Level 3 Build - Rocketry Warehouse Terminator

The Level 3 bug has gotten me again. My last attempt was about 15 months ago. The main failed to deploy and the damage was terminal. So I debated on an original design vs. a kit and decided that if a Black Friday sale produced a kit under $250, the same cost as buying parts to do an original design, that I would go for the kit. The thought being I just want to build it, get it up, and then get it down.

Rocketry Warehouse introduced a new kit on Black Friday, and it is cool looking. Plus it was $229. A GREAT deal. Since I had the recovery system, motor retainer, and electronics from the last attempt, this was a no-brainer.

There is one big challenge. I want to certify at the Geneseo Airport and this little bad boy sims to 11,000+ feet on an M1230. Geneseo's waiver is 10,000'. I wanted to keep the performance aspects, but I also wanted to be able to control the altitude when I needed to. So this will have an adjustable weight system. A 5/16" threaded rod will be affixed to the top of the nose cone and steel weights will be able to be added or removed as needed.

The rocket arrived today so I was able to measure and weigh parts and come up with an very good representation in Open Rocket. With 20 lbs. of nose ballast this will weigh about 41 lbs. I can still use my 10' chute for the main, and I have a 58" chute that will serve as the drogue. I will use either an M1230, an M1830, or if I have the money, an M1770 for the flight. Below is the side view and 3D view of the showing the layout. On social media, a couple people have asked me for this since RW hasn't put together a RockSim file yet, so for those others who bought this kit, attached is my OR file.

View attachment RW Das Terminator.ork

The kit is excellent. Beveled 3/16" G10 fins, 4:1 ogive nose cone with aluminum tip, ogive tailcone. 5" G12 FW airframe. Nice bulkheads for the AV Bay, which is very spacious. Total height looks like almost exactly 100". Here is a photo of the components as well as the dry fit. In the dry fit photo, the ruler to the bottom is 15" long.




I ordered the rocket in natural finish so I can paint it. Not fond of the yellow and black because it reminds me too much of the Pittsburgh Steelers, and I'm a Bengals fan, so that will never do. So I am thinking of a color combination to pay tribute to my college alma mater, Ohio University. Colors are forest green and white, and a little black thrown in as well. I think I will use a metallic green, and if I can find it, a pearlescent white. This is my first stab at a color scheme. Imagine this baby flying on an M1770.



The build will be done over time because I have other projects going on as well. Questions and comments are welcome.

Looks like a great project!

Have you considered using the lower half of the av-bay for electronics and the upper half to hold weights? That would let you keep the altitude down without excessive stability margins.

20 lbs of nose weight... Are you sure?

I thought about that as well. It would actually be a little simpler except for making room for the main ejection charges.

dixontj93060 said:

20 lbs of nose weight... Are you sure?

Click to expand...

I could do it with 15.

Handeman said:

Have you considered using the lower half of the av-bay for electronics and the upper half to hold weights? That would let you keep the altitude down without excessive stability margins.

Click to expand...

I thought about that and it is still an option. Keeping the weight there would still bring the CG forward, but not near as far as putting the weight in the nose. Realistically, I only need the added weight once. From then on, if I want lower flights, I use smaller motors, including mid-to large sized 54mms. A K2045 would still shoot it up to 3,000' or so.

Why so much nose weight? Just to keep it under 10K?

Handeman said:

Looks like a great project!

Have you considered using the lower half of the av-bay for electronics and the upper half to hold weights? That would let you keep the altitude down without excessive stability margins.

Click to expand...

EeebeeE said:

I thought about that and it is still an option. Keeping the weight there would still bring the CG forward, but not near as far as putting the weight in the nose. Realistically, I only need the added weight once. From then on, if I want lower flights, I use smaller motors, including mid-to large sized 54mms. A K2045 would still shoot it up to 3,000' or so.

Click to expand...

The other thing about putting that much weight in the av-bay, or right ahead of the av-bay in the payload tube is that the shear pin/main deploy issues at apogee when using DD should be much less and easier to handle.

crossfire said:

Why so much nose weight? Just to keep it under 10K?

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Yes. This sims to 11K in OR for even an M1101. Stick an M2245 and it sims to 18k. The tail cone adds a lot of altitude. Realistically, I should have proof it only sims to 90% of the waiver. That plus I don't want to recover the thing out of the Genesee River.

Handeman said:

The other thing about putting that much weight in the av-bay, or right ahead of the av-bay in the payload tube is that the shear pin/main deploy issues at apogee when using DD should be much less and easier to handle.

Click to expand...

Very good point.

EeebeeE said:

Yes. This sims to 11K in OR for even an M1101. Stick an M2245 and it sims to 18k. The tail cone adds a lot of altitude. Realistically, I should have proof it only sims to 90% of the waiver. That plus I don't want to recover the thing out of the Genesee River.

Click to expand...

Could you build it in such a way that the tail cone could be removed for a single flight?

watermelonman said:

Could you build it in such a way that the tail cone could be removed for a single flight?

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Not really. The only way to do it is to make the motor tube 2-piece and then reattach it later, but that would compromise the structural integrity of the completed rocket when I tried to put it all back together. The coupler holding the tailcone on is only 2" long with about 1" extending into the airframe. Any FG outer coupler gluing the 2 pieces of the MT together is also a max of 3" long. I'd rather weight it down than to permanently weaken it. I do think I will add the weight into the AV Bay where the threaded rods can hold it together. I can use a 4" airframe to mold a lead shot weight using epoxy and use tubing to create holes for the rods and the wires to the charges. The weight would be 4" in diameter and 4" long, and would weigh 15-17 lbs. if I did my calculations right. The AV bay is pretty spacious and is still forward of the CG. Having it there helps to avoid overstability and also enables the shearpins in the nose cone to withstand the ejection charges at apogee, as pointed out earlier.

EeebeeE said:

Not really. The only way to do it is to make the motor tube 2-piece and then reattach it later, but that would compromise the structural integrity of the completed rocket when I tried to put it all back together. The coupler holding the tailcone on is only 2" long with about 1" extending into the airframe. Any FG outer coupler gluing the 2 pieces of the MT together is also a max of 3" long. I'd rather weight it down than to permanently weaken it. I do think I will add the weight into the AV Bay where the threaded rods can hold it together. I can use a 4" airframe to mold a lead shot weight using epoxy and use tubing to create holes for the rods and the wires to the charges. The weight would be 4" in diameter and 4" long, and would weigh 15-17 lbs. if I did my calculations right. The AV bay is pretty spacious and is still forward of the CG. Having it there helps to avoid overstability and also enables the shearpins in the nose cone to withstand the ejection charges at apogee, as pointed out earlier.

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Makes sense; merely brainstorming.

It's a good thought.

I ordered this same kit & needed a .ork file to play with before it arrives. Thanks for the .ork!
I noticed your fins are set to "airfoil" & paint to "polished". Only the leading edge is actually airfoiled?
Maybe the rocket won't fly quite as high as sim'd. I like the idea of removable weights. Maybe for the Cert flight just add the weight, have just an "ok" finish paint job & put some tape over the air foiled edges....all temporary of course.
I'm showing a tad over 10K with airfoiled fins, smooth paint, & 2 lbs of weight for the Ballast in the nose on the M1101, even with 0 mph winds.

I'm going to be adding foam to my fin cavities plus nose weight.

Good luck!!

I am thinking it could be built so one could remove tail cone with tail cone fins coming off with it. A 2 section MMT. A little longer tail cone coupler that bolts on. Just an idea

I don't know jack about L3 certification, but adding another 100% of the mass in nose weight to keep within 10k feet just seems ... wrong. Perhaps you can add removable drag plates, instead. Or, choose another kit to simply "build it, get it up, and then get it down???"

Buckeye said:

I don't know jack about L3 certification, but adding another 100% of the mass in nose weight to keep within 10k feet just seems ... wrong. Perhaps you can add removable drag plates, instead. Or, choose another kit to simply "build it, get it up, and then get it down???"

Click to expand...

There is nothing wrong with adding weight to stay under a waiver. The waiver at Geneseo is 10K feet. Part of the safety protocols of an L3 attempt is to make sure your simmer flight is 10% under the waiver, so this should not sim above 9K feet. This is to make sure you don't bust the waiver be a use if you do bust it, you don't certify. Also, surrounding our field is this stuff called "corn." Have you ever looked for rockets in corn before? Not fun.

Finally this is my third attempt. Fanciness, mach-busting, high altitude flights decrease the chances for success. I also put a lot of time building the rocket I used for the first two attempts. Both failures were freak accidents with the last one completely destroying my rocket. This time I wanted something that could be built fairly quickly and inexpensively. Maybe I am a little cynical but this time I just want to get the f-----g thing over with.

Modifying the rocket with removable parts or adjustable configurations seems like a lot of unnecessary thinking and a lot of wasted time. I'd rather just bolt in 15 - 20 pound of lead and be done with it. Part of the KISS principle. The time that would have been spent over-thinking one-time changes to what is already a solid design would be better spent giving it a killer paint job. Some times we really don't need to be rocket scientists.

The weight can be made of lead shot and epoxy in a short period of time with tubes used to create the holes to run the AV bay threaded rods and the wires to the charges through it . It is removed and will never be used again after I certify.

Then I'll put an M3700 or an M2245 in it and let her rip at a field with a higher waiver. I want to Cert at Geneseo because I know the terrain, I know the access roads, and the people there are my friends and I can count on there support. Some of the nicest rocketeers in the hobby fly there.

You may think it's wrong, but it feels 100% right to me.

EeebeeE said:

I want to Cert at Geneseo because I know the terrain, I know the access roads, and the people there are my friends and I can count on there support. Some of the nicest rocketeers in the hobby fly there.

You may think it's wrong, but it feels 100% right to me.

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I know exactly how you feel. That is exactly why I had to do my cert at BattlePark. If you want to make an anchor for your rocket to keep it under the waiver and cert at your field, go for it!

BTW, you're not quite right, the "nicest rocketeers in the hobby" fly at BattlePark

I too was torn between nose weight and a different field. I would have been fine with the waiver, but was uncomfortable with recovery from that altitude given how much would be lost with a lost rocket. Losing the motor hardware and electronics along with needing to try again soon would have hurt!

I wound up waiting for a bigger field, though I am kind of spoiled with how many large dry lake beds I can hit in a one day drive.

Why not just fly at Potter instead? They have a better waiver and field.

JD

EeebeeE said:

There is nothing wrong with adding weight to stay under a waiver. The waiver at Geneseo is 10K feet. Part of the safety protocols of an L3 attempt is to make sure your simmer flight is 10% under the waiver, so this should not sim above 9K feet. This is to make sure you don't bust the waiver be a use if you do bust it, you don't certify. Also, surrounding our field is this stuff called "corn." Have you ever looked for rockets in corn before? Not fun.

Finally this is my third attempt. Fanciness, mach-busting, high altitude flights decrease the chances for success. I also put a lot of time building the rocket I used for the first two attempts. Both failures were freak accidents with the last one completely destroying my rocket. This time I wanted something that could be built fairly quickly and inexpensively. Maybe I am a little cynical but this time I just want to get the f-----g thing over with.

Modifying the rocket with removable parts or adjustable configurations seems like a lot of unnecessary thinking and a lot of wasted time. I'd rather just bolt in 15 - 20 pound of lead and be done with it. Part of the KISS principle. The time that would have been spent over-thinking one-time changes to what is already a solid design would be better spent giving it a killer paint job. Some times we really don't need to be rocket scientists.

The weight can be made of lead shot and epoxy in a short period of time with tubes used to create the holes to run the AV bay threaded rods and the wires to the charges through it . It is removed and will never be used again after I certify.

Then I'll put an M3700 or an M2245 in it and let her rip at a field with a higher waiver. I want to Cert at Geneseo because I know the terrain, I know the access roads, and the people there are my friends and I can count on there support. Some of the nicest rocketeers in the hobby fly there.

You may think it's wrong, but it feels 100% right to me.

Click to expand...

Suggestion... Split the weight between the n/c and the top av bay b/h. Both removable. Bolt half up front in the n/c, then use an eyebolt on top of the av bay with a 3" shank. Cast a 2 1/2" long weight, and use the eyebolt to hold it in place. When you want to remove it, use a shorter eyebolt. Try to avoid making the bird 10 calibers over-stable.

Of course, brain-storm it with your L3CC/TAP. I don't have OR. How's she sim with an AT M1297? That's about the most milquetoast M I know of. It's an M like a J350 is a J. Just barely.

Quick edit.. As suggested earlier, reset those sim parameters to something a bit more realistic than "polished."

I start with "polished" to look for maximums. The more appropriate setting is "finished-smooth paint" but all M's even the CTI M1101 (5,200 NS) still blast through the waiver. A single 15 lb. Weight in the aft end of the AV bay will work. That is still forward of the CG, and the stability ranges between 1.4 and 1.9 CA depending on motor choice. With that an M1830 will sim to 8K, which will work. The weight can bolt to the 2 threaded rods holding the AV bay together.

Bam. Sounds solved. Good luck with the L3.

Gotta give credit to Handeman who suggested the idea of this location very early in the thread. Once I started thinking more about it I realized that the threaded rods which are already in the AV Bay could also be used to effectively secure the ballast as well as the sled. Once I started thinking of lead shot and epoxy which can easily be molded into a desirable shape, with the mounting holes created by using paper tubes to prevent the shot and epoxy from filling that area in the molding process, it became clear how much simpler it was to use existing hardware for a second purpose than to drill holes through steel plates and the side of my nose cone.

This is the revised OR file, and for those who felt that "polished" was too ambitious of a paint setting, I used "smooth paint" instead. :eyeroll: Really didn't change the altitude that much. All the M's still blow through the waiver, and with the ballast attached, the M1830 drops from 8,500' to 8,200. The actual altitude will probably net out to just under 8,000' although OR tends to understate the aerodynamic benefits of tailcones.

View attachment RW Terminator - Rev 1.ork

I actually just recently started doing the same thing with OR. I use Polished, airfoiled, 0 deg angle, 0 mph winds, etc.. Just to see the worst "local waiver busting" scenario. Not a bad idea at all, especially for fg rockets with nice rigid fg airfoiled fins. Then there is the tailcone....2.65 Cal stable. Looks good.

Thanks Handeman for that tip! Will have to remember that one.

Let the building commence....

JDcluster said:

Why not just fly at Potter instead? They have a better waiver and field.

JD

Click to expand...

I and a number of other people have lost some rockets there recently, and if this thing were to deploy the main at apogee I may never see it again.

What about some kind of removable (screwed on?) drag inducing components to keep under the local waiver? Something that could be undone when you have the room the let it rip. Probably located very aft, which would also help the CP/CG.

Viperfixr said:

What about some kind of removable (screwed on?) drag inducing components to keep under the local waiver? Something that could be undone when you have the room the let it rip. Probably located very aft, which would also help the CP/CG.

Click to expand...

Simplicity wins. I'm going with a weight in the AV Bay.

A question:

What is the benefit of using threaded rods to hold CRs together. I don't see it, but I know people who swear by them. I am trying to determine if I need to do that because it will make a process to do internal fillets very difficult.

For my internal fillets, I want to tack the fins into the slots using 15 minute epoxy. I will temporarily fit the CRs in place, then temporarily slide the MT in place. Then I will glue the fins...only at the slots. When they are aligned and glued in place, I will slide out the MT, take out the CRs. and have a lot more free space to apply Rocket Poxy internal and external fillets. When that is complete, I will then glue CRs and MT into place. I will repeat the process for the tailcone fins.

Having threaded rods would make it difficult to effectively do this. Do I really need them?