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ANTI-VIRUS Build Thread

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H. Craig Miller

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FULL BODY WRAP

Not the grid fins... I received the fiberglass tubing from Wildman, and the full body wrap from a local vendor, and my excitement got the best of me... I just couldn’t wait to see what it was going to look like. So, a few pieces of masking tape later... knock my socks off...
Wrap.Test.gif
And, that body wrap... there were over 100 iterations before that one was chosen.

Back to the grid fins. Guess what else arrived...
IMG-0857.jpg
 

mbeels

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WOW! This thread continues to blow my mind!
 

dhbarr

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Okay but you HAVE to tell us where you got the outer components and of what the inner components are comprised. Pretty please?
 

H. Craig Miller

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At what weight are the grid fin frames coming in?
The grid fin frames were milled from a block of 6061-T6 aluminum and each weighs 105g. Each aluminum 1" x 1" x 1" grid insert weighs 29g. The total weight of the grid fins is 4 x 134g = 536g, or 18.91oz, or 1lb 2.907oz.

Okay but you HAVE to tell us where you got the outer components and of what the inner components are comprised.
So far, the needle tip was molded from a blunted Semroc conical balsa nosecone [BT-20 2.3" SEM-BNC-20SU] from eRockets and cast using West Systems fiberglass resin with a black pigment; the needle shaft is 20mm OD X 18mm ID X 500MM roll wrapped carbon fiber tube purchased on eBay; the centering rings are 1/4" aircraft plywood purchased from a local hobby shop, and custom cut to the appropriate outside and inside diameters by me using drill press mounted hole cutters with cobalt steel cutting tips; the body tube and coupler material for everything except that airframe and AV-bay is Blue Tube 2.0 purchased from Always Ready Rocketry; the airframe and AV-bay are G-10 fiberglass purchased from Wildman Rocketry; the grid fins were machined by High Desert Precision CNC Machining Nosala's Hobby Shop; the 1" square 1" thick grid material was purchased from 1800Ceiling.com; the nuts, bolts, and other hardware were purchased from McMaster-Carr. The sizes, dimensions, and positioning of the parts are shown in the OpenRocket files attached.

As the build goes forward additional OpenRocket files and parts information will be provided.

I appreciate everyone's positive comments, this rocket has been extraordinarily different, to say the least.

[May I] ask how much those grid fin frames cost? I just have no idea what milled block of aluminum like that would set you back.
About $45 each, I provided the machining file.
 

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neil_w

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Just looking at your dry fit up there... the needle hub really came out amazing.

Would it violate forum etiquette to ask how much those grid fin frames cost? I just have no idea what milled block of aluminum like that would set you back.
 

mo2872

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I'm not sure which is more epic.......this build, or the musket on the wall.........
 

H. Craig Miller

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I'm not sure which is more epic.......this build, or the musket on the wall.........
Authentic civil war piece... bequest from my father-in-law, along with the picture.

I've been trying to figure out how to hang my rockets using the same technique, but my better half is resistant.
 

ether

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awesome build, assume a standoff will be used for the rail button?


1605309209054.png
 

H. Craig Miller

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awesome build, assume a standoff will be used for the rail button?

1605309209054.png
I've been wondering how long it was going to take for someone to catch that... I didn't realize I had a problem until I put the launch rail between the grid fins to verify clearances, and the rail hit the plunger. I have only come up with two options, either use rail button standoffs or cut out the plunger (on all four sides for symmetry). I haven't decided what to do yet... which would you do?
OpenRocket.20.11.02.Grid Fin Section.03.gif
So far, that's the only design error I have discovered... I should have been paying more attention.
 
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ether

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flyaway rail solves the problem, but if not a consideration would do the standoffs the design is so awesome

or you could do a design change and the plunger gets ejected at launch - stays on the ground LOL
 

BABAR

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flyaway rail solves the problem, but if not a consideration would do the standoffs the design is so awesome

or you could do a design change and the plunger gets ejected at launch - stays on the ground LOL
So that would make it a piston?.......

A bit late, but any chance of a “removable for display” external cord mount for the nose, so nose cone descends pointy side up?
 

JoePfeiffer

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Seeing nearly the whole thing assembled is even more incredible. Though I hope that "single use only" label doesn't reflect a lack of confidence in recovery!
 
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neil_w

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Yeah, I think we need to start bugging Craig about this.
 

H. Craig Miller

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I have been struggling with options. When the grid frames were originally designed, the bottom edge was intended to have an internal lip to keep the grids from being pushed through the frames. Unfortunately, the lip did not materialize during the data entry and manufacturing process. So, I have been considering different methods of holding the grids in the frames, while affording grid replacement if damaged.

The best I have come up with is to use four 2-56 set screws, one in each of the four corners, to hold the grids in place.

Grid Fins.Set Screws.jpg

Once I have decided how best to proceed, the grid fin assembly will look something like this:

Grid Fins.Layout.Combined.jpg

Suggestions for alternative attachment methods, for a removable grid in the event of damage, are welcome.
 

neil_w

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If you can get the set screws to work, those would certainly be unobtrusive. The one near the base of the fin seems dicey.

My first thought was clamping the grid between the two edges of the frame, something like this. It will add some drag, and not be invisible. Is that a 1" grid in the picture? If so this may not be super practical, somehow I thought these were bigger.
1613166869972.png
 

H. Craig Miller

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I wonder if Ian knows just how versatile his Badass Rocketry build guides are... they even work for grid fins.

Grid Fins.Assembled.Badass.jpg
I actually used the four-fin build guide to mark the vertical edges on both sides of each grid fin. I love those things.
 
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