LOC-IV Build

Well, I received my LOC-IV kit last week, that I'll be using for my level 1 cert attempt. Overall, I'm pretty impressed with the LOC Precision kit. All components appear to be of very high quality. The 38mm motor mount tube is very hefty, and it came with 1/4" plywood centering rings. The fins are 1/8" plywood, and while I would have liked them to be a little thicker, they should be adequate. All wood parts are laser cut, and seem to be of high quality plywood. The fins are attached through the pre-slotted body tube, to the motor tube.

It's a very simple rocket, which I like. As with almost all of my builds, I started with the motor mount. I drilled a 1/4" hole in the upper centering ring for the eyebolt, and epoxied it to the tube. After the epoxy set, I installed the eyebolt and washers, and covered them with epoxy. I put heavy epoxy fillets on both sides of the centering ring.

I decided to put a simple ejection baffle in the forward end of the motor tube. I cut two "half moons" out of 1/8" plywood, and epoxied them in opposing directions, about an inch apart. I don't know if it's necessary, as I'll be using a Nomex chute protector. But it can't hurt, and might possibly help protect the laundry.

Using a dowel, I put epoxy inside the body tube and glued the motor mount in place. Using the same dowel, I applied a somewhat messy fillet around the centering ring. When I epoxied the motor mount into the body tube, I had the rear centering ring on the motor tube for alignment, but didn't epoxy it yet. That way I could remove it later to apply internal fillets to the fin tabs.

I used a length of 1" aluminum angle to draw the line for the rail buttons.

I also drilled the rear centering ring, and installed 6-32 tee nuts for motor retention. After pressing them in with a vise, I carefully covered the backs with epoxy so they wouldn't be inadvertently pushed out.

Here you can see the rear centering ring in place to make sure the motor tube stays aligned while I epoxied in the fins. I put a couple of long 6-32 screws into the tee nuts so I could pull the centering ring out later.

Using my handy dandy homemade fin alignment tool version 2, I epoxied the fins in place. I had sanded the fin areas on the body tube for better epoxy adhesion. I tell you, with through the wall fins, pre-slotted body tube, and the alignment tool, attaching the fins was a breeze.

After removing the centering ring, you can see the internal fin tab and motor tube structure. I applied fillets to all the tab to tube joints. The fins should be plenty strong, especially after the rear centering ring gets epoxied in. I used Titebond wood & trim glue for the external fillets, which are just for looks, in my opinion. The fin strength will come from the tabs and internal fillets.

I see you setup your fin alignment jig on your stove. There is no way you are married. :roll:

I can't say I've ever seen a jig like that before. Looks like it works well. Are those strings holding the BT on or something else?

-Dave

You're right, I'm not married. LOL

I use elastic to hold the body tubes on the guides. I tried rubber bands at first, but they're too "grippy". They didn't allow rotating the tube. The elastic works much better. Here are the threads on the two fin alignment guides I made:

https://www.rocketryforum.com/showthread.php?t=9694

https://www.rocketryforum.com/showthread.php?t=9859

How long is the motor tube, and did you take into account your longest casing when installing your baffle?

Build is looking great!

Pantherjon said:

How long is the motor tube, and did you take into account your longest casing when installing your baffle?

Build is looking great!

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Thanks for the compliment! The motor tube is 20", and I'll never use more than a three grain I motor in it. The Cesaroni three grain case is only 9.2" long.

qquake2k said:

I'll never use more than a three grain I motor in it.

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Famous last words!

Looks like a good build, did the eye bolt come in the kit?

5x7 said:

Famous last words!

Looks like a good build, did the eye bolt come in the kit?

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Yeah, I know! I should have said I'll PROBABLY never use bigger than an "I". But even a 6 grain case is only 16" long, so I should be covered. No, the kit didn't come with an eyebolt, I supplied that. It's a 1/4" x 2". The instructions say to use a loop of nylon cord and masking tape it to the inside of the body tube, then cover it with epoxy. That seemed pretty lame to me, so I went the eyebolt route, like I have on several of my mid power rockets.

Well, the fins are all done, and I epoxied in the rear centering ring. I also applied my signature messy fillets around the motor tube and body tube.

I just installed my first rail buttons. I feel like a big boy now, with my big boy rocket!

I measured carefully, and was able to drill into both centering rings. Of course, the 1/4" plywood centering rings made it a lot easier. I'll remove the buttons for painting, and when I reinstall them, I'll put a little epoxy in the screw holes. Now I have to epoxy the bulkhead into the payload coupler, and she'll be ready for paint.

The build looks great. I think I spoke to you on rocketry planet. Did you ever make it to Dairy Aire?

Dave

davalf said:

The build looks great. I think I spoke to you on rocketry planet. Did you ever make it to Dairy Aire?

Dave

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No, I never did make it to Dairy Aire. Did you go?

Yeah I made it. The weather was beautiful and there was actually a big turn out. More then I expected seeing that LDRS is so close. You should make the trip down one of these months. A lot of neat stuff flys there.

Dave

After putting a locknut on the eyebolt, I epoxied the bulkhead into the payload coupler. I sandwiched the eyebolt between two blocks hoping the bulkhead would set level, but it was slightly off. Not enough to matter, though. Once again, I applied my signature fillets.

Well, time for paint. I put a couple coats of white primer on the whole rocket. When it was dry, I started painting the fluorescent green. I'm not liking how the green is covering. It doesn't really show up in the photos, but it's splotchy. The fins aren't too bad, the nose cone is slightly worse, but the body tube is terrible.The rest of the rocket was going to be gloss black. My original idea was to put a green stripe towards the top of the body tube, but I just don't know now.

Here is a color test "swatch". The color on the right is key lime. I thought it might cover better and be almost as bright, but nope. It looks like puke in person! Another idea I had was metallic blue and silver, but I don't like the blue. I also thought about black and silver, but that's too common. I really like the black and fluorescent green together. I'm so indecisive!

Okay, here is the payload section painted black, with the fluorescent green nose cone. I really like the combination. I've noticed that fluorescent green parachutes show up really well in the sky and on the ground, and black rockets show up against clouds. I think I'll stick with this combination, and just get over the splotchy green. You won't be able to tell once it leaves the pad, anyway.

My LPRs are launched from at least 15 ft away. All I require on any rocket now is a 15ft paint job. If it looks good at 15ft. it's a good paint job. FWIW most of the guys I launch with don't even bother painting their rockets. I'm working on them though.

Yours is looking good.

qquake2k said:

I'll never use more than a three grain I motor in it.

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I certainly wouldn't either, or unless I was using electronics.

The last time I flew mine, I went with an AT I245G motor for the 38/360 case.

Man, did that thing bolt off the pad in a hurry!!!

Got it back with no problems even though it took a VERY long time to come back down.

Nice job on your build and this rocket will fly very nicely on any 38mm 1, 2 or 3 grain motor.

To date, I have flown mine on:

AT

G61W (landed hard due to tangled chute - broke a fin)
G67R (nice low flight and nice but smallish red flame)
H73J (nice smokey flight and nice 3 second burn motor)
H123W (nice loud, smokey and fiery flight - 2,000 feet or so)
H148R (same as H123W except red flame and a bit harder punch off the pad)
H242T (flown twice on this motor - screams off the pad)
I245G (REALLY screams on this motor - 3,000+ feet easily)

CTI

G69 Classic (nice low flight)
H153 Classic (nice flight to maybe 2,000 feet)

I'm starting to think I'm going to like the black and fluorescent green. Here is a shot with the payload section in place. Now for the masking.

When I masked the first fin, I thought it might be easier to use paper. But I decided just to use 2" masking tape on the other two fins. I sure like how that Rustoleum black covers.

Rustoleum black covers great. I especially like the high contrast paint jobs (like this one) as they seem to stick out on most any background be it snow, grass, dirt, etc. Throw in a florescent orange chute and that will stick out against everything.

Looking great.

I must say, this color combination is really growing on me. I'm thinking about putting a green stripe on the payload section. What do you guys think?

Here is a shot without the payload section. Not nearly as impressive without the extra length, but still a good looking rocket, if I do say so myself.

Very nice. I say fly it on the I800 Vmax.

cjl said:

Very nice. I say fly it on the I800 Vmax.

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Thanks! Actually, I already ordered my cert motor. An H143 Smoky Sam. I can't wait!

Once you get that cert, try it on a H123W. The White Lightning motors are great.

Looking good BTW!