hvengel

On a related note I will also likely have to make changes to how the throttle is handled for WEP settings. Currently the following JSBSim function maps the throttle setting to the desired manifold pressure: <scheduled_gain name="systems/engine/target-mp-inhg"> <input>propulsion/engine/set-running</input> <table> <independentVar>/controls/engines/engine/throttle</independentVar> <tableData> 0.0 10.95 0.97 66.99 0.99 67.00 1.0 75.05 </tableData> </table> </scheduled_gain> Since normal throttle levers do not have a WEP stop this is currently simulated by having what amounts to a dead spot between throttle values from 0.97 to 0.99 for the top of the non-WEP throttle range and then at a 100% throttle setting WEP kicks in. As a side note this aircraft is a late war machine that is setup for 150 octane fuel to 8th air force specifications. British specs called for allowing up to 81 inches with this same fuel. So depending on how the WEP stuff works on this throttle I will probably have to tweak this code.

Mixture in FG is currently an axis and the current P-51D is configured to use axis ranges to set the mixture to the three values (IE. idle cut off - <= 0.1, run >0.1 and <0.9 and emergency full rich - >= 0.9). But the joystick configuration in FG is very flexible up to the point of being able to bind joystick axis or buttons to arbitrarily complex scripts. In addition I have complete control of the P-51D and since this throttle is P-51D specific I can setup the P-51D to do special things if needed to correctly support the throttle. For example I can setup the joystick configuration to set a custom FG property and then in the P-51D code I can look for this property and do things that are specific to this joystick if needed. In other words I can and will do whatever is needed to make the throttle work correctly (I am a software engineer by trade so even if I have to write some complex scripts I will get it done). My preference would be to have the mixture be an axis if this is possible (would make things very simple to setup - IE. a 1 liner in the JS config file - no change to the current P-51D code) but if it needs to be 3 buttons I can live with that and it would end up being perhaps 8 to 10 lines in the config file for the throttle. So either way is basically trivial to do. I also suspect that most sims will expect an axis since that is the general case for a mixture control.

Looking very good. I am more than willing to deal with making a wood mount since I will need to do some customizations to mount, what ever is shipped, to make it fit my desk in any case. So I vote for "instructions on how to make your own are an option...". Lower shipping cost is a win in my book. Looks like you are getting close although there is still some detail work to do before you can start an actual production run. Keep at it that light you see is not a train coming the other direction. This has generated some buzz over on the FlightGear forum although I am not sure how many FG P-51D pilots there will pony up for this. As soon as I get my hands on one I will create a FlightGear configuration file for it and check it in to the FlightGear code repository. So FlightGear should be one of the first flight sims, if not the first, with official support for this. Hal

I suspected that you already had a list of things that were off (even by little bit). It's sort of the nature of the beast that anyone doing something that is beyond the norm is, if anything, more aware than others what can be done better (Dunning-Kruger effect at the high functioning end of the bell curve). Your list has everything I noticed and a few more which is not surprising. So I would say that you are on top of it. Also as I pointed out these are nits and 99+% of those who will be interested in getting one of these will not notice. I only noticed because I have actually done a detailed 3D model from the factory blue prints which is not something that very many people have done (perhaps a few hundred on the face of the planet at most). I am also certain that you will have everything on your list fixed or at least minimized when you start you first production run. Again two thumbs up and I can't wait to get mine.

Having done a 3D model of one of these from the factory drawings for a P-51D simulator and knowing what is involved in constructing one I can say that I am impressed. There are a few things (nits so not significant) that only someone who has studied the factory drawings would spot that could perhaps be improved. But it is a prototype so I didn't expect everything to be perfect. Even if nothing changed in the first production version I would be very happy with this since it clearly captures the essence of the late model P-51 throttle. I want one of these real bad. Fortunately I threw my hat in the ring very early and got my name on the list for one of the first batch. Can't wait to get it.

The real thing is designed to mount to the upper longeron around 8 inches forward of where the windshield bow meets the cockpit split line. The longeron is an H shaped extruded beam and the throttle's has a bracket that has holes that are used to bolt it to the longeron. If this unit has that same bracket it will not be too much of an issue to rig some kind of clamp that can be mated to the throttles mounting bracket to attach it to a desk or table. Hopefully it has the original bracket for those who want to build replica cockpits. Seems like it would since everything I have seen here appears to be right out of the factory P-51 drawings.

Since you are about to start looking at the electronics I will chime in with a suggestion. Please feel free to ignore it for what ever reason. I am assuming that you will be using an off the self controller chip and maybe even an off the self controller board like the Leo Bodnar units. If that is not the case then don't bother reading the rest of this post. If you are going that route then it would be great if you exposed (some of) the unused axis and button inputs since you will only be using a subset of these for throttle functions (3 axis and one button input out of 8 axis and 32 buttons available). The reason this would be a good thing is that this would make it possible for users to easily add things like trim controls and various switches to a virtual cockpit by tapping into the throttle's joystick boards unused capacity.

The problem with that is that the rubber is actually fairly substantial and has heavy ribs modeled in. The handle bar wrap would not be very close to the overall size and feel of the original rubber. I don't think that the urethane molding process is going to be a major hang up. After all we are talking about something that was built in quantity in the early 1940s so it's not like the process they used is high tech or anything. With modern urethane products it should be even easier than it was back in the day when they had to vulcanize the rubber onto the handle. Having looked at the blue prints for this I am fairly certain that making all of the metal parts that has been going on for some time now is a much bigger challenge than coming up with a suitable "rubber" handle process.

The original ribber grip was molded over the metal handle probably almost exactly like you are going to do with the urethane. As long as the urethane has close to same durometer and color this should work fine. It looks like you are getting up a good head of steam on your progress. Of course, things always seem to slow down when it is time to pull all of the little details together. Hopefully those of us that are on the list for some of the first production run will be seeing the results first hand sometime soon. But knowing how complicated this type of project can be I think a realistic best case expectation is perhaps in two to three months and it wouldn't surprise me if it was early fall before the first units are shipped. I am really looking forward to getting mine and I wouldn't mind being surprised by an earlier than expected ship date. About pilot size. Not only were people in general smaller in the 1940s but the USAAF had size limits on fighter pilots. As a result they were smaller on average than the general population and none of them were big by standards of the day since larger individuals were not selected for fighter pilot duty.

To be more specific the throttle grip is rubber molded over a metal tube.

Keep it original. I vote for plastic knobs.

IRL the bomb fuse is setup on the ground and is not configurable from within the aircraft. Late WWII era fuses could be contact, delay or proximity (Doppler radar - air burst) fuses. In Europe proximity fuses were not used until the battle of the bulge since they didn't want the technology falling into enemy hands. In the pacific proximity fuses were only used over the open water until very close to the close of the war for the same reason.

I sent a PM but it does not appear in my list of sent messages. So I don't know if you got it. In case you didn't get the PM please put in line for one of these units.

I am more than interested in the throttle and would like to purchase one of these as soon as they are available. Any idea on cost or availability date? Also I am assuming that everything on throttle is functional including the gun sight range setting twist grip (IE. this is a joy stick axis) and the push to talk button. And that this will be a standard plug and play "joy stick" requiring only some minor in sim configuration (IE. no need for special drivers).