Tri-Trident - A Very Scratch Build

[les]

And we are point to point!

 

[les]

Right now thinking of using matboard. Cut and scored a piece to try.
My thought is to use Rocketpoxy. Put a goop of it on the pan pipes and press the matboard on top.

 

[neil_w]

Angry launch lug would definitely approve.

 

[les]

a few points to ponder.....
My original pan pipes were 0.5" long. They fit, but were a bit short. Will extend to at least 0.6 if not 0.75" (the lugs are 3" to start)

Thinking of soaking the tubes, before using the Rocketpoxy, in thin CA to help strengthen them.
So wood glue in pan pipes in small tube, wood glue to large tube, thin CA, Rocketpoxy.
Thoughts?

 

[Greg Furtman]

I'm BACK!
An 11 day cruise of the inner banks in Alaska, followed by nearly a week in Seattle. Saw whales, eagles, bears, mountain goats, glaciers. Even caught a pix of some minor calving. More luck, but also related to my pix of rocket launches! Did go to the Museum of Flight in Seattle for a "pilgrimage" to the rocket model section (toured the rest of the museum as well).

Now to re-read this thread and figure out where I stopped and what's next........

One of things I discovered in Google Maps is that many museums can be virtually toured, like the Museum of Flight. You do have to click on the little Street View guy in the lower right corner of the screen.

https://goo.gl/maps/b5LS2yfjEmtNxLRK6

 

[les]

Now I am very confused
I used the RocketPoxy and matboard to "finish" the joint.


For kicks, on the small tube I decided to block the one end and blow into the other. The pix shows my fingers blocking the end.
I couldn't get any air through!


I then slipped a piece of paper through the lugs. I did all 6. I also tried a "dental pick" The lugs appear to be open.
But I can't get air to go through. And it is not just I'm only getting a little air, I mean absolutely no air passed into the big open tube!!!!




I'm thinking of cutting the top off the big tube to get a closer look....
I mean, with 6 lugs some air should move!!!

 

[les]

Cut open the Large tube so I could look down. Things appear open



Even slid the handle of a file down



But when I seal the one end of the small tube and blow in the other - NO AIR MOVES!

And obviously the large tube is fully open - both ends and now the "top"

WHAT????

 

[GlenP]

The matte board can be cut on an angle, so that you don’t have a gap in the 90-deg cut butt edge joints of the tubes. They make cutters for this purpose, like when a matte board is used for framing a picture, the window for the picture is a chamfer cut, right? Most of those are fixed to 45-deg, but you could maybe make a shim to change the blade angle or use one as a guide for making your own at 30-deg.

 

[les]

Well, resolved my stupidity for the airflow. Back to work.

Making triangles from 1/16" basswood. Big ones will have 3 layers, smaller only 2. Glued thrm up with grain directions off by the 60 degree angles.

 

[les]

Also worked the motor mount. I cut up a spent motor for a motor block. Installed the motor hook.
Made a triangular piece that I had to round to fit the tube plus glued some card stock to secure the hook.


Final motor mount


Also cut lugs to make 6 sets of "pan pipes" (not all are shown)

 

[les]

One thing that had been bothering me. The upper tube seemed too long.
Per the file in Jim Z's Rocket plans, it should be 16.5" long


I compared it to my "real" Trident and thought it is way too long.
So I went back to the actual directions and instead of the 50V it should be a 50W



I looked up the length of the 50W and it should only be 9.5" long, not 16.5". Fortunately, since it is typically easier to make things shorter rather than longer, it is cutting time!

At this point, all of the tubes are done, as well as most of the motor tube.

I'm going to alternate my time between making nose cones and cutting the slots for the pan pipes.

 

[les]

Also discovered the wrong nose cone is called out for the bottom of the BT5 tubes.....
Started working the top nose cone. Took a section of the reduced cut off tube caused by error in the BT-50 tube. I added 2 layers of matboard to create a shoulder. One of the 3-ply basswood triangles will seal off the cone and have the screw eye for the shock cord.








Showing the "collar" in the main tube - not fully seated for the pix

 

[les]

Spent time slicing slots and installed the pan pipes into the small tubes



Still working how to best do the nose cones

 

[les]

For the nose cone collar, I soaked the edges with thin CA to harden it up.
I realized the screw eye was got to be recessed so I "extended" it using some Kevlar cord.
I glued the triangle on, but neglected to get a shot of that.

 

[les]

I tried a few methods to make the triangular nose cones
1) scoring and bending the matboard (tip was breaking)
2) cutting matboard and trying to glue individual pieces in place - could not get the 3 pieces aligned
3) cutting card stock to fold up. Had troubles with the point again. And the card stock would not be strong enough

So went with 4) cutting regular printer paper to fold up, and lining with matboard pieces

Here is an example of the point issue



With the regular copy paper I was able to bend it to get a good point



Note - the gap disappears once I glue it

 

[les]

Needed to seal the actual tubes using the basswood ply triangles I previously made. I did coat the inner surface with epoxy...
I also recessed the triangles a bit

 

[les]

I cutout the matboard pieces and did a test fit. I cut a bit off the tip, and so that it would align I trimmed one edge where it would overlap another piece by the thickness of the matboard. To keep things straight I clearly marked that edge.

I installed the parts dry, then brushed glue on the inside. To strengthen the cone, I reinforced it by installing an internal triangle. To get it placed, I put a drop of wood glue on the back end of an Xacto knife, and when in place twisted the handle. The piece was locked in due to the triangle shape. Then brushed glue in to secure this.

 

[les]

Since the internal triangles were recessed, I cut some card stock to help center the cone on the tube (a poor man's shoulder). I'm just holding it in place for the pix

 

[les]

9 !

Count them....

1 2 3 4 5 6 7 8 9

9 flipping Nose Cones had to be made! A 3D printer would have been nice for this part........

But they are made. Letting glue to cure then will begin installation...
The big cones are just sitting on the tubes at this time

 

[les]

Epoxied 6 of the 9 cones to the body tubes.
Started doing cleanup of the cone/tube edges.

I'm started to get excited about this!

 

[les]

Need to make the fins. Thinking of making them a bit more triangular. See the green outline.

Thoughts? Somewhat subtle change.....

 

[les]

Finished attaching the last of the nose cones and cleaning up the joints.

Cut out the fins. I will be papering them.



And time to start putting this all together.

Made some additional foam board jigs and using the aluminum rails to ensure alignment. Used titebond gooped on the pan pipes.

 

[les]

Added the epoxy supports to the first tube. Once the epoxy cured, started adding the other tubes

 

[les]

Added supports for the other tubes. My process is to lay a bead of epoxy, place the matboard on, clean up excess epoxy

 

[les]

Tacked fins on with CA using the foamboard guides, followed by epoxy fillets

 

[les]

First pass of primer

 

[les]

Anyone notice the post where I installed the launch lugs???



Me neither - whoops!

Sanded away some of the primer and added a long one on the bottom and a short one on top. Used a launch rod to ensure alignment

 

[les]

Been away a bit. Got the rocket painted white




Then added the red trim on the motor "radiators"

 

[les]

Added decals. I learned a bit from the decals for the Quadradent, so did not ruin as many this time

Note that I cut apart some decals to get the correct name.
I need to add the red stripes down by the motor. Going to try red vinyl tape (but a bit concerned about the impact of the motor heat. I was going to try to use what came with the purchased decals, but I ruined too many........

Our club launch got postponed due to weather, so will need to wait before it can fly.

 

[les]

The club was going to have a bonus launch to make up for the rained out one - but it then got rained out as well
This weekend is looking good though. To make up for last month it will be a 3 day launch - Friday looks best!



That was the good news.
Now the bad news. I weighed the rocket - 13.4oz - OUCH
Went to Thrust curve. the only motor that will work is a D21-4 with a 5' rod.
Club does not have a 5' 1/8". Also does not have 5' 3/16" They think they have a 5' 1/4"

Anyway, decided to remove the original 1/8" lugs - and they had such nice fillets.........


Next issue - need a D21-4 motor. Sent an email to our normal field vendor. He has some!
But next issue - he's not going. He has other launches he is supporting.
Did some digging and found a couple deep down in my ranch box. No clue how old they are though.........