Packaging a custom two quadrant throttle design

[spinningwrench]

DSC_1557-S.jpgJust finished making a custom two quadrant throttle that fits completely in the sidewall of the Patrol. There is plenty of space between the throttle handles and flap lever with this installation. The quadrant is inspired by the Baxter throttles sold through Aircraft Spruce but by making one lever reversing and bringing it out the bottom with a cranked arm I was able to reduce the overall thickness of the quadrant by 1/4" allowing me to bring out all the engine control cables on the outside of the vertical fuselage tube just in front of the quadrant.
DSC_1561-S.jpgDSC_1559-S.jpgDSC_1565-S.jpg There is no impact to the pilots space and everything fits within the sidewall.

[svyolo]

Very nice. I wish I could figure out how to put one in a 4 place.

[JimParker256]

Very cool, and I really like that solution. Unfortunately, I won't be able to steal your idea, since I have a 2nd door on that side (seaplane kit). I think I'm going to wind up with at throttle / mixture controls on the panel (or perhaps a small sub-panel) way over on the left side...

I still have to figure out a way to add at least a throttle (and perhaps mixture as well) for the back seat to make my CFI comfortable with doing flight reviews. Perhaps a throttle cable running under the door sill, and connecting to the primary throttle linkage somehow, and just live with no mixture control from the rear seat?

[spinningwrench]

No mixture in the back is pretty common. I used the A-920 control cables from Aircraft Spruce which have a minimum bend radius of 6" and are very smooth. Maybe you could do an overhead quadrant like on a seaplane? That would look pretty cool.

[Bdflies]

"Overhead"!!! Ooohhh... I like that idea....

Bill

[interstate al]

Well thought out and very nicely made! I love it!!!

[davzLSA]

Wow those look really nice and professionally done. What did you use for friction material between the levers? How are you adjusting the friction between the levers?

[davzLSA]

OK just saw the friction adjust knob, looks great!!!

[spinningwrench]

The friction material is called Garolite. Its a type of phenolic. The friction knob preloads the levers and Garolite and allows for very smooth adjustment and silky feel.

[JJohnston]

I see 5 tabs involved. Did you have to put those on yourself?

[spinningwrench]

Yes three to hold the throttle and two more tabs to hold the cable attach brackets which I purchased from Aircraft Spruce.

[Shopperly]

These tabs look like they were done at the factory! What’s the procedure for welding tabs onto the fuselage tubing? How is the integrity of the tubing assured at the welding site and how do you refinish the area? I have no knowledge of welding and am just wondering how practical it is to make these kind of minor additions to the airframe after receiving the QB kit. Thanks!

[spinningwrench]

In terms of welding tabs are probably the easiest weld to make as the tab kind of produces its own filler material as it melts into the tubing although I will always dab a little filler on to make a nice looking joint. For mounting the throttle I made a sheet metal template with screw holes to hold the tabs in position and then just tacked the corners of the tabs onto the tubing. I removed the template and finish welded each tab. The template makes all the tabs lie in the same plane. The integrity of the tubing is not affected if the weld is done properly. I like mounting real important things like the throttle with permanent tabs so things can never move around. After welding I wire brush, prime with epoxy primer and the next day apply a top coat of enamel which I color matched to the Bearhawk Quick Build paint as applied at the factory. Hope this helps.

[FlyNavy86]

Beautiful install, spinningwrench !

As an ex-Navy pilot, I am hard-wired to want throttle in LH, stick in RH, so I plan to attempt something similar on my eventual Bearhawk build. Will be sure to give you credit

[jaredyates]

Just sit in the right seat and you'll be good to go.

[spinningwrench]

Just let me know how I can help, I’ve produced lots of CAD drawings for my Patrol build.