PML Kits

[jetra2]

I have a question on PML kits.

Why are they so darned expensive?! I mean, look at the AMRAAM 2! It's only 2.1" diameter and 3 1/2 feet tall! BUT THEY CHARGE SIXTY DOLLARS FOR IT!?!?!

How about the Endevour? The 4" diameter version is just about 6' tall and is $134.95. It weighs 71oz (4.43lbs) and comes with the 54/38/29mm Kwik Switch. What makes it so special to charge that much?

Heck, I could scratch build a 4" diameter military-style rocket, like the Endevour, and it would likely cost me less than $50! Or, I could go to LOC and buy an Ultimate (4" diameter by 56.6" with a 7x 29mm cluster) for only $86.95!

I guess my question is that why do they feel they can charge so much for them? Are they really high quality, with great instructions/parts/easy assembly?

Sorry...I don't vent often...but I just had to today

Jason

 

[rstaff3]

Some of the factors are G10 fins and Quantum tube. Whether these are worth it is a matter of debate and individual preference.

 

[Batman]

They are gonna be more expensive, but in my opinion they are better stock kits. I love LOC kits too but I never build them stock. The PML quantum tube has some minor drawbacks, but it is tough as hell and easy to finish. The G-10 fins are also super strong. If you build a PML kit exactly stock you will have an outstanding rocket. The only change I usually make is to use tubular kevlar between the motor mount and piston. LOC kits are cheaper bu by the time I finish modifying them they cost just as much. I find it more fun to "personalize" kits however. PML chutes are way nicer too and we all know how expensive chutes can be. Heck, the Endeavor chute alone is worth $30-$40. PML recovery harnesses are tubular nylon anchored with steel D rings and epoxy, while the LOC ones are elastic. I'm not a fan of LOC cardboard MMT's either, I much prefer the PML phenolic. So in summary, I think you get a lot more with PML if you want to build a kit, but if you like to be creative, stick with the LOC type stuff, but in the end I doubt you'll save much money.

One other thing, the prices on PML's website are ridiculous. Order from a PML dealer and you'll save 15-20%. My two favs are the rocket garden or www.greatlakeshobbies.com Either of these places will save you some cabbage on PML kits.

 

[Austin]

Jetra,

As mentioned, you get what you pay for!!! If you want high quality kits with some of the best materials on the market, along with some of the best parachutes available, you buy PML.

You obviously have not continued your shopping very much and need to do a bit more research. You will find kits like the Estes V2, made of cheap parts with lots of plastic and costing as much or more than a PML Amraam2. The same goes for many LOC kits, and Aerotech is WAY WAY overpriced, beyond any of these. Also, most of those I just mentioned are not HPR capable; that may not mean much, but what you get from PML is a model that is made to handle Mid-High Power motors, not to mention it includes strong, top notch components and quality craftsmanship!!!

Nuf said...buy what you want, but don't complain about something that is more than reasonably priced in this overpriced market.

Carl

 

[BlueNinja]

Agreed.... I may be buying a PML kit soon, and if you shop around you will find GREAT prices on them. Great lakes usually has them pretty cheap.

 

[NewEntity1]

Red Arrow Hobbies also has good prices on them. I consider PML kits underpriced almost. Compared to an AT kit of the same size, the PML kit...

1) costs less...
2) is made of better materials.

 

[Johnnie]

Agreed, Aerotech is way overpriced when it comes to that 4" G-Force rocket that is not worth the $75 I paid for it...

But as far as the PML Endeavor goes, Chad Ring of Ring Rocketry made me a deal on one for $109, so he would not have to drag it back to home base, and I jumped on it... the 4" AMRAAM was priced the same, and now I wished I had gotten the AMRAAM...(hindsight is 20/20)

...but retail, I would never pay full price for a PML kit. The piston I do not trust, and the Chute I end up replacing with one that is sewn together a little better.

The day I bought my 1st PML kit (and only PML kit) I had just shredded my Public Enemy 4" Extreme Performer on a demo HyperTEK 54mm K240. With what I paid then or even retail for the Endeavor I could buy another P.E. Performer, and make it bullet proof...(in the works by the way I bought another Performer for $59.99)

to each his or her own preference, I believe too, that most kits are overpriced...the only reason the venders stay in business is we will buy them because we are rocket nuts, and will always be as such...

Vaughn Brothers had great kits, Public Enemy has great kits...but I make them superb!!!

Incedently, my Endeavor has one flight on it, and it performed flawlessly...it has been kept in the wings ever since.

 

[jetra2]

I guess I ticked some people off...

I should've reworded it a bit - I apologize. I guess I'm just gonna hafta break down and spend the $$$$$$$$$$$$$ for them and check it out.

Again, I apolgize if I PO'd anyone.

Jason

 

[Austin]

Jase...you didn't tick anyone off bro.....it's all about learning here and you learned some differences in kits. That is always a good thing!

Cya and let us know what you wind up buying...

Carl

 

[firemanup]

I always felt the 1/2 off priced AT kits at Hobby Lobby were darn nicely priced.... heh.. They are well designed kits, and fit the mid power nitch nicely. Little expensive maybe and full retail but what kits aren't...?

I've only got one PML kit and that's the 4" Amraam, I was going to get all three but that's a negative now having this one and flying it... now if someone could show me how to retrofit the stock kit for dual deploy it would get flown alot ...but the extra $140 to make a $130 kit dual deploy was quite a bit over the top...

I'm sure there's got to be another way to do it or i'll figure out a way..

I'm with Rstaff the G10 fins are great but to each their own on the QT. It takes quite a bit of careful prep for epoxy adhesion, more so than most paper kits. My biggest issue with it though is that it's a high power kit, and they advise against pushing Mach with QT.. unfortunately i found that out after the purchase.

With paper rockets you can build them to take any motor that will fit into their motor tubes, with QT that's not always the case. Heck check out this thread to see an Estes V2 modded to take a Pro 54 K motor..

https://www.rocketryforum.com/showthread.php?s=&threadid=8296&perpage=20&highlight=estes v2k&pagenumber=2

Paper rockets can be built up.. QT can't.

The QT just doesn't seem as flexible when it comes to making modifications but much more a dream to finish.

I'd seen too many negatives on the net from others about the piston so I pulled it from mine, but there's enough out there about it that i found the stories to have some merit, especially the explanations on the different expansion and contraction temperatures between the phenolic piston and QT.

Chutes are nice, but mine was undersized for the kit or at least mine at 12 oz heavier than PML's estimated finished weight. (90 oz complete and ready to fly minus motor) I do need to measure the chute also as the PML 54" chute is smaller than my BSD 45" chutes.

My biggest pet peeve on the PML Amraam is that Estes seemed to be closer on the decals than PML was, the mixing of the blue and yellow stripes is a contradiction, and maybe they found one in a museum that had been decomissioned I don't know, but in reality the missile should have one or the other.. the chrome area I assumed was a mistake but i have been able to find one missile with this area, visible on it, it's from a ground launched setup.

So yeah PML kits are nice, but they too aren't without their own issues.... Commonwealth, Magnum, and performance were all between $120 and $130 on the stock 4" Amraam, Greatlakes was a little better at around $115 ...

I agree with Jetra they are a little bit pricey, I know nothing about the QT maybe it is quite a bit more expensive than paper tube and that's why..

"I guess my question is that why do they feel they can charge so much for them? Are they really high quality, with great instructions/parts/easy assembly?"

They can charge so much because people will pay it.

High quality yes.

Great instructions, no. Adequate yes.

Parts, they have their pros and cons.

Easy assembly, no, more difficult than paper tubes. (all-though they are preslotted)

Will I be getting more PML kits..?? Only if I can find a reasonably priced way to mod them to dual deployment, (this may just be my lack of understanding with the QT) i like the designed "look" of several of their kits, i'd get the other two amraams and probably an Endeavor or two.

 

[firemanup]

By the way for the issues with the QT there is the option of phenolic tube and fiberglassing.. then the QT issues are gone..

And here's an actual Amraam that shows the correct striping...

 

[daveyfire]

My opinion follows...

Since I'm more of a scratchbuilder, I don't like the PML kits as much. They are expensive, and most of what you pay for (piston, QT, chute) I throw out anyways. QT just does not lend itself very well to modifications or Mach+ flight (which I love to do). It also has some sort of weird internal stress that causes it to warp horribly when slit. I made the mistake of slotting my Quasar all the way to the back of the tube so I could slide in the fin can assembly. When I got around to that step the next week, the QT had warped completely out of shape and I ended up melting it and holding it in the right position until it cooled. I also don't trust the epoxy bond to the QT, even if it is scuffed up. On "fin-landers", I ALWAYS pop a fillet on landing. No big deal, but it is a repair after every flight. I don't like doing that. I also have set QT rockets on a stand sitting in the sun, gone to get a motor for the flight, and come back to a sagging rocket. Not good.

Sorry that it turned into a QT rant. There just isn't much that can be done with it, and what *it* seems to be doesn't work well for me.

IMHO, YMMV, et al. I'd get one and see how you like it. Your experience (flying in Florida or Ohio or [insert state here]) could be completely different than mine flying on a hot dry lakebed in the California desert. I just prefer to make my rockets strong enough to handle the biggest motor that will fit -- because I KNOW I will get that urge someday!

 

[lalligood]

I'll chime in with my $0.02...

First, a guy I worked with once had a sign on his cubicle that read:

"I can do it fast. I can do it cheap. I can do it well. Pick any two."

PML does it well & fast. I've ordered from them a few times (all over the phone) & received exactly what I ordered in a very short period of time. They rock! You get an *excellent* product for what you pay.

And this is especially meant for you, jetra2: All those problems you have heard from folks about their pistons getting stuck and/or QT-related problems--YOU WON'T HAVE ANY. Why? Simple... You, just like me, live in sunny Florida where we typically launch in a fairly narrow range of (warm) temperatures, so it is extremely unlikely that you will have to worry about those shrinkage problems. I've launched my Phobos built stock with the piston 6 times. Zero failures. I in fact really like the QT because the delay on the very first flight of my Phobos was a good 3 seconds too long. Damage? None

BTW, check out my review of the Phobos on EMRR for more information on dealing with QT.

HTH,

 

I'll chime in my .02 cents on QT here since everyone else is. I have two highpower rockets in the fleet, (third coming soon) and they are both made from QT. The biggest drawback I have experienced with QT is that it's heavier than comparable paper or phenolic tubes.

I have a 4" upscale Der Red Max made from QT. It has had several "less than perfect" flights. It has lawndarted twice, once due to delay failure, and once due to bad motor selection on my part. In both cases, the rocket itself suffered no damage, other than a needing a nosecone repaint / replace. Phenolic or paper tubes will not stand up to those abuses, IMO. I also had the nosecone whack the side of the bodytube on ejection due to a too-short shockcord once. It hit hard, with enough force to knock the paint off the NC, and spider-web the clearcoat on the BT. I feel that paper or phenolic with have suffered more damage than a spider-webbed paint job.

My second QT rocket flew beautifully on an AMW K530GG, (see attached pic) and I have complete confidence that she could handle more motor than that. I have not had problems with epoxy adhesion, nor with paint adhesion. As always, preparation is the key.

All that being said, you’d find camps of paper lovers, QT lovers, and phenolic lovers at any launch you attend. Use what makes you happy!

 

[firemanup]

Hey,

That's a purdy rocket joe.... heh..

Needs more power yet though.. they make a 54mm L...??

 

[Stymye]

Jason makes a good point,,you can (what pml lists as) upgrade to phenolic ,free of charge....

 

[Chilly]

I read on Brittan Fraley's website that he determined the best way to mount the piston is backwards. That moves the piston's CG aft and keeps it from jamming in the tube (in addition to sanding the crap out of it).
I'm getting ready to build a Mini-BBX and haven't decided if I want to include the piston or not. I'll eventually stage it to the Terrier booster and figure on some really high-altitude flights.

Having said that, here's a brain-teaser for all of you:
It's common knowledge that QT expands at a different rate than the phenolic coupler used for the piston. So if you're flying in cold weather, it can be a problem if the piston's not sanded well.
But what about temperature lapse in flight? Under ISA (standard) conditions, the atmosphere loses 2 deg. C for every 1000' of altitude. For lower-altitude flights this probably won't be an issue. But let's say I fly my BBX staged to 10,000'. It'll be 20 deg C (68F) cooler at apogee than at the surface. Will the piston get stuck, or is the flight too quick for temperature lapse to be a problem?

 

[lalligood]

Originally posted by Chilly
Will the piston get stuck, or is the flight too quick for temperature lapse to be a problem?

IMHO, it would be too quick to cause ill effect. It's not the ambient air temp that's important, it's the temperature of the QT itself. If anything the QT is more likely to warm up (again, *very* slightly) due to the friction (air drag) during flight. If your piston were to stick in questionable weather, you probably didn't sand it enough to begin with...

Also, it is very important to clean out the inside of your airframe at least between every other flight! A damp paper towel & a dowel or broomstick is all you need...

 

[rstaff3]

Before I fly my QT/piston I always check for binding. In cooler weather, I just fly something else. I have always worried that sanding it for cold weather will make it too loose in warm. I have never cleaned it per-se, but I do run the piston in and out so maybe this does the same thing.

I am not convinced that putting it in backwards will be a benefit. It seems intuitively better to pull the piston thru the tube rather than push it. I haven't read his site however so I could be convinced.

 

[Chilly]

I can't remember the web address but the Vatsaas brothers have a link to it, www.vatsaas.com/rtv. It's very convincing. Take a look at some of the things this guy has done (active gyro stabilization, etc) and you may be sold on it.

 

[rstaff3]

Well, for the case of a loose fitting piston (since he said he could hear it rattling) I tend to believe his findings. It's not clear that this makes a difference in a piston that is snug. But further I guess his findings also have convinced me that it most likely can't hurt to put it in backwards.

BTW the Vatsaas link is incorrect. here is the target site

https://www.deltavrocketry.com/piston.htm


PS - thanks for the reference

 

[BlueNinja]

Originally posted by firemanup
Hey,

That's a purdy rocket joe.... heh..

Needs more power yet though.. they make a 54mm L...??

Yep! On ROL today there was something about CTI certing some new loads, including a Pro54 L.

 

[LampertRocketry]

Originally posted by daveyfire
My opinion follows...

They are expensive, and most of what you pay for (piston, QT, chute) I throw out anyways.

If my calculations are correct, what you are paying for (i.e. what is left over after you have thrown out all the stuff you don't want) is a motor tube, a nosecone and some centering rings. You would be better off purchasing them seperately I think.

Personally, I have used PML product extensively and with the exception of CATO's and Roman Candles (QT does burn well) have had little trouble with the PML kits. They are relatively inexpensive (yep... inexpensive) compared to what I am now building with... all fibreglass or carbon tubing, nosecones, fincans, Rocketman chutes, etc. The difference is simply... you get what you pay for. And the difference of $20 on a hundred dollar kit isn't going to make it or break it for me.... I hope to fly the rocket several times and spend significantly more on AP than on building materials. I have seen carbon and fibreglass rockets come in ballistic and plant themselves in the ground - only to be washed off and flown again minutes later. One simply cannot say that about QT or 'paper' tubed rockets.

I have built a few of the 'other' kits on the market and have not had much luck without enhancing the construction. My LOC kits don't seem to want to stay together (my PML QT kits stay together just fine... trick is in roughing up the surfaces before gluing and using something better than Uncle Jed's 5 minute epoxy paste). I also always foam the fincans. I am sure that with some glassing the LOC kits would be solid as granite... but I would rather spend a few extra bucks and just use fibreglass or carbon tubing. I am essentially lazy and hate making a mess with glassing, although I will and do glass some of the joints for added integrity.

If you are into homebrewing... check out Dave's Hobby Tubing - he sells carbon tubing at very reasonable prices but you will have to mess around a bit to make a nosecone that will fit.... and couplers.

You can also check out Performance Rocketry materials (highly recommended) - but I would definitely purchase them through a dealer that has stock onhand as his delivery is, shall we say, rather erratic. (He has a great product but is suffering growing pains).

Good luck with whatever you decide to do. Remember that you get what you pay for. I am in the process of assembling the Performance Rocketry components for a full size Amraam, a 4" Avenger and my L3, an extended V2 called a Blossom V2 in all carbon and fibreglass - 11.5" body tube and about 11 feet high.

Murray Lampert
TRA 08855 L2
NAR 79489 L2
CAR S589 L3
BRS

 

[daveyfire]

Originally posted by LampertRocketry
I have built a few of the 'other' kits on the market and have not had much luck without enhancing the construction.

I guess that's how I'm different from everyone else -- I can't seem to get ANY kits to stay together without construction enhancements. I like to fly my rockets on the biggest motors that will fit, and as such they need to be modified to fit either the bigger motor, or made stronger to hold up to the flight. I do have a stock PML Quasar, but I'm quite sad about it since it will never see more than a J90 or J180. That's the issue that I have with PML kits -- they are so well engineered, they are near impossible to modify to make them stronger without doing some serious rework. They're great for everyday flying or a quick afternoon build, but to push the envelope, glassed phenolic/cardboard, or all fiberglass, as you mentioned, is the way to go. It's also a lot cheaper to glass a cardboard or phenolic kit than buying a PML kit -- and a lot stronger too.

Once again, IMHO, YMMV, etc.

 

[loopy]

Originally posted by daveyfire
I guess that's how I'm different from everyone else -- I can't seem to get ANY kits to stay together without construction enhancements. I like to fly my rockets on the biggest motors that will fit, and as such they need to be modified to fit either the bigger motor, or made stronger to hold up to the flight. I do have a stock PML Quasar, but I'm quite sad about it since it will never see more than a J90 or J180. That's the issue that I have with PML kits -- they are so well engineered, they are near impossible to modify to make them stronger without doing some serious rework. They're great for everyday flying or a quick afternoon build, but to push the envelope, glassed phenolic/cardboard, or all fiberglass, as you mentioned, is the way to go. It's also a lot cheaper to glass a cardboard or phenolic kit than buying a PML kit -- and a lot stronger too.

Once again, IMHO, YMMV, etc.

You can get most of the bigger PML kits with phenolic instead of QT if you want. Just a thought.

 

[rocwizard]

Originally posted by daveyfire
I That's the issue that I have with PML kits -- they are so well engineered, they are near impossible to modify to make them stronger without doing some serious rework.

Oh but they CAN be modded. You should have known this by now David:kill:

So now i shall unveil my best example of how a PML kit can be made to take a little more, umm, *kick* A PML Matrix...

But not just any Matrix, no, this one is minimum diameter, bwahahaha! The airframe has 3 layers of 6oz glass, the strake and canard fins have been filleted and glassed over with a layer of 6oz, that aft motst fins have 2 layers of 5.7oz. carbon fiber and a layer of 6oz glass. an electronics bay is built into the nosecone. Max motor is a M1297W It just might fly on an L850 or L1150 at Nov. ROCstock XX.

I also have a hydra, that needs a little extra something...

 

[Batman]

It's also a lot cheaper to glass a cardboard or phenolic kit than buying a PML kit -- and a lot stronger too.

You do know that all PML kits can be purchased with the phenolic tubing for the same price. I just bought a Patriot and an AMRAAM 3 for about 20% less than PML's advertised prices and am getting them both with phenolic tubing. Couple layers of glass and that AMRAAM 3 will take any 54 mm motor I'm brave enough to stick in it.

 

[daveyfire]

Yup -- I know that you can get PML kits with phenolic. It's just that, to do that, you have to go straight to PML and order it -- which negates the cost benefits of buying from certain dealers.

Eric -- at that point, I don't consider it a PML kit anymore... it's a scratchbuilt with fins that look like the Matrix

Just an opinion!

 

[BlueNinja]

Originally posted by Batman
You do know that all PML kits can be purchased with the phenolic tubing for the same price. I just bought a Patriot and an AMRAAM 3 for about 20% less than PML's advertised prices and am getting them both with phenolic tubing. Couple layers of glass and that AMRAAM 3 will take any 54 mm motor I'm brave enough to stick in it.

Where? I might check that out.

 

[Batman]

The two i mentioned, the Patriot and the AMRAAM 3, i ordered through the Rocket Garden . His prices are as good as just about anybody's, and his service is great. I've bought my last 6 kits or so from him.