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.

[epl]

Originally Posted by Danal Estes

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.

I have the Glo Swich plugged into the gear channel on 5 volt on the rx. With all swiches in the back position and when I power up the rx the Glo Switch turns on for 10 sec. then turns off.This happens in any position on gear switch. I will look at the Gear channel on the moniter when I get home tonight.The only way to get the Glo Switch to attivate again is to turn off the rx and turn it back on .

[Danal Estes]

Aha! I have mine on the 8v. I know the 8V side does not put out "memorized at bind" positions (for example, the 8V JR8717 servos do not init until the TX links up). I'm not as sure about the 5V side of this RX. It may put out "memorized at bind" like all other Spek/JR receivers. Therefore, May need to re-bind with the GEAR switch down.

Just curious: After heli power up... and TX link up... do the switches then work as expected? Sounds like not, from what you said. If they still don't work... then this isn't a bind issue.

Let me know what the monitor screen says.

[Finless]

Nice write up Danal.... this needs to be a stick but where? It's not just a Trex700 thing. If you like I can move it to my forum where more people will find it? Or the DX radio forum?

Let me know,
Bob

[epl]

Originally Posted by Danal Estes

Aha! I have mine on the 8v. I know the 8V side does not put out "memorized at bind" positions (for example, the 8V JR8717 servos do not init until the TX links up). I'm not as sure about the 5V side of this RX. It may put out "memorized at bind" like all other Spek/JR receivers. Therefore, May need to re-bind with the GEAR switch down.

Just curious: After heli power up... and TX link up... do the switches then work as expected? Sounds like not, from what you said. If they still don't work... then this isn't a bind issue.

Let me know what the monitor screen says.

I moved my connector to the 8v side on gear channel , rebond the RX , low throttle stick , gear switch in forward position . On my monitor when I toggle the gear switch it moves from the + side to the - side. The Switch Glo activates when I power up the RX in both gear switch position. You have to turn the RX off and back on for the SG to activate again. HELP!

[HELINHAWAII]

Nevermind... dumb question!

[HELINHAWAII]

OK so... I'm using the SG plugged into the 5V slot and copied your mixes into my radio to a "T". According to the servo monitor, my gear channel moves past the far right line when in Norm and the SG ignites as it should. My problem is that the SG will also ignite when in IDL 1 or 2 modes so I can still get a hot start.

If I drop the voltage (using 3-4 diodes) of the 8V gear channel and put the SG there will this alleviate my problem?

[HELINHAWAII]

I built a drop down regulator to drop the 8V gear output down to 6V and plugged the SG into the 8V gear channel. It changed nothing... I can still ignite the SG in any mode by flipping the gear switch down. I tried rebinding with gear switch up and down on both voltages to no avail.

Also, upon further inspection of the servo monitor, the gear slider doesn't change with different FM's.

Could use some help with this Danal... What am I doing wrong?

[Danal Estes]

Originally Posted by HELINHAWAII

I built a drop down regulator to drop the 8V gear output down to 6V and plugged the SG into the 8V gear channel. It changed nothing... I can still ignite the SG in any mode by flipping the gear switch down. I tried rebinding with gear switch up and down on both voltages to no avail.

Also, upon further inspection of the servo monitor, the gear slider doesn't change with different FM's.

Could use some help with this Danal... What am I doing wrong?

I've been at "Southern Rotary Classic" all weekend. Great fun fly. Very pleasant weather and people. And, I just discovered I left my DX7 there!! Eeek! So I can't double check...

Meanwhile:

Ensure that Mix2 RATE: numbers are BOTH negative (minus). Upper number should be -20, lower -100. On the "PROG.MIX2" page, ensure that when physical FM switch is in "normal", that it shows "OFF", and when clicked up to 1 or 2 that it shows "ON". Also, examine the "SERVO MONITOR" screen. When in FM-Normal, clicking gear switch should move the gear channel from one side to the other. When in FM1 or 2, clicking gear switch should move gear channel from the negative side to 0 (middle).

Let me know what those screens show.


P.S. Port/Voltage will make no difference, as you discovered.

[Danal Estes]

Bob - Sticky where ever you think best. Your forum for a while... Radios later?

[Danal Estes]

P.S. I've already gotten a call from the folks who found my radio. Thanks Weldon, Micheal, and Ron.