Baffle and other ideas for Fliskits Caution....

[WillyK]

This question is specifically targeted for "El Cheapo", but I'm looking for other ideas as well.

Reading a recent add-on to the "Scratch Building Baffles" thread I noticed an earlier comment from "El Cheapo" about how he has developed a simple baffle design for the FlisKits Caution rocket.

I'd like more details on that, and anyone who may have an idea for tweaks/mods on this wonderful freebie.

With Jim Flis's approval, I've used the FlisKits freebie Caution Rocket on a number of occassions with grade-school kids. I've modified a blank design to incorporate a school logo/mascot and choice text for a specific classroom.

It truly personalizes the rocket.

I don't build it entirely true to form; I don't roll my own MMT and use a standard BT for the MMT, use Kevlar thread for a shock cord, and will often use double thickness for the main triangular BT and triple-thickness for the fins. But this uniquely triangular body-shaped bird is one tough rocket that way and I've lost them (usually on C6's) before I wear them out.

El Cheapo's comments made me wonder his mod and about other mods as well.

Thoughts anyone?

... Bill

 

[El Cheapo]

This baffle is made out of 110lb cardstock. I've also tried using the half moon method (different shapes ofcourse) but proved to be a bit too difficult to assemble versus the one I came up with. I've only tested it on one Caution Rocket model but it seemed to work well in protecting a nylon chute. However, I like to err on the side of "caution" and lay in a piece or two of estes style wadding. Also pictured is the 18mm motor tube with 13mm adapter.



View attachment Caution Rocket Baffle.pdf

 

[jflis]

Just thrilled to know that these free download rockets are being used and creating opportunities for kids and adults alike

 

[WillyK]

Many thanks to you Jim!!!

Thanks as well to El Cheapo for his baffle setup. Perhaps a bit more involved than I'd care to do for a kid's class, but for my own demo flights I'm going to give it a try.

My beefing up (dual BT thickness) of the basic Caution Rocket is my own preference for a rocket that I like to try to "fly it to death". It holds up extremely well. Except for that time it dropped into water ;-)

When I've built it with kids, we build it mostly stock, with a few variations. I do use a standard MMT and engine block because it makes an extremely easy build, even easier and speeds up the process. The gussets (used to seal up the aft end of the BT around the MMT) are too much of a finicky pain for myself. We've stuffed tissue and glue or once I had some balsa filler stuff (like drywall spackle) that we pack a little bit in.

I have found that when using a standard MMT (Estes BT20 stuff) that in order to have the MMT glue to the flat BT walls I have to "press in" on the walls slightly to contact the MMT. This leaves the BT with a slightly concave shape at the MMT attachment point. Being also the place where the fins attach, I want this area to be flat, and not concave. So I've adopted the habit of actually printing the whole rocket slightly undersized.

I print it at some % of less than 100 on my computer printer. Can't remember the exact amount (don't have it in front of me, it's at home) but I think it's somewhere around 95%.

Once again kudo's to Jim for a superb kit. It flies extremely straight and depending upon how "straight" those fins are, you get some nice spinning effects. It's an easy build (always looking to make it easier). Customizable for the occassion at hand and extremely affordable (how often can I say "free"). On this latter point I had heard via the grapevine of some interest from a teacher that wanted to do a rocket build session. But after they priced out the cost of a bulk pack of kits, it was more than the classroom budget had left for the year. If only I had gotten to them first!!!

I am thinking of upscaling it slightly (to fit a D engine). I'd like to see just how rugged a 110 # double-thick cardstock model is. But, right now that's for the "to-be-built" pile.

... Bill

 

[El Cheapo]

Bill, if cost is an issue for school kits, these fly amazingly well on 13mm A3-4T & A10-3T. BTW, I use 4x laminate for the fins. They hold up great and mine don't seem to suffer from the Caution Rocket spin that is mentioned in the EMRR Reviews.

I'm just about to slap primer on a 24mm 2x Caution rocket constructed entirely out of 3/16 Foam Core. I'm cutting my teeth on the 2x to shortly start construction on a 4.25x 29mm. I've learned alot so far. I was hoping to have the 29mm finished for GHS in two weeks but time constraints just won't allow it. I'll have to settle for the smaller one. I am thinking of letting it loose on an F39-9 after the initial flight.

 

[jflis]

ANother thought if your goal is to get a good rocketry program for your kids at a bargain price (meaning that the act of creating a rocket from paper isn't a GOAL of the program) would be to replace the fins with thick card stock, like that which is found on the back of a note pad of paper (you know, that real thick gray cardboard) or the covers of a thick covered note book.

Another source for good stiff cardboard for fins are the stiff cardboard covers of 3-ring binder notebooks (slice open the plastic covers and check out the thick cardboard inside )

These can replace the paper fins. Cost is about the same (zero if you have some of this stuff laying around - I never throw these out when I empty a note book, for example). They are stiff and straight (no warps) and don't need to be folded in any way. Just cut to shape and glue to the rocket...

 

[WillyK]

Jim & El Cheapo... great comments. I go through oodles of those 8 1/2 x 11 pads at work. I've never thought of saving the backs!!!! But you're right, they'd make great fin material.

El Cheapo, on your "4x laminate" I'm assuming you're saying that your're doing 4 layers to the fins rather than 3 as suggested in the instructions?

I've found that when I've white-glued the fins during construction I'm more likely to get fins that aren't perfectly flat. What's worked well for me is using spray adhesive and then pressing between flat surfaces and wax paper under a heavy load. I've done up batches of fins like this to speed up construction time, but Jim's idea of cardboard from paper pads is rather cool. Gluing the fins to the BT with white-glue has always served me well.

I like the idea to fly them on the 13mm A's. Any idea to reduce costs are worthy. My wife's a principal in an elementary school and I know that sometimes a classroom teacher just doesn't have the funds. I remember pricing out an Estes bulk pack of generic E2X (I believe) kits once and it just proved too $$ for a class of 20+ for each student to take home a rocket.

El Cheapo you'll have to post some pics and techniques on your foam core Caution upscale. I've done some cube-like or pyramid-like tumble stuff with foamcore. The all-flat sides of the Caution BT and NC is a perfect candidate for foamcore. Now, you've got me thinking....

... Bill

 

[El Cheapo]

One thing that will speed up construction if flying on 13mm is that zero nose weight or ballancing is needed.

In regards to my method of laminating fins out of 110lb cardstock, it does take two nights. I laminate the two outside pieces each w/one other piece of cardstock under a large flat book & a brake rotor from a 1989 Suburban on top for no less than 24hrs. At that point I mate the two together and let them sit another 24hrs under the same brake rotor.

I've never double wrapped or laminated the body tube nor saw a need for it.

Pics included are of a blank CR templet I made into a Tweety Rocket and my 24mm foam core CR.

On the 24mm I wrapped the corners w/glue soaked cardstock to make the edges more uniform as I used one piece of foam core w/zero cuts for the BT. On the 29mm version I'll use three individual pieces.