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patelldp
9th November 2010, 03:33 AM
And so begins another L3 thread!

I recently purchased a Performance Rocketry G12 Competitor 5 kit with the intent of getting my L3 certification through Tripoli. I have obtained 2 TAP's through MDRA, and so the process begins.

The model will be built exclusively with Proline epoxy. With a 4" motor mount, the plan is to some day fly it on a 98mm-3g EX motor, but for now the cert flight will most likely be a Loki M1882LW. Electronics will be an Ozark ARTS 2 primary with a Perfectflite MAWD backup. The recovery will be drogueless at the top, with a Rocketman R14 ProXP deployed at 1000'.

As I construct the rocket, weights will be figured out and I will narrow in on the simulation. For now, enjoy a picture of the components from Performance, as well as a picture of the first CR being glued to the motor mount!

Rocketman248
9th November 2010, 04:24 AM
Sweet dude! This'll be easy for you. You shooting for Red Glare 10?

patelldp
10th November 2010, 01:57 AM
Some more pictures...

First picture is the top of the motor mount sanded and ready for the fore centering ring to be bonded to it. You can also tell in this picture that Curtis at Performance Hobbies uses his reject tubes as motor mounts...which is fine by me as long as they are structurally sound. This tube (4") looks like it was a practice on his filament winder and he had yet to get it just right.

Second picture is of the JB Weld applied to the motor mount. I went with JB Weld on this CR (Proline on the last one) is because of it's thicker consistency, along with its ease of use. The Proline will be great for tough-as-nails fillets later on, but for this application I needed something that would hold the ring where it needed to be. The choices were this or 5 minute epoxy, and this obviously is the better choice.

Third picture is of the spacing apparatus that I use on every build. I want the fore CR to be spaced in from the end of the tube to accept a healthy fillet and that's it, so I place the glue on the tube, set up the CR on the fins as so, and then push the motor mount through the CR. The result is a CR perfectly spaced 0.1875" from the end of the tube (in this case, the thickness of the fins), ready for a beefy fillet of Proline epoxy.

Last picture is of the JB Weld evened out into a nice fillet. The next step will be to apply a fillet of Proline epoxy to the fore-side of both CR's that are attached. An aft fillet is not advised on the mid CR, as the fins will be mounting there and I need a nice square junction at the motor mount/CR.

Lamp
10th November 2010, 02:15 AM
Nice one Dan, I have been thing of a suitable rocket for my L3 which I may attempt next year. I already have a Competitor 3 and my thinking was for an attempt with its 5" big brother.

I'm only thinking about it at the moment but I'll keep an eye on your thread. :D

patelldp
10th November 2010, 05:19 AM
Nice one Dan, I have been thing of a suitable rocket for my L3 which I may attempt next year. I already have a Competitor 3 and my thinking was for an attempt with its 5" big brother.

I'm only thinking about it at the moment but I'll keep an eye on your thread. :D

Sounds good, Lamp. I had a Competitor 4 that I got about 8 flights out of before I hung it in a tree...everything from 54-800 to 76-3000 EX motors, that rocket flew like a champ.

The Competitor 5 is a good choice for L3 if you use a really small M motor, like the M1297W or M1882LW, just due to altitude. It will still go pretty high on these motors, but it's certainly doable on most HPR fields.

The last picture of the night is of the two CR's that have been bonded to motor mount...this time with Proline fillets. The masking tape is to keep the epoxy from running off, as it is appears to be pretty thin. The epoxy will be perfect for when I insert the motor mount into the fincan tube, as I will paint a significant amount North of the CR's, quickly shove it in to where it needs to be, and then let it all settle to form a great internal fillet. That could happen tomorrow night, we will see.

One other acquisition for the project today was a Rocketman R3 drogue chute. Not sure if I want to go drogueless or not, but I figured it'd be good to have both options available to me.

Anyone have any suggestions on the best place to buy Kevlar for a project of this size and weight at a good price? I was thinking 3/8" to 1/2" Tubular Kevlar, 30' for the drogue section and 20' for the main?

gdiscenza
10th November 2010, 06:08 AM
You could look at Aerocon (http://aeroconsystems.com/cart/products/Kevlar_Tape_for_Recovery_Bridles-150-49.html), I bought my Kevlar there and it is really nice stuff.

G.D.

Lamp
10th November 2010, 06:22 AM
Giant Leap sells some nice 1/2" tubular kevlar.....they sell it by the metre but also have it in 15', 20', 25' and 40' lengths with sewn loops but you might be able to find it cheaper elsewhere.

patelldp
10th November 2010, 01:26 PM
You could look at Aerocon (http://aeroconsystems.com/cart/products/Kevlar_Tape_for_Recovery_Bridles-150-49.html), I bought my Kevlar there and it is really nice stuff.

G.D.

Nuts, I just ordered a bunch of battery holders, switches and rail buttons from Aerocon for this project, never thought to look for Kevlar there...

I do have my doubts that this Kevlar Mule Tape isn't strong enough for this size of rocket. Anyone have any insight on that?

Lamp - I saw GL and I think that is where I am going to have to purchase it from, despite it being fairly expensive, I can have it pre-sewn by them.

Picture for the morning is of the fillets with the tape off....these rings aren't going anywhere!

Rocketman248
10th November 2010, 01:52 PM
How are you planning on attaching the recovery harness to the booster? Those centering rings are mighty thin.

patelldp
10th November 2010, 04:04 PM
How are you planning on attaching the recovery harness to the booster? Those centering rings are mighty thin.

I knew this would come up...off of the top of the motor. There will be a forged eyebolt in the forward closure of every motor this rocket flies on. The eyebolt will be held in place using split washers and nuts to keep it from unscrewing itself.

Rocketman248
10th November 2010, 06:22 PM
Oh yeah, that'll work! :)

patelldp
11th November 2010, 12:18 AM
After about an hour or so of sanding, I have the motor mount to the point that it can slide in and out of the booster tube. Let's just say Performance Rocketry does not make a kit that slides together out of the box, and that's fine for this type of project. It's more or less a collection of parts, not a kit.

At this point, it's time to re-sand everything to ensure a good epoxy bond, and then it's time to mix up a whole crap-load of epoxy and make sure those CR's are firmly bonded to the inside of the booster tube, and in the correct location.

dixontj93060
11th November 2010, 05:59 AM
Let's just say Performance Rocketry does not make a kit that slides together out of the box, and that's fine for this type of project. It's more or less a collection of parts, not a kit.


Uh, yah... Too bad, but that's life a bit of :gavel: and a measure of :bangpan: but in the end a super L3 rocket! Keep up the good work!

patelldp
11th November 2010, 07:03 AM
Uh, yah... Too bad, but that's life a bit of :gavel: and a measure of :bangpan: but in the end a super L3 rocket! Keep up the good work!

I definitely knew it was coming based on past experiences with my Competitor 4 and Wildman Jr. "kits". Once you fine-tune them to fit, the components work really well together.

Project for tomorrow is to get the fin-can glued in, stay tuned.

patelldp
11th November 2010, 08:29 PM
Fin can is in!

You would think that, since this is a L3 project, I am an all-knowing rocketeer, but that is just not the case. I learned a few things, reminded of other things, but in the end it looks pretty good.

So, the first picture is of the fincan (all sanded and ready to go) up against the body tube, also sanded and ready to go. I marked the fincan tube so that I could know how deep I need to go with a dowel to apply epoxy inside the tube just before the final resting spot of the upper CR to create a good fillet.

Second picture shows the epoxy through the fincan (love working with a transparent body tube and black epoxy!).

Third picture shows my method for creating a fillet and bond on the middle CR. It's impossible to apply epoxy to the BT at this joint without it being pushed up by the top CR, so I apply excess epoxy to this CR before installation. The idea is that it will settle out and create a fillet on this CR. It appears that this may not be working as well as I had planned (didn't put enough epoxy on the ring), so I may have to pop a hole and pour in some laminating epoxy to get a good fillet. Or, after the fins are set, I can pour epoxy from the rear end to lock in the leading edge of the fin tab and catch the back of the CR in question.

Fourth picture is following installation of the motor mount, showing the resulting fillet (may not be easy to see). This is where I learned a lot about my techniques:

1. Wear latex gloves with black epoxy. I have always been an "epoxy paw" kind of guy, I have never worn gloves to handle epoxy. Most of you are probably saying "this guy is stupid," but that's not the case. I have good soap that I clean up with after I get epoxy on me, and I have never had a reaction to the chemicals as a result. In this case, however, they must use Lampblack in the epoxy to darken it because it just does not come off right away. I got most of it out, and I am sure it will all be gone by the time I return to work tomorrow.

2. If the CR's fit tight inside the tube, they will slide MUCH easier with epoxy acting as a lubricant. I have experienced this before, but never so drastically. I pushed the motor tube in, which was VERY tight, and when it came to the epoxy, it slid way past the target depth. While this really isn't a big deal, I can see the monster smear through the tube. The fillet may not be as big as it could have been on the top ring now, but that shouldn't be a big deal.

The last picture is what I can see through the translucent tube. Looks good to me, but the fillet that I mentioned earlier on the middle CR just isn't appearing as I wish it would. This is what leads me to believe I will have to pop a hole and pour in laminating epoxy. The fins are in the slots to be sure that no sagging occurs.

Now it's time to wait for that to cure, assess the outcome, and then start tacking fins on!

patelldp
11th November 2010, 08:30 PM
The last picture didn't go in for some reason, so here's the look through the tube at the epoxy settling out.

rocdoc
11th November 2010, 10:18 PM
Anyone have any suggestions on the best place to buy Kevlar for a project of this size and weight at a good price? I was thinking 3/8" to 1/2" Tubular Kevlar, 30' for the drogue section and 20' for the main?

Two things: First, the Giant leap tubular kevlar harnesses are nice, even if a little pricey.

Second, I might consider going a little longer on your harnesses. The GLR kevlar has absolutely no give, so if your ejection is a little overly energetic, you may want to have some extra time for stuff to slow down a bit. On my L3 project I plan to take this one step further by using GLR kevlar for the portion of my harness closest to the charges and 1" tubular nylon farther away. The nylon will give a little, adding shock absorption.

Good luck on your cert flight!

Bryan

patelldp
11th November 2010, 10:58 PM
Two things: First, the Giant leap tubular kevlar harnesses are nice, even if a little pricey.

Second, I might consider going a little longer on your harnesses. The GLR kevlar has absolutely no give, so if your ejection is a little overly energetic, you may want to have some extra time for stuff to slow down a bit. On my L3 project I plan to take this one step further by using GLR kevlar for the portion of my harness closest to the charges and 1" tubular nylon further away. The nylon will give a little, adding shock absorption.

Good luck on your cert flight!

Bryan

Thanks for the tip, I ordered the cords yesterday and went 40' and 30'. 30' on the main seems a little long to me, but it can't hurt.

I am sure the Kevlar harness from GLR are awesome, but I just can't see spending that when I could either tie or sew the cords myself. I may just end up using the Kevlar from Aerocon as a charge-proof leader, with a long length of 9/16" TN for the rest of the cord, as I have done with all of my rockets in the past.

patelldp
11th November 2010, 11:31 PM
More progress - I love these days off...

First picture shows some epoxy on the root of the fin, as well as about 1/4-1/2 of the way up the fin. This allows the epoxy to get caught between the fin and the body tube at the slot, creating 2 more points of adhesion. Also, a small external fillet results which seals the slot so when the real fillets go in, the epoxy won't leak through.

Second picture shows the alignment method I use...Stick the fin in, tape it in place, take a step back, make sure it looks good, and repeat until the fin looks to be in the same place. Looks go to me, and you can see the small fillet that results from the insertion.

Rinse and repeat 2 more times, and it will start to look like a rocket.

patelldp
13th November 2010, 02:05 AM
Not much else to add, except a picture of fin #2 in place.

Also, the R3 chute arrived from Ky at Rocketman. I'm not sure if I will use this as a drogue or a pilot/nose cone chute (I bought it for my Wildman Jr). Very nice chute, but not nearly as tough as my R14 ProEX. Should be fine in either capacity, though.

patelldp
13th November 2010, 08:25 PM
Fin #3 is attached. Here are a few pics showing the fin in, the back end, and then inside the MMT showing that the black Proline epoxy really shows through well so I can tell I got good adhesion.

rocdoc
13th November 2010, 08:57 PM
That proline epoxy looks like you're trying to attach the fins with roofing tar. :p

Starting to look like a rocket! Nice work so far.

patelldp
13th November 2010, 11:02 PM
That proline epoxy looks like you're trying to attach the fins with roofing tar. :p

Starting to look like a rocket! Nice work so far.

It does look that way, and I don't know how I feel about it. It seems like good stuff, we'll see when the fillets are in place. Speaking of fillets, that will dress up the outside of the rocket nicely, right now it looks pretty sloppy with the crappy fillets that were formed from the excess epoxy that squeezed through.

I am at the cross-roads where I can't decide if I want to foam the fin can or try to drip fillets down there. It's a very narrow opening. I know I need to foam the cone (very thin in places), so I might as well foam the fincan as well. Shouldn't have too great of an adverse effect on the stability, especially with the heavy main chute balancing things out.

patelldp
14th November 2010, 01:05 AM
All stacked up, next to my 2.1" Wildman Jr. The tape measure is opened to 5 feet. In my small apartment, it was tough to get far enough away to fit this beast into the frame.

patelldp
15th November 2010, 03:00 AM
First fillet is done.

patelldp
18th November 2010, 06:08 PM
Now for the "bling" on this rocket...98mm Custom Engraved Aeropack retainer.


In the words of Quagmire on Family Guy...."Giggity."

patelldp
23rd November 2010, 12:57 AM
Home for Thanksgiving, so I have access to the machine shop now. Started work on the electronics bay. First picture is of all of the holes drilled in all 3 bulkheads.

Second picture is of all of the "crap" on the bulkhead, including terminals, U-Bolt's, and recycled charge holders I turned out of aluminum for a previous rocket. These were made LOOOOONG before the day of the Blastcap and have several flights on them. Much easier to just steal them from the other rocket to use on this one.

Third picture is of one end of the bay with the all-thread installed.

Fourth and last picture shows the coupler with the internals out of it, showing off the space in this bay.

Next step is to cut the electronics board, mount the altimeters (Ozark ARTS 2 and Perfectflite MAWD), and wire it all up. Holes also need to be drilled in the coupler and payload tube to mate the two for flight.

patelldp
23rd November 2010, 03:11 AM
The drogue end of the electronics bay has been glued in.

rocdoc
23rd November 2010, 05:06 AM
The drogue end of the electronics bay has been glued in.

May I ask why you chose to permanently attach that bulkhead to the electronics bay? Seems like it would be a major PITA to connect your electronics that way. How do you plan to do that?

Bryan

patelldp
23rd November 2010, 05:27 AM
May I ask why you chose to permanently attach that bulkhead to the electronics bay? Seems like it would be a major PITA to connect your electronics that way. How do you plan to do that?

Bryan

I tend to feel it's the exact opposite. Not gluing in the one end requires three hands to put together for me. All I have to do in this case is run two wires from the drogue end to each altimeter, and a sled pulls out attached to those wires. The only difficult part is making sure that you get all of the wires in there without pinching anything, and even that's very simple.

Tomorrow I should have the sled cut and altimeters mounted. From there the wiring will start, and you will see it really is quite easy to use this method.

rocdoc
23rd November 2010, 07:22 AM
I tend to feel it's the exact opposite. Not gluing in the one end requires three hands to put together for me. All I have to do in this case is run two wires from the drogue end to each altimeter, and a sled pulls out attached to those wires. The only difficult part is making sure that you get all of the wires in there without pinching anything, and even that's very simple.

Tomorrow I should have the sled cut and altimeters mounted. From there the wiring will start, and you will see it really is quite easy to use this method.

Cool. Look forward to seeing how you do it. Do you have any concerns about using a single thickness of G10 as a bulkhead in the drogue compartment? I always get worried that an unfortunate deployment event could tear the U-bolt through the G10. Is that 1/8" or 3/32" G10?

Sorry for all the questions.

Bryan

patelldp
23rd November 2010, 01:51 PM
Cool. Look forward to seeing how you do it. Do you have any concerns about using a single thickness of G10 as a bulkhead in the drogue compartment? I always get worried that an unfortunate deployment event could tear the U-bolt through the G10. Is that 1/8" or 3/32" G10?

Sorry for all the questions.

Bryan

Don't be sorry for the questions, I'm appreciative that someone is going through my thread and processing what I am doing!

The bulkhead is 1/8" G10. I have successfully used a single thickness of 1/8" G10 in my Competitor 4 for several flights, the increase to 5" shouldn't make too big of a difference. The U-Bolt utilizes the "bridge" that comes with it, or a rectangular piece of steel that has two holes for each leg. This should prevent the UBolt from pulling out because it distributes the force over a much greater area.

But then again, I could be wrong, you never know!