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Hello everybody, In this post I will catch you up on some work I did before I started this build thread. In my first post I included a video of some prototype instruments I've been working on. In this post I'll give you some information on them. I'm not currently working on the instruments due to one of my distractions – squirrel! – wait, where was I?... Oh yes instruments. I'll get back to them again, just not right at this moment. First, a few words about my decision process and how I ended up on this path. I wanted simulated instruments (physical instruments, not just extracted to another display screen). For me this will bring another level of immersion that I want from my pit. So being the google fan that I am, I thought I'll just find some and buy them. After weeks of searching on the internet, I found that simply wasn't going to be affordable. Then came the thought that has doomed many of us: “That's easy and I can do it myself way cheaper.” (Ranks right up there with: “Hold my beer and watch this!”.) I am able to do it for about half the cost of what I saw on the internet, but it's taking a lot longer than I thought to find a good balance between inexpensive and good enough immersion value. The major components of my instrument system are shown in the figure below. Right now the software apps only support COD. I think DCS will be next, then probably FSX. Cockpit Builder is an app to configure what types of instruments are in your pit. It also lets you configure what sim program you are using and what data goes to what instrument in your pit. Cockpit Interface is an app that runs during simulation. It gets the data from the flight sim program, performs any needed units or data conversion, then transfers it to the instruments in your cockpit. The instrument controller maintains the USB interface to the PC and distributes the data to the individual instruments. It also provides power for the instruments. Each instrument receives the data from the instrument controller and converts it into the physical movement for that instrument. The instruments are daisy chained in “strings” from the controller. Having a single cable that runs from the controller to all the instruments keeps wiring and cabling to a minimum. The controller supports up to 4 strings of instruments. The controller is a custom designed PCB with a PIC micro controller running custom designed firmware. As you may recall from my first post and the title of this thread, I'm working on a WWII pit so my first set of instruments are for that era. I am loosely modeling them on the P-51. Right now, I have working prototypes for the airspeed indicator, rate of climb, tachometer and manifold pressure. You may notice that I started with the simpler single movement instruments. I'm working on an attitude indicator but it's still in the very early design stage. The instruments are driven by custom firmware running on a PIC micro controller on a couple of custom PCBs. The movement is driven by a stepper motor and a planetary gear box. A servo or motor would have given smoother movement, but the accuracy of pointer positioning would have suffered. While flying, I will notice positional inaccuracies much sooner than I will a slight stepping motion so I opted for steppers instead of servos. A few things on my instrument “To Do” list: The pointer movement is pretty good, but not quite as good as I want. I'm fine tuning an algorithm to smooth it out a bit. The front bezels are a bit too obviously 3d printed. I would like them to be smooth surface, but I need to find a cheap way to get that done. Finish the other primary flight instruments. I'm OK with the instrument labels/face plates, but I'm still experimenting with alternatives to get them better. Update the Cockpit Builder and Cockpit Interface apps to support DCS. (Probably others as well, but one thing at a time...) I found a smaller stepper motor that uses a lot less power and lets me reduce the length/depth of the instruments. I need to finish reworking the design to use the smaller motors. Until next time... Dave. What ever you do, remember to enjoy the journey.

testing pic link

John, Thanks for the info. Good thoughts all the way around. You make a good point about screen quality and how important it is. Since the seamless paper is pretty cheap, I think I will get a some and run a test. Sure. It will probably be a few days as I have to gather the info and organize my thoughts. I am back to work for a few days next week so that slows me down a bit too.

As I said in my first post, I don't tend to work in a straight line, so I've jumped to the visual system for a while. My wife gave me permission to turn the guest bedroom into a sim room so there's the green light for a big screen visual system! I'm thinking of a 180 degree curved screen with three projectors. It should be possible to upgrade later with a “top” and a fourth projector to get a view above as well. I ran a few quick tests with DCS on my dual monitor setup to convince myself I could get three or four "out the window" (OTW) scenes to cover left, center, right and above. After reading some posts in these forums, it didn't take me too long to get that figured out. I've got a few constraints I have to work within: - Obviously I have to fit in the room, but I also need to leave space for my workbench. - I want a free standing screen so I don't permanently mount anything to the walls or ceiling. - I want to be able to disassemble it and take it out of the room without too much trouble. - I want to keep costs down where ever I can so that I have the cash for things that require it (like projectors). That leads me to a 180 degree screen with a diameter of 8 feet. I'm thinking to use either MDF or plywood for the screen backing. I think 1/4” or about 6 mm will bend easily enough into a curve. I will make it in three sections, front, left side and right side. The front will be a 4'x8' section with each side being about 4'x2'. This will give me two seams but since they will be to my side view I think they won't be distracting. I've laid out the center section in the pic below. I need to finish laying out the side pieces but with the radius established in the center, the sides won't be too hard to finish. I also need to design some stands to hold it up. Haven't yet determined how high off the floor. I think it will be dependent on the height of the seat in my cockpit (which sets my line of sight) so I might have to estimate that, then build the cockpit to match. I was thinking to paint the screen backing and project on it. But then I read an article at projectorcentral.com about seamless paper. It's used by photographers as a backdrop and according to the article it's a passable projection surface. It's not very expensive. I'm thinking to glue this to the screen surface. The projectors will hang from a tower that I will place behind the cockpit. I saw a neat way to do this over at hornetpits in Baldrick's pit thread. I'm thinking to use electrical conduit for the tower structure as it can be had quite cheap. I need to figure out how to connect the conduit pieces the way I need. Standard conduit connectors don't fit everything I need so I'm looking at options like using galvanized pipe fittings. I just need to check fit. A trip to Lowe's will figure that out. Projectors is where I'll have to spend serious money. From reading what others are using it seems the BenQ W1080ST is a good projector for this. Even though it's at the low end for HD short throw projectors, it's still pretty expensive. I found a couple places that sell refurbished units for a couple hundred bucks less. The video from the three projectors will probably have to be “warped” to account for the curved screen. Most of the warping software is pretty expensive. Right now I'm leaning towards either Simpit Warp or maybe Immersive Display Pro. Some questions for the group: - Does your experience tell you that a 8' diameter will be acceptable for the screen size? (Maybe it's too close to the eye point.) - Have any of you used seamless paper and can comment on it? - Anybody have recommendations for a project that is around $500-$600 and good performance for use in a pit? Anybody have experience with factory refurbished projectors? - Anybody have a recommendation for warping software? 'till next time... Dave.

I will. I think my next post will be on the visual system. I'll post some pics of what I'm doing with that, along with some of the thought behind how I'm doing it.

Hello Everybody, I've been lurking about on this forum and a few others like hornetpits and ATAG for quite a while. It never ceases to amaze me how much information flows through these communities. It's really a great thing you guys do to share. I decided it might be fun to try to document my own pit building experience. First a few words of introduction about me. I am an electrical engineer by degree and have also done extensive software development during my career. I spent the first part of my career working for some of the big boys in simulation (Singer-Link and Hughes Aircraft) developing high fidelity simulation devices for training our armed forces. I can describe that part of my career in two words: “LOVED IT”. My career grew and I moved on to other industries, started a family, etc. But the love of flight simulation never left me. Now that I'm semi-retired, I want to put some time back into this hobby. For this pit (yes that implies that I have in mind to build another one...) I am building a WWII era sim. Currently I fly some on IL-2 Cliffs of Dover, but have recently started using DCS. I'm really looking forward to the DCS WWII map to be complete. My build progress will probably be stop-and-go and I probably won't travel a straight line from beginning to end, but maybe that's OK. It's the journey not the destination right? (I think that's what you are supposed to say when you can't justify the time or money being spent.) Right now, I'm working on a set of simulated instruments and starting the design for a visual system. For today, here's a short video of the instruments in action. In the video, I'm flying in COD. The instruments are moving in response to the data I'm extracting from the sim. I still have a few bugs to chase down, but overall I think they will work OK. (Please excuse the poor lighting in the video. I'm still learning how to make a video look good.) Thanks for looking and hope you find my journey interesting. Dave.