I'm posting a reply to myself... 🙂 Got the fins glassed, and I'm saving any fillets for just before finishing, moving on to construction. Stopped at the Big Blue Monster (Lowe's, as opposed to Denverdoc's Big Orange Monster, Home Depot... have no preference :)) and bought two 3/8" All-thread, nuts, washers, etc.

I need the aluminum plates, and--while I haven't committed myself yet, I still may use 4 all-threads at 1/4"/20 instead of one at 3/8". I'll also admit that just unscrewing one would be a lot easier than unscrewing four... hmmm... still want the plates, but I may rethink this.

Decided on going the 3/8" route (also after re-reading Canepa's second book). With the Schaefer-Plattner metal redundant plate, the old SPMRP, either way I'd be covered. That's my status. Anyone else constructing an L3 bird, and want to ask a question or give an update?

Not necessarily related to L3, but for those folks who live in the Broomfield/Lafayette/Louisville area, ACE hardware on 287 and S. Boulder Rd. almost equals McGuckins for bolts, nuts, threaded inserts, etc. They have it all. And for custom paint (in the spray cans) go to NAPA at 96th and S. Boulder Rd. Sure beats driving into Boulder!

Sorry for the digression.

Hey, Ken, all levels need that information! No digression.

I belive that Bruce has allready checked it out but for anyone else that wants to look at my L3 project and the progress I make until its done can go here

I am currently working on the booster section and update it with pics pretty muchly every week.

Well, spent this week cutting an ebay hatch... took five attempts and five hatches, but that's just me. 🙂 When cutting G10 fiberglass, I recommend using the ol' Dremel #409 cutting wheel. While you go through a few, it cuts the FB like butter after you've scored it. When it begins to stick slightly, replace the blade. Gets dull and full of FB. If you don't, it's going to break. 🙄

Actually My favorite blade for cutting FG with is a diamond cutting blade/wheel. Makes the #409's look very dull. If you necer have tried one you should Bruce.

Agreed 🙂

The diamond wheel goes through phenolic, glass, carbon, and kevlar (not cloth, but layups) like butter. Never seen anything else that cuts quite as cleanly and smoothly as it does.

I've got to have them somewhere. My section of the garage with my tools is so cluttered (hey, there's a project) that I know I have them... somewhere. I just knew where the 409's were. Hmmm... next time, guys. 🙂

Checked my tool stash, and I DON'T have those! But soon I will. Thanks!

Okay, my L3 can fly in three configurations: with a payload section, without the payload section, and using the payload section for dual deployment. Now, the question I have is... has anyone had a zippering or splitting problem with 1/16" G10 fiberglass tubes? I can glass the top sections that will be stressed by the parachute harness. One of the options separates just above the booster with the chute pulling out of the next section--the ol' zipperless design. But other options will expose the BT to taking it. I could also build an L3 version of GLR's Fireball. Love those! I zippered once, and am really and rightfully paranoid about it. I haven't used fiberglass tubes since the late 80's. Never zippered then though. Any input?

Yes, I have zippered fiberglass G10 tubing with kevlar shock cord. However, it was a very long rocket and I was trying to pop the nose cone off first (at apogee) instead of breaking it in the middle.

Doug

Funny, I'm using 1/2" Kevlar harnesses... I'll have the booster at 4', next section holding the chute at 3', that would stay together at 7', and the payload section with the main at 3' with a 2' nosecone, at 5'. So it's about divided in half. Still that bothers me. Doug, does glassing the top help at all? Sounds like it would, but, man, if the stress is there, it's going to slice and dice the G10 or break the Kevlar cord, something's gotta give. 🙄

Bruce, I'm 3 for 3 in warning people about 1/2" Kevlar. Maybe it is me giving them the kiss of death... but all three times I told guys it would NOT hold, and it did not. Is this the MW stuff? I love it, but would never use it for more than a 54mm rocket. I've seen it used for bigger rockets and it just won't hold.

I have 3 shock cords that are 5/8" tubular Kevlar (lengths of ~25', 25', and 30'). You, and for that matter ANYONE in the club can use them whenever you wish. They have flown many, many times.

The 1/2" flat Kevlar is wonderful stuff, but not for a rocket that is over a few lbs, as your L3 most certainly will be...

JW

JW please elaborte.. As far as wont hold. 1/2 inch tubular kevlar should easily hold a 75lb and under project without a hitch according to the ratings of it. In fact its also what I am using. Got mine from Giant leap infact. Like 100 feet of it. I also tie knots in my stuff and I avoid the pre-sewn loops myself. The correct knot will not weaken the shock cord and will not come apart.

But in the issue of the 1/2 tubular kevlar. Bruces project will probably be lighter then mine (mine with the empty case after the motor burns out will be 50 to 60 lbs max) SO you say its not strong enough? curious.

I to have seen shock cord zipper fiberglass tube.. but its a lot less comon then phenolic or cardboards.

He is a tip. Be sure to find the spot where you harnes will rub on the rim of the body tube as it deploys and is under chute and wrap it in duct or masking tape. I have seen that lip cut even Tubular Kevlar harness.

For some reason, I thought Bruce was refering to FLAT Kevlar. Tubular stuff is another matter. Tubular = good for L3, flat stuff is wonderful but not for a project of this size. I've seen flat stuff break three times... as noted, I was suspicious (and voiced those concerns) to all three fliers.

The 1/2" or 5/8" tubular stuff will do fine. I use it all the time...

JW