Tue Sep 21 2010

Fabricating baffle plate (again)

Well after looking at the first version of the baffle some more and the washers I made, I wasn't completely happy, so I decided to make another version. This one is made from some scrap 0.040 thick material. Since it's thicker, it doesn't need the flanges along the sides so it should be easier to make guides for it.

The bottom guide is two pieces. The first piece is 3/16 thick...cut from a leftover piece of aluminum angle.

The second piece was a Z bracket in it's former life...

...but no longer. I trimmed it into a piece of 3/4 x 1/4 angle.

Here's how it'll clamp up. I'll use four rivets to hold the two pieces to the rectangular baffle rib.

After drilling the holes to #40 it fit pretty well, but I thought the baffle was a little too loose, so I took out the cleco at one end, clamped it up and drilled to #30. Rinse, and repeat for the other end and the two middle holes and it was nice and snug.

I also filed this little notch to match the radius at the bottom of the long louver slot. (more for aesthetics than anything).

My 12 inch Di-Acro shear did a great job of trimming off a couple more strips of 0.040 scrap to fashion the top guide.

Here's how the top guide will work.

These two pieces have been drilled to each other.

...and now to the heater manifold. It slides quite nicely. Next will be to make a little lever mechanism. Two reasons for the lever mechanism:

  1. I want the cable to enter from the right side of this heater manifold, but I want the baffle to close the pilot's side when I pull the knob. That means I need to reverse the operation of the cable.
  2. This baffle travels only 1/2 inch, but the heater box on/off valve travels about 1 1/2 inches. I'd like the pull distance for the two handles to be roughly equal, so that means I need to use a 3:1 ratio on the lever. This lever will increase the travel and reverse the direction of travel as noted above. Additionally, a nice side effect is that it should reduce the amount of force required to actuate this baffle.