[F-FT] PML 1/4 Scale Patriot weight

OK guys, I'm finishing up my PML 1/4 Scale Patriot. Just one thing -- it weighs a ton more than it ought to.
The specs say that it weighs in at 50 oz., however, I didn't weigh the
components before assembly.
At this point, it is (almost) fully assembled, and I'm (mostly) doing final sanding/finishing work -- and it is completely unpainted.
At this point, it weighs slightly more than 63 ozs, unpainted. The only changes/modifications I've made are as follows:
Added an Aero-Pack retainer (weight unknown, but seems very lightweight).
Changed out the elastic cord for the piston ejection for Kevlar. However, I weighed them, and they both weighed in at 1.6 oz.
Used 30 minute epoxy throughout. I have used approximately 4 liquid ounces overall. However, that is 'mixed' amount, and there was a huge amount of leftover epoxy for many of my 'gluing sessions', I would estimate actual glue used as 2-3 liquid ounces.
The parachute was also upgraded from 48" to 54". I don't know the weight difference.
The only other 'change' is that I did use expanding foam in the fin-can area to strengthen it for higher-power flights. I would estimate that I used less than 1 liquid ounce overall for this.
The model is the 38mm motor-mount version, and that's all the information I have.
Any ideas why it seems so heavy? Anyone have one they can weigh?
David Erbas-White
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I don't have one I can weigh, but your experience sounds about right. PML makes great components, but they can be a bit on the hefty side. I have a couple of scratch built rockets that used all PML stuff, and they are heavy. Don't sweat it, David, just put in a bigger motor and let 'em rip!
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Joe Michel
NAR 82797 L2
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Huge.
The manufacturer weights used to be (many moons ago) without parachute or piston. Maybe the instructions have not been upgraded.
I know USR has similar discrepencies, albiet with similar size kits that weigh half as much.
Jerry

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Jerry Irvine, Box 1242, Claremont, California 91711 USA
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Should be about 26% more than the stock chute, based on canopy area
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
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Bob Kaplow wrote:

Well, it's neither 'huge' nor 26% more than the stock chute. Turns out to be about 17% more, probably because the weight of the shroud lines is a larger factor than the canopy area. The PML website lists the 48" at 4.1 oz., and the 54" at 4.8 oz..
So, the .7 oz difference has little/nothing to do with the huge increase in weight that I see.
I'm going to go weigh my (unassembled) Black Brant Vb right now (also with an upgraded parachute, from 30" @ 2.4 oz. to 36" @ 2.9 oz.). The website lists the Black Brant Vb as 32 oz.
Okay, just finished measuring. Comes in at 30.8 oz. with the upgraded parachute, so it is nominally about 30.5 oz. prior to assembly, so a 32 oz. weight sounds reasonable.
I guess the Patriot is just way off in the specs...
David Erbas-White
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My BBVb weighs 34.9 oz as built, with paint and everything. I used a strip of white adhesive tape for the vertical stripes, and I used one quick-link at the nosecone connection; other than that I think it is pretty much stock. I have the 30 inch chute, and the thing drifts like CRAZY so I would have to wonder why you need a bigger chute.
-- David
writes:

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Didn't this thread START with inaccurate PML weights?

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Jerry Irvine, Box 1242, Claremont, California 91711 USA
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Particularly when building competition models, I'll weigh the raw materials, then weigh again at several steps in the construction process. As a result, I can usually get a pretty good idea of what the finished model will weigh when I start, based on the raw material weights. Good to know if you're building a BG for NARAM. Somewhat less critical if you're building a L1 cert model.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety. -- Benjamin Franklin Historical Review of Pennsylvania. 1759
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David, I built an Amraam 3 similar to your Patriot but I let out the piston and I also put in a bigger chute. We chase for 5 miles. The rocket went up over a mile and as is typical in South Dakota the winds aloft were much more than at ground level. Advice when you do launch take a good pair of eyes with you. I use my eagle eyed daughter, she can see a lot better sometimes than I can on the ground. I don't know if this is a factor but I was once told on here that if you have the Quantum tubed model it starts out as a kit heavier than what was advertised. This was said it is because the weights listed were for the phenolic models and not the Q tubed ones and weights were different because of this. I do not know if that is true or not but made some sense at the time. Have fun and as a previous post said let er rip.

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But not too hard...I've now seen first hand what happens to Q-tube when you push it too hard:
http://www.bits.bris.ac.uk/niall/reports/earsmarphotos/dotcomet2.jpg
Thankfully the rest of the rocket was phenolic and survived intact. The Q-tube cracked very badly. This was a 3" rocket on a K445, PML say to keep Q-tube rockets below 0.85M, so as long as you don't put anything too powerful in it.
Good luck and have fun!
BTW I did download the sim files from PML, looks like an ATJ350/CTIJ330/J400 or similar will put it to over 0.85M, and a J570 (will it even fit) right in the transonic region.
I guess though if yours is heavier it might keep the speed (and altitude) down a bit!
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Niall Oswald
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yes the J570 fits in my AMRAAM 3 however I do not think I will push it that bad. I used a J350 in mine for it's maiden and L2 qualifying flight mentioned above. It screamed off the pad so fast if it wasn't for that smoke trail would have lost it.

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Sounds like a good flight!
The J350/J570 seem to be 'legendary' motors - I've never seen either, but I've seen the 38/1080 casing, its huge! I believe there are still a few J570's in range boxes here, so maybe one day...
The Pro38 J's are pretty nice, but comparing those to photos/videos of J350s the AT motor has to win on sheer amount of smoke/fire!
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Here's one of my favorite smoke/fire pictures. High humidity is the key!
http://tinyurl.com/6b9yg
-- David

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Nice!
I think I've seen about 2 AT WL HPR motors - an I something and a K550...the K550 was amazing!
http://www.bits.bris.ac.uk/niall/gallery/view_photo.php?set_albumName=UKRA2004&id=cone5
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Dusk / overcast does a great job of highlighting fire and smoke shots. Even a D12 at dusk is pretty cool: you can see all the sparks.
    Bob Kaplow    NAR # 18L    TRA # "Impeach the TRA BoD"         >>> To reply, remove the TRABoD! <<< Kaplow Klips & Baffle:    http://nira-rocketry.org/LeadingEdge/Phantom4000.pdf www.encompasserve.org/~kaplow_r/ www.nira-rocketry.org www.nar.org
They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety. -- Benjamin Franklin Historical Review of Pennsylvania. 1759
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writes:

I'll second that! You can often see the normally invisible glow of the smoke charge burning. I imagine a HyperTek motor would be good at dusk - the flame always seems very bright and the 'glow' lasts a long time as the tank empties fully.
I'd like to do a BP cluster at dusk...especially with quickmatch ignition, it could be quite spectacular.
A D12 CATO in total darkness is pretty cool too.
I took this shot firing a C6-3 in the dark - long exposure time obviously!
http://www.bits.bris.ac.uk/niall/gallery/view_photo.php?set_albumName=rocketphotos&id &7_6761_IMG
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Niall Oswald
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Niall Oswald wrote:

You're not kidding! I burned a J570 last weekend and someone took a great photo of it. For scale, keep in mind that this is a 7.5" Pterodactyl!
http://www.e2scopes.com/rockets/Monroe_2005/source/l2_cert_liftoff.html
Eric Albrecht
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That sounds about right to me. I own a PML Sudden Rush (Quantum Tube) and it weighs in around 5lb. It is quoted at 4lb on PML's website. I have added a 38mm adapter and an Aero-Pack style retainer, but the added weight for your Patriot, does not sound unreasonable. I believe Quantum tubing is upto 20% heavier when compared to the standard phenolic anyway.
Rob House
UKRA 1258 - Level 2
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