EXPjawa
Well-Known Member
OK, I posted this at lunchtime, only to have it disappear into the server fits the site was having earlier. :eyeroll:
Anyway, I know everyone has upscaled the Big Bertha at some point; I've cloned the Super Bertha myself. But I've been toying with a larger one yet. With the announcement that this year's National Sport Launch being local, and then that Vern & Glenda would be attending, I decided that now is the time. As I gained some experience in building and flying, the design evolved from BT101 to LOC tubing to MAC 4" tube. Along the way, it went from launching on moderate G to needing an H at minimum (an I to get to 2000 ft). The design is single deploy (with JLCR), 38mm mount. So, yeah, its Yet Another Bigger Bertha.
I have pulled together what amounts to being more a kit than a scratch build; I'm not really actually cutting out or custom making any parts myself. Late last season, I bought a 4" fiberglass Bertha nose cone from Ken at Performance Hobbies. This is, BTW, my first dealing with fiberglass. I asked Nat Kinsey of Upscale CNC to cut out the fins. Then I gave the fins to Mike Crupe from MAC Performance, and he whipped up the airframe set slotted for the fins. He also ran the fins through his beveling machine, so that saves me a step too. So, its a kit of mixed manufacture.
I am not planning on rushing through this build, as I have a few months. But I am also not anticipating any real complications in building. In some ways, it really is just skill level 1 kit, rendered at 2.5X scale, with some nuances of fiberglass, epoxy and kevlar thrown in. Right now, I've just spread the parts out on the work bench to get a sense of it. Baby Bertha is supervising the job...
This will be the physically largest rocket I've built to date. Hopefully, I'll be able to fly it at NSL, then again at URRF5.
Anyway, I know everyone has upscaled the Big Bertha at some point; I've cloned the Super Bertha myself. But I've been toying with a larger one yet. With the announcement that this year's National Sport Launch being local, and then that Vern & Glenda would be attending, I decided that now is the time. As I gained some experience in building and flying, the design evolved from BT101 to LOC tubing to MAC 4" tube. Along the way, it went from launching on moderate G to needing an H at minimum (an I to get to 2000 ft). The design is single deploy (with JLCR), 38mm mount. So, yeah, its Yet Another Bigger Bertha.
I have pulled together what amounts to being more a kit than a scratch build; I'm not really actually cutting out or custom making any parts myself. Late last season, I bought a 4" fiberglass Bertha nose cone from Ken at Performance Hobbies. This is, BTW, my first dealing with fiberglass. I asked Nat Kinsey of Upscale CNC to cut out the fins. Then I gave the fins to Mike Crupe from MAC Performance, and he whipped up the airframe set slotted for the fins. He also ran the fins through his beveling machine, so that saves me a step too. So, its a kit of mixed manufacture.
I am not planning on rushing through this build, as I have a few months. But I am also not anticipating any real complications in building. In some ways, it really is just skill level 1 kit, rendered at 2.5X scale, with some nuances of fiberglass, epoxy and kevlar thrown in. Right now, I've just spread the parts out on the work bench to get a sense of it. Baby Bertha is supervising the job...
This will be the physically largest rocket I've built to date. Hopefully, I'll be able to fly it at NSL, then again at URRF5.