The A-10C main instrument panel is a wonder to behold. The instruments are wedged in so tight there’s barely any metal showing from the panel itself. So how does this panel, which seems to be all holes, have the strength for high G combat? Well, it’s not a piece of sheet metal with holes cut in it. It’s a lattice structure of bars.

I began to wonder just how I could make an A-10C MIP. I wasn’t satisfied with plywood or plastic having cutouts over a monitor. I wanted to use individual instruments and gauges. I wanted the stepped depth of the real panel. I wanted verisimilitude on par with the real deal to get the sense of immersion that only the best faked reality can bring.

Oh, I could toss a three inch slab of aluminum on a CNC and mill one, but that’s such an obvious approach it’s hardly worth mentioning. No, I was looking for a real challenge. How would I build such a panel if I were stranded on a desert island with only the local Home Depot or hardware store? Then it occurred to me, if the panel structure looks like a lattice of metal bars, perhaps I could make it from bar stock! Welding was out because I was, after all, on a desert island, so I’d have to use epoxy to join those bars.

Using photographs, military standards, postings on cockpit builder forums, and A-10C manuals I quickly assembled relevant dimensional data. (Okay, it was actually more like a week.) I instantly poured this wealth of information into TurboCAD. (For large values of “instantly” roughly equal to several hours.) I was able to use real dimensions for everything except the multi function color displays. The real MFCDs are based on 5” square LCDs with 600 by 600 resolution. These are hard to find on (or off) desert islands. I decided to base my design on 8” diagonal LCDs having 800 by 600 resolution. This stretched the MIP outline, but did not shift the positions of any of the instruments. So far, so good.

I had TurboCAD produce a 3D rendering of the resulting lattice structure.




This is made of 0.125” thick aluminum bar stock. Much of it is 1” wide. In the center of the structure some is as wide as 2.75”. I’ve had good luck using epoxy to join steel components. I’ve used filled epoxies like JB Weld and PC12 epoxy putty. In this application I’ll embed an internally threaded metal spacer. This should both add strength to the joint and provide the means to fasten the instruments and subpanels to the structure. I’ll be using a large amount of epoxy to gusset each joint.




The next steps are to explore the desert island, find out what sorts of bar stock are available, and build a proof of concept test model.

\o/

g.

Just too cool! It occurs to me that if you have access to a large CNC router, you could cut out the outline of the panel in some MDF but not go all the way through the MDF panel, say only 1/4 or 3/8 inch deep. With your routed channels the same thickness as the aluminum bar stock, you could 'dry-fit' all the section and then epoxy weld the exposed area above the MDF template.
I actually have a few dozen short aluminum bar stock pieces I picked up several years ago with no idea what i'd use them for...but they were on clearance at 10 cents/piece. Hmmmm....
Thanks for a another thought provoking post, Mike.
Derek

I wish I had access to a large CNC. That's a good idea for assembling the structure.

About the best thing I can say about my shop area is that I have spare blades for my hacksaw.

The assembly approach I'm toying with currently is to do a partial layout on MDF and use blocks or lengths of aluminum angle screwed to the MDF to support the pieces while the epoxy cures. I'm uncertain how layout and gluing errors with accumulate during assembly so I may assemble the structure cell by cell and measure each with vernier calipers. The longest machinist rule I have is only 12 inches. It looks like the best approach with the tools I have on hand is to draw a horizontal through line then add the two verticals that bound the ADI and HSI. Once those elements are square and properly bonded, I can work outward.

I've got the pieces cut for the proof of concept test. I hope to get them assembled soon and pictures posted.

Being stranded on a desert island myself, this is relevant to my interests. Looks promising! Keep us updated with lots of pics! Anything to keep me distracted long enough for the sick-stomach feeling of just having spent $500 on a HOTAS to go away.

Given that you already have the MFDs and that you're making serious progress on the ABC, the HOTAS purchase was clearly a necessity! There was nothing else anyone else could have done. Nothing to worry about.



I just started assembling the proof of concept item. If it works as expected I'll start collecting materials for a bigger build.

Haha! Thanks for the encouragement, Mike! That plus one other bit of kismet-style encouragement has made me feel a bit better.

Immediately after purchasing my shiny new Warthog, I went looking for a specific quote to update my signature here on SimHQ from my favorite sci-fi series, Doctor Who. While scanning through one of the recent episodes ("Let's Kill Hitler"), I noticed that the stick they used to control the human robot thing was a Warthog!






I figured, "Hell, if it's good enough for the Doctor, then it's good enough for me!"

Anyway, don't want to derail your post or anything! Looking forward to seeing your proof of concept!

A way to build the "welding rig" without access to a CNC machine would be to first cut the outline of the entire panel on some thinner material, and then cut the individual outlines for the single panels to glue or screw onto the larger outline. It ought to be possible using basic tools, and perhaps a fretsaw.

I built a two cell lattice to test the concept. One cell fits a square body instrument with a mounting hole pattern like that used by some of the A-10C instruments. The other cell fits a round body instrument having a different hole pattern.





The square-instrument mounting holes are so close to the corners that I had to tweak the threaded spacers to get them to fit. There was more than adequate room for the spacers in the round instrument cell (and I didn't bother with the spacers there for this test). In fact, there was enough room to add angle aluminum to significantly strengthen the lattice. I can't break it bare handed.

I'm pleased with the concept and expect it to work well in a full-size instrument panel.

Sadly, I've yet to find 3" wide aluminum bar on my island. May have to build a fire and signal the need for bartering with the Onlinemetals tribe a few islands over.

Looking good so far, mate. From what I have heard through the grapevine, depending on which off-island tribe you deal with, you might barter for less goods than you would for an on-island tribe.

Keep those binary smoke signals coming!

I tweaked the design a bit to remove the need to file the threaded spacers. This gives a slightly over size opening for a few of the instruments. If it's noticeable I can easily remedy it. I also decided to use aluminum angles in most of the corners to add strength and to reduce the amount of epoxy needed. Most sub-panel mounting holes and some instrument mounting holes are far enough in from the corner to allow room to do this without requiring any modification of the threaded spacers. Finally, I did a little more research on available LCD panels and displays for use in the MFCDs. I'm not looking for exact sizes or even something that I can hide behind a game bezel. (I'll make my own bezels.) I just want something that works and looks good. I sized the MFCD openings to accept a B-Billion 8" VGA monitor or a Vitrolight 8.4" LCD panel. (Both have 800x600 res.)

I also did some more "desert island" shopping and was very surprised to find that a few islands over I can get the aluminum for less than half (almost a third) the number of coconuts that it will cost to barter for it locally. Even with shipping, it's far cheaper. Guess what I chose.

The aluminum will probably show up in a week. Wish I had a metal-cutting bandsaw. There's a lot of hacksaw time in my future.

Mike, instead of using the threaded spacers, why not cut a triangle gusset and press in a #8-32 PEM fastener?

(and I can slot an instrument panel for you)

g.

The advantages of using threaded spacers are that once glued in they are long enough to add strength to the joints, and I don't have to cut/drill the gussets.


Actually, this is an otherwise good application for PEM nuts. Hmmm, another application is making fake Dzus-rails. I don't see many (as in ~zero) people using PEM nuts in home sims. That's a shame; neat product.


I'll be building this up on a flat piece of MDF. I'll use 1"x1"x1/16" angle to make jigging brackets. Once I have a major horizontal bar and ADI/HSI column properly square, I'll add elements piece by piece using vernier calipers to set accurate dimensions for the instrument openings.

Pictures to follow...

I picked up a ton of PEM fasteners in #6 and #8 from Small Parts years ago. If you have the right drill bit you don't even need an arbor press to set them - you can use a vice and a suitably sized drill bit to expand the flange. It doesn't appear that Small Parts carry them any more.

For those that don't know what we're talking about, here's a product link:
http://catalog.pemnet.com/category/nuts-types-cla-cls-clss-h-hn-s-ss-smps-sp - I'm referring to the type listed in the category in the center of the page.

I don't think many people know about them, otherwise they'd be used more often.

g.

Well, it's taken a while, but I finally have most of the parts cut. I should be able to start building the structure tomorrow.



All these were cut by hand. (Whew!)

Slow, but getting there...

Looking good! Hows the stability and strength?

It's very rigid. The center section pieces are up to 2.75" wide, and are often doubled to make the shifts in panel depth. I expect it will be a bit more flexible overall when I add the outer sections because of the larger openings for the MFCDs and sub panels.

I'm pretty certain I could stand on and have it support my weight.

Loooooking gooood.

g.

I've assembled the easy pieces.



The next pieces have bends in them. The .125" bar doesn't like to bend, so the next few steps may take awhile.

At least up 'til now, this approach has not been particularly difficult. It's time consuming and requires attention to detail, but it's not at all hard to cut the aluminum with a hacksaw then glue the pieces together with epoxy. It does require some care when aligning pieces during assembly, but nothing extraordinary.

All-in-all, this is a viable approach to making a very realistic panel structure.

Hi Mike,

If you rub soap along where you want to bend the bar and then heat it with a blowlamp or suchlike until the soap turns black, you should be able to bend it fairly easily.

Hope this helps,

Andy

Thanks, Andy.

I was able to form the aluminum bar for the curved parts of the structure around a straight coupling for rigid electrical conduit. The aluminum's springback left me with a good radius for the finished bends.

At this point I have the bar pieces pretty much in place. I have a few tweaks to add and a lot of clean up then I'll start adding sheet metal. Some I'll glue on, but most will be the back plates of the sub-panels which are held in place by screws. I'm planning on using the back plates as templates to hold the threaded spacers in place while I epoxy them to the frame work.

Panel Porn! \o/


Good job, Mike!

g.

My palms do get a little sweaty when I fondle, er, work with the metal.