BSD L3 Horizon Booster Rebuild

[FDB]

I flew my L3 BSD Horizon at LDRS, but not for my L3. I just didn't get the paperwork together, so it flew on EX Day on a K&L Motorworks EX M2000. It can be seen on the Extreme Rocketry DVD if anyone bought it, and although they couldn't track the flight fully ( ) it wiggled and then just shot to 11,000 ft!

We then tried a suspect untested EX L motor which sadly cato'd, needing a booster rebuild.

Still, Mark from BSD sent me a new booster and I have rebuilt the beast, and maybe the way I built it that took the EX M2000 would be of interest for BSD fans.

First, build it outside of the Booster tube.

Then cut the booster tube slots all the way to the end.

After big fillets outside on the fin - booster (not shown)...then add the glass...

Now the REAL work begins, finishing it for the car paint shop, but it will EAT hard burning EX M's alive, I guarrentee!

BSD Kits are the deal. Cost effective that can go toe to toe with any spiral wound fiberglass kit for half the cost.

(The marks on the fins are for a 7.5" upscale of the BSD L3 Horizon, currently being built for a M 1939, my real L3. Wish me luck)

 

[daveyfire]

Very cool FDB! Keep us posted on how the finishing and flights go! I can't wait to see what wicked EX motors you guys cook up for this thing

 

[Loki]

What are the threaded rods for? Looks like all they are doing is adding weight. If you are worried about the airframe and motor tube bulking during a high G boost, some wood strakes would add just as much strength at about 1/5 the weight.

 

[Stymye]

I'm not a level 3 rocket builder so bear with me

I have seen threaded rods used internally before
but I don't understand the true benefit, if the component it attaches to
is not metal also....
in the pic it seems that any force would be exerted at the relativly small spots where the 3 nuts contact each wooden ring...
would using thicker or stronger motor mount rings be effective?
I'm just asking/learning because I "plan" to try a level 3 in the near future, the build looks great so far!

 

[gerbs4me]

Looks great, lets see more pics

 

[FDB]

I saw the rods used on L3 builds before and have no idea why they are used. They pry just look cool to me more than anything, and thats why I do the hobby, just to get a kick out of it for no peticular reason! Plus you can clamp the centering rings down hard on the fins, which makes for easy alignment, and more reason for them not to flex.

As far as weight, these kits come in at 12 lbs finished anyway. M1315's really don't care if you put a few rods in to hold your rings in place, and a EX M2000 laughs if your trying to save 9oz.

 

[daveyfire]

I've put 1/4" allthread in some of my big rockets with weak airframe tubing to transfer the jerk of the shock cord on the attachment points directly to the aft centering ring (use big washers). This way, you don't pull out the top centering ring at ejection! Besides, like FDB said... it looks cool

 

[FDB]

Hey, I never thought of that daveyfire, thanks! Now when people ask I'll say it's to transfer the load of the recovery harness, not because I think it looks cool. It's actually real rocket science,lol.

 

[lalligood]

Originally posted by daveyfire
I've put 1/4" allthread in some of my big rockets with weak airframe tubing to transfer the jerk of the shock cord on the attachment points directly to the aft centering ring (use big washers). This way, you don't pull out the top centering ring at ejection! Besides, like FDB said... it looks cool

Conversely, it also is there to help distribute the thrust of the motor to the rest of the rocket & not just the aft centering ring.

Simply put, the allthread rod is there to (help) maintain structural integrity of the rocket.

 

[FDB]

Related, more BSD L3 Horizon goodness.


EMRR REVIEW

 

[EMRR]

Originally posted by FDB
Related, more BSD L3 Horizon goodness.


EMRR REVIEW

Well, this will be officially posted on 2/20. So the added comments will be corrected.

By the way... you can enter your flight log off of this preview version ya know

Nick