PembertonTech 3FNC Build

[gdjsky01]

4in upscale. :daydream:

Looks great so far! Ive always thought this was a creative, fun kit.

Alex

Fun and creative == Pemberton Tech

One thing I forgot to mention. I put a lock washer on the back of the eyebolt and used some locktite.

[gdjsky01]

Being a true builders kit, I'll assume the head Llama figures we'll figure things out or we don't deserve his kits.

Destructions indeed!

Figure 17, 18, 19, and 20 don't seem to correspond to anything in the printed destructions. And they show a body tube pre-ttw cuts even tho the cuts have long ago come to pass.

I will assume that what they are really saying is use the fiber centering ring (since there are not two wood ones) and find out how far down inserting the nose cone will press it into the tube and glue it in there. Or, as I think I will do unless told other wise, simply press it in until it shows in the top of the fin slots, then stick something up the fin slots to make it even with their tops. Then glue it in from the top, and squirk some glue in from the fins slots for the bottom...

Or first put in the fins... the cram the fiber CR on top...

[qquake2k]

Looks like a fun build!

[Scotty Dog]

Being a true builders kit, I'll assume the head Llama figures we'll figure things out or we don't deserve his kits.

Destructions indeed!

Figure 17, 18, 19, and 20 don't seem to correspond to anything in the printed destructions. And they show a body tube pre-ttw cuts even tho the cuts have long ago come to pass.

I will assume that what they are really saying is use the fiber centering ring (since there are not two wood ones) and find out how far down inserting the nose cone will press it into the tube and glue it in there. Or, as I think I will do unless told other wise, simply press it in until it shows in the top of the fin slots, then stick something up the fin slots to make it even with their tops. Then glue it in from the top, and squirk some glue in from the fins slots for the bottom...

Or first put in the fins... the cram the fiber CR on top...

We need your Final Answer, time for a comercial break.

[JPVegh]

Three things I've learned as a Jack of all trades, master of none:

1. Technical writing can be difficult.
2. I'm no good at it.
3. A picture is not always worth a thousand words.

[Tarasdad]

Hmm...my wife is a technical writer...I'm a pretty fair draftsman...hmm....

[Daddyisabar]

Snip

I did fergit... I bought a completed and primed Flis Deuces Wild off eBay for $18 (that includes shipping). I am in the process of maybe making it a Saturn Deuce. Maybe... depends if I can get the decals right.

With all your eBay scores I am waiting for big things in the future - say a clustered TLP build,

[gdjsky01]

Well Landru seems to be on the fritz... but what makes sense to me is to glue the fins on now, then the top centering ring. This allows me access to the inside of the fin can to make sure we have good contact with the MMT and to fillet the fins. (fillet - o - fins?)

So it it shall come to pass... or past...

[gdjsky01]

So here we have the once baffling baffle push down in place. Notice the kevlar is tied as as this would be nearly impossible afterwards. Once it was tamped down, I used a steel rule to measure the distance from the ring to the edge of the nose cone shoulder. I did that at various point around the circumference tapping it this way and that to get it set in the nose cone evenly.

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In this next picture you can see how easy it is to see the ring backlit through the nose cone. This makes inserting tacks the doddle.

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Here we see all three tacks pushed home. Pretty darn well placed tight to the ring. So much so once pirced a tiny bit of the ring.

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Here we are placing globs of 30 minute down in a fillet. I used the stock 30 minute hobby epoxy because it is quite thick and less likely to run. I tucked the kevlar down inside whilst I spread the glue to keep the glue off of it. Once done with the fillet I fished it out so that if the epoxy did run, it would not glue the kevlar down there.

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[Pem Tech]

Looks like a fun build!

Yeah, sounds like real fun....
Old Destructions, over sized CR, incorrect baffle ring....
Woof.....
Good thing Jeff is an steely eyed missile man and has triumphed in the face of overwhelming Llamas.

He is also correct in the fiber ring discombobulation....
Glue the main ring in, glue the fins on, fillet'o fin tabs THEN stuff the fiber ring into place.

And the "other" Jeff is right as well....
Technical writing is difficult in that there can be very few assumptions. What the writer thinks is obvious may be totally lost on the reader. And without reference points or explanation a picture is worth about 35 words.

Gonna have to clear out all the old Destruction manuals and print new ones to prevent this in the future.

We need your Final Answer, time for a comercial break.

And now back to our regularly scheduled build, already in progress....

[gdjsky01]

Yeah, sounds like real fun....
And without reference points or explanation a picture is worth about 35 words.

The issue is not the lack of words... and a picture is worth a thousand words. But the wrong picture is worth a 1000 wrong words.

It was pretty obvious to me what needed to be done... I was only worried about the gotchas that pop up because one does things out of the intended order... which is why it so important to read the destructions first... look at all the parts... decide how they go together.

Like scratch building. But trying to stay true the designers classic design.

[Pem Tech]

And a fine job you are doing.
More pictures! More pictures!

The issue is not the lack of words... and a picture is worth a thousand words. But the wrong picture is worth a 1000 wrong words.

It was pretty obvious to me what needed to be done... I was only worried about the gotchas that pop up because one does things out of the intended order... which is why it so important to read the destructions first... look at all the parts... decide how they go together.

Like scratch building. But trying to stay true the designers classic design.

[gdjsky01]

Having heard back from the Daily Llama, we proceed...

I recall the Llama implanting memories of PML vs LOC tubing... I found the fins tabs just a teeny tiny tad too tiny. Being the quick witted silver tongue devil I am, I split a Starbucks Stir Stick(tm) in half and glued them on to the ends of the fins. There will be NO strength issue here as by the time they are sanded down to make a good fit the internal fillets will cover the stick and the tab. Plus fillets are on the six joints on each fin!

ALTERNATIVELY you could simply sand the edges at the root down a skosh. I decided this would be simpler and looked like it preserved the angle of the fins when the "Shroud of Tailin" gets installed.

Like zo'

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Then each fin had the tab sanded down to make a nice fit on the root edge. MOST of the Starbucks Stir Stick(tm) was stripped by sanding. Little sanding, little fitting... little sanding little fitting...

Like zo'

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Und zo (you can see how thin the SSS(tm) got sanded down)

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Until you have a real Zo and Zo

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The spans of those fin reminds my of the Imperial Transport used in one of the original Star Wars flicks aye what?.

[gdjsky01]

Fillets are done for now. I put several layers (using wood glue) on the outside with just a light sanding in-between each. Later I'll build up smoother, wider, fillets with bondo putty or some such...

Oh man... next comes the fairing... crap I made three of these and they are all a little too big. I roll them, slice them, dice them... process them through the Ronco Vegimatic... nothing worked... well... not so... Just gotta finness it more.

Not to leave you in the lurch, but I am off to the Golden State Star Party for the next 7 days. I need, more than you can know, some quality time under dark skies with dozens of my Astro buddies. See you in a week or so when we'll figure this Shroud of Tailin out...

[Pem Tech]

Well, I may have to use you as a Beta builder, your've run across just about everything that could go wrong.
WHen my shrouds came out too big (and yes I have made a lot of these) I would just glue them in place and sand off the edges flush with the BT.

Fillets are done for now. I put several layers (using wood glue) on the outside with just a light sanding in-between each. Later I'll build up smoother, wider, fillets with bondo putty or some such...

Oh man... next comes the fairing... crap I made three of these and they are all a little too big. I roll them, slice them, dice them... process them through the Ronco Vegimatic... nothing worked... well... not so... Just gotta finness it more.

Not to leave you in the lurch, but I am off to the Golden State Star Party for the next 7 days. I need, more than you can know, some quality time under dark skies with dozens of my Astro buddies. See you in a week or so when we'll figure this Shroud of Tailin out...

[cwbullet]

Nice build thread. This kit appears slightly different front the version I built.

[gdjsky01]

Well I'd LOVE to do that. But don't be too hard on yourself. If the tubes were same as you first started with, all the fit issues would be gone. And the first thing you say in the destructions is this is a "Builders Kit".

So be cool. I am off to gather some ancient photons. I am sure in the end, all will be well. The pay off is in the end results oui?

[cwbullet]

I love builders kits....sometimes.

[qquake2k]

This kit is deceptively complex.

[Pem Tech]

This kit is deceptively complex.

Mwhahahahahahahahaah!!!

Oh sorry, that was supposed to be my inside voice.

[gdjsky01]

Back at it. The star party was am amazingly good time again.

Then came the week of try to catch up at work. So nothing got done... until last night when I examined where I am... man-o-man I made some mistakes!!!

Basically the MMT and fins went in/on too soon (my mistake NOT the destructions). Now I have to jump through some hoops to anchor the tubular nylon to the MMT. Worse, it's gonna be REALLY hard to fit the tail cone on with the fins there as the fin roots extend a bit beyond the rear of the body tube and bend inwards to 'hug' the tail cone. All of which I could have avoided.

The nylon thingy I can handle. But the tail cone is gonna be a bear...

So my plan is either
A) to make the tail cone smaller and fit inside the tube. I'll glue it to the inner perimeter of the body tube whilst it sits on the after centering ring. Then I'll bondo, fill, expectorate around the base to fair it into the rim of the outer tube diameter. And I'll fill and smooth the small fin root that hugs the tail cone with thin balsa strips and more filler goo.

B) try and make the tail cone fit perfectly on rim of the body tube - the issue there is I can not paint it with epoxy then until AFTER its on the rocket as I'll never get it past the fin roots (which as I said, bend inward to capture the cone).

ggrrrrr.... my own fault... just did not think ahead...

[Pem Tech]

Hmmmmmmmmm
Like you said, the shock cord thing won't be too bad.
Now the TC.....
I'll try out a few sizes tomorrow and see if I can get an exact fit. Then I can mail it to you or you can print it off yourself from RS.

[gdjsky01]

No worries. I can do the same. It's really a matter of I wanted to paint the cone with epoxy before hand and thats not possible if I have to squish it a little to get it past the fins. It's okay, I'll work it out!

[hornet driver]

I like this build ! This is fun. BTW, I have to agree with PT--the hose clamp thing was pretty clever---gonna use that one----H

[gdjsky01]

So as I documented I screwed things up by (not following the destructions!!!!! ) putting the MMT assembly in the body tube and the fins on before securing the toooobular nylon and the tail cone.

Lets address the shock cord first
I used 30 minute generic Hobby People epoxy because it's thick and cures in, well, in about 30 minutes. Fewer runs, drips, or errors.

I saturated the toooobular nylon for the length I wanted attached to the MMT. And also spread some on the tube area from the aft centering ring forward for the same length.

I carefully placed the nylon on the tube all the way down to the aft centering ring. I pressed it down with a chop stick (always steal more from your favorite Chinese place.)

Then I took a coupla inches (50mm) of wide heat shrink and used it as a sleeve to press the nylon against the tube. I heated (and melted a bit ) the heat shrink using a long gas fireplace butane lighter.

Then I let it set. This picture shows the nylon (top stuffed into the MMT to keep it out of the way) and the way it's set against the MMT and the heat shrink.

After a few hours, the epoxy was set and the heat shrink was slit with a hobby knife and just peeled away. All is well.

Sorry this is taking so long... I could rename the thread "Fly Me!" (Bradycos don't be mad!! Ya know I love ya!!! Just teasin' !)

[gdjsky01]

Whats this? A 5.5 ounce plastic Dixie cup?

[gdjsky01]

Or an almost PERFECT fit tailcone?

Will it stick?
With sanding I think it will.

Will it melt?
I don't know... I was going to line the inside with aluminum furnace tape - I KNOW it will need a blast deflector that is not flat, but angled away.

Will I try and use it?
Can you see how almost perfect the shape is? Damn straight I am going to try...


UNLESS y'all already know its a lost cause???!!???

[JPVegh]

They don't make a 5.5 ounce paper dixie cup? Do they still make paper cups? Where am I?

[Pem Tech]

Or an almost PERFECT fit tailcone?

Will it stick?
With sanding I think it will.

Will it melt?
I don't know... I was going to line the inside with aluminum furnace tape - I KNOW it will need a blast deflector that is not flat, but angled away.

Will I try and use it?
Can you see how almost perfect the shape is? Damn straight I am going to try...


UNLESS y'all already know its a lost cause???!!???

Hey! That is a cool idea.....
More! More! More!

[gdjsky01]

I decided to pursue plastic Dixie 5.5oz bowl as a tail cone as it looked just too promising.

I took some aluminum tape furnace tape and line the inside of the cup. Notice how the lip of the tail cone is, for the most part clear of tape. That area was scuffed up with 220 sandpaper.

Also note the two corrugated cardboard centering rings glued together under weights.

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