Wayco’s Dark Star Extreme

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I just picked up an Eggfinder and was trying to figure out how best to mount it. Great idea! Looks simple and clean. Question: is the antenna extending through the bulkplate because it's too long for the nose cone, or for some other reason? Have you used that setup, or the Eggfinder, before?

Good questions in your post, I will try to answer them in order:

1.) is the antenna extending through the bulkplate because it's too long for the nose cone, or for some other reason?

My original plan was to be able to move this sled/Eggfinder into smaller rockets, and that worked to some degree for this build. It did not work for my 54mm Blackhawk, where I had to mount the Eggfinder inside the coupler:
037.jpg


That is a second Eggfinder I built for that specific application, which is mounted in a 54mm N/C. Hard to get it in and out, so it's staying in that rocket. Since you pointed out an issue I have had regarding the antenna, I might re-design the sled and dedicate it to my 5" Jart and this rocket, where the N/C dimensions are almost the same. Which brings us to your second question.

2.) Have you used that setup, or the Eggfinder, before?

Yes, I have had several successful flights in my 5" Jart. One of which went to 9330 ft. and never lost lock on the GPS. I also have flown it once in my 3" Blackstar to 6741 ft. on a much faster motor (K513 fast jack) where it finally did loose lock during thrust, but picked it back up before apogee. Installing the Eggfinder in a 3" N/C required me to shorten the sled and that's when the antenna stuck out the coupler/shoulder of the N/C.
The advantage with the Jart is the size of the N/C. It allows you more room and distance from metallic parts. I think that is the key to getting good performance from your transmitter on the Eggfinder.

I want take the opportunity to thank all of you that have made comments and asked questions in this thread. Building a Wildman's Dark Star is relatively easy, I have five of them now, with only the Ultimate to start building. It looms over me every time I walk into the front room. Posting up build threads takes quite a bit of time and effort, especially when you can only type at 25 words a minute. Comments, encouragement, even criticism is appreciated. I might even wear a glove next time I cut an index mark with my dremel....
 
Now back to our regularly scheduled build thread which is still trying to catch up with yesterdays (6-27-14) very productive day. I finished sticking the fins in my post #28 on the first page of this thread. Now I'm ready to inject my internal fillets, which requires me to mix up about 45 ml of West Systems epoxy. That makes five different epoxies I have used for this build. 5 min. "Hammerhead" clear epoxy, for the quickie jobs that don't require much structural integrity, Proline 4500 for it's high temp. integrity and JB weld for the same reason. Proline is just easier to spread for bigger projects. Rocketpoxy which is my favorite for structural integrity, and one of the easiest to mix. And now West Systems 105/205, which works well for flowing out and bonding all the internal parts of my MMT, fins and fincan.
First on the list for flowing is making sure that everything is sealed around the bottom fin:

0016.jpg


This is where the epoxy will go if I have a leak around my fins/CR's up top when I inject. Now, if it does leak, I have an extra internal fillet between my fins and the body tube instead of a big mess on the counter.

Next is to turn the rocket over and level it :

0066.jpg


Not only laterally, but lengthwise too, making sure the epoxy flows evenly throughout the fincan.
I have a special tool for injecting fillets in bigger rockets, which I got at a feed store that carries veterinary supplies. It's a syringe that holds over 60 ml of epoxy. That allows me to mix up two pumps of WS in one container and inject all eight holes with 5 ml of epoxy each. I start by taping off the tip of the syringe. Then I start pumping one pump of resin and one pump of hardener, then repeating it, and it looks like this:

0095.jpg


I look like a mad chemist in that shot. Now I'm mixing it up for at least two minutes with a coffee stir stick:

0105.jpg


Mixing it all the way down into the tip, where you can see it start to change colors:

0135.jpg


Now we add a pinch of cut carbon fiber:

0175.jpg


My trusty assistant got a little too close for that shot. I finally coaxed her down from her ivory tower (where she makes all the money) to help me with documenting my build.
It doesn't take much CF, and too much can be a real hairball type mess that won't inject properly, so a pinch looks like this in the syringe:

0185.jpg


Push it down and start mixing again, for at least another two minutes. Nice thing about WS is it's relatively long pot life. It gets warm almost immediately when you start mixing it, but you can work with it for 10 to 15 minutes even with the fast 205 hardener, which is plenty of time to inject. Getting the CF all down into the epoxy can be a little tedious:

0215.jpg


But once you do it starts changing color again:

0235.jpg


Once you have it all a consistent gray color, even in the tip, it's ready to inject:


0255.jpg


Now "comes" the tricky part. Insert the plunger just enough to seal the top of the syringe:

0265.jpg


Turn it over and let most of the epoxy drain down:

0284.jpg


There will still be some trapped in the tip, and the farther you push the plunger in, the more pressure it will have when you take the tape off. You can probably imagine what happened the first time I discovered this, especially since I had my hands full with syringe and pulled the tape off with my teeth. Yuck! That won't happen again in my lifetime. (I hope)
Moving along now, we push up on the plunger and remove the trapped air. It might be handy to have a little cup to catch any epoxy still trapped in the tip:


0304.jpg


Keep the tip up, so you don't lose any more epoxy than what popped out initially.
You might also notice the timer I started when I pumped the epoxy into the syringe, it's reading almost 5 minutes of mixing time. Does that last picture look a little obscene? Nevermind....

We still have at least 10 minutes of "pot life", and with the rocket already leveled and ready, we can start injecting epoxy, unless you need to go rinse out your mouth that is....

Stick the tip into the first hole, and push down on the plunger:

0353.jpg


Noting where the plunger is located on the convenient scale on the syringe. You want 5 ml in each hole:

0413.jpg


It should just fill the void, and look like this when you're done:

0482.jpg


Check your level, looks like I moved mine a little, but since I'm moving it out into the AZ epoxy oven, I will re-level it there. This was the second set of injections, done late in the day, so the oven (garage) was down to slightly less than 100*. It took about an hour for it to cure, so I was done for the day.
 
Nice thread - minor question - which PEM nuts did you use and from where did you buy them?

Missleworks has them:

https://www.missileworks.com/store/#!/~/category/id=5760492&offset=0&sort=normal

They come in 4-40, 6-32, and 8-32 sizes. I used the 6-32 size.

Just for reference I have attached a chart that shows dimensions for each size of PEM nuts and the correct drill bit for each size.
View attachment PEM Nut Dimensions.pdf
McMaster-Carr is also a good source for PEM nuts but you do have to buy a larger quantity than you need. :wink:
 
Sorry to hear about all the problems you been having, but you always find a solution! What motor are you using and what is the expected altitude? Your build is looking real good, good luck on your flight and I hope to see it fly sometime.
 
Yesterday (6-28-14) I did the last internal fillet injection and started on the external fillets. Since Sharon was busy in the office I just blasted through the first two sets without taking any pictures. Today my trusty assistant was available again so we documented the last set of fillets twice. Yep, for the first time, I ran a set of fillets and they were so bad I removed them. But we will talk about that when we get there. Right now I will describe how I prep for external fillets.
If you get the amount just right with your injected fillets, there will be a little cured West Systems epoxy filling the slots filed. Sealing the slots and joint between the body tube and fins prevents bubbles forming when your external fillets settle into the void. Mine came out fine:

0532.jpg


Even the tape looked good, but I added a little more to the fins, just to be safe. Then I mixed up 20 grams of Rocketpoxy, using my handy little scale:

0115.jpg


and mixed in 5 or 6 drops of black tint:

0166.jpg

0186.jpg


Just a note here. I used a small plastic cup with the first two sets of fillets I did yesterday, and mixed up 40 grams of Rocketpoxy, enough for both sides. Even after the heat gun treatment, there were dimples and bumps in the cured epoxy. It wasn't that noticeable, but the fillets I did on my blackhawk came out better. The only difference I could note was that the epoxy I mixed for the blackhawk were done in smaller batches and mixed on a card. So I was mixing up a smaller batch today to see if it would help with the bumps.
After I had the epoxy thoroughly mixed, I sanded the area with 220 grit and wiped it down with acetone. Checked to make sure everything was level and started laying in the epoxy:

0216.jpg


I'm using a 1" PVC pipe to run the fillets, and dipping it in alcohol, shaking it off and running them:

0275.jpg


If there is excess, I move it down to the aft fin:

0285.jpg


Add what's left on the card to the rear fin:
0315.jpg


Dip my wiped off pipe in alcohol and run out the second fillet:

0354.jpg


Then catch all the drips that form with a finger:

0364.jpg


Looking pretty good, right?

0404.jpg


Lets hit it with the heat gun, that should smooth it out a little:

0423.jpg


after about two or three minutes with the gun:

0443.jpg


Worse than the ones I did yesterday. I'm not liking this at all. I tried some more heat, but it just made the epoxy thicker. I tried letting it sit out in the garage for about 15 min. and no improvement. So I scooped them out:

0493.jpg


Scraped and wiped it all out, removed all the masking tape and walked away. Went shopping at Ace Hardware. Picked up some more denatured alcohol and acetone. Little parts and a 3/8 NF tap for an idea I have for charge cups, later in this build....

More to come tomorrow...
 
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Sorry to hear about all the problems you been having, but you always find a solution! What motor are you using and what is the expected altitude? Your build is looking real good, good luck on your flight and I hope to see it fly sometime.

Snuck one in on me Juan. Yeah, I found a solution, but it's getting late, so I will post it up tomorrow.

I'm thinking an M1770 Skidmark or an M1297 White lightning. Depends on what kind of deal I can get. Should get somewhere in the neighborhood of 10 to 11k. If all goes well in Argonia, it will fly again in Jean, Nevada at Octoberfest.
 
If all goes well in Argonia, it will fly again in Jean, Nevada at Octoberfest.

Octoberfest?! Tripoli Vegas and TRAPHX will be co-hosting Octoberfest. And I'm excited about that. This may be the first official announcement of that, and it's on YOUR thread!
 
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Octoberfest?! Tripoli Vegas and TRAPHX will be co-hosting Octoberfest. And I'm excited about that. This may be the first official announcement of that, and it's on YOUR thread!

Now all we need it the announcement that you will be flying your custom scratch built secret rocket on the Loki 54/4000 motor at that launch... That's something to get excited about!

Back here in the laundry room, not much excitement. I took a couple of days off, partly to consider my options, and partly to supervise Sharon's 4" Jimbo Jart build:

https://www.rocketryforum.com/showthread.php?66843-Sharon-s-4-quot-Jimbo-Jart

I finished the last external fillets, this time using my old faithful Proline 4500 epoxy. It's messier, but flows out better. Starting with the taping of the fins and body tube with the same spacing as before:

0513.jpg


Back to the cup, so I can mix up a bigger batch. Relying on my memory, (big mistake) I thought it would take less epoxy by weight, thinking that Proline was less dense and would be more volume for the same weight. So I mixed up 27.5 grams of resin and 5 grams of hardener. Still using the little scale, I sucked up the resin with a syringe and weighed it out:

054.jpg


Same routine with the hardener, and started my timer when I started mixing. Two minutes later I set it down and re-sanded the grooves with 220 grit and wiped them with acetone:

061.jpg


Leveled the rocket out, across the fins and lengthwise too:

063.jpg


Now I'm ready to spread the epoxy:

064.jpg


Proline is much more viscous, and flows smoothly from the cup. I could tell pretty quickly that I hadn't mixed enough, but started running out the fillets:

066.jpg


Moving the excess to the next fin:

069.jpg


Then running it out too:

071.jpg


Maybe there's enough for one more:

074.jpg


Ran that one out, quickly mixed up another small batch and finished the last fillet. Started touching up the ends:

076.jpg


The beauty of Proline is that it flows out so nice, but that's also the curse. Even with everything nice and level, it still flows everywhere, making quite a mess.
I moved the rocket out into the garage to cure, and came back 30 minutes later to pull the tape.


Final inspection revealed that the last set of fillets were much better than the bubble ridden previous batch, but not up to leaving them naked like I did with my 3" Blackstar. I decided to sand all the fillets down and primer and paint the aft part of the fincan red. And with that, I came up with an appropriate name for this rocket. Living in the Southwest, We have lots of raptors, one of the most common is a large hawk, called the Red Tailed Hawk. So I will be making another order with Stickershock shortly.
 
I have been working pretty steadily on this build for the last week or so, now it's time to update my thread.
After setting the fincan aside, I started working on the avbay.
First up was the bulkheads. These new aluminum bulkheads are so nice, they fit perfectly with a lip to the outside of the coupler. Almost hated to drill holes in them. First came the holes for the all thread. Two 1/4" holes inboard just enough that the wingnuts will clear regardless what position they are in. Then I drilled two more holes 3/8" for my terminal blocks. Since I didn't want to mount them through the conductive aluminum, the hole had to be large enough to fill with epoxy and still clear the posts. I ran a 3/8" tap through them to give the epoxy a grip and filled them with black rocketpoxy. Here is how I mounted the TB's:


001.jpg


After I drilled the two 7/64" holes, I ran two conductor 24 gage stranded copper wire through them, put a little piece of 3/32" heat shrink on each lead, stripped abut 1/4" off each wire and tinned them. My soldering station has the little clips "helping hands", so one clip holds the bulkhead and one clip holds the TB, so I soldered the wires to the TB like this:

042-1.jpg


When I slid them back down on the BH, I put a dab of hot glue under them to hold them in place. If I ever need to replace them, I just heat up the BH and pull them loose. Here is one mounted:

043-1.jpg


For charge cups, I used 1/2" PVC pipe caps. My disk sander flattens the top so it will fit flush to the BH, and a 8-32 screw holds them in place. Once I determine where they will fit, I drill a 5/32" hole through the cap and mark where I want to mount them. Then I drill a #29 drill hole and tap it for the 8-32 screw.
The last hole I drilled was for the external speaker I use with my Stratologger. It mounts on the aft BH and I use hot glue for it too, because I have destroyed a few of them over the years, and hot glue is easy to remove and seals the hole the wires go through. I installed the eyebolt provided in the kit and cut off the excess threads. Here is the aft BH with everything in place:


005-2.jpg


The forward BH is done in a similar manner with the exception of the all thread. I mount both lengths of all thread on the forward BH by using two 1/4" nuts, one on top and one inside, with a little red locktite to hold them all in place.

I cut out a piece of black G10 1/8" fiberglass for my sled. It is 3.75" by 11" long. Then I cut notches in the ends to clear the nuts that hold the eye bolts in place. I rounded the edges with a piece of 220 grit, and started laying out the components for my redundant system. Remember the fins I had to cut down? I made my own double battery box using the scrap pieces from the fins:

016-1.jpg


I sanded down the sled and stuck the pieces on with rocketpoxy. After it cured outside for a few minutes, I brought it back in and ran some more rocketpoxy for fillets around the outside. I had to post this picture, because it's the best fillets I have ever done with rocketpoxy:

037.jpg


Now I'm mounting my altimeters and switches on the sled, and since it's pretty strait forward, I will post a picture of it complete and describe the special touches afterwards. Both the Stratologger and the RRC-3 were mounted using 4-40 stand-offs I get from Perfectflite:

089.jpg


The battery box "lid" is another scrap piece of G10 with two 6-32 button head screws holding it down. When I get some shorter screws, I will replace the ones in the pic. The holes on the sides were done before I made the lid. I tapped the center piece of G10 so the screws attach there.
There are also 3/16" holes at the top and bottom of each battery. They are for zip-ties to hold the connectors in place.
The magnetic switches are held by hot glue and one 4-40 flat head screw through the ground hole in the switch. It is screwed into a tapped hole in the sled. All wires from the batteries and to the altimeters are soldered to the switch. I looped a little slack into them, and hot glued them next to the switches.
The leads from the TB's on the BH's are cut to length and marked with white heat shrink:

045-1.jpg


All the wire ends that fit into the TB's on the altimeters have been tinned. All the wire used for connecting everything is 24 gage stranded copper. I also added some heat shrink to the wire bundles from each BH. The aft has a short piece to keep everything neat, and the wires from the forward BH are run along one of the all threads, this keeps them clear when I slide the sled in place. Here is another shot with the all thread and all the wires in place:

092.jpg


My next post will be assembling the recovery system and ejection tests.

 
Coming right along there Wayne. Looking good. I just wanted to add a tip about gluing terminal blocks to the bulkheads. Sometimes glue can get up in the TB and cause it to either not open or close all the way. Just wanted to warn others, as it's happened to me, ONCE.
 
Coming right along there Wayne. Looking good. I just wanted to add a tip about gluing terminal blocks to the bulkheads. Sometimes glue can get up in the TB and cause it to either not open or close all the way. Just wanted to warn others, as it's happened to me, ONCE.

You're right Bill, you can see that in the third picture in my last post. I almost mentioned that I use a small flat bladed screwdriver to clear that spot out before the glue cools down. Sometimes these sort of details get lost in the three hours of editing, adding pic's to Photobucket to explain some detail I forgot, and re-editing to make a point clearer, that I do just to get one post up in this thread. Building rockets is easy, documenting them is a PAIN!
There are a couple of things I want to share before we move along to the recovery part of this build. One of my TAPS, (Bob Brown) stressed the importance of recovery, and I quote:

“The up part is easy! The down part is the hardest!”
I worked my way through that statement with several key decisions. First was the eye bolt provided in the kit. It's designed for use in my rocket, and combined with the aluminum BH, makes a durable anchor at both ends of my avbay. Although Wildman provides 1/8" quicklinks, I upgraded to 3/16" because they fit over the eyebolt better and have more room for the 9/16" tubular nylon that I'm using for my shock cord. The TN provided with the kit is some of the best stuff I've seen, and that's from a skydiver who trusts his life to his gear. Which brings us to another point. I earned my living for several years packing parachutes, not only mine, but also student gear. Back when I was an active skydiver, students weren't trusted with "squares", the first jumps were done under 35 ft. military chutes called T-10's. I have packed thousands of them, and when you're packing for students, everything has to work right the first time. Mine always did. So keeping that in mind, lets get to it.

I started by attaching a 27 foot piece of 9/16" TN to the kevlar strap that is my "Y" harness secured to the MMT. It came out a little long, so I added an extra knot at the lip of the fincan. As you can see, I use the extra sticky green masking tape extensively on key areas of my recovery system. It is thicker and stickier than standard masking tape and more heat resistant than nomex. Easy to remove or repair too, just add more where you need it, and if you want to undo a knot, rip it off, not like the heat shrink I used to use. Speaking of knots, I use a simple overhand knot for almost everything. The overhand loop for attaching chutes is also a favorite of mine, as you can see in this first picture of my drogue shock cord:

047-1.jpg


On several of my smaller rockets, I have used a 3 foot length of 1/4" kevlar where the shock cord attaches to the avbay, but for this build, I used a 36" nomex sheath to cover the TN where it's exposed to the ejection charge. I've done this before, and it works well. I tried tying this TN to kevlar with a double fishermans knot, and don't like how these two dis-similar lines fit together. So overhand knots at the ends and an overhand loop to attach the drogue. One of the downsides of these knots is that they are hard to undo when stressed, but that's also why I like them. They don't come apart. Period.
Next up was a pocket for my drogue:

020-1.jpg


I buy nomex cloth from Pegasus Racing supply and make most of my own nomex pads and deployment bags. It's a little pricy, but allows me to make what I want exactly as I want it. My little Brothers sewing machine struggles with some of the materials I use, but mostly does the job. It couldn't punch through the TN, nomex sheath and folded over pocket that I wanted to secure, but I got a couple of good lines across it and I backed it up with more green tape. The loop that my new Cert 3 24" drogue is hooked up to is down far enough on the shock cord that the weight of the fincan pulls it clear of the pocket. It's attached with a 1/8" quicklink and comes with a swivel.
Now I'm gonna walk you through how I pack stuff. 27 feet of bridal needs to stretch out without getting tangled, so I wrap it across my hand in an S pattern keeping the drogue attach point clear:

022-1.jpg


Yes, with my big hands, I can wrap all 27 ft. between my thumb and last finger:

024.jpg


The drogue is flaked so all the shroud lines are together and each gore is separate:

026-1.jpg


Everything should be laid out like this now:

027-1.jpg


Fold the tip over to the skirt:

028-1.jpg


And roll it up:

029-1.jpg


Fold it again:

030-1.jpg


Then S fold the shroud lines to the same length as the chute. Grab the shock cord and hold it all together:

031-1.jpg


And stuff it all into the pocket. If you don't have a pocket, roll it up "burrito" style. Here is mine:

032.jpg


All tucked neatly into the bag:

033-1.jpg


I have watched the deployment sequence of another system like this and everything comes out as the fincan falls away, the drogue usually inflates before the fincan pulls the shock cord tight and it keeps the payload (and main chute) well above the fincan.
I fold over the end of the bag before I stuff it in the fincan, and because it fits snug in the tube, everything stays together:


034-1.jpg


As you can see, everything that is exposed to burning black powder is protected with green tape:

035-1.jpg


I even S fold the nomex sheath on top, then add some dog barf on top of that:

036-1.jpg


Next, I'm going over packing the Main chute. I might even get to posting up my ejection tests, which I did yesterday. But right now I have some sanding and priming to do.
 
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What is that green tape?

Great write up BTW...thanks for doing it in such detail.

Ed
 
What is that green tape?

Great write up BTW...thanks for doing it in such detail.

Ed

Thanks for taking the time to share Wayco, have been curious how a Pro packs the laundry .

Think I have 5 types of tape to go with my 5 types of epoxy : Green 1/4 inch, Green 1/2 inch, Blue 3/4, Blue Delicates in two sizes, Electrical and Scotch tape (for AT Hobbyline grains) . No duct tape yet. Have used tape extensively for marking and sizing also.

Kenny
 
What is that green tape?

Great write up BTW...thanks for doing it in such detail.

Ed

Scotch masking tape for "hard to stick surfaces".

Getting responses from other forum members makes it worth it to spend hours posting up these type of threads. I also promised both my TAPS that I would do this to keep them informed on my progress and process. I'm hoping I can copy and paste some of this into the required "Term Paper" report required for a Level 3 certification.

The 60" Recon chute is the biggest I have used to date, and the way it's packed from Wildman is the best way to repack it. Fortunately, it's done the same way I have packed round chutes for the last thirty years. Each gore is flaked out separately with the shroud lines together and even. Here is a shot of my "Main chute" recovery system:

001-1.jpg


The nomex pad is 16"x 16" and I determine what I need by "eyeballing" it. Look at what you want to pack, and cut the nomex to fit. My sewing machine can handle the stitch that binds the loose ends, and even goes through the 1/8" kevlar loop that I attach to one corner to keep it with the rest of the stuff. The main chute is attached to the overhand loop with a 3/16" quicklink, along with the loop of kevlar on my nomex pad. The overhand loop is about 5 ft. down from the N/C. From that shot above, I unfolded the chute and started with it like this:

005-3.jpg


Same process basically as the drogue, tip or "crown" of the chute to the skirt:

004-3.jpg


This chute is easy because it's been folded and stuck in a bag. You can see the next folds:

003-3.jpg


That last step is the same as rolling up the drogue, now we fold in half lengthwise twice to get it the right size for my nomex pad:

010-1.jpg


Next step is where you can really reduce the size you are packing. Squeeze it together with the shroud lines S folded the same length and wrap the pad around it, removing as much air as you can, while tucking the pad around it:

011-1.jpg


Fold the ends into the center with special attention to the lower corners. You want to totally cover any chute material, especially on the side facing the ejection gasses:

012.jpg


Then roll up the shock cord with the next layer of pad:

013-1.jpg


Keep it tight as you roll it, and it will come out like this:

014-1.jpg


Oh, by the way, my main shock cord is 19' long.... Both lengths were pre cut by Wildman and included in the kit. His build instructions include this info. and recommend a 60" Skyangle Classic 2 chute, which is what the Recon was made to replace.
Now, when you stuff it in the payload tube, it's nice and snug. You can also see that the top of the shock cord is in an overhand knot, with a 1/8" quicklink attaching it to my kevlar Y harness I covered in an earlier post:

018-1.jpg


The next post will be prepping for my ejection tests. You can already see the wires coming out of the avbay static ports in that last picture.
 
You're doing a great job on documenting this build.

" Building rockets is easy, documenting them is a PAIN!"

Truer words have never been spoken! I can build a complex rocket in a matter of days. Taking & going through tons of pics to do a thread like this with all the little important details is mind blowing.

Take 10 find the 2 that look best & on & on it goes. Keep up the good work. You take way better pics than I do.:smile:LOL

Good luck on your L-3. Will that be at Airfest?
 
This is one of the best build threads ever on TRF (and no slouching on the actual build itself either!). GREAT job Wayco.

s6
 
You're doing a great job on documenting this build.

" Building rockets is easy, documenting them is a PAIN!"

Truer words have never been spoken! I can build a complex rocket in a matter of days. Taking & going through tons of pics to do a thread like this with all the little important details is mind blowing.

Take 10 find the 2 that look best & on & on it goes. Keep up the good work. You take way better pics than I do.:smile:LOL

Good luck on your L-3. Will that be at Airfest?

Thanks CJ, you probably know this already, but you're one of my hero's on this forum. My build threads are just echo's of what I have learned from you and Tim, along with at least a dozen other members that take the time to document their builds. Even when I don't take your advise, I use it to make the best decision on what I want to do.

Yes, my next launch will be at Airfest, and I intend to fly my Dark Star Extreme on Saturday for my L-3 attempt, if it's maiden flight goes well on Friday.

So I just got back from Black Angus and a delicious filet with white chocolate bread pudding for dessert. That's one of the bennies of being married to Sharon, she likes red meat. Other benefits are listed in the "working from home" thread....:wink:

I'm back in the rocket room trying to get caught up with everything I have done in the last week. Next up is prepping for my ejection charge tests.
One of my other hobbies is collecting military surplus rifles and reloading cartridges for the rare rifles I own and can't find ammo for. If you have seen some of my other builds, I use rifle and pistol cartridge cases for ejection charge cups. I didn't do it on this build because I assumed a bigger rocket would need bigger charges to get the laundry out. It was also pointed out to me at ROCstock that the edges of the metal cases are sharp, and can short out the wires to your lighter. This would be a BAD THING. Thanks to "Skippy" (Gerald Meux) for that tidbit.

The bigger rocket, bigger charge isn't always true. My theory on the reason for this is the way I fold my laundry. If you fill the hole up, it doesn't take as much BP to push it out. So I fold my laundry to fill the tube, like a bullet does in a rifle. Expanding gasses can't get by and all the energy is used to launch the package. That's just my theory, I'm not a rocket scientist, so I might be wrong....
Along the way, I bought a set of handy little scoops made by LEE, which sells reloading equipment. Here's a link to the Lee webpage:
https://leeprecision.com/powder-measure-kit.html

You can probably get it on Amazon too, but it's a great way to measure your ejection charges.
Here's my setup for loading charges:

037-1.jpg


After reading Wildman's instructions and Viperfixers build thread, I decided to start with 2.2 g and 2.7 g in both the apogee charge and main charge. I know Wildman will tell you 1 gram per inch, but his instructions say 2-3 grams for apogee and 2-2.5 grams for main.
I also know there are lots of ways to do this, and I don't claim to have the "best" method. But I do fly a lot of dual deploy rockets, sometimes I can get four DD flights in one day, like last month at ROCstock, and one of the reasons for this is ease of preparation. I build most of my motors at home, and prep my avbays there too. With the use of the little green terminal blocks, all the internal wiring is done right here in the rocket room. No loud noises to distract me, and no one shouting "HEADS UP" over the PA system while I'm listening for beeps from an altimeter. I secure all the wires to the altimeters and pull test them here then seal the avbay up, check it off my checklist and move along. Here is how I set up the charge cups at the launch site:
Cut the "lighter" to fit:

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Spit the ends so they fit into the TB and strip back about a quarter of an inch. I use my fingernails, but we have several tools that do the same job.
LOOK at where you are putting these ends:

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Don't stand over the top of a TB and wiggle them into where you think they will go. LOOK them into the hole and tighten them down. Then pull on each wire with a pair of needle nose pliers. Just a little tug to make sure it's secure.To me, this is the single most important step when making a critical electrical connection. That goes for the TB's on your altimeter too.
Now route the wire into your charge cup and tape it down,covering the TB in the process to keep the BP residue away from that critical connection:

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Don't let the tape run off the BH either, it makes sliding it in the tube harder. Run another piece of tape around the top of the cup. I use 1" tape for this:

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Stick a little funnel into the cup, you want all of the BP to go where it does the most good:

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Measure out your BP:

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And dump it in:

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Check to make sure your e-match (oh wait, sorry CJ) check to make sure your lighter is in the BP:

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and add a wad of dog barf to hold everything in it's proper place:

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Seal it up:

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and repeat for three more cups. Here's the other end:

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Let's see, four rockets a day with four lighters in each rocket. Most of my rockets have redundant systems. Sharon can usually get two or three more a day, so the count can easily exceed 25 lighters a day. Good thing they are cheap and reliable:
https://www.rocketryforum.com/showthread.php?60469-CJ-s-WaCkY-WeD-Doing-dual-deploy-ya-need-these
Shameless plug for my good buddy CJ.

Next up will be ejection charge testing, where we actually get to blow things up!
Looks like that will be posted tomorrow, I need to spend some quality time with my Honey.

 
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Wayne-obviously there is no amount of praise I could heap on you that you haven't heard in one form or another. I do want to personally thank you for showing how to refold my Recon chute and the tip about hot gluing terminal blocks. I really enjoyed posting up with you at Roc39 and look forward to sometime in the future we can do it again. I'll be doing Jean Lake and ROC40. Airfest is out for me as my son is coming home to visit for a couple of weeks after being gone to China for two years.
 
Wayne-obviously there is no amount of praise I could heap on you that you haven't heard in one form or another. I do want to personally thank you for showing how to refold my Recon chute and the tip about hot gluing terminal blocks. I really enjoyed posting up with you at Roc39 and look forward to sometime in the future we can do it again. I'll be doing Jean Lake and ROC40. Airfest is out for me as my son is coming home to visit for a couple of weeks after being gone to China for two years.

"Hanging" with you guys was a . . . UNIQUE experience for me, never done before. I enjoyed our "awake" time together but sleeping was a challenge with the symphony of snoring. I'm used to Sharons "heavy breathing", ( is that suggestive?) and can sleep pretty good unless there is a big project to keep me awake. We might be able to do it again, but not for ROCstock 40, Sharon will be coming to that event.
After Airfest, our next launch will be with Tripoli Las Vegas in October. Hope we can hook up there, and if everything goes well with my L-3 attempt, I should have another M motor to fly. Sharon is also very interested in building the Mongoose 75, so it might be ready for it's first flight by then. I think I can find a small 2 grain motor that will keep the Mongoose under their waiver..

OK, back to the build thread. I spent part of yesterday sanding down substandard external fillets. Hopefully, I can get some primer on this rocket this weekend. Still need to contact Mark at Stickershock about a decal, but haven't firmed up my ideas regarding that yet. Might wait til after I paint the fins. I'm pretty sure the name will be "Red Tailed Extreme", any comments?

I did three ejection charge tests Wednesday, two for the main and one slightly modified one for the drogue.
Charges for the main were 2.2g and 2.7g. As you may have noticed in my last post, I ran the wires from my terminal blocks out through the static ports in the switchband. I built a special 4 conductor wire about 10 ft. long with alligator clips at one end and stripped solid wire at the other to do these tests with, using a 9v battery to fire the charges.

066-1.jpg

Before these tests, I added two handfuls of dog barf behind my new recovery system. Cellulose insulation is a lot cheaper than nylon, so I pack it full:

064-1.jpg


Here is the video of that first test, using 2.2 grams of 4f BP:



The second test was more energetic with 2.7g:



After reviewing those videos, I decided that I would use 2.5g for my primary charge and 4g for the backup. This is in line with what my TAP discussed with me, using 150% for the backup charge. I also noticed that there was some BP residue on the nomex pad, so I might up the dog barf to three handfuls.

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This was after the first test, and as I was repacking the main I noticed there was a little that got inside the pad, but no damage to my chute. Increasing the volume of db, and packing it in tighter, like I would at a launch, should eliminate this.

For my drogue test, I did things a little different. I've always wanted to see how the fincan reacted to an ejection charge, so instead of bracing it on the wheel of my Jeep, I suspended it from the roof:

081-1.jpg



With just a little weight resting on the pillow, the strap is slightly aft of CG. So I hooked up my wires and did another test:

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Here we go with what was actually a 2.8g charge, despite what my commentary says. This was also done with a 4 grain AT casing in the MMT:




I had to review the video to determine that I fired the larger charge on that test, and I didn't fire the other charge. Instead, I took it back in and weighed the BP that was in the other cup. 2.2g was in the unfired charge, so I used the green and red wires for that test. Like I said, I'm not a rocket scientist....
I have three casings in 75mm, one AT 4 grain (5120), one CTI 4 grain and the CTI 6xl casing I bought last year from Wildman on black saturday. It came with closures and two spacers. That last test convinced me that 2.8g was plenty for a 4 grain, and 2.5 would work with the larger 6xl casing. I'm gonna stick with 4g for the backup, unless my TAP's change my mind.
Here's a shot after that last test, showing that the drogue does come out of the nomex pocket and lots of dog barf to clean up:

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Here's the forward charge cups after the test:

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Pretty sure I can get a bunch of flights out of these before they need to be replaced, and that should be easy when I do.
So I'm moving back into the laundry room now, to continue sanding my fincan. So far, I have 16 pages of pictures loaded into Photobucket in this one folder. That's over 360 pic's. Took me three days to post the last five entries. Since sanding fillets doesn't take any special talent, I will probably take the weekend off and not post here again until the fincan is in primer. Still need to drill holes and attach my aerodynamic rail buttons, but other than that, it's sand, paint and add decals then I'm done. I will try to remember to take pictures of anything interesting I do with this build, but no promises there.
Once again, I want to thank everyone that has commented on this post, and want to encourage those of you that have held back that question you have regarding something I did that you might not understand or agree with. So don't hesitate, throw it out there so we discuss it, that's what makes this forum so great!

 
Thanks for this fantastic build thread! Some really great ideas in here.

Speaking of knots, I use a simple overhand knot for almost everything. The overhand loop for attaching chutes is also a favorite of mine, as you can see in this first picture of my drogue shock cord:

047-1.jpg


On several of my smaller rockets, I have used a 3 foot length of 1/4" kevlar where the shock cord attaches to the avbay, but for this build, I used a 36" nomex sheath to cover the TN where it's exposed to the ejection charge. I've done this before, and it works well. I tried tying this TN to kevlar with a double fishermans knot, and don't like how these two dis-similar lines fit together. So overhand knots at the ends and an overhand loop to attach the drogue. One of the downsides of these knots is that they are hard to undo when stressed, but that's also why I like them. They don't come apart. Period.

I have a similar love-hate relationship with overhand knots. You have been so generous taking time to share your ideas; I hope you don't mind if I share a couple thoughts on knots based on my climbing experiences. Figure-of-8 knots are at least as reliable as overhand knots and easier to undo, but bulkier. The figure-of-8 works great for the Y-harness loop adjusted so it hits the edge of the tube. Cover it with a wrap of duct tape to prevent abrasion and you have a poor man zipper stopper. For attaching chutes, the butterfly is a nifty knot. The butterfly knot is used to quickly tie into the middle of a climbing rope. It preserves strength along the shock cord while being easy to undo even after loading. Here's a pic of a butterfly knot used to attach a drogue chute.
View attachment 177310

For tying into eyebolts, I have started using a slip knot with the tag end tapped so it doesn't pull through. It is a super compact knot around the eyebolt, easy to undo (removing tape is the most tedious part) and there is no loop to size or get hung up on charge wells etc. When I first saw this on the Apogee site I was very skeptical of the knot slipping off, but it has been 100% reliable so far (dozens of flights) on rockets up to 8 lbs. I am not sure I am ready to endorse the slip knot with tape for bigger rockets though, probably I would still go with a figure-of-8.
 
Thanks for this fantastic build thread! Some really great ideas in here.



I have a similar love-hate relationship with overhand knots. You have been so generous taking time to share your ideas; I hope you don't mind if I share a couple thoughts on knots based on my climbing experiences. Figure-of-8 knots are at least as reliable as overhand knots and easier to undo, but bulkier. The figure-of-8 works great for the Y-harness loop adjusted so it hits the edge of the tube. Cover it with a wrap of duct tape to prevent abrasion and you have a poor man zipper stopper. For attaching chutes, the butterfly is a nifty knot. The butterfly knot is used to quickly tie into the middle of a climbing rope. It preserves strength along the shock cord while being easy to undo even after loading. Here's a pic of a butterfly knot used to attach a drogue chute.
View attachment 177310

For tying into eyebolts, I have started using a slip knot with the tag end tapped so it doesn't pull through. It is a super compact knot around the eyebolt, easy to undo (removing tape is the most tedious part) and there is no loop to size or get hung up on charge wells etc. When I first saw this on the Apogee site I was very skeptical of the knot slipping off, but it has been 100% reliable so far (dozens of flights) on rockets up to 8 lbs. I am not sure I am ready to endorse the slip knot with tape for bigger rockets though, probably I would still go with a figure-of-8.

Thanks for contributing Dave, I like the butterfly knot also, just forgot it from my climbing days many years ago. Your link didn't work, so here is a favorite site I use occasionally:
https://www.animatedknots.com/alpin...ge=LogoGrog.jpg&Website=www.animatedknots.com
 
I love the target on the Staples box with the nose cone holes. :grin:

Ed
 
Another outstanding build thread, Wayne.

Between your threads and Sharon's I'm learning a whole bunch of fiberglass tricks.

Thanks!
 
Wayne,

Very nice build thread!

I noticed your using a deployment bag for your drogue but wrapped the 60" main in a nice tight nomex barrio roll. Is there a reason you are using a 18" nomex blanket for the main?
 
Wayne,

Very nice build thread!

I noticed your using a deployment bag for your drogue but wrapped the 60" main in a nice tight nomex barrio roll. Is there a reason you are using a 18" nomex blanket for the main?

Nothing logical that I can think of, more like a feeling that the main will deploy better from the blanket. I like the way it fits in the payload tube. I'm gonna revisit the drogue bag too, not real happy with how it came out. I made one for my wife's 4" Jart that came out better, so a redo is in order.
I don't use a set size blanket for anything. I take the chute/drogue and everything I want to go with it and set it on a cutting board with 1" squares on it, then eyeball it for the size I think will work best. Having a nice big piece of nomex cloth available makes this a convenient method for making deployment bags and blankets.
 
Time to update this thread. First with pic's of my progress on the Extreme. I painted the fincan with Dupli-color Metalcast "Ruby" red paint, but instead of using the silver base coat, it went over white primer:

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I liked it so much, I also did the switch band and metal N/C tip, since Airfest has an issue with metal parts.

Mark with Stickershock did his usual magic and got my order to me quickly and the color matches the fincan quite well:

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In other news, apparently I damaged my right shoulder moving furniture last week, and am unable to use my right arm. MRI imaging shows some fraying of the rotator cuff, but it isn't torn, so no surgery is necessary. It is painful, but our doctor thinks that resting it, along with Bromine, a natural anti-inflammatory, will get me back operational in a couple of weeks. So, I'm sitting here with my arm in a sling, learning how to hunt and peck with my left hand. And I thought I was a slow typist before this happened...
Fortunately, my rocket is mostly done, and I do have time to heal. We will probably have to modify our plans for Airfest though, depending on how my shoulder responds to rest and the planned therapy. We are still hopeful that we can make the trip and take a shot at my L-3 flight.
...


 
That red colour is sweet!

I hope your shoulder heals as soon as possible! I think we all want to watch this fly and not mention we all love your build threads, so we need you feeling 100%.
 
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