Rocket 2 XXL, HPR lvl 1 cert rocket

[Hobie1dog]

I use a Rustoleum paint and primer 2 in 1, which I have in black and white. And semi gloss white and orange. And then Krylon black paint and primer, but I’ll probably buy Rustoleum instead, since krylon is just not great.

I bought some of the Rust-Oleum 2X semi-gloss White the last time I was at Ace Hardware and I used it on my restoration of my Delta 2 rocket and it was rather impressive for a rattle can. I'm going to be spraying hopefully on Wednesday when it gets warmer and as soon as I get the primer on that I will probably be using more of that semi-gloss White on two other Rockets.

 

[Voyhager3]

I have made the only semi thought out decision to make the mmt 20 inches, leaving only 4 inches (16pi cubic inches) of space. This may not be a lot, but I saved a 6ish inch section of the BT and will make it into a removable section incase things don’t fit. Creating the R-2 XXL Ext.

 

[Voyhager3]

For nose weight I can just use metal bbs with epoxy resin poured over it, right?
or will the heat cause problems? (using slow cure total boat)

 

[jmasterj]

For nose weight I can just use metal bbs with epoxy resin poured over it, right?
or will the heat cause problems? (using slow cure total boat)

That's the usual way. Usually something for the epoxy to stick to besides the plastic is also important - you can put a couple screws into the nose cone or drill a couple holes on opposite sides and put a small dowel through, then cut it flush to the outside.

If it starts feeling hot put it in some water.

 

[Voyhager3]

That's the usual way. Usually something for the epoxy to stick to besides the plastic is also important - you can put a couple screws into the nose cone or drill a couple holes on opposite sides and put a small dowel through, then cut it flush to the outside.

If it starts feeling hot put it in some water.

I guess that is what those circle markings on the NC are for

 

[Voyhager3]

MMT in, and fins tacked in with CA, fillets tomorrow hopefully…

The fins may not be perfectly aligned, but it’ll probably be fine…hopefully

 

[jmasterj]

MMT in, and fins tacked in with CA, fillets tomorrow hopefully…

View attachment 562438View attachment 562439The fins may not be perfectly aligned, but it’ll probably be fine…hopefully

If you tacked them in with CA, why not break them off and fix the alignment?

 

[Voyhager3]

If you tacked them in with CA, why not break them off and fix the alignment?

I tried to fix the allignment already, I got 2 perfectly aligned, but that last one was being problematic. It’s like 1.5 degrees off, but I might try again later, before I epoxy and whatnot

 

[Voyhager3]

So it turns out superglue is quite strong, so I will settle for this
The other 2 fins are aligned,

 

[tsmith1315]

The other 2 fins are aligned,

As long as it’s straight longitudinally, flight won’t be affected.

 

[Voyhager3]

Internal fillets done!
Now it’s time for the external

 

[bobbyg23]

MMT in, and fins tacked in with CA, fillets tomorrow hopefully…

View attachment 562438View attachment 562439The fins may not be perfectly aligned, but it’ll probably be fine…hopefully

Looks good to me.

 

[Voyhager3]

These abouta be some big ol fillets
Update, I’m making them smaller

 

[Voyhager3]

It went mostly well, a few areas that will need a bit of sanding, and especially the leading area, but that’s tomorrows problem…

 

[Voyhager3]

Fillets have been sanded to the point of “good enough”!
I’ll get the nose weight done this afternoon I think, and start paint too

 

[Voyhager3]

I got these expanding rail buttons, that I guess expand when tightened down, but should I use epoxy to be extra sure?
I would assume yes, but I just want to be sure

 

[Voyhager3]

Also, you would say these are stong enough, right?

 

[jmasterj]

Also, you would say these are stong enough, right?
View attachment 562848

Waaaaaay overkill. That weight rating is a working load limit, which you multiply by 4 or 5 to get the breaking strength. I would wager nothing else in your recovery chain gets close to 6000lb breaking strength. Even 3/16 quick links are generally stronger than you need for a 4" cardboard rocket.

 

[Voyhager3]

Waaaaaay overkill. That weight rating is a working load limit, which you multiply by 4 or 5 to get the breaking strength. I would wager nothing else in your recovery chain gets close to 6000lb breaking strength. Even 3/16 quick links are generally stronger than you need for a 4" cardboard rocket.

Well that’s good to know!
But it rarely hurts to be overkill! Especially for a cert rocket

 

[bobbyg23]

Well that’s good to know!
But it rarely hurts to be overkill! Especially for a cert rocket

In this case it can get in the way of the important stuff during ejection.

 

[Voyhager3]

I'm going to be cutting it close with the painting, with the final painting scheduled for Thursday/Friday, and flying on Sunday. The spirals are not well done, but ill fix them after as i'm not doing the L1 until April (if our launch gets pushed back a weekend, i.e. rain) or May (might not even be flying in may, i.e. crops). I don't need the spirals to be perfect, but I mean they are really deep.

 

[David_Stack]

I got these expanding rail buttons, that I guess expand when tightened down, but should I use epoxy to be extra sure?
I would assume yes, but I just want to be sure

The actual rail button itself should not be tightened down to the point that it deforms.

Without seeing the actual buttons you are using, most are either affixed with a screw that is threaded into the airframe/supporting material inside (e.g. centering ring or wood 'hard point') or the builder installs a T-nut inside the airframe that a machine screw through the rail button screws into.

There have been threads here in the forum discussing whether thread-locker is needed to secure the screw to the airframe.

 

[Voyhager3]

The actual rail button itself should not be tightened down to the point that it deforms.

Without seeing the actual buttons you are using, most are either affixed with a screw that is threaded into the airframe/supporting material inside (e.g. centering ring or wood 'hard point') or the builder installs a T-nut inside the airframe that a machine screw through the rail button screws into.

There have been threads here in the forum discussing whether thread-locker is needed to secure the screw to the airframe.

I'll add a picture of them when I get home, but its the 10/10 rb kit, with the expansion plugs, https://performancehobbies.com/secure/store.aspx?groupid=8302004132588
so that's why I said they would deform, and that's what ken told me

 

[Voyhager3]

It has flown, a bit sketchy but it was fine.


It was on a G74-4

 

[Hobie1dog]

It has flown, a bit sketchy but it was fine.


It was on a G74-4

That is begging for a J motor.

 

[Voyhager3]

That is begging for a J motor.

I’d need to set up some dual deploy or a chute release, but that is intriguing…

 

[Hobie1dog]

I’d need to set up some dual deploy or a chute release, but that is intriguing…

hundreds of rockets are shot off with J Motors with single deploy

 

[Voyhager3]

Got my self an H-motor!...Kinda.
I decided to go the reload route as my vendor had a few H reloads and a used 38/240 case so I decided to pick up that used case and a H123 from AT (well I'll technically wont buy them until the 19th). I've never even flown a reload before so I guess it'll be interesting. But I've heard its not that hard, so hopefully I don't mess up... But I'm still not flying it for 2+ months, but I'd rather have it than not.

 

[Voyhager3]

I have done some thinking (which is dangerous, I know). I was going to build another hpr rocket this season out of some 3inch parts I had, with the goal of having electronics and whatever, but looking at how much it was gonna cost me I kinda started to feel like it was gonna be expensive, especially because I wanted to get my L2 with it this summer on a J in Dalzell. But a few minutes ago I was thinking then I though of Marty saying:

That is begging for a J motor.

and was like, you know what, let me set up some dual deploy and go for it, maybe even do my L1 with the dual deploy, but just single deploy at apogee to be safe plus motor redundancy. I know some people think using the same rocket for your L1+L2 isn't the right thing to do as you don't build enough skill, which I do see where that is coming from. However, I am on a budget, going off to college in the fall for aerospace engineering, so I want get this stuff as it would definitely mean a lot to me.
I might have a way to get a DD altimeter on the cheap with some negotiating, but I'm not going to say whos selling it as I really don't want attention to be brought to the listing and have it "stolen" from me. But i'll probably PM them in a bit about it.
But below is what I drew up for the modifactions.

This config. has the J270 DMS loaded, with a LOC ebay, and a 17" extension. I actually have both parachutes already so that is a bonus. It would be about a $60 upgrade (not include alt.), which is defiantly cheaper than $120, and it wouldn't go as high, which is even better. I haven't decided on going dms or rms, since id already have the closures, and ken has a 720 n/s case that is used. But I haven't decided about that just yet. My only problem with going dual deploy is getting BP for L1 (L2 wouldn't be a problem), but I guess I could run and get it right before.

 

[Hobie1dog]

This config. has the J270 DMS loaded, with a LOC ebay, and a 17" extension. My only problem with going dual deploy is getting BP for L1 (L2 wouldn't be a problem), but I guess I could run and get it right before.

Do what is necessary on your limited budget, forget what the well-to-do/purist say. Ken has old 35mm film canisters he sells cheap with BP in them.