Crazy Jim's "Punisher-4" new flight video with 4in Fly-away-guides

[ChrisAttebery]

I'm curious to see how much nose weight is required. I thought it'd need 24-32oz.

 

[GRIFFIN]

I'm curious to see how much nose weight is required. I thought it'd need 24-32oz.

No way!

 

[BayouRat]

Jim,

I have gone to adding a mix of Cabosil and milled fiberglass @ approx 3:1 by volume. I then add this to the epoxy (US Composites medium in my case) at about 1/4 to 1/3 the volume. Resultant consistency is a little thicker than syrup. I then inject. I also then sit the rocket on end fore/aft for about 3 min. each to get good flow to each slot end before setting back to horizontal. Since beginning this practice I no longer get any leaking. The milled fiberglass kind of interlocks with the CF strands and the Cabosil does a great job of gap filling. I'm probably adding a bit of strength with the milled FG and loosing a bit with the Cabosil, but net-net I believe I'm more than OK, and best, I have no mess without adding tape or any other dam. You might test something like this the next time...

-Tim

That's exactly what I use. the cabosil makes it nice and hard!

 

[bertaadele]

Here's what is looks like sized next to the 3in........just in case it shows up on special.....for those who may be interested in getting one.

View attachment 276732


Who knows, it may even be red already & you won't have to paint it!

So far fin can weighs 4.2lbs
Nc with hardware & sled 2.2 lbs.
Total 6.4 lb

Heck my payload section alone [loaded] for my 4in Wildman weighs 5.8lbs....this whole darn rocket should come in around 9.

Just wondering if you did an open rocket file for this yet....being lazy

 

[blackjack2564]

Just wondering if you did an open rocket file for this yet....being lazy

Not my file...can't remember where I picked it up...thanks someone.

View attachment Punisher 4-6.ork

Time to get going on this.
Working on external fillets, will put up some pics tomorrow.:smile:

Edit....file courtesy of ChrisAttenery

 

[ChrisAttebery]

You haven't finished it yet? WTH?

I got mine on Sunday. I just took it out of the box and drooled for a bit.

 

[ChrisAttebery]

I think that's mine. I just downloaded it and then got confused because the components all looked exactly the same as my working file.

Not my file...can't remember where I picked it up...thanks someone.

View attachment 278369

Time to get going on this.
Working on external fillets, will put up some pics tomorrow.:smile:

 

[GRIFFIN]

Mine is built, prepped and ready to fly (0oz nose weight) in a few weeks. I will report back with flight results. Mine weighs just a few oz over 9 pounds (less motor) and balances just like the 3" version (also 0oz nose weight). I plan on a 2 or 3 grain 75 motor.

 

[blackjack2564]

Spent the day, on & off....finishing the external fillets
Made them quite beefy, as I plan to spank this 4in. with M-motors. Not worried about holding up to M-flight, but the added weight of hardware could be an issue on landing, so larger fillets should negate that.

This will be my go to 4 in rocket due to it's compact size & ease of transport. I used a 1.5 in section of PVC for smoothing & size of fillet.
My standard method of inking the pipe with marker, then sliding back & forth in "V-groove" for perfect positioning of tape, before adding the fortified glue.




Taping to the lines will catch any excess glue after tooling, for easy removal. Press the tape down with pipe, by sliding it back & forth, for sure seal & to check that edge of tape meets edge of tool. If their is an overlap , when tape is removed, you will have a ledge/lip on the epoxy that must be sanded.



My hardener is old and turned dark red, why the glue looks like baby do-coo. I used West 105 resin & hardener. 2 pumps of each with 2 & a half 30ml mixing cups full off West 406 silica for thickener. Resin mixed first for 1 minute, then filler added in 3 steps, mixed till smooth, and lumps smashed against side of cup with mixing stick. More mixing.......less sanding.
I really nailed my tape lines on this one perfectly. You can see the excess glue is right on edge of tape. On side where tape removed [which I do as soon as finished smoothing] you can see there is NO edge/lip of glue. Nice slick transition from fin-fillet-tube. Very little sanding needed.




By morning, everything should be cured enough to sand /shape.

 

[tim cubbedge]

I read somewhere that the fillet radius should be .06 x fin root. Are you making them larger than they need to be or did I calculate wrong?

 

[blackjack2564]

I read somewhere that the fillet radius should be .06 x fin root. Are you making them larger than they need to be or did I calculate wrong?

Well I waited till finished sanding to measure today. Ideally I guess that would be .72in. based on fin size.
Mine are .75 so maybe a bit large.
I think if most, actually measured their's, they are generally small.

Like I mentioned above, in this case more interested in strength, than speed.
This thing will weigh 20-27lbs with a large motor in it.

Here's a little eye candy for ya...... 2 weeks ago in Charlotte.
CarbonCowboy 54 vs CarbonCowgirl on V-max's. Heck of a shot .....huh!



Part of the Punisher's bloodline.......

 

[4kids49]

Here's a little eye candy for ya...... 2 weeks ago in Charlotte.
CarbonCowboy 54 vs CarbonCowgirl on V-max's. Heck of a shot .....huh!

View attachment 278508

Part of the Punisher's bloodline.......

Nice.

 

[SpaceManMat]

Spent the day, on & off....finishing the external fillets
Made them quite beefy, as I plan to spank this 4in. with M-motors. Not worried about holding up to M-flight, but the added weight of hardware could be an issue on landing, so larger fillets should negate that.

This will be my go to 4 in rocket due to it's compact size & ease of transport. I used a 1.5 in section of PVC for smoothing & size of fillet.
My standard method of inking the pipe with marker, then sliding back & forth in "V-groove" for perfect positioning of tape, before adding the fortified glue.

View attachment 278400


Taping to the lines will catch any excess glue after tooling, for easy removal. Press the tape down with pipe, by sliding it back & forth, for sure seal & to check that edge of tape meets edge of tool. If their is an overlap , when tape is removed, you will have a ledge/lip on the epoxy that must be sanded.

View attachment 278401

My hardener is old and turned dark red, why the glue looks like baby do-coo. I used West 105 resin & hardener. 2 pumps of each with 2 & a half 30ml mixing cups full off West 406 silica for thickener. Resin mixed first for 1 minute, then filler added in 3 steps, mixed till smooth, and lumps smashed against side of cup with mixing stick. More mixing.......less sanding.
I really nailed my tape lines on this one perfectly. You can see the excess glue is right on edge of tape. On side where tape removed [which I do as soon as finished smoothing] you can see there is NO edge/lip of glue. Nice slick transition from fin-fillet-tube. Very little sanding needed.

View attachment 278402 View attachment 278403


By morning, everything should be cured enough to sand /shape.

Jim, not sure but think your harderner may have crystallised. Try putting the tin in hot water.

 

[tim cubbedge]

Jim, not sure but think your harderner may have crystallised. Try putting the tin in hot water.

I think that's the results of adding colloidal silica.

 

[dixontj93060]

I think that's the results of adding colloidal silica.

+1.

 

[blackjack2564]

Jim, not sure but think your harderner may have crystallised. Try putting the tin in hot water.

Hi Mat...good to see you here!

I believe you are thinking of the resin...that will crystalize if stored below 40 F. All my epoxies are kept in house under temp controlled conditions,just for that reason. Hardener will turn reddish-brown with age as depicted in the FAQ page for West. The silica additive although fairly smooth, does look a bit wonky, in the photos. However it does sand quite smooth, & add quite a bit of strength, with some flexibility to the fillets.

https://www.westsystem.com/ss/faq-problem-solver/



Since good project & reading are a bit sparse lately on our Forum, some of you may find these links quite interesting:

Mat is building a nice conversion minimum diam. 38 mm , which can be found here along with my 2-stage project.

https://www.ausrocketry.com/forum/viewforum.php?f=6

For some technical projects, dealing with roll & attitude control,[similar to Jim Jarvis project] see these 2.
Some very interesting reading if you've been bored lately with stuff like "how do I retain a motor in my minimum diam"...LOL

https://www.ausrocketry.com/forum/viewtopic.php?f=56&t=5085

https://www.ausrocketry.com/forum/viewtopic.php?f=56&t=5324

Happy Holidays.....Merry Xmas....to all my high flying rocket friends world wide! :wink:

Cj [ who is anxiously awaiting the return of his new Beta,Alpha returned, unit GPS & altimeters, so I can proceed with further flights]!

 

[SpaceManMat]

Merry Christmas Jim. Been holidaying up the Sunshine Coast with my parents, true it its name I got burnt to a crisp on Boxing Day. Anyway build has been a bit quite as a result, so when I got home tonight had to compensate by staying up to 1 am. Will have post some updates tomorrow.

 

[blackjack2564]

Over weekend spent a day sanding fillets to shape.
I lightly prime the fillet area to see what needs spot filling on fillets.
Sits in kitchen sink, awaiting cure time, so I can wet sand the results.




Built out the av-bay, while waiting.................

 

[smarra01]

I think I need a bigger sink.
It doesn't quite fit.

This is a 6 inch version I had Wildman make up for me.

 

[blackjack2564]

FIRST THING IS PLACING BULK-PLATE ON FRONT OF AV-BAY/NC COUPLER WHEN INSERTING IN NOSE CONE FOR FITTING!!!
Do this to get proper fit for vent band or there will be a gap, when bp is finally put on.

Earlier in build I squared up my vent band, and fitted the parts so no gaps between NC...Vent Band & airframe.
Now I slide assembly together and mark/tape open side of vent band.





Remove assembly from NC & mark, remove vent band and tape other side for sanding.



Sand between tape, remove tape from NC side.




Sand inside of vent band & place epoxy on coupler...thin layer

 

[blackjack2564]

Slide vent band into position, with a twisting motion to ensure even glue dispersion.
Pull tape off with excess glue before cure.........or you will never get it off.
Place assembly into NC and check fit, adjust if needed. Let glue cure.

At beginning of build, I inserted the coupler into rear of airframe & used the slots to mark 3 lines, evenly spaced at 120 degrees around the coupler. These marks will now come into play .
After the band is cured I transfer 3 marks onto vent band for breather holes [altimeter] and on NC for sheep pins.



Shear pin location is between vent hole location. Since shear-pins are above vent holes, I don't want turbulence from the pin heads causing problems with altimeter reading [exacerbated due to av-bay in NC!] BY moving pin holes between vent hole alignment....problem solved.

Pins are 1 inch from edge of cone.



Finally "key" marks are made with tip of bit to aid in assembly for flying prep.....finding the pin holes , & airframe parts are lined up square....every time.

 

[blackjack2564]

I think I need a bigger sink.
It doesn't quite fit.

This is a 6 inch version I had Wildman make up for me.

View attachment 279006

I'm at Don Balls over the weekend working on rockets.........

Here's another 6in Punisher [next to the 3in.] with a Fisher aluminum fin can on it [Punisher fin].....Mike if you see this...OUTSTANDING job on can!
Folks he will make what ever your heart desires......of course, cost is proportional to desire...LOL

Umm that's a 5% Q-motor sticking out of the 63 in fin can, Balls project!!! Should go over a few thousand.



Things are starting to get interesting around here....confirmation the GPS is on it's way back to me.....with the bluetooth installed. Direct data to phone via Bluetooth option on one of them.....Whoooppie!
Should fly next weekend.[weather permitting]

 

[jd2cylman]

Things are starting to get interesting around here....confirmation the GPS is on it's way back to me.....with the bluetooth installed. Direct data to phone via Bluetooth option on one of them.....Whoooppie!
Should fly next weekend.[weather permitting]

Who's phone you gonna use... :tongue: :tongue: I thought you had a "dumb" phone... Don't super glue the smart phone to your head, that'll get expensive to remove.

Adrian

 

[blackjack2564]

Who's phone you gonna use...

.........................E.T's

:tongue: :tongue: I thought you had a "dumb" phone... Don't super glue the smart phone to your head,.......

that'll get expensive to remove.

My head........or the phone?

Adrian

Says he who takes 12 years to build a rocket.

 

[dixontj93060]

Slide vent band into position, with a twisting motion to ensure even glue dispersion.

CJ, OK, I totally admit I have not done any (well two, but neither hasn't flown yet) head-end NC deploy designs. But, given that the new Wildman nose cones have an inside lip above the shoulder to inhibit any forward movement of the coupler, why are you using a vent band? Convenience only?

BTW, if there is a real reason I screwed the pooch then with my 3" Punisher as I left out the vent band and simply put a vent/switch hole near the bottom of the NC.

 

[patelldp]

CJ, OK, I totally admit I have not done any (well two, but neither hasn't flown yet) head-end NC deploy designs. But, given that the new Wildman nose cones have an inside lip above the shoulder to inhibit any forward movement of the coupler, why are you using a vent band? Convenience only?

BTW, if there is a real reason I screwed the pooch then with my 3" Punisher as I left out the vent band and simply put a vent/switch hole near the bottom of the NC.

So the coupler doesn't slide down into the body tube on high gee flights.

 

[woferry]

I think the main reason would be for the vent hole(s) themselves. You said you made a switch near the bottom of the NC, you mean both the NC and the av-bay, so you have to line up both holes for things to work?

Also, the NC lip you mention would keep the av-bay from moving upwards any farther into the NC, but what keeps it from moving downwards farther into the airframe during the acceleration forces of lift-off? If it shifted down too much you might lose your alignment on the NC/av-bay holes and seal-off the av-bay from detecting apogee, or worst-case lose enough mating distance to keep the NC attached during ascent.

 

[GRIFFIN]

I think I need a bigger sink.
It doesn't quite fit.

This is a 6 inch version I had Wildman make up for me.

View attachment 279006

Tell me that's not a 75mm hole I see there!!!

 

[blackjack2564]

Dan & Will hit the nail on the head.

Think of flying a 2045 V-max with 500lbs of thrust for 3/4 sec. Gotta have something to keep coupler in place if things go bad.
Also farther back on cone you get for vents the better.[even with altimeters designed for such]
Finally if you're in the twist & tape crowd, need the band for somewhere to tape switch wire to.

Tim....remember what happened at ThunderStruck with your Mach-Madness?
Don't forget ya need a vent hole in NC above the coupler/av-bay, so the NC won't pop off!!!! [Just like in the airframe] I haven't got there yet in this build.

 

[dixontj93060]

CJ (and Dan and Will) I understand what you are saying. But 500lbs of thrust only translates to 75g acceleration on ascent for my 7lb rocket and its drag. So if we do the math, I have shear pins equating to ~240lbs of holding force (three 4-40 and three 2-56 nylon screws) and my av-bay in question is only 1/2 lb (maybe less). That would mean I'd need more than 480g of acceleration for it to break free giving me a margin of more than 600%. Don't get me wrong, I have the extra piece of thrust ring to use (which I'd probably epoxy inside the booster BTW), but with that level of design margin, I don't see how this type of failure would be possible? Has someone had an av-bay break loose in flight? And was it a nominal flight profile? Or did something else occur that may have caused the av-bay movement (CATO, charges firing, etc.)?