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Anyone have any experience with Public Enemy Patriot kit?

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LarryH

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I won one of these kits off ebay, the 4"x52" version, should get here within the week. :D rocketreviews.com have reviews for other PE kits and it seems people are pretty happy with them, but no review of the Patriot, this will be my first HPR kit so I'd sorta like to know what I'm getting into.... the general concensus on rocketreviews.com about other PE kits seems to be they're not suited for beginners because of the brief generalized instruction sheet..... that shouldn't be a problem for me unless assembly methods for an HPR kit is radically different from low and mid power kits.

A couple questions, should I use epoxy for the entire assembly process? and if so, what type? I've used the gel type epoxy before for fin fillets and it worked great for that, it seems like it should work out pretty well for entire assembly... will it, or should I try something else? Also, should I build this bird stock or should I think about glassing or other reinforcement methods? This kit is intended to fly on H and I motors(with some mention of G if you're limited for space), I would like to use this kit for both level-1 and level-2 certs, will it hold up in stock configuration to a J motor?

Thanks
Any and all help appreciated!:)
 

eugenefl

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Greetings Larry! I have a PER 1/4 scale Patriot w/ the 38mm MMT. I purchased mine quite a while ago. When I built it, I had L1 in mind and only made one flight - my L1 attempt. I built mine with CyA (to tack parts in place) and used 15 min. epoxy to reinforce all other joints and for fin fillets. (Make sure you add noseweight) If possible, get someone to RSim it for you so that you can get an accurate CG/CP relationship.

On my L1 attempt (RMS H123W), it lept off the pad in a good flight profile. At some point maybe 250-350ft it either weathercocked badly or fell victim to marginal stability. Either way, I've never been able to redeem the attempt with a finer more stable flight. (HSA ATF garbage) I have since added about 4oz of noseweight.

Some tips I received from the HPR guys - replace the bungy cord with tubular nylon and replace the single bulkhead screweye with a U-bolt.

Also, I don't know that it will be possible to fly it on a G80. Mine weighs over 4.5lbs just with basic building techniques.

Let me know if you have any questions. (BTW, I had purchased my decals from an online vendor via eBay who is either no longer in business or off the web - Stick-It Graphics.)
 

eugenefl

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Here it is boosting on that H123W. It was looking good in this picture. (Jeez, can't we get some HPR regulation relief already?)
 

LarryH

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Thanks eugene, that's a great looking rocket ya got there! So yours came out 4.5 lbs and you built it stock other than the shockcord and eyebolt?!?! Wow! and to think PE says it has a finished weight of only 1.5 lbs, that's gotta be a typo on PEs part, there's no way you used 3 pounds of epoxy! As to your recent stability problems... maybe that H just aint enough engine to keep her stable???
 

eugenefl

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Originally posted by LarryH
Thanks eugene, that's a great looking rocket ya got there! So yours came out 4.5 lbs and you built it stock other than the shockcord and eyebolt?!?! Wow! and to think PE says it has a finished weight of only 1.5 lbs, that's gotta be a typo on PEs part, there's no way you used 3 pounds of epoxy! As to your recent stability problems... maybe that H just aint enough engine to keep her stable???
Thanks! It makes a great living room prop these days. :rolleyes: :)

1.5lbs?!!? Naw! No way. Yep, mine is built to about 4.4lbs. I weighed it last November because I was really itching to fly it on a G80. (That woulda been dumb!) The H123 was plenty motor. I am 99.9% positive the awry flight was do to stability issues. As I recall, the day I flew it (Whitakers, NC July '02) there was quite a bit of wind. We all kinda scratched our heads and pretty much called it a bad weathercock. I'm willing to admit some fault in stability. The 1.5lbs rating must have been for the 3" version. Even at 1.5lbs, I can't see the 3" version weighing less than 1.5-2lbs.
 

LarryH

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LOL! On thier website for the 4x52 Patriot they say "Great Level-1 rocket, or fly it all day long on G motors!", they list the 3x40 Patriot as weighing in at 1.0 lbs.... maybe they've done something just recently to cut down on weight? :confused:

http://www.publicenemyrockets.com
 

LarryH

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Just got my Patriot kit in the mail today, it has a 29mm motor mount.... I was hoping for a 38mm but no biggie, can still fly on H motors, Like you said Eugene it's a pretty heavy kit, I dont think a G engine would be nearly enough, just out of curiosity what did you do for motor retention? Did you glue in an engine block and a motor hook, just tape the engines into place or what? seems the PER kits come with no method of engine retention.

Thanks Eugene
 

HiflyinPRguy

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Hey LarryH, I haven't built the 4" Patriot but I am building a PE 4" BullPup for to fly on a J350W:D

I believe both rockets are pretty similar in construction. I am using 30 minute epoxy to build mine.

If I were you, I would scrap the 29mm tube and upgrade to 38mm. These things are pretty heavy when they are built.

For motor retention, I really like the Aeropack System . Be sure to order the one for LOC Tubing. All you have to do is JB Weld it onto the end of the tube.

Don't forget the nose weight!

I also plan on adding expanding foam to shore up the fin can.

From I can tell so far, PE kits are a little challenging, but not too tough to build.

Have a blast with it!
 

eugenefl

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Originally posted by LarryH
just out of curiosity what did you do for motor retention? Did you glue in an engine block and a motor hook, just tape the engines into place or what? seems the PER kits come with no method of engine retention.

Thanks Eugene
If I could roll back time I would have used blind T-nuts and installed some kind of motor retention. See the <a href="http://www.info-central.org/construction_retention.shtml"> ROL INFOCentral<a/> article on motor retention. For the one and only flight it made I used masking tape to friction fit the 38mm Dr. Rocket casing. (All RMS casings use the aft closure as a thrust ring.) Being that the casing was borrowed from Ken Parker, I was extremely paranoid from liftoff to landing. I think if I ever get the chance to fly it again I will definitely install *something* to hold that casing in place.
 

LarryH

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Thanks guys, so let me see if I understand this, most HPR motors use a flange(thrust ring) at the aft end of the motor that prevents the motor from shooting out the forward end of the rocket? This is good, keeping the motor from falling out the aft end or being ejected by the recovery charge shouldn't be too difficult since you have a rear plywood centering ring you can bolt things to!

HiflyinPRguy, I think I'll just build this rocket with the 29mm mount, should work just fine on H motors, I do have a PE Bullpup lined up in the near future to play with the higher powered stuff, with PE kits being so close to dirt cheap you can afford to own a couple or five!

Thanks for all the advice thus far guys, I feel alot more confident about HPR now that you guys have taught me a thing or two!:D

I'll name my first two CATOs after you..... hehehe just kidding guys!:p
 

eugenefl

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Originally posted by LarryH
Thanks guys, so let me see if I understand this, most HPR motors use a flange(thrust ring) at the aft end of the motor that prevents the motor from shooting out the forward end of the rocket? This is good, keeping the motor from falling out the aft end or being ejected by the recovery charge shouldn't be too difficult since you have a rear plywood centering ring you can bolt things to!

Thanks for all the advice thus far guys, I feel alot more confident about HPR now that you guys have taught me a thing or two!:D

I'll name my first two CATOs after you..... hehehe just kidding guys!:p
Exactly...that's why I love RMS - no masking tape thrust ring to make. In MPR/HPR, the usage of a forward thrust ring is rare. (I've never seen one used) Aerotech uses hooks. I haven't built one of their kits yet, but I do believe the hook functions just like an Estes kit.

Plywood material for CRs leaves plenty of options for mounting hardware. I'd check out HiflyinPRguy's suggestion and look into the Aeropack retention stuff. Seems like it would make for a cleaner and more pro finish.

Name me after a CATO? LOL! Why my girlfriend already tells me I have an "explosive" personality. :D
 
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Mine is 2.5 pounds without the engine. I used 30 minute epoxy throughout.You can see mine at: http://www.scalerockets.com/pepatriot.html


Were flying them with a Pro38 G69. This motor is above 18lbs of thrust for the first 1/3 second and is above 16lbs for the first full second. with a 6g initial launch, there should'nt be an issue with a 4 ft launch rod.
 
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I don't see how you got that 4" patriot to weigh 4.5 lbs. I built an EZI 65, stetched it about a foot, added an electronics bay, glassed the fins to the motor tube, and used modest fillets. I have a 45" main in it, and that rocket weighs 4.25 lbs empty.
 

eugenefl

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Originally posted by boatsandrockets
I don't see how you got that 4" patriot to weigh 4.5 lbs. I built an EZI 65, stetched it about a foot, added an electronics bay, glassed the fins to the motor tube, and used modest fillets. I have a 45" main in it, and that rocket weighs 4.25 lbs empty.
I stand corrected - I just re-weighed it empty and it comes in at 3lbs 6oz. With a loaded G64-7 RMS on the scale, total weight was 3lbs 11oz. Jason can back me up on this, but when I had it loaded with a G80, 38/29 MMT adaptor, and dog barf & chute, the weight was 4lbs 3oz. I was going to attempt to fly it at NEFAR back in April but was concerned about the loaded weight.
 

LarryH

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Using the old standby formula of total impulse in pounds/sec divided by 6 = max liftoff weight, the G80 is "supposedly" capable of a max liftoff weight of around 5.6lbs(assuming 34lbs/sec of total impulse), I know it looks good on paper, but then you have to figure in initial thrust, average thrust, and durration of burn(to which I dont have any of these figures on hand, or a formula worked out to figure them in), anyone have an idea of what a G80 is really capable of in terms of max liftoff weight?

As a side note I do have my Patriot mostly built, all that needs be done is for me to come up with a motor retention scheme, Aeropac retention rings are out because I've layed out a fillet of epoxy around the aft end of the motor tube and there's no room to glue one on, just gonna have to be something bolted onto the aft centering ring, other than that I just have to epoxy the fin/mmt assembly into the BT and lay out my fin fillets.

All in all I'd have to say I'm impressed, the quality of the workmanship and of the materials used In these kits far exceeds the cost of the kit(and these are probably the cheapest HPR kits on the market!), the PE kits have got to be the best bang for the buck in HPR, everything fits the way it's supposed to the first time, these kits are a far cry from the Iffy quality in the Estes kits that I'm used to, this is probably the easiest kit I've ever put together! Will post pics when I get the time to take them..... and find a place to host them.
 
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