Tag Archives: modifications

Making a heater valve bracket

Hours: 1.5
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Time to turn my cardboard prototype into a permanent bracket for the heater valve.

Since this bracket will sit freely, I decided to use 0.05in thick aluminum to give it some strength.

Just like the standard bracket that would usually hold the bowden cable, I designed the bracket to mount into the heater valve unit. So I added the size of the screw mount portion of the original bracket to my cardboard bracket part.

Outlining the bracket to cut
rough outline of the bracket and adding some indicators for the 90 degree bend

With the outline made, I got out the aviation snips and started cutting out the bracket.

Bottom part of the bracket cut
Bracket cut and 90 degree bend location marked

Next step, releasing some tension. To make the bend, I mounted the bracket along the bend line in my bench vise. And then gave it some gentle (read strong) taps with the rubber mallet to form the bend.

Bracket mounted in my bench vise with some wood to bend it along
Whacking the bracket to form the 90 degree bend (very satisfying)

And here it is, a nicely formed 90 degree bend.

Bracket with the bend completed
New bracket along with the original bracket to check the bend is aligned

Next I deburred all the edges and rounded out the corners.

Deburred and corners rounded

And then I match-drilled the holes to mount the bracket to the heater valve using the original bracket.

Match-drilling the bracket holes using the original bracket as a template
Bracket mounted on the heater valve

Finally, time to mount the servo to the new bracket. Quick test fitting with a clamp to get the travel distance right.

Final test fitting of the servo

And then I drilled and mounted it to the bracket.

Servo mounted.

And here it is in action:

Figuring out cabin air assembly

Hours: 2
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Last week I finally received the cabin air parts after the lockdown in the past few months that put a hold at the factory for sending out new parts, but they are back up and running.

The cabin heat assembly for the TSi has a mixture of forced air from a NACA duct getting air from the outside when the plane is moving, together with an actual radiator heater, for those times where you don’t want cold outside air and instead heat it. To shut out the outside air, the TSi has a butterfly valve that’s operated by a handle from the panel.

I am planning to replace the manual handle with a servo instead and also replace the front standard plastic vents that come with the kit, with some ball vents typical in airplanes.

I got the Aveo Air Maxi Vents in black since the front is black leather, so it blends in nicely.

Aveo Air Maxi Vents

Butterfly valve servo

The servo I’m going to use is from TCW that comes with a linear servo from Actuonix, together with TCW’s control board with the control knob to operate the servo.

The first thing I had to figure out is the travel of the butterfly valve, it is around 40mm long. I made a small cardboard panel, clamped it to the bracket of the box that houses the butterfly valve. Based on the maximum extension I then mounted the back of the servo onto my cardboard panel. Then I tested that retracting and extending works correctly from that position and made small adjustments to the travel distance.

Here’s a small video of testing the operation:

With the operation figured out, then I went to check for alignments in the cabin.

First I had to figure out where exactly the vent box sits inside the cabin. Some quick measuring for the distance based on the construction manual.

Marked where the valve box attaches to the skin

Then I put in the channel that moves air to the rear passenger seats to make sure there is no interference wit the operation.

cabin box held in place, along with the channel that pulls air to the rear passengers

Looks all good. Next step will be to fabricate the bracket out of aluminum.