Estes Partizon

Hello all! First post here. Here's a newb question for you. I've got an Estes Partizon kit still in the bag which I'm thinking will be close to a scratch build. The only mods I'm thinking of would be to replace the stupid estes shock cord mount with something else, and to put a sunward chute protecter in. I've launched many an estes rocket with their tri-fold mount and had no problems, but I still don't trust it. How best to do this? I'm thinking about putting an eyelet in the most forward centering ring and tying a kevlar cord to this, leaving the kevlar about 2 inches short of the end of the tube to prevent zippers, and then tying on the shock cord. Does this seem reasonable? By the way, does anyone have any cool paint schemes for this rocket, I've been thinking of painting it stock but haven't decided yet. Thanks!

Welcome, yep thats a good way to do it, I personaly used 1/16" steel cable, but kevlar would work fine.

CRC said:

Welcome, yep thats a good way to do it, I personaly used 1/16" steel cable, but kevlar would work fine.

Click to expand...

Another question. I want to apply glue fillets to the fins on the engine mount tube. How is this accomplished? Do you leave the rear centering ring off until the fins are glued on?

Exactly! Dry fit everything(always) glue the forward centering rings,be carefull to not make the fillets on centering rings too big where fins fit inbetween so fins still fit. A dollar store wood dowel or BBQ skewer works good to spread the glue where the fin tabs meet the Motor mount tube.

I'll use an eyebolt on my next build, but the Estes trifold will hold. https://www.rocketryforum.com/showthread.php?67391-Estes-Ventris-parachute-deployment-speed-question There's some videos and pictures of mine. 'Chute deployment speed sims at 33 fps with the motor I used. I suspect the actual airspeed was higher than that. After 3 launches, the trifold didn't budge.

To answer your question about internal fillets: Yes, you leave the rear ring off until you've done them. If you want to go way overboard, you can do fillets to the inside of the body tube as well.

Thanks guys! I've built a lot of smaller rockets before but this is my first trip into mid-power rockets. I remember building the smaller quest rockets which had the kevlar cord attached to the engine mount and that seems a better system than the tri-fold mount.

timbo32 said:

I'm thinking about putting an eyelet in the most forward centering ring and tying a kevlar cord to this, leaving the kevlar about 2 inches short of the end of the tube to prevent zippers, and then tying on the shock cord.

Click to expand...

That's exactly how I did my Leviathan, works great. I just pack the parachute in nomex and put all of the elastic in on top of it to give it a little protection.

And welcome to mid power! If you haven't seen (or heard) a composite motor yet then you're in for a treat!

Your on the right track. As for shock cord, I would recommend 20' of 1/8" Kevlar with a bunch of tape or two pieces of flat cardboard attached to the cord where it meets the top of the body tube. Either this alone, or add the elastic at the end of it. Elastic is like gravity. What stretches out, must rebound back. The extra long cord allows the NC to decelerate through drag. The elastic can then absorb any residual kinetic energy, but probably won't bring the NC back against the BT. I did this for my Leviathan L1. I also added a baffle, but a chute protector is also good, and keeps the bird closer to stock.

Also, make sure you reinforce the top end of the BT with superglue and don't use the eyelet in the NC. Cut two holes in the end of the NC 2" apart and run some strap through it that is 1/2" or wider. The eyelets are known to break.

If you search Partizon, Leviathan or any other PSII rocket, you will see a lot of threads about people building them for L1, and can get a lot of ideas/suggestions.

Nope, this will be my first launch with a composite motor. I hope it's as loud and as smoky as possible. What do you guys think of papering the fins? I've never done that before with my smaller rockets but I understand the concept. On my smaller rockets I just used a little watered down wood filler to finish the fins, but papering seems easier. What do you guys think?

Thanks for the tip on not using the NC eyelet, I've never trusted those things either, although I've never had one break.

attach the parachute to the shock cord(about 8 - 12" below the nose cone) and you'll reduce the chances of the eyelet breaking. the stock (96" elastic) shock cord seems to work okay for me.
Rex

No need to strengthen the plywood fins. They are strong. On balsa I prefer using watered down wood filler. On plywood I use Bondo Spot and Glazing, thinned with paint thinner. It is available at auto stores, but Wal-Mart has it cheaper. But don't use it on the Estes nose cones. They are Polystyrene, and the solvent will attack it. But HPR NCs are Polypropylene (Loc< Madcow, others) and they can handle it fine. I agree with Rex's positioning of the chute. The chute will decelerate the NC by putting it there.

timbo32 said:

Nope, this will be my first launch with a composite motor. I hope it's as loud and as smoky as possible. What do you guys think of papering the fins? I've never done that before with my smaller rockets but I understand the concept. On my smaller rockets I just used a little watered down wood filler to finish the fins, but papering seems easier. What do you guys think?

Click to expand...

Papering the fins can eliminate all the application of sealer/filler, and a lot of sanding. You may not want it for strength, but for speed, I'm all for it.

You can read more about my method by following the link.

I've decided not to paper the fins but finish them with wood filler. As for the NC eyelet I think I will put the chute on a large snap swivel and attach the swivel directly to the shock cord, that way if the eyelet breaks I'm only gonna be out a nose cone. As for paint scheme I was thinking close to stock except using a mettalic purple and a home printed decal with a purple dragon or purple fire on it. Name the rocket the Dark Fire. Will post pictures when it's done. Anyone got any engine recommendations? I live in central Nebraska and large fields are hard to find around here this time of year, not to mention how hard it is to find a calm day. After the crops are harvested large fields will be in plenty, but the wind will still blow.

Aerotech F20,F23, G38,G77 single use, or Estes F50 single use all great motors for that rocket & if you got a reloadable case then many other great motors.

How do reloadable cases work? I've never launched composite motors before. Are there a lot of little parts that can be messed up easily? Worth the investment?

timbo32 said:

How do reloadable cases work? I've never launched composite motors before. Are there a lot of little parts that can be messed up easily? Worth the investment?

Click to expand...

I've found Apogee videos to be very useful in answering questions like that. https://www.apogeerockets.com/Advanced_Construction_Videos/Rocketry_Video_19

Aerotech has some useful information. https://www.aerotech-rocketry.com/faq.aspx

BTW all the motors recommended for the Partizon are Estes-branded Aerotech single-use composite motors. I'd be partial to the F50T (blue thunder) for a first flight in windy conditions. A nice firm accel to defeat weathervaning tendency.

I recently built one myself. It was my first medium power build. Fun build. I had started a build thread but had problems adding pictures.

I put a baffle in mine in the lower coupling and attached an eyelet to that. I put a swivel on the eye, then some kevlar thread, I got a snap swivel where the chute attaches as well, so I can easily remove the chute for whatever reason. I saw on one thread something that looked like a ball on the shockcord to prevent zippering, I am gonna have to come up with something like that.

I put a plywood bulkhead and an eyelet in the uppermost coupling so the rocket will separate there (right above the lower purple ring, midway up the rocket in the pic). That way you don't even have to worry about the eyelet on the nose cone at all. I used filler on the fins to get a nice smooth finish but used too much water and warped em. Then had a heck of a time straightening them back out. Bungee cords, a hair dryer, a sponge and finally a clothes iron. LOL

For me the worst part of any build is filling the dang spirals. I am working on Super Alpha and decided to try something different. I watered down some filler and covered the entire tube with the stuff using a foam brush. It sanded off much easier and smoother. Of course the Alpha is much, much smaller. The (somewhat careless) sanding fuzzed the ends of the tube a bit as well but nothing I can't fix. I can't really recommend using that method as too much water will probably damage the body tube.

Here is my baffle. Its a cardboard core from aluminum foil and some homemade plywood rings.

View attachment 179619

View attachment 179618

I left the rear centering ring off so I could put my fillets in that way. I put them where the fins meet the motor mount AND where the fins penetrate the body tube. I also put fillets on the outside for cosmetics. I used some wood filler with a little Mod Podge mixed in. Looked kinda like tan Bondo when I mixed it. It made nice looking easy to sand fillets. I taped the fins to get uniform fillets and keep my excess goo off the fins.

View attachment 179620

Then a little sanding:

View attachment 179621

I painted it stock. The red pinstripes gave me fits but I finally got it. Here is (nearly) finished product. I use the cheap acryllics from WalMart or Hobby Lobby then gloss it with automotive clear coat. I still may do some wet sanding and another shot of clear coat. And some stickers or decals. Hope this isn't considered hijacking.

View attachment 179617

Great looking rocket! I remember a vagabond kit where I put too much water in the filler and warped the fins, no fun.

Thanks.

I did the same thing with my Estes Xarconian Cruiser build. I never did get all the warp outta those fins. Now I just rub the filler on "as is" with my fingers. Makes a mess but no more warping.

The plywood fins provided with most of the PSII kits don't really require as much sanding and filling as balsa, unless there is some kind of dent or gouge. The wood is pretty smooth, and the grain is not as deep and porous as it is with balsa. I just sanded the plywood fins on my Leviathan, then sprayed with filler primer a couple of coats and sanded again. I thought they came out nice.

MikeyDSlagle said:

I recently built one myself.
...
Hope this isn't considered hijacking.

View attachment 179617

Click to expand...

This is an A number 1 text book case of hijacking IMO ! Of course it's up to timbo to file a complaint and get the judge to issue a cease and desist order. :wink: (if I had dollar for everyone of my hijacks... )

The (nearly) finished product looks really good; I take it you know your way around a spraygun.


Timbo: I agree with the thirsty one, you can hit those plywood fins with a high build primer and skip the wood filler. I use this:



For balsa fins, I use the wood filler AFTER a couple of coats of sealer to limit water infiltration. Something like this:

Hijacking is Ok to me, I'm here to learn. Thanks for the tips Thirsty and Samb. At this point I have finished sealing the fins and am just about ready to assemble the fin can of the rocket. If all goes well I'll post pictures when the rocket is done.

For single-use motors on not-so-big fields, I like the Aerotech EconoJet motors F20 (White smoke and flame), F23 (Thick black smoke), F27 (Red flame). They also make an F-42, that I have not flown which I understand is fast and does not make much smoke --- same formulation as the Estes F-50 and G80. If you (or your club) have a 12-volt controller, you can use the igniters that are included in the motor 2-packs. If you are using a 6-volt Estes controller, you will need to buy the Estes PSII igniters for these motors. I use these pretty often in my Leviathan, because they cost less than the Estes PSII motors, and my club's low-power launches have a 1,000 foot ceiling --- these are small F's so they don't put the rocket over 1,000 feet. I buy them at Hobbylinc for about $28 for a 2-pack --- for just over $100, you can buy a pack of each "flavor" and try them all out.

Of course, there are other single use motors that will go much higher...