Chris' Punisher 4 L3 build

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

ChrisAttebery

Well-Known Member
Joined
Feb 15, 2014
Messages
2,454
Reaction score
90
I'm on my second foray into HPR. I originally flew HPR from 1998-2002 and was TRA level 2 certified. I built a level 3 project, but I never attempted a certification flight. I did fly it twice on Aerotech L850s successfully. In the last year and a half I have recertified back to level 2 and flown several K and L motors achieving up to 1200mph and 24,626'. I feel it's finally time to get my level 3 certification.

I'm going to be building a Wildman Punisher 4. It will be mostly stock, but I have a couple pieces I want to machine. More on those soon. I'm going to try to take my time and enjoy this build so I'll work on it as I have time.

Punisher Finished.jpg

I started out by machining a pair of new centering rings with notches for the shock cord and PEM nuts for the rail buttons. The front centering rings were tacked into place with CA. I used 10g of Rocketpoxy on each side of the MMT to attach the shock cord to the MMT. I wrapped it will parchment paper and packing tape to help it penetrate into the kevlar.


DPP_0585.jpg
DPP_0584.jpg
DPP_0586.jpg
 
That will be a high flying L3 build. I built mine big and heavy so I could see every part of the flight. Guess I was a bit chicken on the altitude also as I didn't want to chance loosing it after a successful ascent.
 
Awesome! I look forward to seeing this one come together.

Any preliminary thoughts on its big flight?
 
I'll be flying my Telemetrum, so I'll have tracking for the flight. There are a few guys that regularly fly M's at this field so I'm not pushing it by any means.

That will be a high flying L3 build. I built mine big and heavy so I could see every part of the flight. Guess I was a bit chicken on the altitude also as I didn't want to chance loosing it after a successful ascent.
 
Do you guys put some kind of GPS tracking into your HPRs these days? Just asking, since I don't know much about HPR other than it's cool as hell to watch! Imagine if we had the tech of today 40 years ago...
 
Do you guys put some kind of GPS tracking into your HPRs these days? Just asking, since I don't know much about HPR other than it's cool as hell to watch! Imagine if we had the tech of today 40 years ago...

I use TeleGPS primarily. I have borrowed Big Red Bee transmitters and they work well, though I have friends who have had that one cut out on the serious high performance flights.
 
The Altus Metrum Telemetrum altimeter I'm using has a built in GPS and ham band downlink. It will tell you the coordinates of the last known location and you can walk right to the rocket.

Do you guys put some kind of GPS tracking into your HPRs these days? Just asking, since I don't know much about HPR other than it's cool as hell to watch! Imagine if we had the tech of today 40 years ago...
 
Will be watching the build! Looking forward to seeing some APE machines parts for the punisher
 
Somewhere around 14k.

Are you adding significant weight? My custom Wildman on M1101 smashed the 14k simulations and did 16462 feet, while the M1350 did 15200 feet. Your Punisher will have more aerodynamic fins and will be closer to optimal length for the diameter.
 
Subscribed! Looking forward to watching this build for ideas. I still have a 3" Punisher in build pile.
 
It originally simmed closer to 16k, but adding 1515 rail buttons brought it down significantly. Interestingly RasAero2 sims closer to 16k even with the buttons. With my 54mm rocket both OR and RAS were pretty optimistic though, so who knows.

It's going to need a couple pounds of ballast just to be stable.

I'm also considering adding a 24" payload section just for the L3 flight. I could add extra ballast to it if necessary too.




Are you adding significant weight? My custom Wildman on M1101 smashed the 14k simulations and did 16462 feet, while the M1350 did 15200 feet. Your Punisher will have more aerodynamic fins and will be closer to optimal length for the diameter.
 
I've been busy working on the thrust plate over the last couple days. I should have something to show later today. I had to take a break from machining this morning so I decided to get something done on the rocket. I had originally planned to use 1010 rail buttons, but my L3 TAPs recommended using 1515 because our 1010 pads aren't up to a M launch. I'd like to be able to launch off a standard pad with smaller motors though. So I decided I'd install PEM nuts for both sizes. I'll fill the unused holes with set screws so they won't interfere with the rails.

IMG_3416.jpg

IMG_3417.jpg
 
Last edited:
I got the first thrust plate off the mill. I'm pretty happy with it. There will be a thin ring with 6x 6-32 screws to retain the motor.

IMG_3421.jpg

IMG_3422.jpg

IMG_3420.jpg

IMG_3423.jpg
 
Looks like the thrust plate is interfering with the end of the fin slots, do you intend to shift the fins forward a bit, or notch the end of the roots, or...?
 
The slots are about 1/8" too long. I'll notch the fin tabs to butt against the thrust plate though.

Looks like the thrust plate is interfering with the end of the fin slots, do you intend to shift the fins forward a bit, or notch the end of the roots, or...?
 
Yes, I will. I've got three done right now. I'll be working on the retaining rings over the weekend.

The thrust plate weighs 2.2oz. The entire setup will less than an AeroPack 75mm flanged retainer. :cool:
 
I threaded the six screws into the thrust plate until they were flush with the back side. Then I put a small blob of grease on each one so the epoxy wouldn't stick inside the threaded holes. I mixed up 3g of Rocketpoxy and spread it on the end of the motor mount tube. I pressed the thrust plate into place and cleaned up the excess epoxy. Then I put the entire assembly into the body tube to make sure the plate was square with the end of the tube.

ImageUploadedByRocketry Forum1451714718.707216.jpg
 
I love your machining work Chris! Looking forward to following your progress.

Ari.
 
Back
Top