# LOC Magnum Build

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#### davalf

##### Well-Known Member
Well, I am not actually going to start building until next week or the week after, but I am bored so I thought I would get this started.

I have gotten most of the parts that I need. Hopefully, next week I will be ordering the fiberglass and epoxy. Once that arrives I will begin. During this thread please feel free to comment and give advice. I will be doing a lot of learning along the way.

The rocket has a central 54mm motor mount along with 2 29's. I will be placing a timer (Xavien XSSET-1) in the booster section just above the fins for air starts. I have yet to decide what altimeter I will use, but the rocket will be dual deploy capable, eventually. I will be using this for my level 2 so I won't setup DD until after.

I was planning on launching it during Dairy Aires in May, but I think it will be done long before then and I won't be able to wait. We will see.

Thanks,
Dave

#### Chuck Taylor

##### Well-Known Member
You'll have it done before the next launch!! See you then.

Patrick

#### ONAWHIM

##### Well-Known Member
Dave,
Is this your first LOC kit?

What was your initial impression on the kit when you opened it?
I have a LOC V2 (3.9) ordered and on its way.

Keep them posts coming.

Wm.

#### Handeman

##### Well-Known Member
TRF Supporter
The rocket has a central 54mm motor mount along with 2 29's. I will be placing a timer (Xavien XSSET-1) in the booster section just above the fins for air starts. I have yet to decide what altimeter I will use, but the rocket will be dual deploy capable, eventually. I will be using this for my level 2 so I won't setup DD until after.
Why wait on the dual deploy? It is not difficult and I found I actually prefer the dual deploy to motor eject. It deploys at apogee instead of where ever the motor charge goes off. I think you would have a better chance of a successful L2 with the dual deploy then without. Much less chance of a zipper or deployment damage to the rocket. Besides, you could fly a bigger motor

When you start using DD, do a lot of ground testing. I prepped everything like it was flight ready, taped off the av-bay ports, attached tubing to the last port and used that to draw a vacuum on the av-bay (suck on the tube really hard!) This simulates the flight, makes the altimeter operated the same as it does during flight, tests your ematches/xmas bulbs/glow plugs along with ejections charge sizes. By the time you are finished with the testing and are satified with the sizes of your charges and what is firing them, you should have no issues with using the altimeter.

If you want, do a flight on an I284W. That would be a great motor for that rocket, about 1,700 and you'll get to watch the whole deployment sequence. When you get all done with that, slap a K695R or similar motor in and go for the L2!

Good Luck

#### davalf

##### Well-Known Member
ONAWHIM, This is my first LOC kit. So far I am very happy with it. I special ordered it with an extra centering ring and long 29 tubes. The bulk plate was missing in the order, but a quick e-mail and they arrived about a week or so later. Barry at LOC Precision was very helpful and quick to reply. I would definitely recommend them.

Handeman: The reason I am waiting on dual deploy is simply money. Altimeters are expensive and I am thinking I want to run two. I will have most of the alt. bay built and will just have to add the electronics when the money allows.

Patrick: I do not know that it will be ready by next launch, that would be nice, but I am going to take my time on this one. Thanks again for all the help on Saturday, and I will be using your method for installing the bulk plate in the nose cone.

Dave

#### davalf

A quick little update. Went into to town and did some shopping. I picked up some t-nuts, terminal, all thread, screws, nuts, and some other hardware. Ordered my fiberglass and epoxy from Soler Composites. They were nice and very helpful. I also ordered a few more things from Jack at Whats Up Hobbies. And as always he is glad to help. As of right now I think I am into this rocket for about $450. Whew, the price of love. Tomorrow I plan on doing a little sanding and prepping for the build. I do have a question though. I am planning on cutting about an inch section of the body tube to place on the coupler for the AV bay. What is the best way to do this and do I do it before or after the fiberglass? Thanks Dave #### 5x7 ##### Well-Known Member Have you considered arming your electronics through the altimeter breathing holes? You will save cutting the tube and remove a failure point (the extra joint). A quick little update. Went into to town and did some shopping. I picked up some t-nuts, terminal, all thread, screws, nuts, and some other hardware. Ordered my fiberglass and epoxy from Soler Composites. They were nice and very helpful. I also ordered a few more things from Jack at Whats Up Hobbies. And as always he is glad to help. As of right now I think I am into this rocket for about$450. Whew, the price of love. Tomorrow I plan on doing a little sanding and prepping for the build.

I do have a question though. I am planning on cutting about an inch section of the body tube to place on the coupler for the AV bay. What is the best way to do this and do I do it before or after the fiberglass?

Thanks
Dave

#### blackjack2564

##### Crazy Jim's Gone Banana's
TRF Supporter
Have you considered arming your electronics through the altimeter breathing holes? You will save cutting the tube and remove a failure point (the extra joint).
Yep that's how I've been doing mine for years. Saves having to cut and leaves more coupler to go into the tubes for strength.

Drill hole right on airframe joint, half hole on each side. You don't have to do all the vents this way, just one for the wire.

On the large 7.5 tube there are 3 more on joint, not visible. On the small rocket 1 on the joint and 2 more smaller vents in the payload section of bay.

You can mount switches this way if you use them.

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#### Bill P

##### Well-Known Member
Yep that's how I've been doing mine for years. Saves having to cut and leaves more coupler to go into the tubes for strength.

Drill hole right on airframe joint, half hole on each side. You don't have to do all the vents this way, just one for the wire.

On the large 7.5 tube there are 3 more on joint, not visible. On the small rocket 1 on the joint and 2 more smaller vents in the payload section of bay.

You can mount switches this way if you use them.
This is the method I've been using. It works quite well.

#### davalf

##### Well-Known Member
Thank you guys for the advice but I think I will go with the method I had mentioned. It seems easiest to set the rocket it up for flight. And, if I understand you correctly, the two methods are the same except I have a spacer on my coupler and you do not.

So, what is the best way of cutting an airframe and do I do it before or after fiberglass. I am thinking after.

Well, last night I couldn't sleep so I did what any normal man does. I got up and sanded my rocket. For you dirty minds out there, it is not what you think. I sanded the fin slots and 3 centering rings. Then I did a dry fit. I really like the size and look of this rocket. Again, keep your minds out of the gutter.

Dave

#### green dragon

##### Well-Known Member
First off - great choice for both L2 and your first LOC kit.

Attempted my L1 with my own Magnum but an electronics glitch prevented same so went with backup 4" bird.

What I would comment on is the 'need' for glassing it - this, especially with the third centering ring , will hold up to miost any sane motor without glassing it . so if you;re glassing for cosmetics, go for it , but not needed for strength .

my dead stock ,except for altimeter bay ( ie: 2 centering rings, 8" 29mm tubes, no glass ) , Magnum has survived J1500, K1000,J800,J700, and on and on ....

build the e-bay your way, I prefer the old school remobvable bulkhead plate style, other prefer the short section of tube you mention - my only comment there, is why could that section not be part of ( ie: permanently attatched to ) the payload section ? then no cutting would be needed.

question on the Magnum - is this the short 17" payload bay version ? I can say from mine that a rocketman R9 chute fits, with a lot of 1" tubular, but it's tight - the 23" payload section,as used in the Magnum 3 as well as older short nosecone versions, makes for more room for recovery gear.

keep the review coming, as I love this biord, and need inspiration to get my minor repairs done on mine by spring

~ AL

#### blackjack2564

##### Crazy Jim's Gone Banana's
TRF Supporter
So, what is the best way of cutting an airframe and do I do it before or after fiberglass. I am thinking after.

Dave

View attachment 17877
It depends.If you are just going to cut a 2in section off. After.

I always cut my fin slots before. Then cut the glass out of them when it reaches the leathery stage. You can use a box cutter or x-acto then. If you wait till full, it's a bear.

To cut large tubes I use a 10in power miter box. Radial arm saw or even table saw with a stop block. What ever you cut with, feed slow and evenly to get a clean edge. If you use a table saw just expose enough of the blade to cut the tube. The finer the blade, the better the cut.

#### davalf

##### Well-Known Member
What I would comment on is the 'need' for glassing it - this, especially with the third centering ring , will hold up to miost any sane motor without glassing it . so if you;re glassing for cosmetics, go for it , but not needed for strength .

~ AL
When I certed level 1 my rocket landed on a dirt road and put a dent on the top of the booster section. So I am glassing to prevent similar things from happening with this rocket.

Dave

#### davalf

##### Well-Known Member
A quick little update. I am still waiting on the fiberglass and epoxy from Solar Composites. The UPS website says it will be here the 9th. Unfortunately I will be playing Mr. Mom because my wife will be out of town. So no building until after all that. My debit card has been getting a lot of use though. Today I broke down and ordered a PerfectFlite Mini Alt. I also received the parachute from rocketman, and the Avbay components from Whats Up Hobbies. I do not want to even think of the total cost of this rocket considering I haven't even started construction. I think I have all the components or they are at least on there way.

Thanks
Dave

#### davalf

##### Well-Known Member
Finally, I was able to start construction today. I spent a good 4 hours in the shop today and got the main body tubes fiberglassed. This is only my second time fiberglassing but the first in about 10 years. It was also my first time using a sleeve. And now I will use them on every build that I am fiberglassing.

After I got those all glassed up I focused on motor retention and getting all the holes drilled through the centering rings. For motor retention, I am using a t-nut with a bolt and washer. Pretty simple, and I think it was worth \$90 in savings if I was going to use aeropak retainers. They are nice, but expensive.

#### davalf

##### Well-Known Member
Next, I started my timer sled. My timer will be mounted in between the middle and fwd centering rings. It will be similar to an altimeter bay in that I am using all thread to mount it. I had ordered some of the electronics mounting hardware from PerfectFlite for the timer. The threads were a little to short so I had to sorta countersink them. Sorry if they a little blurry.

I then mounted a small row of terminals to the bottom. I will actually use these to connect the igniters. The timer can only be mounted in one direction. That is with the output on the top and the power inlet on the bottom. These seems to be a little backwards but it will work.

This is just a quick dry fit of how the timer sled will be mounted. This will be accessed through a hatch. I have not yet figured out how I will be cutting the hatch out yet. Any suggestions?

Until next time.

#### Chuck Taylor

##### Well-Known Member
Looking good Dave!!! Can't wait to see it fly.

Patrick

#### stickershock23

##### Never Fly Naked
Very Nice Dave. Keep it going!

#### ONAWHIM

##### Well-Known Member
...not yet figured out how I will be cutting the hatch out yet.
Dave,
PM sent.

You may wish to check out Modern High-Power Rocketry 2.
There is a section on hatch accessed electronics.

I think it refers to non-sled type of bay but it may provide ideas for adapting to your needs.

Wm.

#### davalf

##### Well-Known Member
Monday allowed me to spend more time on the project. Today was the first day I was able to see my fiberglassed tubes all cured. I must say, there is a real satisfaction to that end result.

Today: I got the motor mount assembled and centering rings epoxied in place. I did not epoxy the top centering ring yet. Once the motor mount is epoxied into the rocket, I will remove the top ring and slide a coupler down to meet the middle ring. This will give me a place to mount the hatch. I also fiberglassed the inside of the coupler, which was a real pain in the ass. I have seen how some have used balloons inflated to hold the glass in place, which if I had some, I think would have been real helpful. But, it all worked out.

Until tomorrow,
Dave

#### mgarrett

##### New Member
Dave - It's looking good! And it motivates me to get moving on my Mad Dog DD.

So, you think sleeves are pretty slick for glassing tubes? I have been thinking about glassing the Weasel 38 I got at Ocober Skies. I've never really glassed anything except small hole patches on a boat deck. I have a vacuum press that should make bagging fins easy.

MG

My life summarized - Too many projects, not enough time or money ...

#### davalf

##### Well-Known Member
Mike,

In my opinion the sleeves are awesome. I did not have a single bubble in either tube. After I was done glassing I gave Patrick a call and he gave me some advice on how to keep the sleeve tight. He said tuck the excess fiberglass into the rocket and then pound a centering ring to pull on it. I will use this next time.

Dave

#### DMehalko

##### Well-Known Member
What is the point to the threaded rod in the motor mount? excuse my ignorance

#### davalf

##### Well-Known Member
What is the point to the threaded rod in the motor mount? excuse my ignorance
The all thread is what I will be mounting the timer sled to. It really just seemed the easiest way to do it.

Dave

#### new2hpr

##### Well-Known Member
Is the timer sled going to be removable or ? I also questioned the allthread. I ended up just epoxying the sled to the fore-most centering ring and the central motor tube. Much less weight and hassle that way. Plenty secure.

BTW, the hatch as described in Modern High Power Rocketry is simple and works well. Carefully cut out your hatch (save the piece), then slide in a coupler and draw the outline of the hole. Offset that inward by a half inch on all sides and cut the smaller rectangle out of the coupler. Epoxy in the coupler, using the markings to center it in the hatch hole. Epoxy the remaining rectangle of coupler to that of the airframe. Drill rivet holes in the 4 corners and you're done.
-Ken

#### davalf

##### Well-Known Member
Thank you new2hpr for the advice. As for the hatch I am doing what you had mentioned. Like I said previously, I think the all thread is the easiest. I do not think the weight added is significant and I do not plan on breaking any altitude records with this rocket.

Today I got a little bit done on the rocket. I attached the fins to the motor mount. I do not have any jigs for fin alignment, so I place the motor mount into the rocket and place epoxy on the bottom of the fin and slid it in. I let the fin cure and moved on to the next. I then removed the motor mount with the fins attached to add fillets.

The part I have been dreading doing on this rocket was the hatch. I had no idea what to use to cut it. Mark from stickershock had told me that he used a dremel, so I did the same. First I took a piece of paper and folded it down to the size I wanted it and taped it to the body. I then traced the outline and removed the paper.

Following Marks advice, I went and bought a dremel blade that looks like a tiny table saw blade. It wasn't to bad to cut it out. It didn't come out as perfect as I wanted, but it came out pretty good.

I still have a few more fillets to add to the fins and then the motor mount will be installed into the rocket. After that, the major construction will be complete.

Dave

#### davalf

##### Well-Known Member
First off, I am pretty bummed out. My work just called, I have to go into work tomorrow, and since I work a 48hr shift, I do not get to go to the launch on Saturday. In a glass half full way of thinking, I get to save a little money.

With all that said, I did get some work done today. I added a couple more fillets. Inside the shop, the epoxy was taking forever to cure, so I placed the whole assembly outside.

I also fiberglassed the inside of my avbay coupler. Not the best job in the world but it will work just fine.

I then cut the base off of my nose cone. The bulk plate will be removable so I can adjust the amount of nose weight I have in there.

And then lastly, I did a little wiring on the timer bay sled. Nothing real fancy, but it will help the ease of setup for flight.

I probably will not get anything more done until Sunday.

Dave

#### new2hpr

##### Well-Known Member
Looking good, Dave.

Before you get to the point of putting the fincan into the airframe, don't forget to run your conduits for your airstart wires. I used carbon tubing from a kite shop, but aluminum could work, or archery shafts.

Just pop them through your bulkheads and epoxy in place. Put them where you can reach (through your hatch) the ematch leads with your fingers or long-nose pliers. My first rev. had 6 airstarts, so lots of wires to fish. I revised to 3 larger ones later and with much better success.

-Ken

#### davalf

##### Well-Known Member
Looking good, Dave.

Before you get to the point of putting the fincan into the airframe, don't forget to run your conduits for your airstart wires. I used carbon tubing from a kite shop, but aluminum could work, or archery shafts.

Just pop them through your bulkheads and epoxy in place. Put them where you can reach (through your hatch) the ematch leads with your fingers or long-nose pliers. My first rev. had 6 airstarts, so lots of wires to fish. I revised to 3 larger ones later and with much better success.

-Ken
Thanks for the heads up Ken. I already installed a copper tube to run the igniter wires through. You can see it on one of the pics of the fin can. Do you have any build threads of your rockets that are air start capable?

Dave

#### Chuck Taylor

##### Well-Known Member
First off, I am pretty bummed out. My work just called, I have to go into work tomorrow, and since I work a 48hr shift, I do not get to go to the launch on Saturday. In a glass half full way of thinking, I get to save a little money.
The build looks great Dave!!! Too bad you are going to miss this month's launch. Are you going to have the Magnum done for next month's launch?

See you next month.

Patrick