DX7 + AR7100R + Switchglow

[Danal Estes]

Goals:

1. Fit within DX7 and AR7100R constraints
2. No hot starts from Flight Mode switch (Idle 1 or 2)
3. RPM regulation set by Flight Mode switch (independent for each FM)
4. RPM regulation can be disabled via switch for diagnostics and curve setups
5. RPM regulation limits for each mode set are easily calculated and adjusted (no byzantine math!)

[Danal Estes]

Radio Setup:


Transmitter

• Hold Scroll Down and Select buttons while powering up
• [INPUT SELECT]
• Ensure Aux2 set to Aux2 (default unless you’ve previously changed it)
• Ensure Gear set to Gear (also default)
• Note: This assumes you are controlling gyro gain with either the Aux2 switch (endpoints on Aux2 channel) or the Gyro menus. Either one will work fine.

• Power up normally
• Press Scroll Down and Select to access menus
• [REVERSING SW]
• Set channel 5 (Gear) to REV.

• [TRAVEL ADJUST]
• Ensure GEAR set to +100 and -100 (default unless you’ve previously changed it)

• [PROG.MIX1]
• GEAR->GEAR
• RATE: -25% (Set to amount subtracted from 100 to yield desired gain. Example: -25=75%)
  +20% (Always, needed to enable Switchglow with switch down in FM Normal)
• SW:F-NR
• OFFSET: 0

• [PROG.MIX2]
• GEAR->GEAR
• RATE: -20% (Set to amount subtracted from 100 to yield desired gain. Example: -20=80%)
  -100% (Always, needed to disable RPM limit with switch down in FM 1 or 2)
• SW:F-S12
• OFFSET: 0

• [PROG.MIX3]
• GEAR->GEAR
• RATE: +5 (Mix2 stays active; so this is how much RPM to add to Mix2 position; 80+5=85%)
• 0% (Always, Mix2 still active in FM 2)
• SW:F-S2
• OFFSET: 0

The notes above mention specific % gains for the RPM limiter... of course, you really set these with a tach, not a fixed percent. I'm just mentioning the percents to show exactly where and how they occur in these mixers.


Receiver

• Plug SwitchGlo into Channel 5 (GEAR). Note that SGs come in two flavors, a "5V" and "8V"; you specify when you order. On an 7100R, there are two GEAR slots... plug the SG into the appropriate one, by voltage.

[Danal Estes]

Operation:

Startup

1. Power on TX with all switches “back/away”.
2. Power on Heli
3. IMPORTANT!! WAIT 3 SECONDS. Otherwise, the governor could go into calibration mode! You really should wait for the Gyro to init anyway… so, WAIT 3 (or more) SECONDS
4. Flip Gear switch down – you should hear Switchglo
5. Start!
6. Note: If Switchglow “times out” after 10 seconds, flip gear switch up and back down.
7. Once started & engine warmed up, Flip Gear switch up.
8. Go fly and have fun!

Flying

1. All flight modes, Normal, FM 1 and 2 available as usual.
2. If desired to disable RPM limiter in any flight mode, flip gear switch down.
3. In normal only, this will disable RPM limiter and turn on the Switchglow; this hurts nothing… and the Switchglow will go off after 10 seconds.

Calibrating RPM Limiter

1. Inhibit MIX1 by pressing CLR key while on {PROG.MIX1] page.
   Note that DX7 will keep your settings; later when you re-enable this mix, they’ll all be there!
2. Ensure your Normal Throttle curve has 0% and 100% points.
3. Calibrate RPM limiter as per manual
4. Re-Enable MIX1.

[Danal Estes]

Variations:

The above setup eliminates "hot starts" that result from the Flight Mode switch. It does not prevent you from starting when the throttle stick is up. There is a mix that will prevent ALL hot starts, even throttle stick based hot starts. The cost is that the RPM limiter will not work in "Normal".

To use this variant, change MIX1 as follows:

• [PROG.MIX1]
• THRO->GEAR
• RATE: +125% (Always, this is what forces the Switchglow off if you raise the stick)
  +50% (Always, needed to enable Switchglow with stick down)
• SW:F-NR
• OFFSET: -90

You may have to play with the offset just a bit... it is what establishes the "tipover" point at which the throttle will suddenly mix the gear WAY down (SG off) or WAY up (SG on). You can look at the servo monitor screen and see the effect.

Note that throttle trim DOES contribute to the "tipover". Again, you can see this on the monitor screen. This prevents hot starts that would be caused by the trim being all the way up, or similar.

Note that I personally DO NOT FLY this variant... it is for the truly paranoid!

[Azlum]

Nice work... should be stickied IMO

[Danal Estes]

Caution:

DO NOT use the RPM Limiter during break-in of your engine! It can "hide" behaviors that you should be seeing as the engine leans out and similar. Therefore, DO NOT use the above mixes (or any other form of limiter) until you have a good, working, fully broken in setup that flies on throttle curves.

[HELINHAWAII]

Great work! Needs a sticky fo-sho! You don't know how long I played with the mixes to try and acheive this affect.

Questions:

So you're running on the rpm limiter in Norm mode but only above 25% throttle right?

Are you getting the glow to lite when switching into hold from any flight mode?

I will tach the head upon trying this setup but are these %'s actually what you're using? Could you hook us up with the real %'s if these are listed as examples?

Also, which rates do we adjust to change the set HS's for N, IDL's 1 & 2?

[Danal Estes]

Originally Posted by HELINHAWAII

Great work! Needs a sticky fo-sho! You don't know how long I played with the mixes to try and acheive this affect.

Questions:

So you're running on the rpm limiter in Norm mode but only above 25% throttle right?

Correct, as the limiter just works this way.

Are you getting the glow to lite when switching into hold from any flight mode?

Not based on Hold at all. Glow lites when GEAR switch is down and Flight Mode is normal.

So, a "Truth Table" for the GEAR and FM switches looks like this:

              Gear Up                         Gear Down
Normal   Limit On, Glow Off               Limit off, Glow On
FM1      Limit On, Glow Off               Limit off, Glow Off
FM2      Limit On, Glow Off               Limit off, Glow Off

Note the "Glow off" in FM1 and 2 is the "hot start preventer"
Also note that Switch Down always= No Limit, Up = Limit. Easy to remember.

I don't like starting in hold because you have no Throttle Trim when in Hold on a DX7.

I will tach the head upon trying this setup but are these %'s actually what you're using? Could you hook us up with the real %'s if these are listed as examples?

Yes, this is what I'm using at the moment. I plan to refine those %s a bit over the weekend and will post more speed to percent gain mappings for the Trex 700. If I recall, 78% = 1850 on stock pinion, sensor on backplate of a YS91SR (pulled away from backplate to read steadily).

Also, which rates do we adjust to change the set HS's for N, IDL's 1 & 2?

They are set in "natural order", that is FM-Normal is set in Mix1, FM-1 in Mix2, and FM-2 in Mix3. In all cases, it is the "First part" of the rate in a given mixer.

Calculations are shown in each mixer, but here's a rephrase for clarity: For Mix1, it's -x where 100-x=the rate. For Mix2, it is the same... just because of the DX7, Mix2 stays active as Mix3 kicks in, so Mix3 has to be different. Assuming you want higher headspeed in FM2, Mix3 becomes the % to add to Mix2.

And, yeah, my examples are "real" for the T700.

[epl]

Hi Danal Estes, thanks for the info . I have very carefully followed your steps in setting up the mixes , but the Switch Glo goes off when you power up the heli with the gear switch in the up or down position. This was happening even before I tried the mixes. Anyone have any thoughts. I did calibrate the rev limiter and it turn on at 25% throttle. I have not used the limiter or the Switch Glo yet. Only 7 tanks throw theYS so far.

[Danal Estes]

Originally Posted by epl

Hi Danal Estes, thanks for the info . I have very carefully followed your steps in setting up the mixes , but the Switch Glo goes off when you power up the heli with the gear switch in the up or down position. This was happening even before I tried the mixes. Anyone have any thoughts. I did calibrate the rev limiter and it turn on at 25% throttle. I have not used the limiter or the Switch Glo yet. Only 7 tanks throw theYS so far.

SwitchGlo is plugged in where?

When you say "goes off", do you mean runs and then quits? Or, do you mean "won't stay enabled?" SGs time out after 10 seconds.

Use the servo monitor screen and look at the GEAR channel. With all switches back/away, it should be at about 75% (to the right of the mid mark). Switching only the GEAR switch down should cause it to move to the left, all the way slightly past the normal endpoint, about -120%.

Let me know what's happening on that screen.