Modification Meanie w/Quick Change Motor Mount Modification

Modification - Meanie w/Quick Change Motor Mount

Contributed by Nick Esselman

Manufacturer: Modification

Rocket PicI had t' idea one day t' make a switchable motor mount so that I could fly a rocket on various motor sizes and configurations. Begad! Blimey! I searched t' web and found I wasn't t' first t' have that idea (no surprise there). Then I connected with Mark over at True Modeler Rocket Kits. Begad! Blimey! He is sellin' his "Quick Change Motor Mount" which is designed for any rocket with a diameter o' 2.6" or larger. Avast, me proud beauty! Blimey! Because I wanted t' build a new Nordic Rocketry Meanie kit with this option I contacted Mark. Avast! Blimey! Ya scallywag! Blimey! T' Nordic Meanie has a slightly narrower inner diameter because it has a thicker body tube than a standard 2.6" kit. Well, blow me down! Blimey! But Mark customized t' Motor Mount for me. This also only allowed me t' get three (3) configurations; a 3 x18mm, ya bilge rat, a 1 x 24mm and a 1 x 29mm. Blimey! Blimey! T' 1 x 29mm was special also due t' t' short space requirements, shiver me timbers, it is only designed t' handle EconoJet F motors.

CONSTRUCTION:

Construction o' t' Nordic kit went as described in its instructions and builds nicely. You can see me previous review here. Aye aye! Nordic had changed two things since I had purchased me first kit. Blimey! Avast, arrr, me proud beauty! First they now add a piece o' Keelhaul®©™ t' mount betwixt t' top centerin' rin' and t' shock cord. And second is their new LaserLineRocket Pic. Arrr! Blimey! Previous kits from Nordic utilize t' technique o' punchin' holes along t' edge o' t' fin mounts t' allow t' glue t' seep in creatin' a "glue rivet". Arrr! Blimey! Begad! Blimey! Now Nordic is usin' their LaserLine™ which puts t' holes in t' tube for you. Avast! Blimey! You can see a picture o' this in me review on t' Nordic Rocketry Phaze kit.

There were only two other construction items that needed consideration. First t' installation o' t' Quick Change Motor Mount. Begad! Arrr! This was extremely easy as t' main motor mount housin' is built inside a 2.6" coupler. Aye aye! Avast! This way it just slides into your airframe and glues in place. Aye aye! On me Meanie no consideration for thru-the-wall fins was needed as they are surface mount.Rocket Pic I installed t' motor mount housin' before t' fins since t' kit uses t' glue "rivet" holes that may penetrate into t' inside surface o' t' body tube and could have made it difficult t' install afterward.

You'll notice that each o' t' 3 motor mount variations all mount in t' main motor mount and then are held into place with a clip.

T' second consideration for usin' t' changeable motor mount be t' Center o' Gravity (CG) relationship. Ahoy! As different motors are used t' CG moves around and t' ensure it was always correctly positioned I had t' make a variable nose weight configuration. Ahoy! I did that by drillin' a 1" hole into t' balsa nose cone t' a depth o' 2.75". Next, I built a 24mm motor mount, ya bilge rat, includin' a standard Estes' motor hook. I worked a groove into t' nose cone where t' motor hook would be and then glued t' motor mount into t' nose cone.Rocket Pic

After finishin' t' rocket, I measured where t' CG be on me standard Meanie with an F motor. Avast, me proud beauty! Begad! I then compared that t' me new changeable motor Meanie with 3 x 18mm C's, ya bilge rat, 1 x 24mm F, and a 1 x 29mm EconoJet F. Well, blow me down! Ahoy! I then was able t' use spent Estes' D motor and filled them with various amounts o' BB's and glue until t' CG be t' same as t' standard Meanie. Each o' these weighted 24mm motors can simply be installed in t' 24mm mount that I glued into t' nose cone.

I finished t' rocket me normal way, ya bilge rat, with Plasti-Kote Primer and sandin' betwixt coats. Avast! Ya gotta love those balsa nose cones . Aye aye! . Begad! . Begad! which require multiple coats and sandin' t' get it right. Arrr! I painted this Meanie me (now) traditional Meanie Yellow but instead o' only a single dark blue fin, me bucko, I painted two o' its fins dark blue t' set is apart from me other Meanie. Blimey! I then applied t' vinyl decal lettering.

FLIGHT/RECOVERY:

3 x 18mm
Download RockSim file here!
3 x18
1 x 24mm
Download RockSim file here!
1 x 24
1 x 29mm
Download RockSim file here!
1 x 29

My first flight was usin' t' 1 x 24mm mount on a AT RMS D15-4. Well, blow me down! T' flight be perfect with deployment at perfect apogee. Because is was a little windy, matey, I used a smaller (14") parachute. Begad! Definitely too small as it bounced on t' ground. Avast, shiver me timbers, me proud beauty! No damage.

T' second flight was on three C6-5's (pictured, me hearties, but notice it only looks like two motors lit . . Well, blow me down! . Begad! Aye aye! Blimey! but they all did!). Arrr! Blimey! All three lit and she flew nice and stable. Avast, me proud beauty! RockSim says about 500 feet. I agree. Begad! It ejected past apogee with t' nose cone pointin' down. Ahoy! This time it came down on an 18" parachute. Arrr! Ya scallywag! Blimey! Much better, me bucko, ya bilge rat, shiver me timbers, but I think I'm goin' t' go a tad bit larger for t' next flight.

I'm lookin' forward t' flyin' it and hopefully nay loosin' it on an F20.

Regardless o' t' motor size, I always enjoy flyin' this rocket, t' Meanie, ya bilge rat, but now it has some versatility that adds t' t' enjoyment!

Rocket PicNARAM-43 Update (8/01):

I finally was able t' fly this one on a 29mm motor. Ahoy! Ya scallywag! I choose an Apogee F10-6 and I was impressed. Avast! Begad! It be designed t' fly on EconoJet F20's so t' Apogee F10 be much longer and stuck out t' top o' t' motor mount. Blimey! I used that as an opportunity t' retain it and therefore taped around t' top o' t' motor and t' bottom fully securin' it into t' motor mount.

T' rocket is really borderline for weight on when usin' such a low average thrust (F10), matey, ya bilge rat, but it came off t' pad slowly and burned for 7 seconds on its way up. Well, blow me down! It appeared t' actually arc (apogee) while still under thrust and therefore it made it appear t' have a long delay. Aye aye! It did eject and recover nicely. I really enjoyed that F10 motor. Blimey! I will want t' go t' an EconoJet F20 though t' ensure adequate lift-off thrust.

T' next NARAM flight was three (3) Apogee D10-7's. Blimey! Blimey! I dipped and matched 30# ignitors just for this launch. All lit and varooom. It was great! Blimey! Check out t' flame. Ejection was early and it probably could stand another 1-2 seconds because it still seemed t' have a good head o' steam. Begad! Blimey! Recovered and successful. Avast! Blimey! Blimey! Blimey! I've ordered more D10's because this is a very excitin' combination t' me.

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