Glasspacks' LVL II Build

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Thank you all for the feed back..... The nose cone is the "Pinnacle" model from Giant Leap. It was like $25.00 and seems like a very nice nose cone.

Handeman, I will take up close photos of the nose cone after recovery testing and post them here.

I really like those nose cones, can't beat the cost/value (Plus they look cool :cool:). Seems to me that there is plenty of "meat" in the shoulder to file a recess for shear plates without too much trouble, if testing shows they are needed.

I'm really looking forward to your test results...
 
Are the Pinnacle cones the ones with the raised ribs on the shoulder?
If so, those are the easiest ones to install shear plates onto.
 
Yeah. So those you can just J B Weld your shear plates in between the ribs. No having to thin the area down first before you place the plate.
 
While the Dog was trying to hide from the neighborhood fireworks display, we spent sometime in the basement marking and drilling. My tiny drill bit and 2-56 Tap won't be here until Monday, so I moved onto the Rivets. I used the simple paper wrap method to get my straight edge around the tube and marked the bottom end of the upper airframe for the 5/32" Rivets that hold the Avionics bay onto the airframe.
20200704_165823.jpg20200704_165924.jpg The first Rivet was lined up with the Altimeter Arm Switch; as you can see, its got blue tape protecting the switch during build, sanding and painting. The Vents for the altimeter (Small holes on 1" switch band) are purposely in another part of the airframe to ensure smoother airflow. All the lines for the Pins, Rivets, Vents and fins are 120 degrees apart. The Vents are about 60 degrees away from the rivets and pin lines.

20200704_174932.jpg20200704_175742.jpg The tiny semi hole right under the rivet at the vent band & airframe joint is an alignment mark. Neat little trick I learned from The Rocketry Forum. Thank you CJ. Of course the tape held it all tight as I drilled and installed the rivets. After they were all done I disassembled it and coated the drilled cardboard with Thin CA Glue and am waiting for it to fully cure before smoothing the holes and inside /outside areas.

20200704_181100.jpg20200704_181054.jpg It really is thin and flows like water. Perhaps I should have waited and done one hole at a time..... It looks messy now.

Happy Fourth Of July EVERYONE
 
Ooph, I hear you there. Puppy refused to stay outside long enough to poop/pee last night (and the night before becuase the baseball stadiaum did 3rd fireworks) Fortunately he's old enough to hold his bladder for the night.

Hurts my heart since I love fireworks

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It really is thin and flows like water. Perhaps I should have waited and done one hole at a time..... It looks messy now.

Happy Fourth Of July EVERYONE

A lot of folks (me included) like to soak the entire tube ends with thin CA. Hold the tube horizontally, drip a bunch of the ca in there and roll it round until it coats everything. Let it cure up real well, then sand it smooth. Makes it all nice and plastic-y inside and really toughens up the tube.

Mike
 
Not to offend or cause trouble, but I would ditch the tap. You don't want the broken off piece threaded into the tube, because you wont be able to unscrew it easily. Yes, the portion with the head will unscrew, but the other side is a little more difficult. I started out doing this also, then got tired of wrestling the threaded piece out of the tube. Now I use numbered drill bits and friction fit the nylon screws into the airframe. For 2-56 I use a #46 drill, then go back with a #45 or 44 for just the outer airframe. For #4 shear pins I use a #36 drill and then the same, a slightly bigger drill for the outer airframe. Just my humble opinion, YMMV.
 
Not to offend or cause trouble, but I would ditch the tap. You don't want the broken off piece threaded into the tube, because you wont be able to unscrew it easily. Yes, the portion with the head will unscrew, but the other side is a little more difficult. I started out doing this also, then got tired of wrestling the threaded piece out of the tube. Now I use numbered drill bits and friction fit the nylon screws into the airframe. For 2-56 I use a #46 drill, then go back with a #45 or 44 for just the outer airframe. For #4 shear pins I use a #36 drill and then the same, a slightly bigger drill for the outer airframe. Just my humble opinion, YMMV.


Adrian,

Thank you for the input. My thought was if it were threaded I could use the tip of an Xacto blade to unscrew it. Otherwise, I will have a handful of little pieces of nylon trapped in the nose cone after a few flights. I know the weight will be a moot point, but I think It will drive me crazy. Would it be just as much a pain in the ass, to tap only the outer tube. Do the pins shear just as well with a pressed in fit instead of a tight threaded fit. ?
Do know an effective way to get the little ends of the screws out of the cone ?

I did think I could use a small tube: After the cone is tipped, they all fall to the tip. Then like a straw, slide the tube down to the inverted tip.
Then, while holding it; tip it right side up so they fall out the tube. Thanks again. …..
 
Thank you for the input. My thought was if it were threaded I could use the tip of an Xacto blade to unscrew it.
You can also get some small left-handed drill bits and drill the pieces out. You need to be careful, but when the drill bites well enough it unscrews the stub. I have done this, before I gave up on tapping the inner hole.
 
I found this information on the WEB as well...………… Thank you all for the feed back.

" Shear pins/screws should be equally positioned around the circumference of the rocket. Never use just one pin, because the coupler may cock and bind.

When using screws, don't tap both the body and the coupler and cause premature shearing. The slight threading mismatch will add stress to the screw. Tapping the body tube only makes removal of the sheared screw easy and does not stress the screw. "
 
I drilled and tapped the upper air frame and nose cone for the shear pins. Holding the nose cone tight in position to the air frame, (Once I started to drill) with plenty of tape. I am going to have to find a new tiny drill bit to re-drill just the Nose Cone shoulder and just take the threads out, like we talked about. I also made an index mark (much like the other end) to align it up later.

20200706_192824.jpg20200706_195516.jpg20200706_193701.jpg

Then I realized after looking at it all again; if the shear pin halves are not somehow taken out of the nose cone shoulder after flight......
they will will be forever trapped between the two bulkheads in my Nose cone. See the red dot on my graphic below.......

Trapped Pins.jpg
There is NO way to get the other half of the 3 pins out, if they are pushed into the shoulder between those two bulkheads.......
Maybe its no big deal.... or Maybe a small 3/8" hole in the side of the shoulder to tip them out, would be OK ?
 
I either let them fall in, or use the sharp tip of a xacto to unscrew them. Depends on how I feel that day (although most of my pinned noses have the interior accessible anyway
 
I've only drilled the same size hole through both walls (only in fiberglass) for the shear pins, never tapped anything. Push the remainder into the av-bay/nose cone when you put the next set in. The rattle never bothered me. I just clean them out when I get around to opening the av-bay/nose cone the next time.
 
Well I think I found my test flight motor...……… I really like the CTI I445 VM simulation data..... You think that punch from the VMAX will be too much for the cardboard airframe. I think it will be fine, since its just an I-445. The speed off the rail is good and the low altitude is what I want to test fly this think prior to LVL2 Cert.

That other "Sim" with the K1440, I am sure would most likely shred it....
I445 Vmax.jpg

Going to get back to it this weekend and do a lot of sanding and priming...
 
I think the K1440 may be too much. You'll be going supersonic, plus near 40g. Even if you didn't shred it, you'd melt the nose.

Is the 9ish pounds weight with motor correct? I'd have to weight my L2 bird again to confirm, but I think it was around 6-7lbs and I did a K360. But that was also a much cleaner 3" profile. I missed it somewhere, what size is your motor tube again?

-Hans
 
Hans,

Its a 54mm Motor Mount, to which, I have 3 Cesaroni casings. The model is currently at 7.8 lbs without a motor. May come in a little lighter when I verify the Actual weight, Center of Gravity, and all that. Yea I never intended to fly a K1440 just messing with Sims. Was a little bit surprised to find the Avionics bay alone is like 20 oz !!
I think It could do Mach 1 at some point, after talking about it here reading other posts. Just maybe to heavy and wide bodied to make that happen. I plan to do a handful of ground testing and flight tests before my Certification attempt. Did you, like most others, use fiberglass for your level 2 ? I had ALWAYs planned to use my Cardboard and Plywood Binder Design Kit for LVL2 but repurposed its pieces when I fell in love with that model form Argentina.
 
Even if you didn't shred it, you'd melt the nose.
Not even close to melting the nose. Don't worry about it. Shredding is another story :).

My L2 was a Velociraptor by Binder Design with cardboard airframe. No problems around Mach at all. What thickness are your phenolic fins?
 
Not even close to melting the nose. Don't worry about it. Shredding is another story :).

My L2 was a Velociraptor by Binder Design with cardboard airframe. No problems around Mach at all. What thickness are your phenolic fins?


The Fins are Canvas Phenolic at 1/8" Thick..... From Mac Performance Rocketry. They started out as 3/16" Thick but I changed them to thinner material after talking to company owner Mike.

I have even talked to "Crazy Jim" Hendricksen a little bit about his experience with a Heavy Wall Paper Tube Air frame Model at Mach 1 Speed. So, Other than the fact that it will be difficult to push it to that Speed BECAUSE this beast is 90" tall and 4" Diameter. I think it is Plausible for it to survive with the way I am building it. I do think I am arrogant enough to try ...... but smart enough to know JIM is WAAAAAAYYYYYY smarter than I am about Model rocketry and I know better than to try the K1440.
 
Was very happy to get a little bit done this weekend. First coat of primer on the tall model. Now the fun begins.....so much sanding to do. That's all of it together, except, shock cords and chutes. The weight without recovery gear is just a hair over 6 lbs. So the weight seems to be right on track with Rocksim so far......
Thank you Reese for the help !!
20200719_180529.jpg20200719_180927.jpg20200719_180921.jpg
 
If you don't have the VMax motor in your hands, you'll probably have trouble finding one. They've been discontinued post-CTI-fire, so they're getting pretty rare. Of the other options, the I218 has the most oomph but would still be a little light on thrust off the pad. There's some 4-grain 38mm motors (eg I285, I303, I470) that would be great if you have the hardware and adapter.

I haven't posted before on this, but I've been lurking. It's been really cool to follow it!
 
If you can switch to using AT 54/426 motors, there’s the I599N. They’re still available. Should be plenty of punch...
 
If you don't have the VMax motor in your hands, you'll probably have trouble finding one. They've been discontinued post-CTI-fire, so they're getting pretty rare. Of the other options, the I218 has the most oomph but would still be a little light on thrust off the pad. There's some 4-grain 38mm motors (eg I285, I303, I470) that would be great if you have the hardware and adapter.

I haven't posted before on this, but I've been lurking. It's been really cool to follow it!

Thank you Boatgeek

:facepalm:Too bad...…. I just put my name on the list at Apogee to be notified when the I445Vm is back in stock ! LOL

I do have CTI Pro38 and Pro54 Hardware...……
So I feel like I have several options. But unless I get a different Case.....those options are within the Cesaroni Motor Lineup......

On a good note ... was just playing with the Rocksim file, compared the actual current assembly you see with the primer on it, to the model in the file with the parts removed that are not attached yet; turns out, the actual model is about 1 pound lighter than the model in the file.
That makes me a little more happy....
 
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Just ordered me some MJG Initiators from Cobra Firing Systems for my inventory. https://www.cobrafiringsystems.com/ Nice price and nice service.......
I ordered the ones with bare wire ends (Standard), of course. I only wish they were shorter than 3 feet long...... but no worries, they are easy to cut to size.
I will most likely do the ground testing of Deployment System soon, before I put the final paint on it..... Heck, I may test fly it before I final paint it.
 
Did some sanding after that first coat of primer. The lower airframe Tube joint and the Tailcone/Tube joint is proving to be a challenge. The Tail cone is fiberglass and is slightly larger diameter than the Airframe tube. Got a lot of work ahead to hide them seams properly...…..
 
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