Level 2 Build Finished: Madcow Frenzy

Amidst packing up to move I was able to finish it in time for Red Glare this coming weekend.
Cert Flight on a J430 White Thunder to an est. 3400'

Didnt do a build thread but I do have a couple pics of the process im going to post later in my album.
The FIRENZY:

I Like it, looks awesome!!
All the best on your Certification and your move.

That's a great looking rocket. What altimeter do you have in it?

TheSamurai said:

That's a great looking rocket. What altimeter do you have in it?

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Thanks Samurai! Im using the RRC3, and depending on the winds, either an 18" drogue or a 12" if its windy, then a 42" Heavy Duty from Spherechutes at 700 or 500, again depending on winds, It also has OneBadHawks 25' Kevlar shock cords. I've used this RRC3 in my Patriot on 3 successful Dual Deploy flights already.
Was supposed to have flames on the nose, but running out of time to get them applied (Vinyl from Mark @ Stickershock)

Looks awesome!

Great looking bird! Good luck on your flight and cert attempt.

I've got two flights on my fairly stock built Frenzy, an Aerotech I366R to 2028' and a CTI J410R to 3354'. It was damaged on its first flight due to a fouled main deployment, so I'll probably fly it one last time this weekend and retire it and build another one since I love it so much. Although it doesn't whistle as loud as my split fin Thor, it does put off a noticeable sound all the way up to apogee after the motor cuts out.

One question - did you reinforce the tail at all? I cut down a 1" piece of body tube and epoxied it into the rear behind the centering ring so it could absorb impacts better. I also added a third centering ring between the fins, I don't think the stock kit had that.

neond7 said:

Great looking bird! Good luck on your flight and cert attempt.

One question - did you reinforce the tail at all? I cut down a 1" piece of body tube and epoxied it into the rear behind the centering ring so it could absorb impacts better. I also added a third centering ring between the fins, I don't think the stock kit had that.

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Jeff, Thanks for the compliments, should be a great flight, I did reinforce the rear with a cut down Madcow coupler, essentially tripling the thinckness back there.
I used 4 CRs. One on each end of the rear fins, one on the aft end of the forward fins and another up higher for the Ubolt/kevlar attachment point. So shes built heavy in the bottom, but that evens out with the payload bay, and AvBay (with altimeter and battery the Madcow AvBay weighs in a little over a pound) Wasnt too much concerned with weight flying on 54mm, plus the length gives me plenty of stability (over 2cal) all the way up to a 4 Grain.

great looking paint job, I did my lvl2 on Frenzy too CTI J380 , height unknown no electronics in it other than BRB RF tracker , I really wish I would have built DD

neond7 said:

One question - did you reinforce the tail at all? I cut down a 1" piece of body tube and epoxied it into the rear behind the centering ring so it could absorb impacts better.

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Agreed. I did the same. The aft end of the BT behind the last CR is just asking for damage. I glued in a heavy duty piece of coupler.

The instructions also mention adding nose weight. Does anybody do this? I adjusted the ratio of the two body tubes and added an av-bay to get the CP-CG relationship I wanted without having to resort to nose weight.

Rather than giving a CP location, the instructions mandate a CG point to achieve, which I find rather backwards. So, I had to build a RockSim model just to find the CP, since the manufacturer didn't provide it directly.

Nice finish, degreger.

Buckeye said:

Agreed. I did the same. The aft end of the BT behind the last CR is just asking for damage. I glued in a heavy duty piece of coupler.

The instructions also mention adding nose weight. Does anybody do this? I adjusted the ratio of the two body tubes and added an av-bay to get the CP-CG relationship I wanted without having to resort to nose weight.

Rather than giving a CP location, the instructions mandate a CG point to achieve, which I find rather backwards. So, I had to build a RockSim model just to find the CP, since the manufacturer didn't provide it directly.

Nice finish, degreger.

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I also added an avionics bay for DD to mine, so no nose weight was needed. I don't have the sim I ran on it with me right now, but it was very stable. With a 54/38 adapter, I used a 38mm CTI 6 grain J410 motor and it was straight as an arrow.

Even without the avionics bay, it is a tall rocket (which improves CP) and I don't think it would need nose weight unless you were using a large 54mm motor. But as always, run a simulation first to get a ballpark and then balance it to verify.

Same here, no nose weight needed, once the main, shock cord, nomex and quick links go in, it is a very stable bird.
Cant wait to see what altitude I get with it, should be personal best, current is 2226ft with my Patriot on an I236. This thing should be around 3400' for cert then I might push it over 4k on sunday

neond7 said:

I also added an avionics bay for DD to mine, so no nose weight was needed. I don't have the sim I ran on it with me right now, but it was very stable. With a 54/38 adapter, I used a 38mm CTI 6 grain J410 motor and it was straight as an arrow.

Even without the avionics bay, it is a tall rocket (which improves CP) and I don't think it would need nose weight unless you were using a large 54mm motor. But as always, run a simulation first to get a ballpark and then balance it to verify.

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Yes, mine flies straight and true, also. I simulated the CP/CG with the smallest J to the biggest L inserted, and there is plenty of stability margin on my design. I think the stock build would be similar. Of all the threads on the Frenzy, I have yet to see any mention of nose weight. I wonder why Madcow suggests it? He must assume the 99th percentile builder who will put a ton of epoxy in the fin can.

I'll chime in with the straight and true with no nose weight crowd. I've flown mine five times now and it is a true performer.

Here it is on flying on an Aerotech I327DM. Love this photo.

That is a fantastic shot! I have this kit sitting on my bench as we speak, as my L2 build candidate. It sounds like most folks went stock- I am being encouraged to glass the tubes and fins...did anyone else feel the need to do this, or does that put me in the "99th Percentile" that will need nose weight?

Level 2 Achieved to 3467Ft on the J430. Arrow straight flight perfect recovery on friday. Flew it again on Sunday to on the J280 Smokey Sam, very windy but another perfect flight and recovery. Long walk though! Forgot the altitude, I dont think I broke 3k with it on this motor.

Here's the Video of the Cert Flight

https://m.youtube.com/watch?v=mnuZjll_XSA&list=PL2LMq2TTPTZpMZOVZ7vsC8KM7F9uRrZaE#

Gotta love the whistle of the split fins!
Thanks go out to:
Dave Weber @ MDRA for witnessing my flight.
Mark @ Stickershock for the Vinyl
Teddy @ OneBadHawk for the Kevlar Shock Cords
Robert and Gloria @ Animal Motor works for the Cert motor and Case.
Glenn (G-DOG) @ Rat Dog Rocketry for the help, advice and constant agitation!!!
Thanks again Peter Abresch for filming mine and all the other flights from the weekend.
Tommy Higgs for the use of the fields and the Awesome Chicken!!
MDRA for another world class Launch!

Thanks to Andy Cook for this Awesome lift off shot of the second flight on a J280 Smokey Sam on Sunday!

Congratulations! Well done.

Good flight and nice looking rocket. Either I missed it in the thread or its not there. What size drogue chute did you fly in it? You said it was going to be either an 18 or 12? I am just finishing up my Frenzy for level two cert. Put a tail cone on instead of extra cardboard on the rear. Waiting need to get electronics sled done and paint on it then ready to fly.

BrAdam said:

Good flight and nice looking rocket. Either I missed it in the thread or its not there. What size drogue chute did you fly in it? You said it was going to be either an 18 or 12? I am just finishing up my Frenzy for level two cert. Put a tail cone on instead of extra cardboard on the rear. Waiting need to get electronics sled done and paint on it then ready to fly.

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I too am curious about your drogue size- my sims are pointing to 12". BrAdam- do you have any photos of the tail cone you used? I like that idea a lot, but have never used one. Is it the aeropack retainer?

BrAdam said:

Good flight and nice looking rocket. Either I missed it in the thread or its not there. What size drogue chute did you fly in it? You said it was going to be either an 18 or 12? I am just finishing up my Frenzy for level two cert. Put a tail cone on instead of extra cardboard on the rear. Waiting need to get electronics sled done and paint on it then ready to fly.

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soopirV said:

I too am curious about your drogue size- my sims are pointing to 12". BrAdam- do you have any photos of the tail cone you used? I like that idea a lot, but have never used one. Is it the aeropack retainer?

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For both the Cert flight and the second flight I used an 18" drogue, it was 9 lbs on the pad so I went a little bigger. In the video Neil says its a small looking main but it is actually a 42" heavy duty from Spherachutes. If I were to build another one, I would use a PML Tailcone instead of the coupler.

I was thinking 12" as well. Here are a couple of pix. Not the greatest but you can get the idea. I had to cut a new motor mount tube to do this. The stock tube is not long enough.

I like that look!

Ditto- looks sharp. Did you have to add weight to the nose to move the CG forward?


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I don't think any will be needed. Picking up the chute this weekend and will throw everything in it to see where I'm at. OR predictions say yes with some larger motors. 4 grain 54s and larger. Not sure I will do that though. If I do, I have a removable bulkhead in cone I can add temporary weight in.
Primer just went on but need it rigged, tested and ready for a June launch. With kids and work and other hobbies (brewing beer) I should just have time.


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I'll add my two cents too . I just did my L2 cert at NY Power with my Madcow Frenzy. I did single deployment since the size of the launch area and the conditions allowed it. It flew on a CTI J381SK to about 2500'. In my case, I glassed the tubes and foamed the fin can for reinforcement. It does have an a-bay but only a GPS locator was on board at the time. since you guys were discussing it, I did add about 300g of weight to the nose to accommodate a ~ 1kg motor if ever needed.

BillG said:

I did add about 300g of weight to the nose to accommodate a ~ 1kg motor if ever needed.

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Thats alot of weight, I simmed mine with Rocksim all the way up to a CTI 5 Grain 54mm and still had almost 2 cal stability.

dgreger said:

Thats alot of weight, I simmed mine with Rocksim all the way up to a CTI 5 Grain 54mm and still had almost 2 cal stability.

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If I recall, the Madcow specified CP is forward of the OpenRocket specified Cp (not sure about RockSim.) Same was true for my Madcow Pike. It was definitely less that 1.0 calibre when using a 1kg equivalent motor mass. Cg measurement was done by hand with a loaded CTI motor tube.