Engine and prop control knob placement

[DBeaulieu]

Okay, need some thoughts on how others considered where to place their control knobs. I have the Seaplane version Patrol (doors both sides) which seems to preclude me putting anything on the left side of the airframe/door without getting really clever. I've kinda decided to place them on a small subpanel as shown by the posterboard template below the instrument panel to the left. Seems to easily clear the flap lever and getting in and out of the seat is not an apparent issue. Mainly wondering about knob spacing and if I should break the lineup and put one of the knobs just above the subpanel on the instrument panel. If so, do I keep the mixture or prop with the throttle on the subpanel? Appreciate any/all comments and ideas?

Dave (from Maine)

throttle subpanel 1.jpg

[Steve W]

Don’t know if this helps. Scratch built plane with both doors. Like to use the left side of the plane. Have baggage door on the left. Put all controls on the right side. Cluttered the left when I put on the amphibs. I’m 6’ and it is a bit tight getting in and out but doable.

I guess if you have a kit fuse then the baggage door is on the right so the right side would mostly be your working side. So Id say yes, put your controls on the left out of the way.

[500AGL]

Dave, I’ve seen numerous combinations for that. All three in the panel above all three in the sub panel, mixture up and throttle and prop down and even throttle and prop in a post mounted quadrant

Really comes down to ergonomics. Sit in the seat and envision how you want to use it.

[paulodonnell]

Hi Dave, I'm literally looking at the same thing here this morning - SP QB kit - the Patrol 'Manual' I got was a USB key featuring a seaplane build which shows photos of this arrangement. Am thinking of doing the same idea with front and rear throttle quadrants mounted on the door itself. Have been eyeballing the plain single lever quadrants on Aircraft Spruce's site. Am planning to use a UL Power 520T motor, so no mixture lever required. A panel mounted throttle could work too, but I think I'd like to offer the rear seat passenger/instructor throttle control also.

[paulodonnell]

Also saw these on the Sonex site:-

https://www.sonexaircraft.com/eshop/cart.php?target=product&product_id=16557&category_id=333

[Bcone1381]

should break the lineup and put one of the knobs just above the subpanel on the instrument panel. If so, do I keep the mixture or prop with the throttle on the subpanel? Appreciate any/all comments and ideas?

Dave (from Maine)

throttle subpanel 1.jpg

Panel real estate is precious. Yes, that flap lever is a driving factor to placing these. Keeping the three engine cables near each other is good logic. I have the prop and mixture where your cardboard template is. I like it. If the throttle fits I’d do it just like your template shows.

Some details for the subpanel design.
- I’d design it so the sub panel is easy to remove…..place the top of your L-shaped subpanel on top of the instrument panel base and secure where your Cleco is with a machine screw plus one more.

- I fit my sub-panel under the panel base and it’s diffacult to remove. You get into removing the entire instrument panel to get it out. And that is connected to the boot cowl. Don’t do what I did.

- I’d make the sub panel so each knob can be removed without removing the entire cable. If I want to move my knob, I have to unhook the opposite end and feed all 5 feet of cable thru that sub panel hole. What a pain. Slotting the holes is an idea.

- the bottom edge of the sub panel needs treatment to prevent injury in an accident. 1/4” Versa-a tube soft aluminum tubing you probably used for your brake lines can carefully be slotted lengthwise with a dremel cutting disc. Then push the slot on the bottom edge of the subpanel and take it all the way around the corner. It will stay on with its own clamping pressure encouraged with some pliers if needed. Looks good too.

[rodsmith]

Dave, the spacing for your three controls looks a little tight to me. I would have all 3 controls available to check spacing before cutting metal. I'm speaking as someone who originally had the holes too close and had to redo them.

[Bcone1381]

Rod's onto good data...To expand on what he said....

-Visualize one knob pulled out about 3 inches to where your first knuckle is, then space it so when you grab the adjacent knob and turn it the knuckle has good clearance.
-I'm sure you can mess around with stuff in the shop and get spacing without buying the cables yet.

[alaskabearhawk]

Since you are building a Patrol, have you considered a throttle quadrant on the left side of the aircraft? It would free up panel space.

https://www.aircraftspruce.com/menus/ap/controls_quadrants.html

[rodsmith]

Dave has the sea plane version of the Patrol with two doors.

[Pbruce]

I’m just finishing this process myself. It’s interesting how different things turn out between builds once a few variables are introduced. Specifically, my Patrol is not a seaplane so no left door. I like to fly with a throttle lever in my left hand and stick in the right. I kept a a much-loved Garmin 796 which is too big to fit in the panel so it’s hard-mounted externally, with a cooling fan behind it. Some people would recoil at this strategy (I did at first) but it works great and I’m a “form-follows-function” kind of guy.

The EFIS (big square cutout top center of pane) is a 7” GRT Sport EFIS. The EMS is a remote GRT box which will hang on a bracket well in front of the panel. The GRT EFIS will provide transponder, ADSB and EMS controls. The radio (below the big EFIS cutout) is a Garmin experimental unit with a two-place intercom. It negates the need for a com panel. The other kind of unique element is that since I have one mag and one Race-Tech CPI ignition system, I needed a sub-panel to mount the ignition controller on. It’s mounted on an articulating panel under the Garmin 796. It can be folded away until needed to change a parameter.

Two throttles levers from Avipro are ganged together in the left cockpit wall by a steel rod. I wanted to keep the other controls on the panel, roughly in line with the throttle. This just seemed more ergonomic to me at the time of planning.

Placement of the prop vernier control was dictated by required spacing from the throttle lever. (If I could do it again I’d move the prop a quarter inch to the right to provide a titch more knuckle room). The mixture vernier knob location was in turn dictated by spacing from the prop, and the primer pump from the mixture. I started with the carb heat next to the mixture, but I liked the idea of being able to push the throttle forward and close the carb heat in a simultaneous movement with one hand, so I placed the carb heat (small silver Bowden cable knob) above and to the right of the throttle.

I put the park brake knob on the right side by the door so I can release it by reaching in from outside the plane. The cabin heat goes beside it because it’s the same type of bowden cable, with the same knob and it looks good there.

One important consideration in the placement of controls along the bottom of the panel: the steel tube braces extending from the bottom corners of the panel to the centre-top of the firewall angle inward to form a v. They also angle upward slightly. In my case, my panel angles slightly, causing the cables to angle downward. Also, the vernier controls in particular have a long fixed portion forward of the knob. It’s very likely that they will intersect with the plane of the v-braces. It’s really a challenge to get this right, and it’s imperative that you do, since bending the cables to avoid the tubes causes friction. I drove myself nuts trying to measure and provide clearance for all the controls, and then finally drilled. I think I got lucky.

I mounted the compass at the top of the panel just left of centre. I received a few comments about placing it close to the EFIS as I have done, but called Grand Rapids and they said it’s no problem.

In the end, the big variables which dictated the look of the panel were the single right-hand door, dual throttles on the left, the 796 and my personal sense of good cockpit ergonomics. I expect this will vary greatly from one builder to another. It’s a fun part of the build, projecting your own philosophy onto sheet metal and ending up with an instrument panel and controls.

[DBeaulieu]

Thank you all for such great response. I hope to get my front seat back from the upholstery shop soon, then I can get my seating position dialed in a bit better for engine/prop control placement. In the meantime I can mull things over. Having the seaplane version adds another layer of challenge to this...

Dave (from Maine)

[Pbruce]

It seems reasonably straightforward to me if you only need a front throttle. You can just use vernier controls along the bottom as I did or below the panel as many others have. How you would manage a second throttle aft of an opening door is beyond me, but I salute anyone who has done it.

[DBeaulieu]

Pbruce I think I will prefer along the bottom as it brings the knobs a bit closer to me and my reach length. At this point I'm not concerned about adding a rear throttle and am on the fence regarding rear brakes.

[paulodonnell]

Thinking again about the door mounted throttles on the Seaplane Patrol ...what would make this terribly simple (unless I'm missing something here regulation-wise or 'good practice' ) would be to just link two quadrants with a rod and use a flexible cable then to the throttle body... the arrangement I saw (and posted earlier in this thread) used spherical bearings and linkages which seems like hard work and also the door can't be opened when the motor's running.

[spinningwrench]

For what it’s worth this cluster of engine controls in my panel worked out perfect for placement and distance between controls. Everything is mounted on a sub-panel cutout which allows for easy removal.
Panel Design.jpg

[DBeaulieu]

spinningwrench That is a nice, clean panel layout. Throttle right below the mixture and prop knobs (on subpanel) would likely work well for me. Thanks for posting!

[spinningwrench]

You have a pay a lot of attention to the depth of your controls behind the instrument panel as they can easily interfere with the fuselage diagonal tubes in that area.

[Bcone1381]

I have good spacing that measures 2.5” space between vernier prop and mixture on my sub panel.