Tailwheel Conversion: Toe Brakes?

[chrisg]

Hi all,
I'm slowing moving forward on my experimental pa-22/20 project and I have a question regarding the toe brake cylinders: does the Univair conversion call for a tab or clevis of some sort to be welded to the fuselage for the bottom part of the toe brake cylinders to attach to (on the horizontal tube at the bottom of the firewall)? Or is there some sort of bolt-on option?

Thanks,
Chris

[Steve Pierce]

There is the Williams Brake option which bolts in. There are fittings welded in on the Univair conversion. If you have the SWPC Drawing CD it shows the deminsions. I have the belly of my Pacer opened up and will get a picture and post.

[Steve Pierce]

Well my PA22/20 has al plate between the left and center rudder bar clamps with brackets welded to it for the brake cylinders to bolt to. This all sits on top of the floor.

[Stephen]

Mine also has a double plate bolted to the existing welded brackets and riveted to the floor board, which is reinforced on both sides of the floor boards. The brackets for the cylinders are bolted to the plate. Below is an original PA16 installation.


[attachment=1:2cjkq22g]P1010284.JPG


[attachment=1]P1010284.JPG[/attachment:2cjkq22g]

[chrisg]

Wow, that was fast! Thanks all, for the great feedback....the pictures really help!!!

Does anyone have an opinion on which method is "better"? Should I expend the extra effort now (while the fuse is bare) to weld fittings on or just follow my procrastinating nature and do the plate once I get all the brake parts and rudder pedals?

[JohnW]

I'm going to mildly "pirate" this thread for a second, just because of how "visual" the difference is in the height of the "bellcrank" on the outboard ends of the rudderbars between the original Piper taildragger designs and the later "nosewheel pushers"... in the two pictures that Stephen posted. I mentioned this in another thread about Clipper dual brake issues, and these two pictures are timely, in that regard.

I'll reiterate that the "mechanical advantage" and/or "ratio of input" differences for rudder actuation by the pilot is completely "invisible" to the operator. As I said in the other thread..."you do what you hafta do" (even with the taildragger "conversion" and the "shorter throw") and the length of these bellcrank "arms" is not evident to the "Driver", at all. Ya can't tell there IS a difference, until you can SEE it.

[Stephen]

Wow, that was fast! Thanks all, for the great feedback....the pictures really help!!!

Does anyone have an opinion on which method is "better"? Should I expend the extra effort now (while the fuse is bare) to weld fittings on or just follow my procrastinating nature and do the plate once I get all the brake parts and rudder pedals?

I have no opinion about which way to go. John is correct in that you will never notice the difference. Do what your IA says or what you think is best.

[chrisg]

Stephen (et al), I have another question:
On the PA22/20 conversion with the bolt on plate, do I need to move the whole rudder pedal assemblay back away from the firewall to make room for the brake cylinders? It looks like I have 3" from the firewall to the center of the rudder assembly tube...not much.

I think I've read somewhere that people move the front floor mounting screws to the back position. I would assume that I'd then need to weld some attach tabs onto the fuselage...is that correct?

Thanks!