Pem Tech
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No updates this weekend. Ran off and left the fin alignment guide at the office and I refuse to go back into Little Rock just for that.
Pem-Tech's Level 2 Build - "Certify With Us" program
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Pem Tech
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stealth6
insert witty tagline here
Yep, those I what I often use - cheap, easily available, and small enough to fit where "real" u-bolts won't.
Layne, I'm sorry but you must get back in the car and head back to Little Rock. We demand updates.
s6
Pem Tech
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All righty! Got the wings mounted and will work on the fillets this week. No pics right now, will post later.
Pantherjon
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I hear that Llama spit/loogies make excellent fillets, but, can be very messy! Make sure you wear your latex gloves!:wink:
Pem Tech
Notorious Member
And funny you should say that.....
I might as well have had llama loogies during last night's fillet catastrophe.
Taped off one wing root and made up a batch of West System and proceeded to poor a fillet. It leveled out OK, and a quick (gloved) finger swipe smoothed the edges. It was left to set up. Well, the allergy meds must have kicked in and I started getting sleepy. Well crap, I say to myself, I need to get more than one fillet done tonight. So after waiting till the left over epoxy in the cup was pretty stout, I flipped the bird, taped off another wing root, mixed the epoxy and poured away. This fillet was looking pretty good as well, level, smooth and so forth.
Then it happened....
Over the top of the airframe I noticed a strange drop on the wing that I had just filleted.
No, no, no....
Yes....
The epoxy in the first fillet had not setup and was running down the wing.
Several naughty words later it seemed clear there was no way to save either fillet. So, in disgust, I scooped out both fillets, then wiped out what I could with paper towels.
*sigh*
:sigh:
Guess I will try again tonight.
CarVac
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Did you put anything in the West to thicken it?
This is why using the right tool (epoxy) for the job is helpful, just like using Titebond Molding & Trim instead of regular wood glue for fillets. A good structural epoxy doesn't run, so you don't have to mess around with mixing powders in (a real pain) or chopped fibers (breathing hazard), and getting possibly inconsistent results.
blackjack2564
Crazy Jim's Gone Banana's
If there is much extra left in a mixing cup, it will cure faster due to concentrated heat build up, caused by the chemical reaction.
They fillets are "spread" out, releasing heat from cure, taking longer to do same.
Don't flip fillets till set enough that a fingernail/screwdriver pressed into surface experiences stiff resistance or hard rubber like texture. Then you are "golden"
They fillets are "spread" out, releasing heat from cure, taking longer to do same.
Don't flip fillets till set enough that a fingernail/screwdriver pressed into surface experiences stiff resistance or hard rubber like texture. Then you are "golden"
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Pem Tech
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Yep, I didn't even think about that until after the mess.
Pem Tech
Notorious Member
All righty...
Got two of the four HUGE fillets poured, this time without disaster.
No pictures until I get the evidence from the last mess sanded away.
Got two of the four HUGE fillets poured, this time without disaster.
No pictures until I get the evidence from the last mess sanded away.
Pem Tech
Notorious Member
Now on with the build!
(Thanks Coop for shaming me into getting back to work)
Here are the wings fit into their slots and slid into the alignment guide. Lots of urethane glue is poured over the TTW tabs on the interior. The rear CR is affixed with tape strips for removal and slid onto place, to assure alignment. A strip of tape is run from wing tip to wing tip to hold them in place and a length of angle placed on the wings.
(Thanks Coop for shaming me into getting back to work)
Here are the wings fit into their slots and slid into the alignment guide. Lots of urethane glue is poured over the TTW tabs on the interior. The rear CR is affixed with tape strips for removal and slid onto place, to assure alignment. A strip of tape is run from wing tip to wing tip to hold them in place and a length of angle placed on the wings.
Pem Tech
Notorious Member
Robert,
Thanks for the heads up....
The Llamas and I were up till 0100 working on the outage.
Everything seems to be working now, and the TRF Logo rocket is finally listed for sale!
Thanks for the heads up....
The Llamas and I were up till 0100 working on the outage.
Everything seems to be working now, and the TRF Logo rocket is finally listed for sale!
Pem Tech
Notorious Member
As a flashback, here is the filleting setup for the first run that went bad.
You may notice the black contaminate in the fillet, this should have been the first hint things were going to so south. SHort on Dixi cups I reused a cup that had previously been used for graphite ignitor mix. The thought process was like this:
"It is late, I am tired and can't find any d**n mixing cups. SUrely the dope/graphite mix is solid enough not to flake off."
Then the previously mentioned fillet running occurred.
The next morning this taping process was followed again and good fillets poured. (Try to imagine it with out the black crap in the epoxy)
You may notice the black contaminate in the fillet, this should have been the first hint things were going to so south. SHort on Dixi cups I reused a cup that had previously been used for graphite ignitor mix. The thought process was like this:
"It is late, I am tired and can't find any d**n mixing cups. SUrely the dope/graphite mix is solid enough not to flake off."
Then the previously mentioned fillet running occurred.
The next morning this taping process was followed again and good fillets poured. (Try to imagine it with out the black crap in the epoxy)
Pem Tech
Notorious Member
BALLZ!!!!!!
Yes Ballz, big, satiny, golden beauties.
Here is the process for prepping the Ballz for mounting.
Yes Ballz, big, satiny, golden beauties.
Here is the process for prepping the Ballz for mounting.
Pem Tech
Notorious Member
One issue that had given me a bit of concern was mounting the Ballz to the airframe. They had to be flush with the exterior of the airframe, be sturdy enough to resist crushing or cracking on landing and finally be mounted sturdy enough to not pop loose in case of a hard landing.
My solution was to fill the Ballz with expanding foam, insert a bit of heavy dowel rod, then insert the dowel through the airframe and in contact with the MM tube. The final steps will be to urethane glue the heck out of the interior dowel and fill any remaining space with foam.
A countersink bit was chosen to give a slightly undersized hole for the 1/2" diameter dowel lengths.
The dowels are test fit.
And to the foaming station!!!!
My solution was to fill the Ballz with expanding foam, insert a bit of heavy dowel rod, then insert the dowel through the airframe and in contact with the MM tube. The final steps will be to urethane glue the heck out of the interior dowel and fill any remaining space with foam.
A countersink bit was chosen to give a slightly undersized hole for the 1/2" diameter dowel lengths.
The dowels are test fit.
And to the foaming station!!!!
Pem Tech
Notorious Member
This is what happens when you don't keep a close eye on you Ballz. At least the overflow wasn't too bad.
And this is what happens when you forget to check on the other ball in time.
Got the foam sawed and sanded off and drilled out a pilot hole for the dowel. Next step a shot of urethane glue and jamming in the dowel.
And this is what happens when you forget to check on the other ball in time.
Got the foam sawed and sanded off and drilled out a pilot hole for the dowel. Next step a shot of urethane glue and jamming in the dowel.
rbelknap
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Why? Why not build it designed to pop loose and glue back on with some 5 minute epoxy or CA? Keep it lite and a quick fix when it pops off.
Pem Tech
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That would disqualify my L2 flight would it not?
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Discuss it with the person who's going to sign off before you fly. See if they're okay with it -- you may need to let them physically see the rocket, and show them sims.
-Kevin
Pem Tech
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Actually, the question is moot at this point, the first two ballz are Gorilla glued in place.
Pem Tech
Notorious Member
All right, here is a quick update, the Ballz are attached and the rear CR is in place.
Here are the assembled L2 Bonestell and I.
And for your viewing pleasure, a picture of me cupping my Ballz.
More pics and info to follow.
Here are the assembled L2 Bonestell and I.
And for your viewing pleasure, a picture of me cupping my Ballz.
More pics and info to follow.
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Okay, that gave me an idea of scale! I'm not sure why, but I kept visualizing this thing as much smaller!
-Kevin
-Kevin
Pem Tech
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Too large for you, big boy?
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A response comes to mind, however I'd have to issue myself an infraction, so I shall refrain!
-Kevin
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