X-Git-Url: https://git.gag.com/?p=web%2Fgag.com;a=blobdiff_plain;f=rockets%2Fprojects%2Fyikstik%2Findex.html;h=da72f6c53a1ec2c3404d61021afb5c275ef255e9;hp=9ed814eb9725a3a304bf014b0a68d4487a9aa4a2;hb=1ba0db5d53c9d2a44f5c1a9a7eff12862e406ffc;hpb=189d33d9a2b3532a368293c018eb2f764061585f diff --git a/rockets/projects/yikstik/index.html b/rockets/projects/yikstik/index.html index 9ed814e..da72f6c 100644 --- a/rockets/projects/yikstik/index.html +++ b/rockets/projects/yikstik/index.html @@ -1,10 +1,12 @@ -
Copyright © 2008 Bdale Garbee
- This document is released under the terms of the +
Copyright © 2008 Bdale Garbee
+ This document is released under the terms of the Creative Commons ShareAlike 3.0 license. -
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Revision 1.0 | 28 October 2008 | ||||||||||||||||||||||||||
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Revision 0.2 | 27 March 2008 | ||||||||||||||||||||||||||
Cleaned up for initial review | |||||||||||||||||||||||||||
Revision 0.1 | 16 March 2008 | ||||||||||||||||||||||||||
Initial content |
Table of Contents
Please note that I stopped adding photos to this document at some point. I have many more photos of the YikStik build, but haven't decided how best to present them yet... update coming someday! -
Table of Contents
+
Table of Contents
This is the rocket I'm designing for my NAR Level 3 certification flight. The general idea is to build a fairly cheap rocket capable of reliably flying this year's Aerotech level 3 special, which is an M1297W reload. @@ -36,20 +38,19 @@ could safely fly on reloads as small as a J for economical fun. Those altitudes mean the certification flight will need to be at a site with a high-altitude waiver like the NCR north site. -
+
I've always thought the high-gloss red paint job on one of my son's rockets when out on a launch rod in the sun looks a lot like glistening wet lipstick.
Combine that with the fact that my wife who isn't fond of the stuff refers to lipstick as "yik stick"... and the rest should be obvious. -
+
My planned paint scheme is a bright red nosecone, gold tube, and black fin can, which is the mental image I have of what lipstick applicators look like, most likely from a stick my mother or one of my grandmothers had - when I was a child. Something like the image by Calliope1 that I found - on flickr.com. -
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YikStik is a fairly simple "three fins and a nose cone" dual-deploy rocket using a 75mm motor mount, 4 inch glass-wrapped phenolic airframe with zipperless fin can, plastic nose cone, plywood fins, @@ -57,17 +58,17 @@ The primary electronics bay will be designed to hold two altimeters, and a distinct payload bay may carry an experimental altimeter, GPS receiver, and downlink transmitter. -
I intend to cut the airframe components from two 48 inch lengths of 98mm Giant Leap Dynawind tubing. The 30 inch main bay and 18 inch drogue bay will be cut from one length, while the 33 inches of fin can, 2 inches of electronics bay, and 8 inches of payload bay will be cut from the second. -
The fins are designed from scratch, and I intend to build them up from two layers of 1/8 inch birch plywood, three layers of carbon fiber, and two layers of 6 oz glass. The stack will be glass, carbon fiber, @@ -84,18 +85,18 @@ The airframe will be slotted to allow the completed motor mount / fin assembly to be inserted from the rear, with fillets of epoxy applied inside and outside the airframe after insertion. -
All centering rings and bulkheads will be custom machined from 3/8 inch birch plywood using my 3-axis CNC milling machine. Some rings will use laminated pairs of 3/4 inch total thickness to enable use of threaded inserts for 1/4-20 rail button screws or deep routing for fin alignment slots. -
I will embed three 8-24 T-nuts in the aft centering ring spaced to allow the use of home-made Kaplow clips to retain 75mm motors. The same holes may be used to attach custom motor mount adapters for smaller diameter motors. -
The recovery system will feature dual redundant barometric altimeters in an electronics bay similar to the LOC design located between the drogue and main parachute bays. @@ -108,7 +109,7 @@ Each altimeter will have a separate battery and power switch. A 4PDT slide switch will be used as a SAFE/ARM switch configured to interrupt connectivity to the ejection charges. -
This design has been thoroughly analyzed using RockSim @@ -133,7 +134,7 @@
These simulations will be refined as the build proceeds and as-built stability verified before flight. -
The Aerotech M1297W reload should carry this vehicle without ballast to just over 14 thousand feet AGL. It should make over 16 thousand feet AGL on an M1850W, and should fly stably to roughly 2.5k feet AGL @@ -146,7 +147,7 @@ If the cert succeeds, then I might try an optimal mass flight sometime later on an M1850W or equivalent "bigger M" reload to join the "three mile club". -
The recovery system will use dual redundant barometric altimeters firing black powder charges. At apogee, a drogue chute will deploy from just forward of the fin can, @@ -179,7 +180,14 @@ of 1/2 inch tubular kevlar, bonded to the motor mount. If available, a screw-eye attached to the forward motor closure may be used instead of or in addition to this recovery attachment loop. -
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+ I have collected all of my + + build photos + + in one place, they may show better than I can explain how various + aspects of YikStik went together. +
The tubing for the airframe, couplers, and motor mount was all cut using a carefully aligned and adjusted power mitre saw, and the ends lightly sanded to remove rough spots. @@ -188,14 +196,14 @@ bay were cut from the second. The three couplers for the fin can, electronics bay, and payload bay were cut from Giant Leap 98mm phenolic coupler stock. And the motor mount was cut from Giant Leap 75mm - phenolic airframe stock. This photo shows the airframe tube on the - left, the motor mount in the middle, and the coupler sections on the - right. Note that the motor mount is the longest piece because of + phenolic airframe stock. + Note that the motor mount is the longest piece because of the zipperless design with full-length motor mount. -
+
The airframe tubing selected includes a wrap of 10oz glass in epoxy - over the base phenolic tubing (visible in the previous photo as a - shine on the outside of the tubing), but the coupler stock is unreinforced. + over the base phenolic tubing (visible in some photos as a + shine on the outside of the tubing), + but the coupler stock is unreinforced. To ensure the couplers can handle the anticipated loading, I reinforced each with one layer of interior carbon fiber, using the "kitchen vacuum bagging" technique documented by @@ -212,8 +220,7 @@ after reinforcing to get "perfect" ends. The technique worked marvelously otherwise, and the resulting couplers look and should work great! -
-
Six pieces of 1/8 inch birch plywood were stacked, edge-aligned on what would be the fin root edge, and clamped. The outline of the fin design was marked in pencil, and three 1/8 inch holes drilled through the @@ -221,23 +228,24 @@ blanks together while making the initial cuts, so that they would all be matched in size. The clamps were removed to avoid interference during cutting. The fin outline was then cut using a radial arm saw. -
- A router table with 1/8 - in roundover bit was then used to round over the outer edge, 3 blanks on +
+ A router table with 1/8 inch + roundover bit was then used to round over the outer edge, 3 blanks on one side and three on the other. This edge might have been left square, but I prefer the look and feel of rounding. The router table with a 1/2 inch diameter straight cutting bit and a fin beveling jig was used to impart a 10-degree bevel on the leading and trailing edge of each fin blank, again 3 on one side and three on the other. The resulting 6 - blanks thus form 3 pairs of fin components with a modified airfoil shape. -
-
+ blanks thus form 3 pairs of fin components with a modified + airfoil shape. +
The fin assembly started with a simple lamination of two layers of ply sandwiching a layer of carbon fiber. Each fin used "one pump" of West Systems epoxy and the stack was vacuum bagged using the Foodsaver with wide bagging material. To keep everything flat while the epoxy cured, the stack of fins was sandwiched between two unused extra shelves for - a storage cabinet I had on hand (particle board covered in laminate, very + a storage cabinet I had on hand + (particle board covered in laminate, very flat and smooth, nearly inflexible at this loading), and stacked with about 75 lbs of loose barbell weights.
@@ -245,10 +253,7 @@ 1-2mm in the longest axis. The other two are nearly perfect. Light sanding should allow me to match them before laminating the outer layers of carbon fiber and glass. -
-
-
-
+
After the fins cured, they were bulk sanded with medium and fine sandpaper and an electric palm sander. Final sanding of the leading and trailing edges was done using 400 grit paper on a flat surface, @@ -273,26 +278,26 @@ sides were done one at a time and allowed to cure before proceeding. The results look good, and in combination with internal and external airframe filets should yield a super-strong fin can. -
Pairs of 3/8 inch birch plywood blanks were laminated using Titebond wood glue and clamped while curing to form 3/4 inch blanks for centering rings. From a strength perspective, 3/8 inch should suffice, but there are two reasons for going with thicker blanks in some places. The first is that the rail buttons chosen use 1/4-20 mounting screws, and threaded - inserts in that size are nearly 3/8 inch outside diameter (and thus would + inserts in that size are nearly 3/8 inch outside diameter + (and thus would tear up a ring only 3/8 inch thick on insertion). The second is that I like to mill slots in the centering rings on each end of the fins to "lock" the fins into position. Doubling the blanks used to cut those rings will allow me to cut 1/4 inch deep fin slots and still have a half inch of unmolested wood in the rings for strength. -
-
+
The aft centering ring and the one just aft of the zipperless coupler section were edge-drilled for the installation of brass 1/4-20 threaded inserts to hold rail buttons. The inserts were locked in place with epoxy, then ground down until nothing protruded beyond the OD of the ring. -
The forward two centering rings were installed on the MMT using JB Weld high-temperature epoxy, and incorporating an aircraft cable loop for recovery system retention since there just wasn't room for @@ -344,7 +349,7 @@ motor mount and zipperless-design coupler tubing was filled with epoxy and milled glass. Minor gaps in the airframe behind each fin were filled with epoxy clay. -
The avionics bay contains the two commercial altimeters used to record information about the flight and deploy the drogue and main recovery systems. It is constructed of a piece of Giant Leap 98mm @@ -409,7 +414,7 @@ formula for a bay over 100 cubic inches the answer is 0.261 inches. The closest standard drill size, which happens to split the difference, is 0.250 inches. Easy enough! -
The construction of the payload bay is very similar to the avionics bay, except that there is a hard-epoxied rear bulkhead, and only one screw ring to hard-mount the nose cone. The forward end of the @@ -417,7 +422,7 @@ anticipation of extending downlink antennas above the carbon fiber reinforcement in the coupler and into the nose cone, since carbon fiber is opaque to RF. -
Pre-sewn 1/4 inch tubular kevlar harness sections were purchased from Giant Leap, along with a small kevlar deployment bag and two kevlar chute protectors. @@ -429,7 +434,7 @@
The main parachute will be sewn from 1.9 oz rip-stop nylon purchased from the - + Mill Outlet Fabric Shop in Colorado Springs. Using the spreadsheet from @@ -452,7 +457,7 @@ and its main charge at 900 feet. Thus the MAWD is primary and the miniRRC2 is the backup. Since the M1297W has a burn time of about 5 seconds, mach inhibit is programmed on both altimeters to 8 seconds. -
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This rocket uses dual deployment.
The apogee event separates the @@ -483,7 +488,7 @@ The anchor points are all 5/16 inch u-bolts, except for on the booster which is equipped with an embedded loop of 3/16 inch stainless aircraft cable. All connections are made with suitable quick-links. -
The LOC-style avionics bay between the main and drogue bays is populated with two commercial altimeters, a PerfectFlite MAWD and a Missile Works miniRRC2. @@ -548,7 +553,7 @@ the designers of this chute pattern, sanity checked using the descent rate tables of similar commercial parachute designs, like those from The Rocketman. -
Simulation using Rocksim v8 with a variety of motors showed that the rocket is unconditionally stable with all motors likely to be flown. The worst-case stability among 75mm motors is actually with the @@ -560,7 +565,7 @@ The smallest motor I can conceive of flying in this rocket (a Cesaroni J285) would leave us overstable with margin 3.79 on the way to about 1800 feet apogee. -
On the certification flight, using an Aerotech M1297W reload and associated hardware, the anticipated apogee is round 14,700 feet. This is just under 75% of the NCR North Site standing waiver of 20,000 feet. @@ -572,7 +577,7 @@ add description of anticipated flight profile here, including launch weight, estimated drag coefficient, velocity leaving the rail, max expected velocity, altitude, and acceleration -
YikStik was flown on an M1297W on Saturday morning at NCR's Oktoberfest 2008. The boost was beautiful. Unfortunately, we lost visual as the rocket climbed into high clouds near apogee. Radio tracking signals @@ -772,7 +777,7 @@
Reward if returned posters were placed in the area during the week following the launch but have elicited no useful reponses yet. -