Acceleration comparisons

[RPS69]

Originally Posted by MaxGunz

Only as precise as you align the sensor and magnet.

Make sure you get linear analog Hall sensor, *not* one of many others especially the bipolar switch security type.

Being non-mechanical in operation they are preferable.

Agreed, aligning it could be tricky. The linear is also truth.

It also have a great advantage. You could place it at the bottom of a long stick, and still have precision, while pots moving in a very short arc are far less reliable.

To achieve that kind of precision with optics, you will need some demultiplying system.

Now... so much precision got a draw back, filtering is MANDATORY!

[RPS69]

Horseback, I agree.

A better triming interface should enter the wishlist.

Still, from your findings, I may build a guess, and it is that the coding got a min¡mum value that don't allow you to achieve a middle step, meaning that the optimal trim position can't be achieved the way it is coded, at least not allways.

Also, some of your headaches, must be related to the trim delay insert. That could make trimming any plane far more tricky than it was supposed to be. Originally implemented to avoid the "online trim exploit". A bad solution to a questionable problem.

[MaxGunz]

Originally Posted by RPS69

Agreed, aligning it could be tricky. The linear is also truth.

It also have a great advantage. You could place it at the bottom of a long stick, and still have precision, while pots moving in a very short arc are far less reliable.

Distance from the magnet is not how to get linear angle from a Hall sensor! The Hall reads only on 1 axis. You align the axis dead center over the magnet center between N and S poles. When the magnet turns, the strength of the field along the Hall axis changes. That is what you measure.
Try the other way, you will need more than 1 magnet and the fields will affect each other, merge, and you won't get good results.

To achieve that kind of precision with optics, you will need some demultiplying system.

Now... so much precision got a draw back, filtering is MANDATORY!

Optical... a lot can be done using laser-printed transparency graphics you can get printed at most any office store.

Have you ever looked at how ball mice track motion? Or used a vernier?

I have read that working with the dimensions of a Young's double-slit can yield a high number of interference bands. Perhaps diffraction from a single slit can also be used.

Really, the number of ways is a study in itself.

[RPS69]

Originally Posted by MaxGunz

Distance from the magnet is not how to get linear angle from a Hall sensor! The Hall reads only on 1 axis. You align the axis dead center over the magnet center between N and S poles. When the magnet turns, the strength of the field along the Hall axis changes. That is what you measure.
Try the other way, you will need more than 1 magnet and the fields will affect each other, merge, and you won't get good results.

You wrong! believe me! just one sensor is enough.

Optical... a lot can be done using laser-printed transparency graphics you can get printed at most any office store.

Have you ever looked at how ball mice track motion? Or used a vernier?

I have read that working with the dimensions of a Young's double-slit can yield a high number of interference bands. Perhaps diffraction from a single slit can also be used.

Really, the number of ways is a study in itself.

There are many optical encoder devices available, and I have tried them. Magnetic is better.

This is a good topic on itself, meybe we start it into another thread, or we may end hijacking this one.

[MaxGunz]

Originally Posted by RPS69

You wrong! believe me! just one sensor is enough.

If you say so. I have sensors and AVR's, I'd like to see better ways. ;^)

There are many optical encoder devices available, and I have tried them.

I made my own to test ideas out, digital and analog but I won't say they're better than industrial resolvers because they aren't.

Magnetic is better.

It's only as good as your alignment and your ADC... unless you do something like use gears/spokes and magnetic tooth counters or better.

This is a good topic on itself, meybe we start it into another thread, or we may end hijacking this one.

I agree. I will look for it.

[horseback]

I apologize for the delay; I started adding screenshots to the track review process in order to track the nose drop phenomenon and I think that I have found some interesting things, but I need to do some more research before I start that thread.

Here are the Mid War USAAF Fighters, the Japanese Fighters and the FW 190 series. A couple of notes: the P-40E and P-40M disparity appears to have been fixed in 4.12; the M version is both quicker and faster than the earlier E version, and they seem to me to need a bit more trim adjustment (but still not nearly as much as the P-47, the Hellcat, Corsair or Mustang).

The acceleration of the A6M3 and A6M5 from 270 to about 400 kph is almost jaw-dropping at 100m; I don't chart the intervals between 270 to 350, but I feel that from 270 to about 330, these two fighters may be quicker off the mark than all but the La-5FN and possibly the Seafire LIII. Below 1600m/5000ft, Allied fighters are well advised to keep their speed up and not attempt any change of direction (including climbs) until they have 3 or 4 km of separation. Zekes don't appear to loose any energy in a turn or climb, so in any low and slow scenario they hold all the cards.

The P-38 is pretty impressive at this altitude as well, but that should not surprise anyone; with the turbosuperchargers it packed, its Allison engines drew full power from down in the weeds right up to 30,000ft.

FW 190A is fairly tractable at all speeds; I realized early on that I was doing myself more harm than good when I tried to make small rudder adjustments--it hardly needs any except at slower speeds, and the Turn & Bank ball is a bit behind the Wonder Woman vector ball, and the Wurger is not affected by small offsets in the ball the way a Corsair or Hellcat is. The nose drops noticeably at around 360-380 kph indicated (but not nearly as much as most of the US heavyweights) and the gradations on the gunsight's crosshairs make it easier to measure your attitude and fly a more level course most of the time. The hardest thing with this bird is losing speed; it will burble along at 300 kph at less than 30% throttle almost forever before it slows down to 270.

Enjoy.

cheers

horseback

[MaxGunz]

Design Analysis of the Zeke 32 (Hamp)
(That's a Mitsubishi A6M3 Zero for those not up on WWII Allied code names. - Ed.)

http://rwebs.net/avhistory/history/zeke32.htm

I see a very light plane 5155 lbs normal gross wt with a 1020 HP engine.
It's small and light, which cuts drag at all speeds.

[majorfailure]

Originally Posted by horseback

Here are the Mid War USAAF Fighters, the Japanese Fighters and the FW 190 series. A couple of notes: the P-40E and P-40M disparity appears to have been fixed in 4.12; the M version is both quicker and faster than the earlier E version, and they seem to me to need a bit more trim adjustment (but still not nearly as much as the P-47, the Hellcat, Corsair or Mustang).

I would bet there has not been a large change in the P-40s FM.
It has all to do with Full throttle height - and the way the power curves get due to it. P-40M very low will have an advantage, then its steeper power curve (higher FTH) crosses the P-40Es, and in medium height it is slower than the P-40E. But the P-40E maxes out at ~3000m, and then the power cirve goes backwards again, and crosses the P-40Ms curve again, so at alts of around 4k the P-40M should be faster again.

[horseback]

Originally Posted by majorfailure

I would bet there has not been a large change in the P-40s FM.
It has all to do with Full throttle height - and the way the power curves get due to it. P-40M very low will have an advantage, then its steeper power curve (higher FTH) crosses the P-40Es, and in medium height it is slower than the P-40E. But the P-40E maxes out at ~3000m, and then the power cirve goes backwards again, and crosses the P-40Ms curve again, so at alts of around 4k the P-40M should be faster again.

No, there definitely were some changes--the Hawk 81A is quite a bit faster in the 4.12 patch at 100m, and so is the P-40M, although I must have tossed the chart I did on it before the new patch came out. Fortunately, I kept my 'original' 4.11.1 version and reloaded the 4.12 version on a different drive from the original DVD and patched up from scratch, so I re-flew the 4.11.1 P-40M and re-recorded the intervals.

Attached is the chart I created just for you; there is very little, if any, change in the P-40E from 4.11.1, but the P-40M is a good deal faster, as one would expect from an upgraded engine and better (full wartime) production quality.

cheers

horseback