the trailing edge @ 10deg. I made the fins with 3/8" ply
I got one leading edge sanded, after work I'll sand some more, also I'll prob glue 1 fin on.
View attachment 156997View attachment 156998View attachment 156999

Nice fins, is the material balsa or something else?
Is the mesh in the baffle, what is the material?
I like the look of the fins, personally, and it looks like they should be a fine size by my eye.
IMHO, the BT-60-80, and the 35-45" length are the sweet spot for most 24mm motors, and this should fly real nice on most of them!

Nate

 

[CRC]

Nice fins, is the material balsa or something else?
Is the mesh in the baffle, what is the material?
I like the look of the fins, personally, and it looks like they should be a fine size by my eye.
IMHO, the BT-60-80, and the 35-45" length are the sweet spot for most 24mm motors, and this should fly real nice on most of them!

Nate

no balsa on this rocket, the fins are spruce 3/16" ply(strong like bull, but still a lighter wood)
no the mesh is in the bt, between The engine mount & baffle, so I can "clean out the mesh"
it is aerotech cooling mesh, looks like pan scrubber pads, just a little bit less dense, so a thin metal I think.
I kinda wish I made the fins a bit longer, 1" longer, but I think they will work....we will see anyway.
I too think bt-60 35-45" is great size for 24mm motors, but I like the bt-80's for f & g's with them being 40-55"

 

[nute]

no balsa on this rocket, the fins are spruce 3/16" ply(strong like bull, but still a lighter wood)
no the mesh is in the bt, between The engine mount & baffle, so I can "clean out the mesh"
it is aerotech cooling mesh, looks like pan scrubber pads, just a little bit less dense, so a thin metal I think.
I kinda wish I made the fins a bit longer, 1" longer, but I think they will work....we will see anyway.
I too think bt-60 35-45" is great size for 24mm motors, but I like the bt-80's for f & g's with them being 40-55"

Very nice, I like working with plywood so much more than balsa; it won't chip, take fingernail marks, and it can be sanded without the fear of it shattering, but most importantly-the finishing is always so much easier!!

 

[rocketgeek101]

Well we did put an 29mmf-50-4 in the shortend magician(bt55)....he did lose it though....but it was really cool & I think I'm smarter then him so I think I can pull this off with a 24mm E30(sorry I thought there was a 24mm F) since I care more about things like delay,chute size ect. Which I am recreating his one he lost, slightly diff though & will SUCCESSFULLY launch AND retrieve it.( I feel you lurking Ryan:dark lol he has not joined TRF but I told him about it. But that build is for another day/thread, first back to my(think I got a name for it) current rocket.

I got my baffle glued up & fillets applied
I got my MM installed & made & 3rd ring/endcap with a notch out of it so the engine hook can flex
I made it out on 1/8" picture matting.
View attachment 156960View attachment 156961View attachment 156962View attachment 156963View attachment 156964

What type of tube did you use for the baffle? Looks to be a vulcanized fiber (the stuff Blue Tube is made of) tube. Or is it just grey wrapped cardboard?