# 18mm MD 2000 ft on a C6

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#### TRFfan

##### Well-Known Member
Hi,

This is a build thread for my 18mm MD rocket which i hope to hit 2000 ft with a C6. The build will start tomarrow.

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#### Todderbert

##### Well-Known Member
I'm a bit of a newb with open rocket, do you have an engine block or recovery device? Tumble? Looks cool, made me look up a Yankee rocket with its est alt of 1850ft.

#### TRFfan

##### Well-Known Member
I'm a bit of a newb with open rocket, do you have an engine block or recovery device? Tumble? Looks cool, made me look up a Yankee rocket with its est alt of 1850ft.
I dont think a yankee would actually get 1800 ft (in openrocket its perdicted to get 1300). Also, this rocket is alot more optimized than a yankee.

And yea, im using tumble recovery since the rocket is so light. I didnt add an engine block to the file since im just doing the basics, an engine block would only add one or two grams so its not really a significant addition.

#### Bat-mite

##### Rocketeer in MD
What altimeter will you be using?

#### Todderbert

##### Well-Known Member
I dont think a yankee would actually get 1800 ft (in openrocket its perdicted to get 1300). Also, this rocket is alot more optimized than a yankee.

And yea, im using tumble recovery since the rocket is so light. I didnt add an engine block to the file since im just doing the basics, an engine block would only add one or two grams so its not really a significant addition.
Nice, balsa fins? Another rocket that came to mind was the Zinger from circa 1992, I remember building one and firing it away on a C and never seeing it again.

#### TRFfan

##### Well-Known Member
Nice, balsa fins? Another rocket that came to mind was the Zinger from circa 1992, I remember building one and firing it away on a C and never seeing it again.
No im using 1/32" plywood.

#### TRFfan

##### Well-Known Member
What altimeter will you be using?
I'm using a 1.5$buzzer to help me find the rocket. An altimeter would be too expensive and i can get all the parts for this rocket under 10$.

#### Bat-mite

##### Rocketeer in MD
I'm using a 1.5$buzzer to help me find the rocket. An altimeter would be too expensive and i can get all the parts for this rocket under 10$.
Oh, I thought you wanted to confirm you hit 2000'.

#### Flyfalcons

##### Well-Known Member
Nice, balsa fins? Another rocket that came to mind was the Zinger from circa 1992, I remember building one and firing it away on a C and never seeing it again.
Ktesh made an .ork for that one. I never got one when I was a kid so I'm going to use those plans to build a clone. '80s motif color scheme and all.

#### TRFfan

##### Well-Known Member
Oh, I thought you wanted to confirm you hit 2000'.
Theres a good chance that the rocket will get lost so i dont want to spend to much money on the altimeter and to then get it lost.

#### Mugs914

##### Pardon me for talkin' while you're interruptin'...
I was just playing with an MD 18mm design a couple of days ago too. ORK says 2011' on a C6, no altimeter, but does use streamer recovery. Tower launch envisioned, so no lug. I didn't have any kind of altitude goal, just doing it for fun. Might even build it...

View attachment Chaparral.ork

#### BuiltFromTrash

##### Well-Known Member
This is probably a pipe dream unfortunately. Motor variation will kill you. All this is moot though without hard data. If you had a radar you could determine the height with out adding an altimeter.

#### Peter Olivola

##### Well-Known Member
I fiddled with this a bit. Changed the fin shape to a short clipped delta, in 1/8 basswood instead of ply and airfoiled the fins. Sims to over 2100 at my altitude (4800'.) Your original sims to less than 1900 at my altitude

Hi,

This is a build thread for my 18mm MD rocket which i hope to hit 2000 ft with a C6. The build will start tomarrow.

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#### Todderbert

##### Well-Known Member
squeeze an inexpensive Firefly in there...but I would bet it may be hard to recover but keep the weight and cost down. then theres the APRA and Pnut that have the audible locator. Though your in for added weight.

#### TRFfan

##### Well-Known Member
I don't need to really verify the altitude though, just building this for kicks.

#### Cabernut

##### Well-Known Member
Some tips I found from fiddling with your OR file: 1/16" fins that are rounded give more altitude than 1/32" square-edged. Also try 3 fins instead of 4 for reduced drag. Use the Rocket Optimization tool in OR to find the optimal nose weight, also create a plot of the stability caliber throughout the flight. You may be able to get away with lower calibers that you might think. 1.8 cal is more than plenty if subsonic(M <= 0.5).

Forgot to add: losing a rocket is less fun that you might think. Even losing a cheap mosquito on an A10 @ 800' wasn't as fun as I'd thought.

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#### TRFfan

##### Well-Known Member
Some tips I found from fiddling with your OR file: 1/16" fins that are rounded give more altitude than 1/32" square-edged. Also try 3 fins instead of 4 for reduced drag. Use the Rocket Optimization tool in OR to find the optimal nose weight, also create a plot of the stability caliber throughout the flight. You may be able to get away with lower calibers that you might think. 1.8 cal is more than plenty if subsonic(M <= 0.5).

Forgot to add: losing a rocket is less fun that you might think. Even losing a cheap mosquito on an A10 @ 800' wasn't as fun as I'd thought.
haha i know. One time me and my friend brought 8 rockets to a launch and we ended up losing 6 of them. And yea, ill try a 3 finned design and see what i get.

#### Nathan

##### ☢
TRF Supporter
Nice, balsa fins? Another rocket that came to mind was the Zinger from circa 1992, I remember building one and firing it away on a C and never seeing it again.
I once flew an Estes Hi-Flier (which is a 18mm MD) on a C6-5. Never saw that one again either.

#### Mugs914

##### Pardon me for talkin' while you're interruptin'...
The old WAC Corporal was an 18mm MD too. One of my old favorites. B6 was the biggest motor I was ever able recover in one of those. Used to call it a "C6, see-ya"...

#### T-Rex

##### Ordinary Average Guy
TRF Supporter
The old WAC Corporal was an 18mm MD too. One of my old favorites. B6 was the biggest motor I was ever able recover in one of those. Used to call it a "C6, see-ya"...
I had one back in the day and built a clone a couple years ago. It generally flies on 13mm motors in the backyard.... I think the biggest my original saw was a B4. I like getting my rockets back.

#### TangoJuliet

##### Well-Known Member
Y'all got me curious now. I'm gonna have to drill a couple of small holes in my Hi-Flier, attach my JLA2, shove a C6 in it and see what kind of altitude I can get the next time I get to launch. I don't usually have too much difficulty keeping an eye on them, but I might need to add a mylar streamer for some added visibility.

#### BuiltFromTrash

##### Well-Known Member
What you need is a brightly colored rocket, a clear partly sunny day, no wind, and a well trimmed field big enough to account for wind differential. I launched a MD rocket on an E9 to a projected 3k ft. and barely got it back. I posted a summary of the flight on here, just got to find it.

#### 75Grandville

##### Well-Known Member
I'd suggest thinking about ASP Rocketry's 0.016" G10 fiberglass fins. https://www.asp-rocketry.com/ecommerce/Pre-Cut-G10-Fiberglass-Fins.cfm?cat_id=68

That's what I use for competition rockets. You can airfoil them, they stick well with CA, and they are pretty smooth.

Also, you might want to see if you can get your hands on a Quest C6 motor. They've got a different thrust curve, and a slightly higher predicted altitude.

Best of luck with your endeavor.

Of course, you've got me thinking about the NAR record now. Seems like beating 508m should be possible! (508m is NAR C Division record with altimeter. I realize you're in Canada - not sure what/how CAR does records - and if I remember correctly you'd be in B division)

#### Mugs914

##### Pardon me for talkin' while you're interruptin'...
Also, you might want to see if you can get your hands on a Quest C6 motor. They've got a different thrust curve, and a slightly higher predicted altitude.
Wow, that is a bit of a difference... I simmed mine real quick with the Quest motor and no other changes. Predicted altitude jumped by 140 feet!

#### Kallahan11

##### Well-Known Member
TRF Supporter
Some tips I found from fiddling with your OR file: 1/16" fins that are rounded give more altitude than 1/32" square-edged. Also try 3 fins instead of 4 for reduced drag. Use the Rocket Optimization tool in OR to find the optimal nose weight, also create a plot of the stability caliber throughout the flight. You may be able to get away with lower calibers that you might think. 1.8 cal is more than plenty if subsonic(M <= 0.5).

Forgot to add: losing a rocket is less fun that you might think. Even losing a cheap mosquito on an A10 @ 800' wasn't as fun as I'd thought.
I like to launch at least one yankee a year on an Aerotech D motor, I almost recovered it last year, I suspect the fiberglassed fin fillets and the chuff kept it in sight. Saw it come down but trying to find a yankee 1/2 mile from the launch site beyond a line of trees in tall grass is next to impossible. Here's the launch, the chuff almost takes it off tower. https://youtu.be/oOm9-Tckfc0?t=156

#### TRFfan

##### Well-Known Member
I'm not actually trying to break a record, Im just building it with the materials available locally and for cheap. If i wanted to break a record then i could probably get it alot higher.

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Looks like fun!

#### TRFfan

##### Well-Known Member
So anyway, today I'll cut the tubes but the nose cone and fin sheet shouldn't come in until next week.

#### retortec

##### Well-Known Member
I just finished my 18mm MD C6 project this summer. It took two extra spotters and a lot of tracking powder to get it back. I am really interested to see what you come up with. op: