Nytrunner
Pop lugs, not drugs
Have you done any work on the Ebay you can share?
Rich's GLR Nuclear Sledgehammer...continuation of original build thread
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rharshberger
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The E-bay is actually in the thread that I linked in post #1 of this thread. Brett had already built the Tri-Bay and it came to me pre-equipped with 2xMissleworks RRC2 (older pre-mach immune ones, never flown afaik) and one each section (drogue and main) Rousetech CDD3 Co2 ejection systems. Really the fin can is the only part I have to finish along with the nose cone bay I want to add (hoping to get time on Saturday between my 4 year olds B-day party and tip to tip glassing the wings to do that mod).
Nytrunner
Pop lugs, not drugs
Ah! Now I see it. That is an interesting system.
rharshberger
Well-Known Member
Very, changing to BP ejection is just a matter of changing one "module". Of course BP ejection requires building a modified version of a piston that GLR intended to prevent scorching of the laundry.
Nice work, Rich.
rharshberger
Well-Known Member
Gettin' there Steve, hoping to do external fillets tonight and Tip to Tip tomorrow.
It’s amazing how much more work a large diameter rocket requires, isn’t it?
rharshberger
Well-Known Member
Especially when you want to both save weight and keep it strong. This has been a fun one so far and I really am only getting to build the fin can section as Brett had the forward section pretty much built.
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It is. I’m still amazed at how long I’ve been working on the motor mount for my L3... usually my builds are much further along by now!
I think that's what I said when Sharon bought the Ultimate Darkstar for me.
I've been following your build, and really like what you have done to this rocket. The fins are a work of art, and I agree with your decision to leave out the foam.
Are you planning to fly it with the old RRC-2's?
Tell me about it. Two years with a team to build the 7.5" scratch built "Tweety Bird".
It all pays off when you get to watch it go up.
rharshberger
Well-Known Member
Wayco, I will probably remove one of the RRC2's and use either a Eggtimer Quantum or my Missleworks RRC3 Extreme as the RRC3 has flown in every rocket that has been important to me so far. The RRC2 I will leave as a backup and once I have real data from either the Quantum or the RRC3 and confirm there is little chance of mach issues. Of course both RRC2's will be tested in my vacumn chamber to verify they haven't been damaged over the years. Something this large definitely will need/want redundant altimeters. If needed I will replace both RRC2's with the aforementioned altimeters.
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rharshberger
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Fillets fillets fillets....
Ready for tip to tip or it will be once the epoxy has set enough to give a final wipe with denatured alcohol to smooth the edges. Fillets were pulled with 1" PVC pipe, my wife bought me a set of fondant tools for fillets but the large size of these fillets kind of make them too small for the task at hand.
Ready for tip to tip or it will be once the epoxy has set enough to give a final wipe with denatured alcohol to smooth the edges. Fillets were pulled with 1" PVC pipe, my wife bought me a set of fondant tools for fillets but the large size of these fillets kind of make them too small for the task at hand.
Nytrunner
Pop lugs, not drugs
A rocket is good when you can total fillets by the yard.
That and body spiral cordage, although you cheated and glassed it.
That and body spiral cordage, although you cheated and glassed it.
rharshberger
Well-Known Member
I cheat lots on my HPR rockets, love my LOC airframes but the vast majority in my collection are ummmm....modified, as in at least two layers of fiberglass fabric wrapped, so no spirals for me, just pinholes. It took approximately 90grams of epoxy and fillers (1/32" milled glass fibers, and cabosil in US Composites 635 3:1) with the heat cranked up to 80F in the garage/shop they set pretty quick.
Nytrunner
Pop lugs, not drugs
L2200G. Tame the green dragon!
Have you compared your fiber filled US vs Aeropoxy 6xxx (structural)?
Have you compared your fiber filled US vs Aeropoxy 6xxx (structural)?
rharshberger
Well-Known Member
There are US Composites 150 structural epoxy fillets under the new ones. From comparisons in the past between the two epoxies they are close enough that cost is the deciding factor. I have on occasion used Sytem Three T88 as well. Internal fillets will be more US Composites 150 ones. The 150 epoxy is a stroner bonding but harder curing epoxy, the 635 is a bit more flexible. One of these days I need to go back and reformat my old epoxy comparison thread from a year or two ago, the comparisons were for both Aeropoxies varieties, West, System Three, Rocketpoxy, and one or two other iirc. All were close enough in each application that unless high performance properties were called for they were good enough for most hobby rocket projects. High performance epoxies are ones like Hysol, Cotronics, and similar ones.
Nytrunner
Pop lugs, not drugs
I recall that thread! It was great
rharshberger
Well-Known Member
Okay, actually finally got to work on the bird today at about 4pm, the daughters B-day party kind of waylaid my plans along with a headache shortly after waking this morning. First thing up was to modify my cradle setup to allow a bit more rotation of the rocket, luckily I had a section of 7.5" coupler to extend the airframe a bit as the tip to tip for the wings goes right past the edge a bit so it can be trimmed flush. The dummy motor came in handy along with the rollers for my airframe rotisserie. I decided to use perforated release film instead of peel ply to attempt a bare carbon fabric look, my guess is its going to be no dice and a lot of sanding. Oh well that was plan B anyways, Plan A was to come up with a stealth like color scheme, something along the lines of a Soviet Shark Camo in grey and black, or the grey and dark blue version or possibly the digital shark camo, another option is a white prototype style with orange stripes and stuff. Still looking for ideas for my paint scheme (feel free to submit a few photo's TRF'rs and see what comes up).
The actual placing of the single sheet (yes I said sheet, that section of FG fabric is like putting bed sheet on the rocket) each of 10oz and 3oz glass was a bit of a pain, and the epoxy was getting really tacky toward the end of the process, enough so that I pitched the last ounce or so and mixed up some new stuff. The single fin was also a bit of a pain to work around the the double fins on the backside are going to be even more fun tomorrow. The glass even fully wetted out didn't show the carbon well enough in my opinion so its going to be covered by paint. Sometime around 2300 or midnight I will go an trim the excess off, and remove the release film if its cured enough.
The actual placing of the single sheet (yes I said sheet, that section of FG fabric is like putting bed sheet on the rocket) each of 10oz and 3oz glass was a bit of a pain, and the epoxy was getting really tacky toward the end of the process, enough so that I pitched the last ounce or so and mixed up some new stuff. The single fin was also a bit of a pain to work around the the double fins on the backside are going to be even more fun tomorrow. The glass even fully wetted out didn't show the carbon well enough in my opinion so its going to be covered by paint. Sometime around 2300 or midnight I will go an trim the excess off, and remove the release film if its cured enough.
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Looking good, Rich! I'm looking forward to seeing this beast fly at Sod Blaster! Maybe we will have to M flights that weekend!
rharshberger
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Hopefully we get a few more than two M's
, after all the new Coker style pad is almost ready to go and its a beast. Dave K, has said he is getting ready to build the away cell wireless launch controller. Really hoping you are there to take some awesome pics of the flight and Ryan and his camcorder, the flight of this monster should be easily visible as none of the sims exceed 5k AGL, and its most likely going to be a dark colored rocket. Did I mention that the motor I am hoping to fly it on will possibly be certified in the next 30-45 days (according to ATGM) the M1955DM
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Hopefully we get a few more than two M's
Oh, Ill be there for this beast to fly! I saw that about the M1955DM! I would love to fly one of those on the Sandhawk, but I'd bust the waiver at the sod farm! If the Coker pad is ready soon, I might just have to fly the Sandhawk at the farm before FITS, and maybe go for my L3 there instead... Im eyeing one of the big 75mm L DM motors for Sod blaster...
rharshberger
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Hold on to that motor choice thought....sometime shortly before SodBlaster II we will announce what the motor color theme will be (kind of like last years sparkies). The Coker pad should be ready to go by no later than April...the Sledgehammer is whats holding it up.
rharshberger
Well-Known Member
Last of the tip to tip is on, instead of a single large piece for each layer the main section was left in a large piece and the smaller sections done individually. The peel ply will definitely leave a better surface than the release film did. The release film had plenty of wrinkles and "left its mark" (I am very disappointed in ACP Sales for shipping the release film folded, even immediately un-folding and rolling onto a rod 2years later the wrinkles are still there). Peel ply on the other hand layed down nice and flat and it was easy to work the air bubbles out of the layup.
rharshberger
Well-Known Member
Sanding, Sanding, Sanding.....and more fillets, internals this time. Just for fun the nosecone fitted to the fincan, for some reason it doesn't work for me, of course the motor will be nearly flush with the top of the fin can, and the nose cone wouldn't even fit without cutting the base off in preparation for the nosecone bay and nose weight. The real reason for fitting the nosecone was to check that the forward end of the fincan was still square after sanding the excess FG off from the tip to tip process, since the wings come within about 2" of the forward end of the fincan I ran the FG all the way to the forward end so there would be no need to blend an edge like at the rear of the wings. The sanding took about 4-5 hours for the fin can to get everything levelled, the areas where peel ply was used sanded the fasted, and the areas where the perforated release film was used took the longest (due to the wrinkles in the release film). The raw carbon look would not look as good as I would like due to a large number of very small air bubbles between the layers of fiberglass, that show up nice and white on the carbon sections even when dampened so the carbon shows through. Built like a tank is kind of an understatement, fillets were done internally using a long reach tool (large craft stick aka tongue depressor on a steek....) to reach the middle CR and do the fin tab fillets. Fillets are US Composites 150 3:1 epoxy with 1/8" and 1/32" milled FG added with enough Cabosil/AeroSil to thicken to cake frosting consistency, it took about 140 grams (epoxy without additives) to do all 10 fillets, its really nice have that HUGE gap between the MMT and the Airframe. Excess epoxy cleaned from the area the forward CR will sit. Hopefully the forward CR will go in tomorrow once I have had a chance to inspect the fillets a second time. Overall I am pleased with the tip to tip, after sanding filler primer should take care of most of the little pin holes and blems anything else thats left over Bondo Spot and Glazing putty should deal with nicely. I made a custom sanding block for blocking out the fins and airframe its visible in the lower right corner of the center picture, without that block sanding those large slabs flat would have been very difficult.
Nytrunner
Pop lugs, not drugs
Hah! The nose makes it look like a giant rocket dart
Giant projects may be inconvenient to store and sand, but boy is it nice to work on the internals!
Giant projects may be inconvenient to store and sand, but boy is it nice to work on the internals!
rharshberger
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Yep, I can if needed actually reach between the MMT and airframe, of course I cant really do much once my hand is in there but I can get it in there.
rharshberger
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Planned flights (fingers crossed) are June Swoosh 3 day event and Sod Blaster 4 day event over Labor Day weekend.
rharshberger
Well-Known Member
Forward CR and rail button backer block in place, that is the last of the major components for this rocket with the exception of the nose cone av-bay and nose weight. All parts were roughed and or notched (CR) then painted with neat US Composites 150 structural epoxy, then a thickened epoxy with milled FG (1/8" and 1/32") and Cabosil was thickly beaded above the final position of the CR, the edges of the fin tabs were also given a nice "buttering" and then the CR was pushed into place using a extra coupler (from the ejection piston assembly) to keep it square to the bore of the airframe. Coupler was immediately extracted and excess epoxy was cleaned from the interior walls of the airframe. A bit more straight epoxy was mixed and poured on top of the CR and "painted around to seal the wood and fill the chamfer on the edge of the CR. Near the two lines with the X some of the FG amended epoxy can be seen squeezing up along side the CR, and at several other spots around the CR so I am confident that the backside of the CR is fully filleted and the area between the CR and the airframe has good bonding as well. The rail button backer block is a piece of 18mm Baltic Birch ply glued and pinned to the CR then shaped to match the contour of the airframe I.D. The extra epoxy poured on top the CR was too thick to settle smoothly (as seen in center right picture) so I hit it with a heat gun for a minute or so and it flowed out nicely (far right pic). In a couple of hours I will go back out and add thickened epoxy fillet to the forward edge of the CR and around the MMT once the epoxy on top the CR has had time to set (and underneath so it doesn't shift position) but still hasn't cured so far that the fillet can't get a chemical bond with it.
In the second pic I ground off some of the JB Weld so that the ubolt nuts could straddle the wing fin tabs.
In the second pic I ground off some of the JB Weld so that the ubolt nuts could straddle the wing fin tabs. 
