CJ's "PUNISHER" build!

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Speaking from experience, YES!!! nosecone vent IS needed. I forgot to add one and had a failure, Wildman has done it once....maybe twice and has had failure.

If the rocket is moving fast into an altitude of lower pressure, the high pressure that is in the nose needs somewhere to go. I would consider yourself lucky that you experienced a good result from a non vented set up.
 
blackjack2564 said:
Are you doing DD, using the NC for the main?

If so read this thread [again]. Shear-pins are definitely needed, unless you want to risk the main at apogee.
Don't forget to vent both fincan & NC for pressure relief,[not the vent/switch band] or risk popping off payload at Max-Q where things will get very ugly quick, when flying high thrust & larger motors

It's all in this thread.

Now if your asking about pins in payload to fincan, that is not needed, unless you have a sloppy loose fit.

If just flying with motor deploy nothing needed, you still need to vent fincan & NC.

Next time, please supply a bit more info on how you built & intend to fly your rocket. The Q is very vague....
Click to expand...

Sorry, yes plan on flying DD with NC main. I did vent both sides. My coupler feels tight fitting but I'll install shear pins anyways. Thanks for reply.
 
Mine looks "ratty" as it has to earn its paint by more than one successful flight:

21000002.jpg

Tracker nosecone. If I could figure out how to get a 16 second delay, on I200 would fit and get it north of a mile. A Jolly Logic Chute Release is mandatory. Plenty of H's are workable though. The Punisher was to replace
the Formula on the left after a motor burn out but it was salvageable. Details on the Formula are here: https://www.rocketryforum.com/showt...-Dual-Deployment-Flight&p=1627130#post1627130
Now I have two rockets for GPS tracker mules. Kurt
 
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Just went through the prep sequence (again) on my Punisher. This will be my first flight on it and I'm stressing on the TRS I have mounted in the avbay with an RRC-3. The TRS is the back up alt. and I have no worries that the RRC-3 will do it's job, but for some reason this flight is driving me crazy! Going up on a CTI K360 so I should be able to watch the flight to just over 6,000 ft. It will have a CSI beacon on the drogue, so it's not like I can't hunt it down if the TRS doesn't work.
So what's BUGGING me about this? I've gone back over this thread, vent holes, shear pins, all the quick links are attached, aeropac tailcone for motor retention..... Maybe it's just because it's the first launch of the season with TRA/PHX, I'm definitely excited about that!
 
Wayco said:
Just went through the prep sequence (again) on my Punisher. This will be my first flight on it and I'm stressing on the TRS I have mounted in the avbay with an RRC-3. The TRS is the back up alt. and I have no worries that the RRC-3 will do it's job, but for some reason this flight is driving me crazy! Going up on a CTI K360 so I should be able to watch the flight to just over 6,000 ft. It will have a CSI beacon on the drogue, so it's not like I can't hunt it down if the TRS doesn't work.
So what's BUGGING me about this? I've gone back over this thread, vent holes, shear pins, all the quick links are attached, aeropac tailcone for motor retention..... Maybe it's just because it's the first launch of the season with TRA/PHX, I'm definitely excited about that!
Click to expand...

Have you tested the TRS altimeter by pulling a vacuum to simulate a profile? Might be a good idea.

Regarding the TRS. I HIGHLY recommend a checklist for the TRS arming procedure. In my haste to do my initial L2 flight in July, I did not get a checklist together and I missed the last step in the arming sequence (the 7 second hold to start flight) which resulted in the flights ballistic profile. It's a rather involved start procedure and worth having a simple document for.
 
NateLowrie said:
Have you tested the TRS altimeter by pulling a vacuum to simulate a profile? Might be a good idea.

Regarding the TRS. I HIGHLY recommend a checklist for the TRS arming procedure. In my haste to do my initial L2 flight in July, I did not get a checklist together and I missed the last step in the arming sequence (the 7 second hold to start flight) which resulted in the flights ballistic profile. It's a rather involved start procedure and worth having a simple document for.
Click to expand...

Nate - Cris puts a pretty good check list in the operations guide.
 
I picked one of these up during the Black Saturday sale and I'll be starting the build before long. On my Wildman Demon 98, I use a rotary switch to power my altimeter, and it's mounted in the switch band, but with this being a 3", I'm doubting there is room for that. I was planning on using a 3D printed sled. What methods is everyone using for power? I see CJ used "twist & tape", I'm just curious as to other methods. This will be my smallest DD bird so far. Thanks everyone.
 
noffie79 said:
I picked one of these up during the Black Saturday sale and I'll be starting the build before long. On my Wildman Demon 98, I use a rotary switch to power my altimeter, and it's mounted in the switch band, but with this being a 3", I'm doubting there is room for that. I was planning on using a 3D printed sled. What methods is everyone using for power? I see CJ used "twist & tape", I'm just curious as to other methods. This will be my smallest DD bird so far. Thanks everyone.
Click to expand...

I use a sled with two screw switches mounted right on the sled. Plenty of room for an RRC3, RRC2+, 2x9V, and switches.
 
ImageUploadedByRocketry Forum1484315472.028067.jpgImageUploadedByRocketry Forum1484315504.564768.jpg
There is a lot of room in the AV bay. Enough for another battery, switch and altimeter.
 
4kids49 said:
Nice sled setup. I get the general options with all thread, couplers, eye nuts, etc. How do you attach the all thread to the sled? I don't see any ties. I couldn't tell from CJ's pics if he epoxied the all thread to the sled.
Click to expand...

Magnifying the photo a bit makes it look as if there's a black tube along the length of the sled that the all thread slides through.
 
4kids49 said:
Nice sled setup. I get the general options with all thread, couplers, eye nuts, etc. How do you attach the all thread to the sled? I don't see any ties. I couldn't tell from CJ's pics if he epoxied the all thread to the sled.
Click to expand...

Steve Shannon said:
Magnifying the photo a bit makes it look as if there's a black tube along the length of the sled that the all thread slides through.
Click to expand...

I epoxied a piece of fiberglass tube onto the sled that is used as a kite spar, the 1/4" all thread fits through nicely.
 
ksm2001 said:
I epoxied a piece of fiberglass tube onto the sled that is used as a kite spar, the 1/4" all thread fits through nicely.
Click to expand...

Nice. Where did you get the eye nuts? I got some from McMaster Carr, but the eye is much shorter.
 
hobie1dog said:
Awesome build, also want to know about the nice looking eye bolt setup, thanks for all the pictures.
Click to expand...

The pictured eyes are eye nuts. The eye part contains a nut instead of a bolt. This allows the builder to use one all thread and two eye nuts. Clean and simple. Traditionally, people have used eye bolts. CJ discusses all of this earlier in the thread. An eye bolt must be connected to the all thread with a coupler. Eye bolts, couplers, all thread, and eye nuts give the builder quite a bit of flexibility.
 
Thanks for the comments guys.
I like the eye nut configuration over an eye bolt in that it keeps the av bay cleaner looking.
I ordered the SS eye nuts a couple years ago. From what I remember it was a seller through Amazon.com. If you do a search on 1/4" eye nut there are few options to choose from. Hope this helps.
 
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4kids49 said:
Nice sled setup. I get the general options with all thread, couplers, eye nuts, etc. How do you attach the all thread to the sled? I don't see any ties. I couldn't tell from CJ's pics if he epoxied the all thread to the sled.
Click to expand...

No I did not epoxy the all thread to sled.

Just a 1/4 tube slathered with black dyed epoxy [left over from doing fillets].

All thread slides right through.
 
blackjack2564 said:
No I did not epoxy the all thread to sled.

Just a 1/4 tube slathered with black dyed epoxy [left over from doing fillets].

All thread slides right through.
Click to expand...


Thanks CJ. Good idea. I will get some 1/4 inch tubing. Off topic question, have you ever done internal fillets via injection with West Systems at temp of 50 degrees? I am more concerned about the epoxy being to viscous to give good internal fillets rather than the curing temp. Aeropoxy seemed to viscous to me to inject at 50 degrees F.
 
I have several L935 and K1440 flights without a nose cone vent in mine, maybe my sheer pins or luck differ from others.

However on my four inch Punisher I certainly gave it a little hole in the nose before loading up the M3700.
 
blackjack2564 said:
No I did not epoxy the all thread to sled.

Just a 1/4 tube slathered with black dyed epoxy [left over from doing fillets].

All thread slides right through.
Click to expand...

I use the Aerotech igniter tubes for my sled runners ..

All my best techniques i learned from CJ ..

Kenny
 

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