[Ironflight]

As I've mentioned on a few other threads, we're getting ready to build a whole new instrument panel for Louise's RV-6 in the next month or so. We have almost all the major components sitting in the staging area, and hope to get started next week cutting metal, so I have spent the last couple of nights doing the detailed panel layout - transferring all of our ideas and sketches to the actual panel, to make sure that everything fits the way we want before cutting or drilling the first hole.

In an excellent and thought provoking thread started by Bob Collins just the other day, folks shared their ideas about getting stuck (and unstuck) on their projects. It is easy to get paralyzed by choices, especially when you aren't sure what the ramifications of those choices might be down the road, and laying out the panel is a good case in point. I have a list of everything that goes int eh panel, and with only a very few minor exceptions, their dimensions. I have the cartoon of what we want. But I sat for awhile with my pen hovering over the blue-coated panel, wondering where to begin. Why? Because many of the choices that we have to make are essentially arbitrary! OK, so I want a D-180, and I want it just to the right of the left-side panel support rib. That fixes it's left/right position....but how about vertical? Well, I want a row of 3-1/8" instruments underneath. OK, I have a template for those, so I can draw them in. But how much panel to leave below them? 1/2"? 3/4? In fact, either will work.....and then shouldn't I use the same spacing above that for the D-180? Hmmmm - yes, that will work? So again, what spacing works best?

Well "best" is a relative term, and we can agonize over it for a long time - or simply draw what looks good. It's arbitrary! So I pick a spacing that is esthetically pleasing, and press on. The radio stack is easy to position left/right - I am going to put it where it was originally, because the forward sub-panel is already cut out for it. But the stack only takes up about 2/3rds of the panel height - so should I bias the stack high or low? Or put it in the middle? I prefer high or low, because that leaves expansion room later on - I like radios high, but anything we might ad later will be fancy, and we might want it up top. Arbitrary again! No right or wrong answer. Of course, I'm not cutting metal TODAY, so I cut out a template the size of the stack, and taped it on the panel. Decision to be made later - I might decide I need to put a row of Circuit breakers underneath.

Ahhh, the Mag and Master switch. I know just where I want them. Left side of the panel, ow, to the left of the row of 3-1/8" backup instruments. But....that space is big enough that I can slide them around a good inch in every direction - so where to put them EXACTLY? Arbitrary again! Crowd them to an edge and leave room for something else later? Sure, why not - that might be a good location for a trim indicator!

Now you might wonder why I am not just doing all this in CAD! Well, frankly, since I enjoy cutting out panels, I am not going to hire it done by CAM, and I have found that no matter how good my CAD program, it all falls down to having a perfectly;y scaled printer if I am going to trust the resulting print to literally cut metal - so I am more comfortable doing the final layout by hand. We used the free panel design software available around the RV world to do our conceptual design, but in the end, I don't want to make metal chips until I have transfered the known templates for my instruments and mounting racks to the work piece.

The arbitrary nature of the task points out that essentially, there is no single "right" answer. There are, in fact, a wide number of workable solutions, and all I need is one - so when I have it, I press on. Now, on to the sub panel....

Does anyone, by chance, have a good, working number for the spacing between the Throttle, Prop, and Mixture Controls (center to center)? Seems like just another arbitrary number to me, but I've been avoiding marking those holes for a day now.....

Paul

 

[petehowell]

Knob Dist

Iron,

I used 2.75 for mine and am very happy with it. I can zap you the visio file if you can use it.

When are you headed back up north? They are talking SNOW!!

 

[Norman CYYJ]

Paul 21/2 inches is a real comfortable distance between the throttle mixture and pitch controls 11/2 inches from the mixture or pitch control to the cabin heat etc works well.
Don't be afraid of repositioning the rib on the left side which is directly in front of the pilot to afford the position of the flight instruments. I quite often cut that rib flush with the sub-panel and move it over to the right and then build another rib and install it to the left. The panel then has ample support. This is quite handy in making the glass panels all fit and look good. When laying out the switches I usually place them in order of use. eg. master,alt,primer,ignition,then starter. I put the avionics master on the right and work left from there with A/P. cabin lites landing,nav then strobe. It makes it easy to remember where they are in the dark and when under pressure. Hope this gives you some ideas.

 

[PCHunt]

Does anyone, by chance, have a good, working number for the spacing between the Throttle, Prop, and Mixture Controls (center to center)? Seems like just another arbitrary number to me, but I've been avoiding marking those holes for a day now.....

Paul

I have just finished re-doing the throttle, mixture, carb heat, and cabin heat cables and mounts on my recently purchased RV-6A, and experimented with various spacings. Ended up with 3.0" centers for the Throttle and Mixture, with the carb heat and cabin heat 2.o" outboard.

It depends on your hand size, I s'pose. I have fairly large, "clubby" hands, and the old control cables were WAY too close together, at 1.75" on center.

YMMV

 

[Baseball Dad]

I hope you don't mind me throwing a question in here but it's all related to your original post. The responses given so far are very helpful to me laying out my panel. What about spacing between toggle switches? Also I plan to surface mount my GPS on an angled bracket right above the throttle. How much room is needed between the edge of the throttle knob and the edge of the GPS for hand clearance.

 

[Ironflight]

Thanks for the spacing numbers guys - I'll play with those a little bit. Norman added some really good info to the thread in regards to laying out the relative position of switches - I do a lot of cockpit operational engineering stuff, and am always very careful to put them in "the order of use" so that checklists can flow logically around the cockpit - very important if you want a cockpit that fits like a glove! Those kind of considerations are NOT arbitrary in my mind.....

(I had read about moving the rib before, and intended to do that if I needed to, but with the equipment we ended up with, it actually worked out as a good landmark - and besides, the original forward sub panel has been cut so many time already that it would be hard to find a new place to anchor the rib.....)

AS for spacing between toggle switches, I usually use a minimum of an inch, but open that up to 1-1/4" if I have the room. It does sort of depend on the size of the switch body (behind th epanel) - some are larger than other. Circuit breakers are also different sizes - the smaller Klixons can be as close as 3/4", but that gets pretty tight when you later add panel labels!

Paul

P.S. - Pete - not sure when I'll be headed up north. Might drop in for a two-day around Christmas - we've got another shuttle flight between now and then, and that's driving my schedule. If I get the chance to come up, I'll give you guys a holler!