Red's A-10C Pit

Great book (have it in my collection) but a little outdated already

Mine is like 9.20 X 2.15. I just scaled it from sight basically for clearance around the buttons. Kinda funny that it matches up LOL!

I still have to add in the master caution reset button. Slight oversight on my part lol!

I've been slow working on the modeling the last couple days, been doing a lot of researching and sourcing parts. But I'm doing some work right now so here's an as I go update..

I re-drew the entire UFC front panel. I used the "standard" button size of .375" as a reference and drew the rest of the panel to scale. Come to find out it's smaller than I though. about 1.75" top to bottom and 8.35" wide. The nice thing is that now the buttons for the CDU and UFC are both the same size minus the rockers.

Also, seeing as obtaining a proper Korry pushbutton indicator for the Master Caution is nigh impossible, I plan on making my own out of a push switch, some acrylic barstock, and a couple of amber LEDs. Once it's dressed and done you won't be able to tell the difference.

Off to draw the rockers, then layout a pcb design and housing...

Red

UFC - 27MAR11 by KLaFaille, on Flickr

UFC - 2 - 27MAR11 by KLaFaille, on Flickr

Nice work as usual! :thumbup:

Those are about the same numbers I came up with measuring the UFC from drawings using screen calipers (after I calibrated them to the MFD display of 5"). I rounded mine up to 9x2 to allow for a little extra room. :D

Remember to leave the sapce around your switches to accomodate the size tolerance for your switch covers. The standard is 10%

Thanks pitbldr. I'm actually not using switch covers in my design for the UFC or my CDU, Total. I'm creating custom PCBs with 6x6 tactile switches which will mount inside the "head" of the UFC and CDU. I am leaving room to grow on the sides though. ;)

At this point all I have to do is draw up the housing, and get the thing made and I'll be good to go. I have a BU0836X that will drive this.

First pic is the finalized UFC, minus a few tweaks with font stuff. Second is the back of the UFC where the switches will live. Third is a close up of the rocker button, just for grins.

Red

UFC - 1 - 28MAR11 by KLaFaille, on Flickr

UFC - 2 - 28MAR11 by KLaFaille, on Flickr

UFC ROCKER - 28MAR11 by KLaFaille, on Flickr

Pics look great, but building what you draw is a different beast.. even with Cnc machines.

How do you plan to build the UFC?

Thanks. CNC will be the way to go on this. During the design phase of each panel I take into account the machining process. There are no weird bevels or cuts that can't be made with a three axis CNC, so far as I can tell. Whoever cuts these for me will know more about the subject and will be able to fix / inform me off inconsistencies.

Luckily, I have nothing but time getting these made.

In real world news, the CDU / UFC switches came in today along with my 0-30vdc 5A regulated lab top power supply; so if I stop posting, I probably electrocuted myself. :doh:

Another piece of the puzzle came in also. A real ARU-2B/A ADI made for simulator use. Pics to follow when I get home from work tonight, but here's one from the seller.

Pics of ADI as mentioned earlier. I managed to get the leftmost needle moving up and down in a controllable manner. I may have to end up cracking it open to try and work out more of it. I'm glad I didn't go and do what I had thought originally, putting the power supply on 5V and just going pin to pin, instead I did the smart thing and checked for continuity between pins first.This is a good thing because I foun two points only had 1.8 ohms between them. 5V, 1.8ohm = 2.77A = crispy ADI = Bad Juju

I really really need the TO on this thing, or a schematic at the minimum. That would help immensely.

ARU-2-BA ADI (1 of 8).jpg by KLaFaille, on Flickr

ARU-2-BA ADI (2 of 8).jpg by KLaFaille, on Flickr

ARU-2-BA ADI (3 of 8).jpg by KLaFaille, on Flickr

ARU-2-BA ADI (4 of 8).jpg by KLaFaille, on Flickr

ARU-2-BA ADI (5 of 8).jpg by KLaFaille, on Flickr

ARU-2-BA ADI (6 of 8).jpg by KLaFaille, on Flickr

ARU-2-BA ADI (7 of 8).jpg by KLaFaille, on Flickr

woww! where do you find all this stuff??? :huh:

Hi icemaker,

Most all the real parts I have collected thus far have come from laboriously watching and sifting through eBay all the time. Every once in a while you get lucky and find that piece you need at the right price mixed in with the rest of the junk that you don't.

Red

I spent the better part of last night building a prototype UFC switch board. Apart from two switches that seem to be shorted to ground, and one that acts up intermittently, it works great. I'll sort out those little minor issues later on.

UFC Prototype Board (1 of 3).jpg by KLaFaille, on Flickr

UFC Prototype Board (2 of 3).jpg by KLaFaille, on Flickr

UFC Prototype Board (3 of 3).jpg by KLaFaille, on Flickr

The TACAN panel showed up yesterday. Functionally it's fine, it just needs a few missing pieces replaced, the clear plexi replaced, and a cleaning. The volume knob was missing so I just threw on a knob that I had lying around, that's not the proper one.

TACAN (1 of 1).jpg by KLaFaille, on Flickr

Dam man that look great and you said you had no experience with the wiring lol Looks like your doing 300 in a 50 zone good work!!!:thumbup:

These kind of switches feel terribly cheap. Are you going to replace them at some point?

Knowing you plan on etching your own PCB's, I still thought I'd post a hint from someone who, as an electronics technician, has dealt with more wiring of breadboard designs than I care to remember lol

For the wiring coming off the board, pick one side of the board and work across it laying your wires flat on the board towards the exit side. Laying them flat will prevent breaking of solder joints. As the solder ages, the stress from the wires being perpendicular to the board will cause cracked solder joints or can even create an open in the wire beneath the insulation (if the solder wicked up the wire beneath the insulation). Work from the outside edge of the exit point inwards - no sense in trying to solder around wires if you don't have to.

As you solder them on, bend and route the wires so you group them together at the exit point. There can be more than one exits point btw. On the board you pictured, there would be both right and left exit point.

This way, you can then zip tie the wires after they are all soldered on.

The bending and routing of the wires will not only neaten up the appearance of the board, but also allow you to solder on the board without having to jam a hot iron down between wires that are sticking out everywhere.

Done correctly will minimal stress on the organized wires, a perf board (or prototype board) design can last just as long as a printed circuit board with plated through holes.

I'll see if I still have any old project boards laying around from back when I enjoyed tinkering. If I still have any and I find one, I'll post a pic of what I described above :)

What switches would you both suggest?I could use a bit of help with a bezel pcb design

Thanks deadman. I can do switches, you start throwing components in the mix and I'm lost. I did have a good hands on demo of Ohm's law with 3V and a 1-1k pot. Let's just say when you crank it to the low end (1 ohm) and 3 amps start going through the pot, it's like a little 4th of July show on the bench.

Total, thanks for the great information, I think it will really help me out. I'd love to see an example or two if you could find your old boards. This is my first board ever so it's definitely a bit rough, but I'm glad it worked (mostly) in the end. The board itself is to small to go into a working UFC model, this was more a challenge to myself and proof of concept type thing.

Regarding the switches, these tactless require about 260 grams of force to actuate which is decent and gives a nice snap. I do plan on using tactiles in the UFC and CDU, but i will likely go with 500 gram switches. They should be sufficient.

Regarding the switches, these tactless require about 260 grams of force to actuate which is decent and gives a nice snap. I do plan on using tactiles in the UFC and CDU, but i will likely go with 500 gram switches. They should be sufficient.

Pushbuttons on avionics I have experience with don't do "click" at all. They operate more like desk calculator pushbuttons. Or like a stiffer version of PC keyboard keys.

Yeah, these aren't rubber membrane or dome switches like what's in keyboards or desktop calculators. These are more mechanical in nature with a pre-requisite amount of force needing to be applied before the switch gives and completes the circuit, hence the word "Tactile" in tactile switch.

If you want to stay with the keyboard analogy, think old IBM style mechanical "clicky" keyboard keys. The switches I have right now feel similar in use but take much more force to actuate, and the switches I'm going to use in the final version require twice as much force to actuate as what I have now.

On to my proto-board UFC thingamabob.. I fixed my three little issues. The two switches that were shorted to ground were easy to fix, one had a trace that needed to be cut on the board, the other was a piece of debris causing a short. I just changed which pin I ran a lead to for the intermittent switch. It works great now.

A shittay vid of me playing around with the UFC board. I'm not a videographer, sorry. :music_whistling: Oops, didn't realize one clip went in there twice. Oh well.

Red

BU0836X

Have you considered different options of different manufacturers? Are there any considerable competitors?

Have I considered a different option, no. Are there competitors, yes.

I grabbed this with the express intent of using it for the UFC. I know there are other people out there that offer USB interface cards, cheaper too, I couldn't tell you who they are though. I have no idea what IO cards I'll use for the rest of the pit at this time.

Oh, and this:

I can make all the needles and little doo-dads dance around now, and I have solid values to make them go where I want them to when I want them to. The fatbody in the middle is the next goal.

Red

Hey Red. You are same guy that said something a while back about you ok with switches and knobs etc only ? LOL

Seems you getting far ahead already... seems that syncros will be the next challange. Very greatfull if you could share the pinouts and values to control the needles and flags. Got an HSI very likle yours but haven't yet gutted it.

This is the final design of the UFC. Externally this is complete. Internally there are a few things to work on, some holes, a connector for the PCB, a few screws here and there, etc.

Electronics will be the cheapest thing on here likely. I've priced all the actual components, and excluding the cost of PCB (may etch my own), and the BU0836X I already have, it will be just a bit north of $20 dollars in switches and the like.

The nice thing is everything fits inside the head unit of the UFC and it's nicely accurate in dimensions and design to the real unit.

I have an option I will pursue on getting the faceplate and buttons crafted, which may work out to everyone's advantage, but I will say nothing more on that matter at this time.

I have a pattern created that once cut and bent will form the rear box, I'll have to find someone competent in aluminum welding to close the seams.

Everything I have designed here can be laser / water cut from .063" and .125" aluminum sheet, and the head unit and buttons easily milled on a three axis CNC.

UFC FINAL - 1- 2APR11 by KLaFaille, on Flickr

UFC FINAL - 2 - 2APR11 by KLaFaille, on Flickr

UFC EXPLODED - 1 - 2APR11 by KLaFaille, on Flickr

UFC EXPLODED - 2 - 2APR11 by KLaFaille, on Flickr

Impressive stuff!! Are you going to actually use an amphenol connector?