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

CONSTRUCTION:

Construction o' t' Nordic kit went as described in its instructions and builds nicely. Avast! Ya scallywag! You can see me previous review here. Avast, ya bilge rat, me proud beauty! Nordic had changed two things since I had purchased me first kit. Begad! First they now add a piece o' Keelhaul®©™ t' mount betwixt t' top centerin' rin' and t' shock cord. Avast, me proud beauty! Begad! And second is their new LaserLineRocket Pic. Blimey! Ya scallywag! 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". Blimey! Now Nordic is usin' their LaserLine™ which puts t' holes in t' tube for you. 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. Begad! Avast! First t' installation o' t' Quick Change Motor Mount. Well, blow me down! Well, arrr, blow me down! This be extremely easy as t' main motor mount housin' is built inside a 2.6" coupler. Ya scallywag! This way it just slides into your airframe and glues in place. Ya scallywag! Ya scallywag! 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. Ya scallywag! As different motors are used t' CG moves around and t' ensure it be always correctly positioned I had t' make a variable nose weight configuration. Begad! I did that by drillin' a 1" hole into t' balsa nose cone t' a depth o' 2.75". Ya scallywag! Next, I built a 24mm motor mount, arrr, includin' a standard Estes' motor hook. Aye aye! Ya scallywag! 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 was on me standard Meanie with an F motor. I then compared that t' me new changeable motor Meanie with 3 x 18mm C's, arrr, 1 x 24mm F, shiver me timbers, and a 1 x 29mm EconoJet F. Ya scallywag! Blimey! I then be able t' use spent Estes' D motor and filled them with various amounts o' BB's and glue until t' CG was 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, with Plasti-Kote Primer and sandin' betwixt coats. Begad! Blimey! Blimey! Ya gotta love those balsa nose cones . Begad! Blimey! . Arrr! Avast! Blimey! . Ahoy! which require multiple coats and sandin' t' get it right. Avast! Begad! Blimey! I painted this Meanie me (now) traditional Meanie Yellow but instead o' only a single dark blue fin, I painted two o' its fins dark blue t' set is apart from me other Meanie. 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 be usin' t' 1 x 24mm mount on a AT RMS D15-4. Begad! Avast! Blimey! T' flight was perfect with deployment at perfect apogee. Aye aye! Because is be a little windy, I used a smaller (14") parachute. Definitely too small as it bounced on t' ground. No damage.

T' second flight be on three C6-5's (pictured, but notice it only looks like two motors lit . Avast! . Blimey! Avast! Blimey! . Ya scallywag! Ya scallywag! Blimey! but they all did!). Begad! Blimey! All three lit and she flew nice and stable. Ahoy! Blimey! RockSim says about 500 feet. Begad! Avast, me proud beauty! Blimey! I agree. It ejected past apogee with t' nose cone pointin' down. Ya scallywag! Blimey! This time it came down on an 18" parachute. Much better, 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, arrr, t' Meanie, ya bilge rat, ya bilge rat, arrr, but now it has some versatility that adds t' t' enjoyment!

Rocket PicNARAM-43 Update (8/01):

I finally be able t' fly this one on a 29mm motor. Begad! I choose an Apogee F10-6 and I be impressed. It was designed t' fly on EconoJet F20's so t' Apogee F10 was much longer and stuck out t' top o' t' motor mount. Begad! 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), me hearties, but it came off t' pad slowly and burned for 7 seconds on its way up. Avast! Begad! Blimey! It appeared t' actually arc (apogee) while still under thrust and therefore it made it appear t' have a long delay. Begad! Begad! Blimey! It did eject and recover nicely. Blimey! Ahoy! Blimey! I really enjoyed that F10 motor. Arrr! Blimey! I will want t' go t' an EconoJet F20 though t' ensure adequate lift-off thrust.

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

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