Cheap, tough as a tank kit for research

I'm looking for pointers for a good kit to be used as a research[1] platform that would be easy/quick to build and isn't very delicate[2]. Here are some off the cuff 'requirements' that we'd be looking for:

* ~ $20 per rocket
* Body Tube >= 2.5"
* Standard Sizes so that spares and custom configuration aren't a problem
* $5-$10 per launch

I'm sure that there's more but I think that's the gist.

I was moved to ask because I was about to buy 5 or so Partizons from Estes, but they are sold out. Besides, there is probably an other platform out there that I should be considering. I looked into building them up from parts but kits on sale often seem to end up cheaper than the sum of parts.

Thanks for your help.

1. The fact that it is a 'research platform' basically means that it's going to be flown a _lot_. Ugly is fine, delicate is not.
2. Tough as a tank was a silly thing to say. This is a cardboard rocket that I'm talking about. But there are things that are handy... e.g. fins that don't sweep back etc.

Check out BMS https://www.balsamachining.com/# they have all kinds of parts the BT-80 based ones should meet most of your criteria (BT-80H with PNC-80KH) about $21 the cost could be reduced further if the airframes is used in 17" sections (2 pieces) instead of 34" (whole tube).

Not sure on the kit aspect. Estes PSII are relatively cheap, pretty sturdy, and are a different size from just about everything else in the known universe, although Balsa Machining will cut you new centering rings.

Especially since I don't know what your research goals are, I would suggest designing something yourself around a BT-80. At Balsa Machining, a 34" tube is $6, and a FatBoy-style NC is $5.50 (PNC80BB). You can fly it on anything from a 24mm C probably up through a not-too-vigorous G. You can fit 5 x 18mm, 2, 3, or 4 x 24mm or a 29mm mount (all stock parts at BM). BT80 is as universal as it gets. You could pick up 5 N/C, 5 or 6 BT, some bulkheads and centering rings, a coupler tube to make opayload bays, and some motor tubes. Get some 1/8" light ply at your local craft store and you are good to go. Get some 110lb cardstock and you can make tailcones.

Here's a basic design (modified from an egg-lofting rocket I was designing for my 6yo daughter using some existing parts). View attachment BT-80 Basic.ork View attachment BT-80 Basic.pdf

If you need more durability, go with BT80H, although that will up your price per rocket.


@rharshberger: Great minds think alike

Until you said it I hadn't realized the proprietary (except the 3" Leviathan) dimensions on the PSII models . Basing our platform on the BT80 isn't a bad idea at all.

~$5 plastic nose cones are a great place to start. It's the NC that get's us in trouble price wise. We can laser cut the rest.

wcravens said:

Until you said it I hadn't realized the proprietary (except the 3" Leviathan) dimensions on the PSII models . Basing our platform on the BT80 isn't a bad idea at all.

~$5 plastic nose cones are a great place to start. It's the NC that get's us in trouble price wise. We can laser cut the rest.

Click to expand...

Actually if you look around you can get the PNC-80BB for less than $4, I just bought two for $3.88 each off the amazon or ebay.

I have no idea what these BT numbers are, but Estes tubing is weak. Even PS kits do not seem to appreciate something as simple as extra charges or shear pins for dual deployment.

If you truly need tough as a tank, you need fiberglass. However I bet you will do well with some of the heavier cardboard tubes. LOC and Madcow for example make 54mm and 75mm tubes that double as motor mounts, and using those for body tubes is solid.

Another interesting option is Aerotech kits. I have friends who leave the fins unglued, and simply snap them back into the locks if they pop out on landing. The tubing is not as strong as the others I mention, though.

wcravens said:

I was moved to ask because I was about to buy 5 or so Partizons from Estes, but they are sold out.

Click to expand...

What do you mean sold out? They're still on the website's special page. I put one in my cart, then updated the quantity to 5, and it looked like I could get them if I went farther (no "exceeds availability" message).

K'Tesh said:

What do you mean sold out? They're still on the website's special page. I put one in my cart, then updated the quantity to 5, and it looked like I could get them if I went farther (no "exceeds availability" message).

Click to expand...

Yesterday (Nov. 1st) they were reported as 'Out of Stock'. Thanks for the heads up that they are back. I wasn't that interested in the Partizon at first. But I bought one because it was a great deal at the sale price. I'm just about ready for paint on my first one and it's grown on me quite a lot. I might pick up an other one now that they are back in stock.

Cheers!

watermelonman said:

If you truly need tough as a tank, you need fiberglass. However I bet you will do well with some of the heavier cardboard tubes. LOC and Madcow for example make 54mm and 75mm tubes that double as motor mounts, and using those for body tubes is solid.

Click to expand...

I apologize. I should have been much clearer. I meant 'not a lot of fins to break off', 'through the wall fins' or 'plywood instead of balsa' kind of tough. Not 'ready to go after being dug out of subterranean exploration' kind of tough.

Basically the thread is on the right track. Something that can launch on D, E, F, G motors, and is wide enough to easily manipulate electronic payloads will do the trick. Some friends and I want to tinker around with home grown onboard electronics and need a test platform. And I want to be able to knock up new clones really easy. Some of these rockets will meet an early end and I don't want much invested in them. But I also want to increase the chances that a recovery deployment error won't result in total destruction, as long as separation occurs.

wcravens said:

Yesterday (Nov. 1st) they were reported as 'Out of Stock'. Thanks for the heads up that they are back. I wasn't that interested in the Partizon at first. But I bought one because it was a great deal at the sale price. I'm just about ready for paint on my first one and it's grown on me quite a lot. I might pick up an other one now that they are back in stock.

Cheers!

Click to expand...

I understand what you mean by "it's grown on me"... I wasn't too thrilled with it originally (couldn't wrap my mind around that shade of purple). Then I modeled it in green, and it looked better. Then I modeled it in what I imagine as a metalic purple, and I was hooked. I've got two now, but I think I need to score another, plus a 4th Argent (one became the Cherokee D upscale), two more Ventris kits (I've got one), and another pair (or trio) of MDRMs.

Problem is... I need income, and that means moving to China.

I would not call estes kits "tough as a tank"

Estes Maxi Alpha for $15 on sale from Estes direct is the only thing that truly meets your $ criteria. Epoxy fillets added to the plastic fin can and rimming the interior of the cardboard tube at the top will help greatly in strengthening it.

mkadams001 said:

I would not call estes kits "tough as a tank"

Click to expand...

Awwww. . . no love for Estes? How about TLP kits? Real MPR, it says so right on the face card! A 2.6" Folgore can be had cheap! Give me a 2.6 kraft paper tube, their squishy balsa, some label paper and a whole lotta super thin, quick cure CA and real quick like I will be doing some bad booty research.



Just don't poke your eye out with those paper witches hats. Soaked with CA or finishin' epoxy they can really poke at high speed.

Let's hear some love for TLP kits! Great for parts! For some reason many folks will just give them to you. Can't beat that price!

wcravens said:

But I also want to increase the chances that a recovery deployment error won't result in total destruction, as long as separation occurs.

Click to expand...

Had this happen to my daughter's Partizon. It involved me trying to make some last minute fixes, and accidentally gluing the shock cord to the body tube. NC came off, and the whole thing came down in a flat spin, pretty much undamaged. They are good rockets. Wouldn't want to fly one on a D, though.:wink:

Daddyisabar said:

Awwww. . . no love for Estes? How about TLP kits? Real MPR, it says so right on the face card! A 2.6" Folgore can be had cheap! Give me a 2.6 kraft paper tube, their squishy balsa, some label paper and a whole lotta super thin, quick cure CA and real quick like I will be doing some bad booty research.

View attachment 275426View attachment 275427View attachment 275428View attachment 275429View attachment 275430View attachment 275431

Just don't poke your eye out with those paper witches hats. Soaked with CA or finishin' epoxy they can really poke at high speed.

Let's hear some love for TLP kits! Great for parts! For some reason many folks will just give them to you. Can't beat that price!

Click to expand...

I like that thing whatever it is.....

mkadams001 said:

I like that thing whatever it is.....

Click to expand...

It's Daddyisabar's take on the Japanese Kyushu J7W "Magnificent Lightning" fighter.




(And an AWESOME job of it to boot!)

I built a tough bastard, but it is in 1.6 inch tube.

I reinforced the top of the tube. It uses 24 mm motors. I put large launch lugs. The fins are plywood and have epoxy fillets. The motor retainer is a plastic screw on type. Added weight to nose cone.

This thing won't lose a fin on landing as long as the nose cone pops out, even if the chute remains closed. [emoji3]

You will need your rocket to be able to fly with 24mm motors or using BP F15s in your price range unless you know something I don't about prices of 29mm motors. Through the wall fin tabs do not classify as "easy" in my book. Room for some error there. Pre-made plastic fin cans are "easy." Let us know what you decide and lets see how it met your initial requirements.

By the way, adding some additional coupler stock to the inside of your maxi alphas would still come in under your price point.

Nantucketdink said:

Estes Maxi Alpha for $15 on sale from Estes direct is the only thing that truly meets your $ criteria. Epoxy fillets added to the plastic fin can and rimming the interior of the cardboard tube at the top will help greatly in strengthening it.

Click to expand...

IMHO: The Maxi Alpha III is better suited for cloning the Optima/Shadow

Laminate cheap light paper tubes using wood glue & couplers, or go for light glass, or simply soak with CA. Make cheap light fins by laminating Balsa over a thin basswood core. It all depends on what kind of MPR - weird science research you are doing. Your bond is only as good as the weakest layer bond of the paper tube you are gluing to. The glue never fails - it is strong, it is always that darn paper tube - it is weak!

BULLETPROOFING RULES!

Scratch build to be top dog, a real MPR rocket scientist. You will spend all your cash on VMAX anyway. Look at my light and strong, reinforced MPR paper rocket the "Magic Man," now you see me, now you don't. Awesome. Bye Bye speed of balsa, bye bye MPR and paper tubes. Soon, only the big boy motors will fill the need for speed. Hello aluminum tips and fin cans!

Stick an H410 into a stock built AT Initiator kit you bought at the garage sale fer cheap. Fly nekkid, it can take it! Darn! I need more motor! But you will then be certified.

mkadams001 said:

I like that thing whatever it is.....

Click to expand...

It is MPR research with free TLP parts that some folks consider sub standard. No reinforcement and the thing sucks all the power I can get from the MPR AT F 24 motor. I need more POWER!

Daddyisabar said:

Laminate cheap light paper tubes using wood glue & couplers, or go for light glass, or simply soak with CA. Make cheap light fins by laminating Balsa over a thin basswood core. It all depends on what kind of MPR - weird science research you are doing. Your bond is only as good as the weakest layer bond of the paper tube you are gluing to. The glue never fails - it is strong, it is always that darn paper tube - it is weak!

BULLETPROOFING RULES!

Scratch build to be top dog, a real MPR rocket scientist. You will spend all your cash on VMAX anyway. Look at my light and strong, reinforced MPR paper rocket the "Magic Man," now you see me, now you don't. Awesome. Bye Bye speed of balsa, bye bye MPR and paper tubes. Soon, only the big boy motors will fill the need for speed. Hello aluminum tips and fin cans!

Stick an H410 into a stock built AT Initiator kit you bought at the garage sale fer cheap. Fly nekkid, it can take it! Darn! I need more motor! But you will then be certified.

Click to expand...

yes, fiberglass low power rockets!!!!! Then, they become mid power to lift them off the pad...how much power can an Alpha take?

wcravens said:

I'm looking for pointers for a good kit to be used as a research platform that would be easy/quick to build and isn't very delicate[1]. Here are some off the cuff 'requirements' that we'd be looking for:

* ~ $20 per rocket
* Body Tube >= 2.5"
* Standard Sizes so that spares and custom configuration aren't a problem
* $5-$10 per launch

I'm sure that there's more but I think that's the gist.

I was moved to ask because I was about to buy 5 or so Partizons from Estes, but they are sold out. Besides, there is probably an other platform out there that I should be considering. I looked into building them up from parts but kits on sale often seem to end up cheaper than the sum of parts.

Thanks for your help.

1. Tough as a tank was a silly thing to say. This is a cardboard rocket that I'm talking about. But there are things that are handy... e.g. fins that don't sweep back etc.

Click to expand...

You are looking for an off-the-shelf Estes Partizon equivalent rocket for $20. Not going to happen. It's below the cost to make and sell the rocket at breakeven.

Let's do a cost breakdown of a $45 list price product.

• The unit production cost of a retail product should be 20% of the retail list price, but could be as high as 25% before you can't make a profit on the product.
  • 0.2 x $45 = $9, 0.25 x $45 = $11.25.
• The overhead costs of having a product oriented business is typically 20% of the list price, and these are real costs of having a brick and mortar business with real employees.
  • 0.2 x $45 = $9.
• The wholesale price of a retail product varies with the size of the order and usually varies from 50% for large orders to 60% for small orders.
  • 0.5 x $45 = $22.50, 0.60 x $45 = $27.
• The G&A and profit of a legitimate small for-profit product oriented company is generally 20% of the selling price. The cost associated with larger wholesale orders is lower than the costs associated with smaller wholesale orders and both are much lower than the costs associated with much smaller retails sales fulfillment.
  • (0.2 x 0.5) x $45 = $4.50, (0.2 x 0.6) x $45 = $5.40, 0.2 x $45 = $9.
• 40% of the retail cost of the in-house retail sales is due to: 1.) inventory costs, sales staff, credit card and order processing which represents 20% of the retail price, and 2.) marketing with represents 20% of the retail sales price.
  • 0.2 x $45 = $9 retail sales costs, 0.2 x $45 = $9 retail marketing costs.

These are just fundamental business rules of thumb that can be universally applied to any legitimate product company.

Note the $22.50 special prices of the Estes Partizon on their website is 50% of the $45 list price which is the best wholesale price to large wholesalers. Hobbylinc.com was selling it for $31.39 (-30% off list) but it is now listed out of stock and discontinued. I'll speculate Estes has a hard time selling the Pro Series II rockets in-house at list price when the on-line discounters are selling it for 30% less, and the wholesale sales to distributors are slow because the launch equipment and motors are not compatible with traditional Estes product lines. So IMO it's not unreasonable to speculate the product line is being discontinued, and Estes is eliminating inventory. Further evidence of this is the introduction of 3 new rockets as a web exclusive made from the existing parts inventory and not packaged in standard retail sales.

It's too bad as these are nice kits, but most do not fly on BP motors, so while Estes could probably continue to sell these kits at slow rate, they won't sell any BP motors with them which is Estes niche in the hobby.

Bob

wcravens said:

I was moved to ask because I was about to buy 5 or so Partizons from Estes, but they are sold out.

Click to expand...

FYI, as of 11/3 @1:56pm EST the Partizon is back in stock on the clearance section of Estes site, and if you order 5 as indicated, they ship free. Just FYI.

mkadams001 said:

yes, fiberglass low power rockets!!!!! Then, they become mid power to lift them off the pad...how much power can an Alpha take?

Click to expand...

I saw a similar upscale Bertha go on one of those 24mm Six grain, slow burn, I Max Canadian G's and the altitude junkie dude launching it had to do some RESEARCHING to find it.

I updated the OP. The fact that it is a 'research platform' suggests that it will be flown a heck of lot. Several flights per launch day. Really it just needs to be durable and easily repairable.

Tough bastard looks the part, that's for sure.

If you want a cheap workhorse, you will need to scratch build it. Tell us more about your needs and limitations and I'm sure we can come up with a design you can build and launch with minimal costs and repairs!

So, what are you design constraints in terms of motors, materials, tools... For example, can you cut plywood fins and bulkheads, can you use epoxy...?

I like your project. It is a problem I also need a solution for although not for research but just to have a durable rocket that is on the cheap side and flies on F and G motors.

I have a WM Vindicator, a FG rocket that has fallen out of the sky from a mile up .. had a motor burn through the case & the MMT - it is still flying ...next up a AT L1000W that was NOT part of the recall . .. will see how it fares .

Definitely not $20 but fairly instructable - so a good value . RW has a BYOK that is fairly cheap for what it is ..FYI .

Two cheap rockets that are strong (not indestructible) are the BAR Crayon...nose BT and tail for $8? Just add CR MMT Fins and a Estes Retainer .. can fly on a G motor .

Other is mentioned above a single layer of FG wrap on the PS II series kits yield a very light weight but strong flier - mine weighed less than Blue Tube and alot less than traditional FG .

Kenny

Ok. I think from what I've learned here and asking around that we'll definitely be putting together our own design. Sometimes kits can be sold for much less than the sum of their parts, so I figured I'd ask. Not surprised at all to find out that the PSII Sales are pretty much the best offering in this space.

But in this case I think I'm convinced that we'll roll our own. We have no problem laser cutting parts ourselves so I think that this should be straight forward.

Once I zero in on putting a design together and getting the BOM sorted out I'll bring it back to this thread.