A Trio of Tres And A Tri-bute to Jim Flis

A while back I purchased three of Jim Fli’s Tres style motor mounts.
One each in 13mm, 18mm, and the 24mm-“E” versions.

I wanted to do something a bit different with each of them and here are the results.


First up is the 13mm version I call “Tri-cone-ect” launched once successfully on 3x A3-4Ts.


Here’s the business end of it with the launch-lug passing through the cone at the lower left.
There is a second cone at the top which funnels the ejection charges from all three motors into the common BT 20 airframe. From its first and only flight I have determined that it needs a much longer shock cord than originally installed; either that or I need some way to vent a bit of the pressure.


Next up is the 18mm “Round Bottom Rocket” based on the BT60 tube with matching “Big Bertha” nosecones front and rear. On three C6-5s, this rocket will soar.


The three motors are buried within three of the tube fins so you can’t see them from the side.
Makes for an odd looking smoke trail.


Last but far from the least is “Tri-Oomph!!” with its three 24mm motors pushed up into a BT101 tube. Launched successfully on both D12s and E9s. The ginourmous “Big Bertha” nose cone was 3D printed for me by a fellow forum member for a danged reasonable price. I mean; who’s really going to miss their first born?


It’s an interesting view from the rear what with the BT70 tube centered in the BT101 tube and the three fins meeting in the center. I tell people they are “Composite” fins as the lower part is Basswood while the upper strakes are Balsa.

Those are great designs. Jim will love what you've done with the mount kits.

Schweet.

You definitely build some outta the box rockets.

Well done!

I love that Tri-oomph. Well done.

jsargevt said:

I love that Tri-oomph. Well done.

Click to expand...

Thanks. The “Tri-Oomph” stickers are courtesy of Sticker Shock.

The BT70 tube which houses the Tres MM also acts as a stuffer tube so the ejection charges don’t have to pressurize the entire volume of the BT101. There is also a BT70 based baffle installed so I don’t have to shovel in half a cubic yard of Dog Barf or an entire roll of Estes wadding.

You can have so much fun with the Flis Tri Motor Mounts! They are easy to assemble and make you feel more secure than scratch building with leftover tubes, a centering ring and six drops of super glue.

wow! these look fantastic!!

Round Bottom Rocket is very neat, do you see any charring or soot on the ring fins?

mjennings said:

Round Bottom Rocket is very neat, do you see any charring or soot on the ring fins?

Click to expand...

No; but the lower nosecone is showing some carbon scoring, it looks like it was in a battle.

The smoke trail from “Round Bottom Rocket” tries to form the typical spread pattern you see with canted motors.

But with the motors inside of a tube fin the airflow passing through the tube appears to cause the diverging smoke to recombine at a point somewhere below the rocket.

that sounds really cool, love to see a pic if you can capture it.

Those are some nice Fat-Bottomed rockets you built. Great designs!!!!!

FYI; the funky big BT-70/BT-101 centering rings used on “Tri-Oomph!!” are a Totally Tubular product I found at eRockets.
They are actually a “Universal C-Ring” that allows you to cut them to the desired size. As near as I can tell they are the only commercially available rings for a BT-101 tube.

(This has been a shameless non-profit plug for Randy and eRockets.biz)

Very cool designs!

Really well done stuff there - hats off to you sir