LOC Bruiser EXP L3 attempt Mk1

[Kyle Goodwin]

So this is my lvl 3 attempt using a 7.5in LOC Bruiser EXP. The plan is to fly this rocket at LDRS 40 on an M685.
Taps are Robin Meredith and Mark Clark.

Components used.
22 in Loc Precision 7.5 in nose cone.
30 and 60 in cardboard tubes
centering rings and bulkheads
75mm Motor mount.
75MM aeropack motor retainer
3 fiberglass fins
5/8 in rail guides
kevlar shot cord
96 in main chute with a 24 in drogue.
AV bay was 3d printed
Hardware as needed, all is grade 8 stainless steel.

For the motor mount, due to the kit being a tube within a tube set up the inner area where the fins do not mount was filled with expanding foam. All centering rings were mounted using epoxy with the inner rings having 3m micro-beads mixed into the epoxy. The motor retainer is a 75mm Aeropack flanged connector which was mounted to the aft centering ring over a bead of 5 min epoxy. The screws were then bolted to the centering with red LocTite to ensure they did not ever move again.

Afterwards the tubes were encased in fiberglass sheeting and epoxied onto the tube. Due to weather, expecting 75 degrees for a week instead got sub 40 degrees and snow, the epoxy took several days to cure.
Once the fiberglass was dry the fins were attached to the inner tube. A slit was made in the fiberglass and the fins were slid into them. 5 min epoxy was used to bond the fins to the inner and outer tube with a bead of 1 hour epoxy with micro beads mixed in.

The coupling tube was glued to the payload bay using 5 min epoxy with the upper bulkhead being glued in using 1 hour epoxy to ensure rigidity.
The nosecone had a 16 in all thread inserted into it with 3 in fender washers spaced on the rod using nuts to ensure spacing. After that expanding foam was placed in the nosecone locking the allthread in place.

Lessons learned so far.
Temp has a significant effect on epoxy cure time.
Make sure you properly measure epoxy amounts. Used a new epoxy I have never used before and screwed up on measuring and this caused some of the resin to not fully cure.
Make sure to take pics and save them and not have your phone auto delete them.


More to come with pics and RASAero data as I finish rocket.

 

[ThePlmbr]

The rocket looks good. Good-luck with your level 3 flight. Greg Olson

 

[cwbullet]

Good luck.

 

[DMehalko]

Watch your weight and rail departure speed with that motor, good luck!

 

[Kyle Goodwin]

After completely forgetting about this post and watching the video and reviewing the parts that were left over. The coupling failed where the upper section met the booster section right around the rocket hit max velocity. Fault is on my for not reinforcing that area knowing that was a weak spot. Next attempt will be at balls this year.

 

[Hobie1dog]

live and learn, good luck next attempt

 

[kswing]

Good luck on your next attempt.....I just recently got my L3 using a slightly modified LOC Bruiser EXP.

 

[mikec]

I can't tell from the pics, did your avbay include the internal "stiffy" coupler that LOC typically provides or did you not get that or omit it?

 

[KenECoyote]

Did you use the coupler in its stock form?

I've been reading about coupler failures happening more recently and for my future L3, I plan to fiberglass the inside of any couplers. One TRFer noted that many people forget to do so.

 

[kswing]

On my build, I didn't fiberglass the body tubes, but, I did use the LOC couplers with the extra stiffy tubes and it worked with a M1350. I modified the e-bay slightly to have it use the entire length of the coupler instead of just half, but, other than that it was mostly stock. Also, I used a thicker bottom CR on the 75mm MMAS and an Aero Pack flange retainer.

 

[Kyle Goodwin]

Hey all, so this kit I bought when I was 18(22 years ago) so it really didn't have the most up to date internals. That being said, I wrongly believed my full length av bay would help with the structural rigidity.