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Summer Build Contest 2017 "PRAXIS PROBE"

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Scotty Dog

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Too cool dood.. that is awesome. So glad you are a member of TRF.
 

Gary Byrum

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Thanks Scotty I wuv U2!!

Praxis is the moon of the Klingon home world Kronos. Well, what’s left of it anyway. Modeled after an overhead view of a scout ship, Praxis Probe is one of the few devices left that the Klingons are capable of manufacturing on the remnants of their gutted moon.
This 2D rendering gives you some idea of what this 3 finned model will look like.

Praxis Frpm Draw.jpg
 

Gary Byrum

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The pieces and parts are all laid out here in their raw form with the exception of the balsa cuts, fin skins and overlays. The two blocks will need to be turned for the nose cone and boat tail. There’s a shroud print on the left but it’s hard to see it here. And I may or may not need to use that 2nd 60/80 CR. It just depends on how well the dry fit goes down the road.

1.JPG
 

neil_w

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Certainly gotta win some sort of prize for "best first post" of a build thread. Subscribed!
 

Gary Byrum

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I figured I’d get the balsa stuff started, so I cut the three pods from ½” stock. The wood is a bit soft so I’m going to laminate the inside flat surface with basswood. This should strengthen it up enough…..I hope. I cut all the templates and hand formed the shroud until I had a nice curve. Then rolled it tighter and rubber banded it. After I undo the banding, I’ll re-roll it from the other end so both edges of the shroud get a chance to be on the inside. I think this method helps make a more uniform curve. Especially for these longer than usual shrouds. It’s also easier to glue the ends together if I can pull the shroud out rather than having to pull it in toward my glue area.

2.JPG
 

Gary Byrum

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I can make doing a long shroud look easy, but truth be known, it never was. I’ve done so many of these things and I do have a trick or 3 that helps me get an even bond. I still do the overlap method so, taking the above pre-formed shroud and spreading it out gently, I use a very thin layer of white glue. Titebond is better but white is more forgiving and slower to dry. I’ll press and tug at the top & bottom of the shroud getting it almost completely in place, then start pressing/sliding and such until I have it right where I want it. Once I get it in place, I’ll flip it over on wax paper and take a large dowel and firmly press evenly on the glue joint. Carefully rolling back and forth across the joint until all of the glue is distributed evenly between the paper edges. Too much glue and you’re going to have a mess on your hands. Not enough, and you’re going to have sticky-uppy edges.

3.JPG

Then I hold the shroud up with the dowel and use another one to slide gently back and forth from top to bottom making sure any would-be lumps or loose edges are secure.

4.JPG

By this time, your glue is usually ½ set and you should be able to hold the shroud with your hand and form that joint you just pressed with a dowel from the inside. Chances are, it’ll be flat and you don’t want that. Once you form out the flatness, you can set it aside to dry. I’ve made shrouds that were 18” or better using this same method.

5.JPG
 

TangoJuliet

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Sub'd! :pop: (and still considering my own entry)

I'm kind of new to "rolling my own", but my method of forming shrouds is very similar to yours, so I guess I must be doing something right. :wink:
 

Gary Byrum

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my method of forming shrouds is very similar to yours, so I guess I must be doing something right. :wink:
Making shrouds fit perfect has always been one of my nemeses and keeping the edges from lifting was certainly a constant problem. I knew it would require a lot of practice and knowing how to cut them out was at the top of my list. Thicker stock requires cutting on the outside of the line, and average stock falls pretty much on the line. Way back when I did kits, (mid to late 60's) those supplied paper shrouds were all we had. Usually they would be too loose or too tight, but that paper stock was no thicker than copy paper. I was terrible at making them fit. So, I 'copy machine printed' a dozen or so and started experimenting. That was helpful and I figured out how to make the thin walled ones fit. I had to do the same thing all over again after the computer age arrived and started using thicker stocks.
Then came the bonding issue. I dumped white glue from my supplies years ago for better gripping glues but I soon learned that I couldn't make the best fit with these glues. So now, I have come full circle knowing there are still very good uses for good ole white glue.
 

neil_w

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The best thing about paper shrouds is that they cost close to zero, so you can practice all you want, and keep making more until you get a good one. I haven't made nearly as many as Gary but I've definitely seen myself getting better at them as I make more of them. And if one comes out bad I just chuck it, make adjustments, and usually the next one is good.
 

TangoJuliet

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I've been using TBII to glue the shroud together with an "overlap" tab on the inside. I apply a thin layer to the tab and another to the overlapping (in)side of the shroud and allow them to "set" for a few moments, then stick them together, and use an appropriately sized dowel to press the seam on the bench top. When gluing the shroud into place I recently used the TB "Quick & Thick". That seemed to work pretty well. It fills any gap and sands well.
 

Gary Byrum

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The best thing about paper shrouds is that they cost close to zero, so you can practice all you want.
AMEN to that!

I've been using TBII to glue the shroud together with an "overlap" tab on the inside. I apply a thin layer to the tab and another to the overlapping (in)side of the shroud and allow them to "set" for a few moments, then stick them together, and use an appropriately sized dowel to press the seam on the bench top. When gluing the shroud into place I recently used the TB "Quick & Thick". That seemed to work pretty well. It fills any gap and sands well.
Never tried Q & T before. I already know TBII is a PIA to sand though.

Hey, I work for Praxis Engineering. Now we're going to sue you!

J.K., of course. Looks cool. Maybe my CEO would buy one.
OH? You work for Klingons?
 

Sabrina

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That first post with the art easel... very cool, inspiring. Off to a great start!

Got me thinking maybe I should enter this contest too. Looks like fun! :)
 

Gary Byrum

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Cool Klingon ship!
It's a probe Daddy....a probe...:wink:

That first post with the art easel... very cool, inspiring. Off to a great start!

Got me thinking maybe I should enter this contest too. Looks like fun! :)
If you want a good read, last years contest had some umpf to it. Great lotta scratch builds. That's my cup-o-tea.
I'm a bit of a cartoonist as well. That's me in the opening. If you keep up with the thread, you might get to meet some of my other rocketry cartoons. There's Angry Launch Lug, Satanic Spiral, Freddie Fin, Ronnie Rail Button, Moody Motor....yadda yadda. Just my way of spicing it up a bit.

Get you something started. It's a lot of fun to see what everybody is workin on.
 

TangoJuliet

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Not to get too far off topic, but I used to frequent the Finescale Modeler plastic forums, and there was a very skilled modeler there who was also a very skilled professional animator and he had a "crew" of cartoons that he would include in his build threads; compositing the images and including shadows to the characters in the image. Unfortunately I don't recall his name and I haven't been to the forums in quite some time, so I can't link to it.
 

Gary Byrum

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Here's a pic of my rocket toon buds. It's almost a sure bet that Angry LL will get his :2: worth in when it comes time to install that lug.

Angry LL Gang.jpg
 

neil_w

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Man, they are not a cheerful bunch, are they? You treating them ok?
 

Gary Byrum

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Man, they are not a cheerful bunch, are they? You treating them ok?
Rockets take a pretty good beating for the most part. So yeah, they aren't very cheerful. Angry LL is just angry about how often people forget to install him.

Found the thread I was referencing on Finescale.com:

https://cs.finescale.com/fsm/modeling_subjects/f/2/t/111699.aspx

Extremely talented!
Which is why I am not a commercial cartoonist / artist. Mine are just for fun.
 

Gary Byrum

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I don’t know what the deal is, but having wound up with a lot of softer balsa blocks this time around, I have turning issues. The tapered part of the boat tail & nose cone are smooth as a baby’s butt, but when I get close to the shoulder area, I end up with a ton of splinter pits. It’s nothing I can’t fix, but I wish I didn’t have to. Good ole Elmer’s straight from the tub does the trick.
These are all of the balsa parts and everything is in the rough sanding stage. I’ll have to do a fine sanding, put on the sealer and sand again before they’re actually done. The fins are 2 piece construction because of that flat leading edge on top. The joints are looking real good too. That shroud got a 2nd seal with CA tonight, so it’s ready to be fine sanded also. Still gotta get the seam sanded flat and do a Bondo fill on it.
Had to stop for the evening. My bench chair kills my back in about an hour or so anymore. Prolly won’t get any more postings until after the weekend launch. Too many things to do before I leave Friday.

6.JPG
 

Gary Byrum

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On the boat tail/motor mount, there’s a couple of pull strips on that black CR that get’s removed after the motor tube dries solid. I used a 50/80 just to keep it centered in the BT 80. Why? Cause I had to drill that hole with a stinking paddle bit! Lord only knows where I put the Forstner bit. At least I thought I had some of those.
If you ever drilled a hole in balsa with a standard bit, you prolly already know how easy it is to booger it up. Some necessary inside sanding had to happen to get rid of the bulky shavings, and yes, I still had some nice little gaps at either end of the boat tail. Those I’ll have to fix. No biggie though. I’ll install the necessary 50/60 CR tomorrow I suppose.
I mounted the transition on the BT 60 with a CR and that’s drying. The pods got a fine sanding and I had already marked the flat side where the recesses would be cut. Those came out nicely and make for a great friction fit for the fins. None of those are glued yet. That’ll happen after the fins get mounted. I’ve already cut my vinyl cut since I had another job to get done prior. Might as well get em all at once, eh? Oh, I have way more cuts of vinyl than I need. Lesson learned years ago.

7.jpg 8.jpg
 

Gary Byrum

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Usually these long shrouds will cause the CR’s to install a little further in than usual as you can see in the 1st pic. That’s about 3/32” and it’s likely to present a problem if I don’t fix it. I took a couple of different sizes of poster boards/stock and cut a couple of CR shim rings thick enough to run flush with the end of the shroud. After they dry, I’ll prolly have to sand them down a smidgen so the shroud fits flush to the BT 80 when installed. I do this because that gap would be venerable to dings and I wouldn’t get a good putty fill on that joint. It just makes sense to me. The whole transition to the BT 80 will go a lot smoother.

9.JPG

The 50/60 ring and engine block are now in place as well as the CR shims.

10.JPG

The final 60/80 CR is now in place and I broke out the sanding sealer to get the wood treated. I don’t usually do that until all woods/fins and such, are assembled as a general rule of practice, but I have no fears of fins not adhering to that boat tail. TightBond sticks very well to the sanding sealer The BT 80 supports those fins also, so we’re in pretty good shape.

11.JPG
 

Gary Byrum

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The slow process of building 1 rocket at a time with all the stuff drying, seems to be taking forever. The three fins got mounted and a coat of sanding sealer on them and the pods, made for shop down time so this stuff could dry over night.

12.JPG

Then we had to sand some more today! Once that was done, I got the pods mounted about an hour apart from one another. Just long enough for them to set pretty good for yet another over night drying spell. Slopped a little Bondo on that shroud seam and shut her down again. Oh….there’s another little project going on in the background with some more drying time going on with the DOM Plan # 73, Orbital Transport Laboratory. I had to have something to play with alternately.

13.JPG
 
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