Throttle Quadrant

[Bcone1381]

The original post had problems, so I cut/pasted and slightly improved it with good photo links in Post #4

[Bdflies]

I’m excited about your quadrant! But don’t see any pictures.
Is it just me?

Bill

[marcusofcotton]

Nice write up, pity the pictures aren't coming through.

[Bcone1381]

Let me start over.

http://baxterquadrants.com

I got my Throttle Quadrant from the above company. My connection with Baxter Quadrants is merely as a satisfied customer. Maybe I should say ...so far. I have no experience using a Baxter Quadrant, as I am still building, but they seem real nice. Quality is felt in the control of the friction device.

One of the problems I needed to solve is specific to the Patrol. The position of the quadrant needs to avoid the flap handle. My desire is to have the Throttle and the Prop Controls on the front throttle quadrant, with the Mixture Control located in the instrument panel. So, having two levers makes the quadrant wider than a quadrant with one lever control, (see Bob's below). After looking at other builds at Oshkosh, I preferred the quadrant's position to be below the window sill.

Bob has his positioned below the sill.

IMG_5887.jpg
The blue line of the photo below is my fuslage. The tube with the blue line seemed to me to be the initially obvious place for the throttle quadrant attachment. It shows a whole lot going on in that area with the flap handle and the window latch.
Screen Shot 2018-08-20 at 9.40.35 AM.png

In the photo below of Bob's Patrol, the red line represents the flap handle....the friction knob sticks out about an inch past the body of the Baxter throttle quadrant. If I simply attached it to the inside of the tubing below the window sill, the friction knob became a knuckle buster.....scratching the knuckles on the knurled knob in every application of full flaps.
IMG_5882.jpg

So after OSH I knew I wanted my quadrant to fit under the sill, and allow pain free extension of full flaps.

The quadrant came with a straight throttle lever (Black knob) which I modified about 1/2 way (a slight bend) up to make it fit under the window sill. The prop lever (Blue knob) viewed in the photo was not altered. I liked the vertical position of the knobs because when my hand is placed on the flap lever, its above the friction knob, and under the throttle lever. Unfortunately, the horizontal postion of the black ball was too close to the fuselage tube and didn't feel good at all.

So I made a new lever out of 1/8" 6061 Aluminum to move the ball inboard another inch.
IMG_6065 (1).jpgIMG_6068.jpg

Now the throttle knob feels just right! The knuckles dont interfere.

Now, lets look at the Quadrant's mount. I fabricated two mounting plates, one inside the other.
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One is permanent, one is removable.The larger Fuselage Mounting Plate was fabricated from .032 2024-T3 sheet AL. The smaller inner plates is secured to the Quadrant Body and is 1 inch larger than the body itself. In the photo below, this smaller inner plate is clecoed to a larger Fuselage Mounting Plate. I stiffened the larger Fuselage Mount Plate by putting a flange on each edge of its perimeter. Its attached to the fuselage tubing with one Adle Clamp, and attached to the front fuselage former with clecos. (my fabrication method was to make a pattern out of poster board, then the real one out of AL.

Notice my mount does not require welding and allows easy removal of the quadrant after I replace the clocos with nut plates and machine screws. I think a 4130 welded steel mount could easilybe lighter, but I am a novice, and am avoiding welding. If one welds with confidence, I would go that route.

You might be interested in a backside photo of the assembly.

IMG_6061.jpg

I am running out of factory parts to install. The environment of building changes significantly after all the factory parts are installed. There is no Throttle Quadrant installation information or parts included with the kit or in the plans. It requires thinking and problem solving. So will the electrical, avionics, firewall forward....I guess thats why I wanted to share my throttle quadrant install. It might help you understand one persons barriers, problems, and solutions and improve or speed up the decision making and building process.

[Sir Newton]

Very nice engineering. I would prefer to have a design similar to yours as a center throttle quadrant in BH5. The look is just better!

[Mark Goldberg]

Looks good Brooks. I assume it all feels real solid with the two mounting plates and how you have attached them to the fuselage with the Adel clamps and to the former? Mark

[Bcone1381]

Yeah, it feels solid...for a throttle mount that is. I will be using the fuselage tubes to hoist lift and hoist myself into the front seat instead of the throttle knob though.

But if I think about slamming the throttle forward like one could possible do if they are in an unexpected panic go-around situation, its solid and not moving...same when its brought back to idle.

[Bcone1381]

Mark;

After some reflection about your question, I wonder if it would improve things to position the black throttle knob above the window sill (instead of beside it) to reduce stress on the quadrant when downward pressure is applied to the knob. That is probably a good idea...easy fix.

[Bcone1381]

Lets update this thread. When I wrote the original post, I neglected to accommodate for attachment of the control cable to the levers. The education process of amateur built aircraft prevailed though. You can see in post #4 that a steel fuselage tube is right in front of the quadrant. It was unworkable ......And I was so proud of my creation! Famous saying "What you see is all there really is." I was so focused on getting a two lever quadrant to fit and accommodate the flap lever that I did not see and understand the cable aspect of the job.

This first photo shows the Baxter quadrant with a single lever and a friction control knob mounted to the window sill using the quadrants AN3 bolts and nut plates. It's solid and secure. Also see the window latch. I am not going to use the kit provided J hook. The tab will rotate into a slot that i will cut and reinforce on the window will after the window is installed. Mark G used this design on his first patrol. The interconnect bar between the rear and front throttle is 1/16" X 3/4" 2024T3 AL that I had on hand. Attempts at using tubing proved difficult for me. This bar was a super simple and solid solution.
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A view from the rear throttle quadrant. Note, no friction control knob on the rear quadrant. Only the front Quadrant controls the friction.
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Close up view of the front quadrant and the window latch.
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Here is a corner panel I fabricated from .050 AL. It secures the Throttle Cable, a parking brake cable, and a dual USB jack to charge cell phones and iPads. There is plenty of room to actuate the flap handle.
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This is the big picture. The Mixture and Prop and knob are on the left side of the instrument panel.
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[Bcone1381]

This is how the Throttle quadrant finished out. You can see I moved my Mixture and Prop down off the Instrument Panel. I like keeping the panel free from all that I can to keep it clean and easy to service. The shroud over the throttle quadrants has the headphone jacks installed under it using Phenolic sheet to secure them rather than conductive aluminum. That means more items moved off the instrument panel.

The shroud is attached to the quadrants using nut plates and #6 machine screws. It takes 30 seconds to remove it. I will be installing fabric on the interior to finish it out. To do that, the quadrants will be removed from the window sill, interior dacron fabric attached to it, extending down to the bottom fuselage tube at the floor to cover the side panel.

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[davzLSA]

That is a very professional looking throttle install Brooks. It makes me want to clean up my throttle install.

[Bcone1381]

Thanks, Dave! What I ended up with now seems so simple and obvious. I'd hate to guess the hours I spent designing, fabricating, and installing things that did not work. Design is not an a strong attribute or an enjoyable task for me. I do better with directions and simple repetitive tasks. Those head set plugs I think are my fourth design and installation!! That why building takes me so long!! A design issue is like throwing out an anchor for me.

[davzLSA]

Im the same way Brooks, most people would have been flying by now. But no I want to build this thing 10 times before I fly!!!

[Pbruce]

Really looks good. Functionally excellent and takes up very little width. Im guessing that both from and rear headset jacks are located in the aluminum piece. Or are they for another purpose? Are those vernier-type prop and mixture controls, or just the push/pull type? Where do you find them?

[Bcone1381]

Both front and rear headset jacks (four total) are installed on the bottom of the shroud and serve no other purpose.

The Prop and Mixture cables are 48 inch long McFarland Vernier Assist cables. I hope I like them. They are kind of pricey. The labels on those two knobs simplifies panel labeling. Labels on an instrument panel complicate simplicity.

Here is a link to McFarland's web site. It's hard to navigate. If anyone needs more info on these let me know and I can get specifics. The knobs are purchased separately.

https://www.mcfarlaneaviation.com/products/product/MCVA2035-20-048/
https://www.mcfarlaneaviation.com/me...lyerwebdoc.pdf
https://www.mcfarlaneaviation.com/me...ttle-specs.pdf

[Bcone1381]

One more thing. I had a report after I committed to these McFarlane vernier assist cables that the Prop Cable was unable to maintain a constant rpm on the BH five prototype. I understand that Its been replaced. The prop governor's spring was able to overcome cables the friction lock mechanism. They also weigh more than a classic bowden cable. So beware.

[davzLSA]

yes they are pricey!!