Jason's Magnum Mini build thread

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J Blatz

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Hello all, and welcome to my build thread!

A couple years back I want bananas and bought about 150 very old rocket motors. In the pile were several 18mm AeroTech D8-12's and E25-10's and E25-12's. These motors are just so cute. The slip on AeroTech band and graphite nozzle really pull at me.

Anyhow, these motors are challenging to fly because the delays are really too long for most any application and probably aren't very accurate anyhow. So rather than risk a prang, and also to nerd harder, I am purpose building an airframe specifically to use these old motors (and it of course it can run modern motors as well).

The bones of this thing are a LOC Magnum Mini. It will have papered fins attached with wood glue, slightly upgraded recovery gear, and will ran a very old Adept ALTS1 altimeter for ejection. The payload section will be extended about an 1" to accommodate the ALTS1.

Here's most of the pieces:

Magnum1.JPG
 
Next I papered the fins. Basically, I took a sheet of make your own label sticky paper, peeled the backing off, and then laid the fins on the sticky side of said paper and pressed down to make a good fit. Then I used an X-acto to cut around the fin and free it from the waste paper. After both sides of were fin are done I used the barrel of the knife to smooth the edges a tiny bit.

Then I marked the body tube with supplied marking guide and lightly sanded the area where fins and launch lug will be attached. Next, I set up my super whizbang fin jig from BMI and also made shims to make sure that the fins would be right as these fins are 3/32" thick and the jig is built for 1/8" thick. Then apply glue to the root edges and on they go (one at a time of course). This goes quickly as there is no need to wait for the glue to dry since clamps hold the whole mess in place.

Tube3.JPG

Tube2.JPG

Tube1.JPG

Fins3.JPG

Fins2.JPG

Fins1.JPG
 
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Looks like fun. I like the papering of the fins...sure beats filling and sanding. Would love to see those old motors fly!

Derek
 
Yeah papering is quick and easy. Not as good as fill and finish, but hours less work.

I am planning to fly these under NARs expired motor program and get stills and videos to add to the thread. Though a D8 with classic propellant ain't gonna be much in the way of fire and smoke.
 
I can't recommend it to anyone buy being unemployed is conducive to both building rockets and day-drinking. I have been trying to emphasize the first.

So next a put a nice set of fillets on the fins. I like to use a 6CC loaded with my glue of choice, Titebond for this application. I run a fairly even bead, then smooth it with my finger. This technique works very well for anything LPR and many MPR applications as well.

Fillets.JPG
 
Next I modded the front centering ring by peeling away a small amount of the ring both inside and outside so that a piece of 50# aramid could loop around the CR. Then I wrapped the cord around said CR, tied a knot, and secured the knot with thin superglue. This isn't in the pics but I did also make a notch on the inside of both centering rings for the motor hook to pass through. Said motor hook has the front bent flat....I do not want the hook poking into the the motor tube because it would impinge on the ejection charge cap they use on RMS 18MM.

Motor mount then glued up with thick CA and front ring added as well, completing MM assembly.

MMT.JPG

Centeringting.JPG
 
Next up I started the payload section. I cut a piece of tubing with the same specs for ID/OD as the supplied payload bay but about 1.5" longer to accommodate the altimeter which was too long for the stock payload bay. Then I used the fin marking guide to mark locations for the three venting ports and also three holes for 4/40 machine screws to hold the NC on.

I cut bit of the bottom part of the base of the nosecone out to make sure that there will be plenty of room where the altimeter's harness connects to the altimeter. Then The nosecone was inserted into the payload tube and I drilled the three holes and then tapped the nosecone. I will be using low profile allen pinhead type screws cuz they look cool. Venting ports are quite large at .125" but they need to be that big if I ever use tape n tuck for altimeter arming.

The bulkhead plate on this model come with the smallest screw eye in the world to secure it to the shock cord. I don't like that, so I drilled four holes in the bulkhead plate - two for attaching a short length of 50# aramid and two for wire from altimeter to pass to ejection charge in the main airframe. Then I glued the bulkhead plate into the coupler, making sure once again to leave enough room for the altimeter.

Payload1.JPG

Payload2.JPG

Payload3.JPG
 
Hope the job situation resolves itself soon, Jason. Glad to see you making the best of it!
 
Wow.... that might be the last one I know about!!! Send us your address so we can also send you one of the new ones.... Might be able to skip some of the "mods" you're doing here... Or to jsut have an extra!!! =)
 
Wow.... that might be the last one I know about!!! Send us your address so we can also send you one of the new ones.... Might be able to skip some of the "mods" you're doing here... Or to jsut have an extra!!! =)
Nope, I got one still in the plastic box packaging, its in the build pile eventually. Love my Loc rockets (paper and wood rocks, the CherokeeD upscale in my avatar pic is built with Loc 5.38 airframe and a Loc 5.38 Long nose, with 98mm MMT, it is FG wrapped though instead of double tubed). Looking forward to building these two with my three kids.

Nice work so far!

EDIT:Actually I have Loc Magnum Mini and a Loc Ultimate Mini.
LocMinis1.jpg LocMinis2.jpg
 
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Looking Good Blatz. I built one back in 2011, it was a fun build.

LOC Mini-Magnum 015 small.jpg

I have the Hyper-LOC mini, and LOC-IV mini in the box that need to be built, but the news on the Rocketry Podcast is that they are coming back out with more, that sounds great!
 
Is this an offer for a free rocket:cool:?

Wow.... that might be the last one I know about!!! Send us your address so we can also send you one of the new ones.... Might be able to skip some of the "mods" you're doing here... Or to jsut have an extra!!! =)
 
Next I put the Aramid lines through the holes in the bulkhead to form a bridle.

Then I married the elastic cord to the Aramid line that I had connected to the motor mount.

Can't forget launch lugs. I cut the provided lug in two parts and cut the leading and trailing edges into a streamlined 45 degree angle, since this is a super hi-performance composite motor powered machine. I used two or there passes of white glue to make a smooth joint here.

And then of course it was time to glue the MMT into body of the rocket. I used white glue because it is less grabby than wood glue. I like to put a removable weight on the end of the cord so it doesn't get caught up in the glue when I insert the mount.

And here's a picture of the rocket with some of the motors I want to fly in it and the ALT S1. Not a lot of extra space in this thing.

FinishedMMT.JPG

LLugs.JPG

GluingMMT.JPG

Dryfit.JPG
 
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LOVE my LOC minis! I added a little nose weight - one came with a warning slip not to build it with the payload bay due to stability problems so I figured nose weight would help. One is a Magnum the other a Hyper LOC. Both fly great on BP motors so I can’t wait to see how yours does on those old Aerotech 18mm!

Other than the plywood fins are ther other major differences between the old LOC Minis and the new LOC 1s?
 
Yeah. Behold the mighty AeroTech D8. It's like 14 Ns of pre White Lightning glory. Check out the hand made graphite nozzle.

Takes a very, very small "starter".

D8A.jpg

D8B.jpg
 
Next up I started the payload section. I cut a piece of tubing with the same specs for ID/OD as the supplied payload bay but about 1.5" longer to accommodate the altimeter which was too long for the stock payload bay. Then I used the fin marking guide to mark locations for the three venting ports and also three holes for 4/40 machine screws to hold the NC on.

I cut bit of the bottom part of the base of the nosecone out to make sure that there will be plenty of room where the altimeter's harness connects to the altimeter. Then The nosecone was inserted into the payload tube and I drilled the three holes and then tapped the nosecone. I will be using low profile allen pinhead type screws cuz they look cool. Venting ports are quite large at .125" but they need to be that big if I ever use tape n tuck for altimeter arming.

The bulkhead plate on this model come with the smallest screw eye in the world to secure it to the shock cord. I don't like that, so I drilled four holes in the bulkhead plate - two for attaching a short length of 50# aramid and two for wire from altimeter to pass to ejection charge in the main airframe. Then I glued the bulkhead plate into the coupler, making sure once again to leave enough room for the altimeter.

I LOVE Baffles! Guess what I'm putting in the NEXT round!!! Thanks for the inspiration!
 
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