My first High Power rocket

[daveyfire]

J350W is a good choice, if you have a little more cash, a J275 is a great motor (I believe they are $65 now). It burns a little longer and is gentler than the 350, so your rocket will really cruise. It also has a little more total newton seconds, so that'll help with altitude.

I think as long as you don't fly with any of the higher thrust 54s (eg J800T, K1100T, K550W, K700W, K1275R), you should be all right without tip to tip glassing. If the tubes aren't glassed, I'd stay away from those motors anyways. (Ask Kermie about the punch of a K motor )

Glasswise, if you can get it, a tighter weave or a satin weave makes finish really easy. They usually sell this stuff at the hobby shop. Loose weave stuff is cheaper, and you can find it at the hardware store, but is a pain in the butt to finish without the proper materials. You can glass with 15 minute stuff (thin it with alcohol to allow it to work into the cloth), but I'd recommend going with 20 minute finishing resin, or if you have the money, West System or Aeropoxy. The latter are professional laminating resins with superior strength to hobby shop epoxy, and are very thin and easy to work with in fiberglass, Kevlar, and carbon fiber situations.

Hope this helps! Post more pics!

 

[Ryan S.]

You can have something to do with the motor, actually, buying a casing does not violate and laws, anyone can buy the casing, after all it is just a piece of metal. I have all the Aerotech 29mm cases except the 360 and I have all the Pro38 casings as well. It is the propellant you are restricted from buying.


The J360 (J330) is a 6 grain motor that is different from Aerotech propellant. It has a bright white flame that is skinny and in some cases you can see the mach diamond in them. they have smoke, but not alot, more than blue thunder but less than white lightening.

 

[havoc821]

I will have to run some simulations when I get back home but the J275 sounds like just what I wanted. And the price isn't too bad.

As with fiberglass, I was at aircraft spruce (I think that is the name of the site) and looked at their aeropoxy pint kit for only $8! Is this a good deal and how good is this for fiberglassing. I think I might order from them and while I'm at it, I will get some fiberglass cloth too. What kind of fiberglass would you recommend that isn't too expensive (I only need about 2-3 yards so I can have extra later on)? I will get more pics as soon as I get more done. BTW does anybody have a liftoff shot of a J275 and and J350? And what is the price of the J350 just in case I need to save money. Thanks everybody!

 

[Hospital_Rocket]

I saw an earlier pist about the possibility of using a razor to slot phenolic, and while that is a way of doing it, here are a couple of things I found work with almost any airframe material:

1. Mark your line and drill a series of holes. Then use a file.

That was a lot o' work so...

2. I found that yiou can buy a rotary saw attachment for a Dremel tool. ($15 @ Wal-Mart) You can plunge cut and just saw away. I found that was very helpful in another project I was working on.

 

[havoc821]

hospital,

I used my dad's hand jug saw to slot the tube. It worked fairly well, I had to make a couple of passes to get the right thickness but it turned out good.

everybody else,

I am in the process of figuring out what kind of fiberglass and epoxy to order and where from so I probably won't have any pictures for a while but if anybody has and suggestions for fiberglassing tubes (another project of mine), it would be greatly appreciated. Thanks!

 

[MaverickLV]

Hey,

Read through the posts and just thought i'd toss in my .02

First, the J275W is a great motor in my opinion. I have seen several of them fly this past year and the flame was larger than a J350W and it was quite a bit louder. It also has a significant burn time...not exactly as long as a J135W or K185W...but good for what your looking to do and at a reasonable price.

Also, US Composites does have great 'glass and epoxy but you might want to check out some local hobby shops if you don't want to worry about shipping or waiting for the stuff to show up. I found that my local Hobbytown USA has a good selection of fiberglass from 1/2 oz. to 10 oz. A yard sells for about $6. They also carry Bob Smith 20 minute finishing resin which is the perfect consistency I believe for 'glassing...it really takes more like an hour for it to set-up. It may not be as strong as West systems but it is cheaper and readily available.

I would stay away from the Home Depot fiberglass though. I used it for my first 'glassing job and it works fine for adding strength but the weave is really loose and this makes finishing a difficult task...quite a bit of bondo on that project.

Anyway, just my thoughts. One question though: I think you mentioned it somewhere in your posts but now I can't seem to find it...what kind of plywood are you using for your fins? I know the thickness is 1/8" but what wood...3-ply birch or luan?

Dave

 

[slim_t]

Chris;

I just now caught up with this post and just wanted to say great job man. I too have flown with HARA about 3 times this year, but I guess not at the same times as you since I don't recall seeing you, but I hope to meet you and see this one fly. I was wondering where you plan on flying this thing? Are you hoping to fly at a HARA launch if they get a new field, or will you be taking it somewhere else?
I will be building my first 4" rocket this winter, but I hope to keep it light enough to fly on a G. It'll be from scratch, but will probably be similar to an AT G-Force.
Keep up the good work.

Tim

 

[havoc821]

Maverick,

The fins are 1/8inch 3 ply birch that I picked up at a Michael's craft store. I checked at my local hobbytown but they don't have fiberglass. Lmazza sent me a message this morning about some fiberglass he just ordered off ebay and it looks pretty good and if shipping is reasonable I might order some 6oz for this rocket. My local RC hobbies has the bob smith 20min epoxy that I will use for the fiberglass. Thanks for the help with motor selection and I am pretty sure I will fly the rocket on a J275 now.

Slim,

Currently HARAs field is Walt's Stafford's farm/backyard and I won't be able to fly this rocket on the J275 at HARA because the field is too small. If they get a new, bigger field, then yes. If I have enough money after the J275, a couple of H128s and another G64 reload and a few other odds and ends then I will get an I211 and fly this rocket at HARA with the I211. It will be a low altituide flight, ~800', and probably won't use dual deployment. I will try to be at HARA's first launch this year which is February, I think and do a couple of smaller stuff there and then I will try to travel to Music City's launch around the same time to fly the big rocket. I will let you and everybody else know when it will fly so if you want to see it you can. BTW the rocket's name has been chosen and it is "Andrus 1", named after Chuck Andrus, who supplied most of he parts and provided LOTS fo help throughout the project. It was the least I could do to say thanks.

Anyways, I haven't done anything else with the rocket except for break off a few fins, not on purpose. When I glued the fins to the MMT I used JB Weld because it instantly popped into my mind that JB Weld was stronger, so I used it. Well, silly me dind't think very well and JB Weld is thicker that epoxy and didn't soak into the tube and just bonded to the outside layer of the paper tube and everytime I touch a fin, it breaks off. So now I have to glue them back on and add epoxy fillets to the fins for now untill fiberglass arrives. Well, that's all for now. Thanks for all the help guys!

 

[havoc821]

Slim,

I forgot to mention, this year I flew in June, August, and October. We got rained out in september. Where exactly is Slema in relation to HARA? Which launches were you at?

 

[slim_t]

I went to the April, May, and September launches. When it rained in September, Walt was nice enough to let us hang out in his garage until it cleared up, and then we all had a pretty good day. The wind was bad, so I didn't put up anything too high, but it was still a good day. I managed a nice launch of my whiffle missile (see pic below), and a few other small ones.
Now that I think of it, I may have seen you when I first got there, but you left when the rain started. Was that you with the tall skinny rockets laying on a blanket on the ground? I was hoping you'd come back so I could see those things fly, but it was probably too windy anyway.
Selma is about 3 hours south of Huntsville, near Montgomery. I'll be going to the SEARS launch in February, so I'm not sure when I'll get to another HARA launch.

Here's the whiffle missile. It's a plastic baseball bat that flies rather well on D's (about 600-700ft). I haven't tried an E yet.

Tim

 

[slim_t]

Here's a lift off pic.

Tim

 

[slim_t]

and an in flight pic....

Tim

 

[slim_t]

Last one, a safe recovery pic.

Tim

 

[havoc821]

Very cool rocket slim! Yeah, that was me at the september launch. My mom didn't want to hang around in the rain or the garage and we had to leave. That tall skinny rocket was the Aerotech Mirage that I kinda didn't do so good on the paint job. It won't be able to fly for a while beacuse on its second flight in October at HARA, the ejection charged popped the upper 5 ft and its parachute off but not the booster's parachute and the booster came in ballistic from about 800ft. Anyways, I was going to say that if Selma wasn't so far away you could come to the meeting we are having this Thursday at Hobbytown in the Target shoping center of University dr. (in case you are familiar with huntsville) because I am bringing the high power rocket along. Well, I hope to meet you sometime.


I will try to order the fiberglass today so that I can work on the rocket some more. I'll keep you posted when I get more done.

 

[Neil]

Yer a Yankees fan????? <CENSORED. LOTS OF BABBLING ABOUT BASEBALL RIVALRIES>... ok. ill leave it. Cool lookin rocket, though! One note on your sime on the first post.... Why so many mass objects? You can just go to "mass override" and enter in your desired weight, and forget about llthe little "Ms". Looks like a cool rocket. How many fins? By the way, looks like your really divin in the deep end. Why not start with a 38MM rocket (yeah yeah, I know IM the one to talk.... All my evil plans for 3" motors and plans for world dominion )? My first was a 29MM 4" V2. Real nice rocket. Yours is... well... BIG. are you going to use glass onit? Pardon me for the un-spaced words... my keybord has gone mad and half-killed teh spacebar. We REALLY need to buy a new computer.....

 

[Ryan S.]

get a mac.....it would be perfect

 

[Neil]

We already own a mac. I kinda like those new PCs, though. The Dell ones. Sure look nice...

 

[havoc821]

Neil,

1) The reason for all the mass objects instead of mass overide is that if you do mass overide then the weight is spread out over the entire rocket and not just where you want it to be. Example: I wanted a 2.4 oz ublot in my altimeter bay but if I used mass overide and put in 2.4 oz to rocket weight, then the rocket would weigh the same in both simulations but the weight of the u bolt in the first simulation is toward the front of the rocket and in the other simulation the weight is spread out over the entire rocket. Make sense?

2)6 fins

3)Going off on the deep end, um let me think about that.......NO. I do plan on doing an H powered flight before I stuff a J in this puppy. I going to do the H flight to prove that I am really going through with this project and that I am capable of doing high power motors. The difference between you and me (when it comes to high power and the reason you got fussed at) I had lots of help. EVERY idea I had that I wanted done, I ran by Chuck to see how it would work and if he knew of anything better. You just started off wthout help and half way through the project you would ask for help. You would just start buying parts for the HUGE rockets and not have a clue about what you are about to do. I'm not trying to be mean, but I think you are the last person to be making a comment about "going off the deep end".

4) Yes I am using glass on it. I already have the fins epoxied to the MMT and fillets on them. Monday I will epoxy the foward CR on the MMT and slide the MMT into the booster and fill with expandable foam (my foam is from US Composites and unlike PML, this faom doesn't break easy and isn't soft. It sets uf and is like concrete once it is cured). After that, I will epoxy the rear CR on and put epoxy fillets where the fins meet the outside airframe. After those fillets are done, I am glassing tip to tip on the fins, not the entire rocket because I don't plan on doing anything in this rocket higher than a small K. I know the rocket has a 3" MMT that can hold Ms but this rocket will not fly on Ms. When I first started building this rocket, I thought about what I had always heard: Put the biggest MMT in because you can always adapt down. I also thought about when I get certified I can fly this rocket on big motors, but by the time I get certified, the rocket will probably have crashed or someting catosrophic.

5)My first high power motor flight will be an H128 in my LOC 4inch V-2. BTW I WAAAAAY OVERBUILT this rocket. I did epoxy everywhere, then filled the tailcone with expandable foam and that add a LOT of weight to the rocket. I replace the shock cord mount with an eyebolt JB Welded into the CR. I replaced the elastic with 12' of tubular nylon and will use a PML 48 chute for recovery. After this flight, I will go to Music City's launch sometime early this year and fly my 4" Horizon on an H128, a scratchbuild on a G64 and following these two rockets I will fly the ANDRUS 1 on a J275 at the same launch.

Well, that's all for now. No pics. I'm sorry. Will post when I have more done.

 

[slim_t]

Originally posted by Neil
Yer a Yankees fan????? ... ok. ill leave it. Cool lookin rocket, though! .....

Actually, I'm not a fan. I just wanted to choose some of the older baseball teams. I had 3 fins, so 6 penants to choose. They are the Braves, Yankees, Dodgers, Red Sox, White Sox, and Mets.
It just seemed like a cool item to turn into a rocket.

It'd be even cooler if I get Roger Clemens to sign it, "Rocket".

Tim

 

[Neil]

Oh. Well thats ok, I guess.... Though the sox and theyankees should never be used on one object, if you ask me.

 

[havoc821]

IMPORTANT NOTE TO ANYONE USING EXPANDABLE FOAM!!!!!

If you plan on using expandable foam to fill the inside of your rocket to add strength and etc. then you must add epoxy fillets on the outside of the rocket BEFORE foam filling. When I slotted the tube for this rocket, I started from the very bottom and went up to the fins length. Well, I had to make a couple of passes to get the desired thickness of the slot to get the fins to fit. Well, I cut the slots a little to big and there was a small gap there. I couldn't do fillets because the epoxy would hold and leak through to the inside so I decided to fill with foam and THEN go back and do fillets because once the foam was there the epoxy would have something to sit on top of. I had to put tape around the bottom of the tube to keep the desired diameter while the foam set up and didn't want it expanding the bottom and making it wider on the bottom than top. Well, it never occured to me (untill now) that when the foam expanded (when there was no fillets on the outside), that it would push the tube out (because there were no fillets to hold the airframe between the fins from getting "pushed out" some) and leave the rocket with a bump at the bottom. The pic attached isn't the best quality but you get the idea. So now, I will try to use a heat gun to get the foam sticky again and use a wooden dowel to pull/scrape the foam out. I hope that none of ya'll make the same mistake I did because it will be a pain to fix.

*sigh*Hopefully something good will have come out of this.*sigh*

 

[Neil]

Ouch... Ill remember to put the fillets on first from now on.....

 

[Ryan S.]

bummer dude, time to do some work. Something like this always happens to me, and eventually it results in the rocket being more strong.

Good luck!

 

[havoc821]

Anybody ever had problems with heat gun and phenolic tubing and plywood fins and LOC type tubing? You know, don't wanna catch my rocket on fire even though it is to the point where I want to because of frustration, but my rocket has to have some form of a booster section.

 

[havoc821]

Time to revive an old thread. I haven't done anything else to the rocket except for build a new altimeter mounting board. I haven't got around to using the heat gun to undo my mistake. Too much other stuff going on. I got this 45 page autobiography to do for Honors English and I have to do 2 pages a night. I was browsing Giant Leaps website other day and was looking at their motor selection. The J275W was $63.95 and the J540R was $75.95. I added weight to the rocket in rocksim to get an approxamite of the final weight of the rocket and re simmed it. The J275 would put the rocket at 2000' and the J540 would put it around 3500'! For only $10 more, I can get 1500 more feet and besides, Redlines are cool! I have included a more recent picture of the rocket with me and Chuck. The last picture was just me and the rocket and it was kinda blurry. The only bad thing about this picture is the red eye reduction thing didn't work and I look kinda weird with red eyes. Anyways, that's all for now. I will try the heat gun this weekend.

 

[slim_t]

Hey Chris,

Have you considered cutting off the damaged portion of the BT and starting over on that part, instead of trying to undo and repair it? I don't know how much you would have to cut off, but I think the rocket could stand to be a bit shorter anyway. Just an idea. If you could do that and still recover your motor mount and fins, it may be a bit easier. ????

Tim

 

[loopy]

Originally posted by slim_t
Hey Chris,

Have you considered cutting off the damaged portion of the BT and starting over on that part, instead of trying to undo and repair it? I don't know how much you would have to cut off, but I think the rocket could stand to be a bit shorter anyway. Just an idea. If you could do that and still recover your motor mount and fins, it may be a bit easier. ????

Tim

If you don't want to sacrifice the length, cut it off high enough that you could fit a coupler in there, and couple a new body tube with the new fin can. Could also set it up for dual deploy that way...

Loopy

 

[havoc821]

Can't cut off the bad part beacuse the WHOLE booster is filled with expanable foam, well, just between the centering rings, but that space is 2 ft long of expanable foam.

Loopy, The rocket is set up for dual deployment. Read back a page or two and you will see my altimiter bay stuff and etc.

I am trying to order fiberglass tonight, so I gotta go. Thanks for the suggestions, although they won't work, I am still very appreciative of comments!

 

[slim_t]

Originally posted by havoc821
Can't cut off the bad part beacuse the WHOLE booster is filled with expanable foam

Oh,
That's too bad.

Tim

 

[rocketkyle]

Hey Chris, is this thing done? have you flown it yet? Wow, you are one luck duck for getting all of those parts. I saw Chuck Andrus in Wendy's not too long ago with his work buddies. I haven't seen him on the field in a long time though...

Thanks,
Kyle