Bucky Jones (PemTech) build thread

[Pem Tech]

So having that wire in front of the jet plume won't affect anything?

The wire/motor retainer is designed to be offset as to catch the rim of the motor, and allow easy removal of the casing, but even if it is a little too far toward center the retainer should not be long enough to slip over the nozzle.
You will notice the qualifying "should" in that statement.
Let's just say that problem hasn't been reported yet.

 

[jcsalem]

Finally finished a bit more since coming back from NERRF... Alas, it won't be ready for the CMASS launch on Saturday.

Below you can see the finished "exhaust tube" assembly. To keep everything square while the glue was drying, I used some scrap 29mm tubing placed in the CR and a rubber band placed around all the tubes. Had to remember to carefully turn the 29mm tube on occasion so it didn't end up glued as well. Per the destructions, I wicked thin CA between the tubes. It's quite solid.

Painting this bird is a little tricky. The inside of the BT is supposed to be gold. The easiest way to do this is to before the gluing in the MMT. On the right, you can see the inside of the tube after I've primed it. I've masked the area where the aft CR will be glued.

The destructions are a little vague about when to paint everything. They're worth reading all the way through and strategizing how to make the paint job easier on yourself. If I could do it over, I'd paint the MMT silver before attaching the retainer.

Next steps are to paint the inside of the body tube gold and the MMT and exhaust assembly silver. Then I glue in the MMT followed by the fins. I'm planning to toughen the fin MMT joints with some strips of 2oz fiberglass.

<img src="https://www.rocketryforum.com/attachment.php?attachmentid=41203&d=1183083594">
'til later,

Jim

 

[jcsalem]

So having that wire in front of the jet plume won't affect anything?

BTW, the picture makes the retainer appear more in the center than it really is. It's really well away from the nozzle. If it was really in the plume, I'd be worried about giving the rocket vectored thrust.

Jim

 

[jcsalem]

BTW, I've sealed with fins with a couple coats of Delta Ceramcoat sanding sealer, sanding before and after each coat. While it's not nearly as necessary as it is with balsa, I like getting some of the finish work done on the fins before they're attached to the rocket.

Of course, I leave any of the areas to be glued free of sanding sealer.

 

[Pippen]

Here's a photo of the dry fit (pre-glue) assembly. You can see those scary nose probes lying on either side of the rocket.

Sounds very ominous to me.

Great looking kit--thanks for posting your build. How is the cockpit handled on this?

 

[jcsalem]

I've glued in the dorsal fin. However, the wings look a little flatter than I expected (i.e., they're nearly at right angles to the dorsal fin). The photos in the instructions make it look like the wings should be at more of an angle.

Layne, can you shed some light? Below is a photo of the rear of the Bucky Jones with the wings dry fit. If I sand down the fin tabs a bit, they'll be at more of an angle.

BTW, I realized that it wasn't so smart to put fiberglass over the ends of the motor retainer (see photo above) as it gets in the way of the wing attachment. Fortunately, I noticed this prior to gluing in the MMT and was able to remove some of the fiberglass.

Jim

 

[Pem Tech]

Your Bucky wings are perfect.......
The TTW tabs are cut long so that they will rest against the underside of the motormount tube. This gives Him a bit of an "aircraft" look as opposed to typical perpendicular fin mounting, and this arrangement holds up well for horizontal recovery.
Well, that is how He was designed anyway, he should fly just fine with the fins a more of an angle.....
Whatever floats your boat...
Blows your skirt up...
or frosts your Twinkie....

I've glued in the dorsal fin. However, the wings look a little flatter than I expected (i.e., they're nearly at right angles to the dorsal fin). The photos in the instructions make it look like the wings should be at more of an angle.

Layne, can you shed some light? Below is a photo of the rear of the Bucky Jones with the wings dry fit. If I sand down the fin tabs a bit, they'll be at more of an angle.

BTW, I realized that it wasn't so smart to put fiberglass over the ends of the motor retainer (see photo above) as it gets in the way of the wing attachment. Fortunately, I noticed this prior to gluing in the MMT and was able to remove some of the fiberglass.

Jim

 

[Pem Tech]

Sounds very ominous to me.

Great looking kit--thanks for posting your build. How is the cockpit handled on this?

The Kit comes with a hunk of balsa, very detailed destructions with pretty pictures and a goat.

Beyond that, you're on your own.........

 

[skippy-2]

[snip]... with pretty pictures and a goat.

Aw man! I thought it was pretty pictures of a goat.

 

[Pantherjon]

You mean I get a GOAT if I order a Bucky Jones kit?? I sure hope he is potty trained!:rotflol:

He can always help with my yard maintenance! My lawn is growing as fast as weeds...oh wait, it because it IS weeds..

 

[skippy-2]

PemTech design team discuss release of new SciFi kit:

 

[Pem Tech]

Aw man! I thought it was pretty pictures of a goat.

No, no, no...
Pictures OF a goat will run you extra. But don't get too broken hearted, we can work something out. Just give me your credit card information and I'll take care of the rest.

 

[Pem Tech]

You mean I get a GOAT if I order a Bucky Jones kit?? I sure hope he is potty trained!:rotflol:

He can always help with my yard maintenance! My lawn is growing as fast as weeds...oh wait, it because it IS weeds..

Potty training a goat???
You heathen!
:surprised:
Somebody call PETA!
Or Amnesty International House of Pancakes!


Now back to your regularly scheduled thread.

 

[Pem Tech]

PemTech design team discuss release of new SciFi kit:

Point, set and match my Aussie pal...

Bravo...

:rotflol:

 

[jcsalem]

Glued in all the fins last weekend. I used ~1.5" wide strips of 2oz fiberglass to bond the fin tabs to the MMT. This helps spread the load on the fin tabs to more of the MMT. The kit recommends just epoxying the fins in place followed by filling the fin can with 2 part expanding foam. However, on rough landings, I've had several instances where a fin tab breaks away from the MMT even with the foam. Having a strip of fiberglass on either side of the fin tab to MMT joint keeps it securely bonded.

I'm carving the canopy now and then next up is painting. Unfortunately, the "gold" paint I bought turned out to be copper color, so it looks like I'll be doing a "low rent" version of the Bucky.

Jim

 

[jcsalem]

BTW, for the first time, I'm using Future Floor Wax to cover the metallic paint. It's the first clear coat I've found that doesn't completely dull metallic colors.

Works great!

Jim

 

[Pem Tech]

Glued in all the fins last weekend. I used ~1.5" wide strips of 2oz fiberglass to bond the fin tabs to the MMT. This helps spread the load on the fin tabs to more of the MMT. The kit recommends just epoxying the fins in place followed by filling the fin can with 2 part expanding foam. However, on rough landings, I've had several instances where a fin tab breaks away from the MMT even with the foam. Having a strip of fiberglass on either side of the fin tab to MMT joint keeps it securely bonded.

I'm carving the canopy now and then next up is painting. Unfortunately, the "gold" paint I bought turned out to be copper color, so it looks like I'll be doing a "low rent" version of the Bucky.

Jim

The more I think about it the more I like the idea of using fiberglass on TTW fin tabs instead of just fillets.
Hmmmmmmmmmmmmmmmmm
Maybe Bucky 1.1?

But He won't be the "Low Rent" version.
:rotflol:

 

[jcsalem]

It's done! Yay! The copper-colored beauty is lookin' good and the Future Floor Wax coat keeps it nice and shiny.

The only thing I'm concerned about is that it's more top heavy than I'd like. It's about 22oz (2oz heavier than its RockSim file) and its dry CG is about 7-9" ahead of the large fins. I'm thinking it's going to weathercock more than I'd like. Depending how it flies, I may make another nose cone with less weight in it.

It flies tomorrow!

Jim

 

[jcsalem]

So what motor should I use for its first flight? I'd like to keep it around 500' given the windy day tomorrow and the weathercock potential. I'm thinking an F20W-4 or a F23FJ-4.

Thoughts?

 

[Pem Tech]

So what motor should I use for its first flight? I'd like to keep it around 500' given the windy day tomorrow and the weathercock potential. I'm thinking an F20W-4 or a F23FJ-4.

Thoughts?

How about an F39 Blue Thunder?
He will reach stability in less than 48 inches but only hit about ~600' at apogee.
This is my favorite low altitude test motor.
And as long as the CG is about 2.5 to 4 inches from the fore end of the BT (dry) you should be fine. The first prototype Bucky was built with PML Quantum Tubing, weighs over 23 oz. and flies great on the F39-6.

What about pictures?
We demand pictures!

 

[jcsalem]

The Bucky Jones had a terrific first flight on the F23FJ-4. It was a VERY windy day (10-15mph) and with the Bucky being nose heavy, I was suspecting some significant weathercocking. However, it flew perfectly straight up.

With all the wind, it carried off the field into the swamp but I recovered it without incident. The 32" parachute might be a little large for our soft but small New England fields.

LOTS of "oohs" and "aahs" at the field, both before and after launch.

I don't have the 24mm case so the F39 was out. I was very happy with the F23FJ. If I was going to try again in the same conditions, I might try an E30T or E23T to keep the altitude down.

Photos to come... Unfortunately, I don't think I got a good launch photo.

Jim

 

[Pem Tech]

The Bucky Jones had a terrific first flight on the F23FJ-4. It was a VERY windy day (10-15mph) and with the Bucky being nose heavy, I was suspecting some significant weathercocking. However, it flew perfectly straight up.

With all the wind, it carried off the field into the swamp but I recovered it without incident. The 32" parachute might be a little large for our soft but small New England fields.

LOTS of "oohs" and "aahs" at the field, both before and after launch.

I don't have the 24mm case so the F39 was out. I was very happy with the F23FJ. If I was going to try again in the same conditions, I might try an E30T or E23T to keep the altitude down.

Photos to come... Unfortunately, I don't think I got a good launch photo.

Jim

He flew that well on an F23??
In 10-15 mph winds???
Holy creeping cruds...
On that motor RockSim shows him not reaching stability until about 70 inches!!

Either I did a good job on the design or the Rocket Gods were looking out for you.

 

[jcsalem]

Yes, it's finally time for some photos!

First up are a couple more build photos. On the left is my "cockpit" after I was done sanding. It came out a little different from the one shown in the instructions. More of a "streamlined VW Bug" look if you ask me.

The right photo shows the detail of some of my epoxy fillets.

Jim

 

[jcsalem]

And now we have a couple photos of the paint job.

I used white primer, followed by light sanding with 300 grit, followed by more primer and then the top coat. I used copper metallic paint rather than the traditional gold but I really like the look. Followed it up with a couple coats of Future Floor Wax which keeps those metallic colors shiny.

<img src = "https://www.rocketryforum.com/attachment.php?attachmentid=42892">

 

[jcsalem]

And here's a photo of its maiden launch on an Aerotech F23FJ-4 at last weekend's CMASS launch. The photo came out pretty good after all.

Wish I had more photos of it in the air, but I was having too much fun watching its stunningly straight flight WAAAY up!

Wish I had a photo of it under 'chute, but I was too busy getting a good bead on it as it drifted over the trees into the swamp. It made a nice landing into some soft grasses and away from the water. I recovered it without even having to break out my swamp boots.

<img src="https://www.rocketryforum.com/attachment.php?attachmentid=42893">

View attachment Bucky Liftoff F23FJsm.JPG

 

[jcsalem]

He flew that well on an F23??
In 10-15 mph winds???
Holy creeping cruds...
On that motor RockSim shows him not reaching stability until about 70 inches!!

Either I did a good job on the design or the Rocket Gods were looking out for you.

I did launch it from a 6' x 1/4" rod, so I had almost enough length. Still I was surprised that it didn't weathercock more. It'll be fun to see how it does in calm winds with a G (or an H!)

Jim

 

[tonypv]

Bill got some good shots, they can be seen on the CMASS web site gallery.

 

[Pem Tech]

And here's a photo of its maiden launch on an Aerotech F23FJ-4 at last weekend's CMASS launch. The photo came out pretty good after all.

Wish I had more photos of it in the air, but I was having too much fun watching its stunningly straight flight WAAAY up!

Wish I had a photo of it under 'chute, but I was too busy getting a good bead on it as it drifted over the trees into the swamp. It made a nice landing into some soft grasses and away from the water. I recovered it without even having to break out my swamp boots.

Man, that is a beautiful shot!
I am still just shocked that He flew so well on an F23 Black Jack.
That 6" rod must do the trick.

ANd I am glad you got Him back without incident.

 

[Pem Tech]

Bill got some good shots, they can be seen on the CMASS web site gallery.

Hey Tony, thanks for the link!
Got some cool pictures in the gallery, but the Bottle Rocket was killer.
I have to try that...