Estes Mini A Heli #007272, Build, Part 7, Tube Slotting

The great thing about multiple instructions in different languages - You can cut out templates from the sheet you can't read!

The gray areas are the ejection relief slots in the upper body tube.

I did a lot of practice cutting on some scrap BT-5 tubes.
It's easy to punch and cut the corners, but also easy to punch and cut too far and beyond the opposite corner.

On the left, notice the flat back of the blade is in the corner, the sharp tip and side is facing to the left. Punch and slit to the center of the top.

On the right, the blade is flipped over with the sharp side to the right. Set the tip down in line with the half slit you just made. Lightly punch and cut to the right joining the two cuts.

BT-5 tubing is thin. You want the corners clean and strong. It's very easy to punch and cut beyond the opposite end corner. TIP: Practice on scrap tubing! 



I used an aluminum angle to cut the lines down the sides.


Here I'm stopping before I get all the way down to the left corner. The low end (going up) is cut by flipping over the knife with the flat, dull side of the blade facing up.




After cutting the slots, the piece is still held on the tube. I went back and freed up the corners.










The sides were cleaned up using a small diamond file.
In the end, the corners are pretty clean, stronger without any over cuts.

Estes V2 Build Part 5 Fin Slots

I'm going to save the fin slot cut away pieces for a future build.
They might make some interesting tunnels or "runways".



It's a little hard to see in this picture,
The slots at the top of the picture are right after cutting.

The slots at the bottom have been sanded smooth.
The instructions don't say to sand the slots edges down. (For that matter, the instructions don't say much at all!)
You should sand down the edges.
The root edges of the fins won't fit flush with the plastic edges in the way.

Estes V2 Build Part 4 Fin Slots

The fin slots don't cut easily. Take your time and use a sharp knife.

You might find it easier to follow a pencil line.

Set a sharp pencil into the "trough" and draw a line all the way around the eight fin slots.

Cut following the pencil outlines.

Work on the straight sides first. Stop before you reach the rounded bottom!

Cut almost to the bottom. (shown in the picture)

Flip over the tail cone and finish from the other end.

Your knife will slip off the round end if you get too close to the end.

It took four passes to cut through the plastic.

I found it easier to "rock" the knife blade around the rounded ends.

Set the blade on the pencil line before using any pressure.

This is the other side of the "rocking" motion

Again, it'll take a few passes to cut through the plastic.

Centuri Vulcan Build Part 13 The Rod Slot!

After I thought the model was finished, I went back and checked the lug and rod slot.

THERE WAS TOO MUCH LUG BINDING THROUGH THE FRONT SLOT!
The slot had to be extended to 3" long!

In the original kit, this is why the lug was glued to the outside of the cone body under a fin.
Too many reviews talk about the Vulcan "tail wagging" on the way up. Most assume (like I did) it was from the launch angle caused by the lug glued on at an angle.
I was trying to correct this by moving the lug to the center.



Some glue was snuck under the slot edges and a dowel rolled over to set the edges down.
Don't go too far back, you don't want to change the profile of the cone.






The tips of the fins were pointed, weak and prone to bending.
Just the tips were cut back and the underside strengthened with white glue applied with a Q-tip.

Centuri Vulcan Build Part 10 Rod Slot Cutting

NOTE: Doing an internal lug requires a long slot to be cut in the conical body. After the model was finished, I wished I had just glued the lug under a fin like the Centuri instructions showed.




With the motor mount tube pressed flush with the top of the cone body, the launch rod is pushed forward until it makes contact with the angled shroud.

I marked the intersection point with a pencil.




Using the rotary punch, a hole was made slight above the pencil mark.

With sharp scissors, the side lines of the slot were cut.

As mentioned before, I made a guess as to how long this slot would have to be to allow a launch rod to fit without binding. I was way off!



With the forward slot cut, glue the internal motor mount tube into the small end of the cone.

Look from the back and center the tube.
Be sure the launch lug is in line with the cone seam and the forward slot you just cut.

Apogee Heli-Roc Build Part 5 Ports

I used a strait edge to cut the slots.

Be careful not to over cut the corners. I pressed the tip of the blade into the corner and stopped the cut before reaching the end of line.

The tube was turned around and the cut was finished from the other side.

To strengthen the body tube and the cut out ports, thin CA was applied to a cotton swab and rubbed inside the body tube around the cut port edges.

A small amount of CA was also run around the ports from the outside. Any buildup of the super glue is easily sanded smooth.

Here's a finished port after sanding the CA glue smooth.

Apogee Heli-Roc Build Part 4 Ports

On my BT-5 tube, the fin marking guide was a little to wide. It over wrapped by about 1/32".

I knew the fin marks and ports (or slots) would be critical, so I made a new marking guide.

After the three fin marks were made, I centered the ports over the three lines.

I only cut one box out and rotated the same "master" around the tube to draw three consistent rectangles.

Here I used the top of the wrap to check the top and bottom of the ports to be sure all lines were level with each other.