LOC Precision Mega Magg build – Session One – Dec 2018

Last night wound up being a productive night.

I got a ping from one of our colleagues on Facebook Messenger.  He had some questions on the LOC Mega Magg which was on sale from AMW for a ridiculous price.  Anyone who has ordered large kit from a LOC dealer has probably seen that LOC drop ships these rockets to YOU directly.  In this case, LOC did exactly that.  Here is a LOC Precision Mega Magg in dry fit mode!

LOC Precision Mega Magg dry fit!

I got my kit a couple of weeks ago.  I usually post something on Instagram when I get them because I’m a grown child and need to tell everyone.

In helping out our friend, I started sorting through the parts and finally got to the point where I wanted to “dry fit” the kit, which all of us have done with large rockets.  Basically putting it together without glue to see how it all fits, etc… Well in this case, I had to do some sanding and even some cutting.

12/122/18 - LOC Mega Magg build
12/122/18 – LOC Mega Magg build

One of the first things I like to do is set out all the goods and make sure I have the proper inventory.  In this case, I have MORE than the normal inventory.

This kit has the new Loc-N-Fin system.  It ALSO, includes the MMAS system.  It ALSO has the RNWS.  I totally was expecting the previous version without all the new bells and whistles.

Let’s talk about this.

First the Loc-N-Fin system is a new way that Dave and Jason, the current owners of LOC, are doing the motor mounts to the fins assembly.  Basically, they slot the Centering Rings (such as North Coast Rocketry and Estes have done in the past) so that the fin fits INTO it.  Why is this important, well, if assembled correctly, your fins will ALWAYS be straight.  I like to think of it as having a build in fin jig.  In order to fly straight and true, you need to have the fins perfectly straight.  I personally don’t use a fin jig.  Mainly as I don’t want to spend the time to make one or pay for one.

LOC-N-Fin system for 5.5" Motor Mount Assembly

The packaged includes the forward ring, middle and after ring.  The four holes on the forward ring allow for your U-bolt connections for your recovery.  The middle ring only has three slots on it, for the three fins that will sandwich between itself and the aft centering ring.  The aft ring has the three slots/tabs as well as the holes that the motor mount Z-clips will attach to.  Those are help in place with the T-nuts, which i’ll talk about later.

Directly related to this system is the main Motor Mount Tube that will be used for this build. The pictures below show what I’m talking about.

Pic on the left, shows the large 5.5″ main motor tube.  Now… no actual motor fits in this.  Its a “housing” for the various modular MMAS (Motor Mount Adapter System) motors to fit, including 98mm, 75mm, and the kits included 54mm assemblies.  The 98mm and 75mm are available separately from LOC, however, more advanced building for those would be required to make those work adequately without shredding in flight.  Picture number 2 shows the aft end of the dry fit, showing how the fins fit in the tabs.  Picture number 3 on the right shows the Centering Rings compared to the forward ring.  Its upside down, but hopefully you “get” the picture.

MMAS LOC Step 1 Instructions
MMAS LOC Step 1 Instructions

For these purposes, this “motor tube housing” to be able to adhere the fins to instead of using the old LOC way which had tabs that get epoxied to the internal main body tube wall holding the fins in place.  This newer method adds weight to the rocket, but eliminates the need for a HUGE fin tab.  To be frank, this way seems better simply as you can build epoxy walls between the Centering Rings to do the mount. See the example below from the LOC Goblin provided from Jason at LOC.

I’ve been using this picture for explanation purposes on other social media sites as well as my last blog post to show HOW this would mount to the motor tube assembly.  As you can see, if you flood the two fins together with epoxy, those fins are going nowhere.  Anyway… moving on…

So what the hell is the MMAS.  Well, like I sort of described earlier, it stands for modular Motor Mount Adapter System.  Its exactly that.  More than just a motor mount adapter, it allows ONE rocket to fit several types of motor mounts.  You’ll see this commonly on a 4″ LOC Goblin.  Here is some more information on the MMAS system.

5.5" Thick Motor Wall tube for LOC kits.

Along the same lines for the main motor tube assembly, you can see that I started to SAND the tube.  Why? Well, this removed the Glassine from the tube, allowing epoxy (or your favorite glue) to the paper of the tube instead of the outer stuff used for ease of paint, etc.  If you look at the instructions from LOC (below), Step 2 tells you to tear off the glassine.

MMAS LOC Step 2 Instructions

I usually like to adhere to instructions as much as possible, but for these purposes, I just sanded down the tube, as when I tried to peel it (from my LOC VII) I peeled WAY too much and now I’m going to need to order a new 5.5″ tube or repair it as I ruined the original integrity of the tube.  I’ll talk about that in my LOC VII post.

Mega Magg 54mm Motor Adapter for MMAS
Mega Magg 54mm Motor Adapter for MMAS

The next thing I want to talk about is the Motor Mount Adapter.  This particular one is a 54mm mount, which is great for I and J motors.  The original Mega Magg came with this as the main motor tube.  If you note the bottom main ring, attaches to the MMAS bottom centering ring with T-nuts and #8 screws.

Here is an example from the same link for the LOC MMAS page:

LOC Precision MMAS

This gives a better idea of HOW this should mount in your assembly.

The LAST thing I want to talk about is the RNWS (Removable Nose Weight System)

12/122/18 - LOC Mega Magg build
12/122/18 – LOC Mega Magg build

Top left of the picture, you’ll see the nose cone with a ton of other stuff around it.  This contains a cartridge that you build and epoxy into the nose cone which allows you to make a weighted tube which will move your CG to a preferred stable path for the forward end of the rocket.  Here is more information for this from LOC.

So… here is the kick for this kit.  LOC sells it on their website for only $225 plus shipping at the time of this writing.  This nose cone is almost half that alone, along with the Loc-N-Fin, MMAS, and RNWS, this becomes a GREAT value.  I feel its priced accordingly and you should buy one! Who doesn’t love a short huge fat rocket?


Click the link above to do so!

So in helping a friend who bought one around the same time I did, as well as going through the parts and feeling overwhelmed at how much this rocket contained, I’m super excited to carry on.

I pulled out my Drill Master palm sander from Harbor Freight (approx $18) and went to town on the 3/16″ 7 layered ply fins that were router cut for this beast.  Also a great value if you ask me.  The wood is supplied from a local provider for LOC and is a high grade quality.  It requires light filling and is pretty easy to handle.  I rounded the leading edge on all three fins.

For the bottom of the fins, I also just slightly rounded the trailing and aft edge.  They look good.

Everything is sanded to fit, and is ready to get epoxy applied!

LOC Mega Magg build - Session 1
LOC Mega Magg build – Session One

Follow me on Facebook, Twitter and Instagram @modelrocketguy to see where I end up with this.

Please feel free to message, email, comment, whatever.  I welcome both any feedback, both positive or negative.  It’s how we learn!



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