JR XG11 Throttle Curves
 

Hi, I've just got a new ESC (Debowski D3) that requires 4 throttle curves. I have only seen 2 Throttle Curve screens on the XG11. Does anyone know if you can set up 4 throttle curves and if so how do you do it?

Thanks.

In ACRO there are only two curves. Looking up your ESC on the web, I see why you are asking about more than two throttle curves. Using a throttle curve to disarm or kill the ESC on the 11X is in my opinion hazardous. There are better premixes on the transmitter to do that. Using a throttle curve for that purpose is not sure fire if the throttle trim is left active. So what you may need are three curves at most.

You can create a third curve by using a curve program mix. This will require a bit of work to make the third curve act the same as the two other curves if the throttle trim is not inhibited.

Allan

There are several ways to get four throttle curves on the 11X. To have the curves set up as Debowski specified will require, as a minimum, the use of the THRO CURVE premix and two program mixes. The transmitter’s custom flight mode feature makes the programming easier to follow but it isn’t mandatory.

My transmitter is a XG11MV. If anyone is interested, I can post the program.

Allan

My apologies for being so rude and not replying Allan. I thought I had!

I'd be very grateful if you would post your program for the XG11.

Thanks

Peter

The ZIP files contain two programs that provide four throttle curves for the F3A Governor. Two switches, AUX2 and MIX, are used in the same fashion to select the throttle curves. The four curves are: ground, normal, spin and landing.

AUX2 SW Position___________MIX SW Position_______________Throttle Curve

0________________________not applicable_________________Ground
1________________________not applicable_________________Normal
2________________________0________________________ ___Spin
2________________________1________________________ ___Land

The switches in the TCURVE.JRX program control the throttle curves and the two program mixes directly through each mix select switches. In the TCurves-FM.JRX, the switches sets up four custom flight modes and the modes then control the curves via the select switches.

To set up the throttle curves and program mixes for illustration, the maximum rpm was assumed to be 5000 rpm in order to establish mix numbers for mid-throttle and the idle rpms. In actuality, these mix numbers will have to be determined experimentally as described in the F3A Governor manual instructions.

In the System List’s TRIM SYSTEM menu, the throttle trim has been inhibited by setting it to zero. If left active, the throttle trim could mess up the mixes.

In the Function List’s THRO TRIM > IDLE ADJUST select switches were turned off as this mix used the AUX2 switch.

Mixes are additive. Whenever the ground or normal conditions are selected, the Pos0 curves for program mix 1 and 2 are selected and are added to the whichever throttle curve is selected. As both of these Pos0 curves are set to zero, they add nothing.

When AUX2 SW is in position 2, the throttle curve for Pos1 (normal) is not selected so the Pos0 throttle curve is active. It is added to the Pos1 curve for either program 1 or program 2 mix depending on the MIX SW position. Note that the program mixes select switches has the AND button on. This is also true for the Spin and Land custom flight mode select switches.

Allan
Many thanks for the information. I will now go and lie down and try and set up this ESC. I'll let you know how I get on but it might take me a little time to get this all sorted out!
Thanks again
Peter

Peter,

I didn’t described where the parameters, that you adjust to get the appropriate rpm’s, are located in the programs. Perhaps you figured it out already; but if not, here they are.

The Pos0 curve in the THRO CURVE menu fully describes the throttle curve for the ground condition or mode. The P-1 y-coordinate number of 64 should be replaced by a number that results in mid-stick rpm of 3100-3300.

The Pos1 curve in the THRO CURVE menu fully describes the throttle curve for the normal condition or mode. The P-L y-coordinate number of 28 should be replaced by a number that results in an idle rpm of 1300-1500. The P-1 y-coordinate number should also be adjusted as was done for the ground condition.

The spin condition is a combination of the THRO CURVE Pos0 curve and PROGRAM MIX1 Pos1 curve. The P-L point of +12 in PROGRAM MIX’s1 Pos1 curve controls the spin idle rpm. It should be change to give a 300 rpm idle. Be careful not to change the Pos0 curve.

The land condition is a combination of the THRO CURVE Pos0 curve and PROGRAM MIX2 Pos1 curve. The P-L point of +6 in PROGRAM MIX2's Pos1 curve controls the land idle rpm. It should be change to result in an idle of 100-200 rpm. Again, be careful not to change the Pos0 curve.

If you have questions, let me know.

Allan

Allan
Many thanks for the additional notes. I had not worked it out! I was just beginning to scratch my head when I saw your amplification. I will get back to you to let you know how I get on.
Thanks.
Peter

Hi Allan
Just to check that I've got this right, the four throttle curves are created by using 2 progamable mixes and the Throttle Curve function is not used at all. Is that correct?
Thanks
Peter

No, the throttle curves in the THRO CURVE menu are used for all four of the flight modes or conditions. Also, the two program mixes are always being added to one or the other of the throttle curves for each of the flight conditions. Whenever the ground or normal condition is selected, the program mixes’ spin and landing curves are the Pos0 curves which add nothing. That is the reason for the warning for not changing the program mixes Pos0 curves when setting the spin and landing idles.

For program mixes such as PROGRAM MIX1 and premixes such as THRO CURVE, the Pos0 curves (or rates) will always be active unless the select switches conditions are met. If the conditions are met, then the Pos1 curve or rate comes into play.

If either the spin or landing condition is chosen, the AUX2 switch is in position 2 which is not the select switch condition for the THRO CURVE menu's normal curve. So THRO CURVE menu's ground (Pos0) curve is active and added to it is the Pos1 curve from either Program MIX1 or MIX2

BTW, as the throttle curves differ only in their idle settings, there is a way to get the same results with only one throttle curve and no program mixes. Once flight modes have been declared for each throttle condition, you can set the throttle trim separately for each flight mode. In the System List’s TRIM SYSTEM, set the trims to be flight mode based. In the Function List you only need to modify the Pos0 throttle curve for the mid stick rpm.

The main disadvantage of doing this is that the rudder, aileron and elevator trims for each flight mode have to be set separately. There is no common flight trim for all the modes.

Allan

Allan

Thank you for your patience. The penny has dropped at last as to what you have done. The two prog mixes merely add or subtract from the bottom end of the throttle curve! I was attracted to your idea of selecting different trims for each FM. This would not be a problem for me as there is very little trim on the aileron and elevator so easy to set up in each FM. However, I can understand how this works for a digital throttle trim but would it also work for the analog throttle trim? I have one Tx with digitial and one with analog throttle trim.

Thanks once again.

Best regards

Peter

Peter,

Concerning setting up flight-mode-based trims, you may have to use both curves in the THRO CURVE menu. I made the assumption that the top rpm was 5000. Based on that assumption, the throttle trim range was just barely able to accommodate setting the idle trim for the normal mode at a number I believed represented1400 rpm and zero for the ground idle with the trim lever. The trim offset in the menu had to be set at 100.

I doubt this method of throttle control will work with a transmitter that uses an analog throttle trim. On my 12X with analog throttle trim, the throttle trim is common for all flight modes while the other stick trims, that are digital, can be mode-based. If you wish to try this scheme on your transmitter with the digital throttle trim, use the Tcurves-FM.JRX program and copy it to a new memory. This setup uses both curves in the THRO CURVE menu which will assure that you won’t have a problem with the trim range.

Several changes will have to be made. In the TRIM SYSTEM menu, reset the throttle trim to its default value, 4. It was set at zero to inhibit the throttle trim lever. Change the trims from COM to flight mode in this menu. Inhibit the two program mixes. They will not be used.

The idle for the normal flight mode should be close. You can use the throttle trim lever to get it spot-on. The spin and landing idle will initially be the same as the ground idle. After you enter each mode, use the throttle trim lever to adjust the idle for that mode. When the idles have been set to your satisfaction, you can go back to the THRO SYSTEM menu and set the throttle trim to zero to lock in the throttle trim settings.

Allan

Allan
Thanks for confirming my feeling that an analog throttle trim will not work in the same way as the digital trim. That being the case, I shall stick to your FM set up as the Tx are backups for each other so the model memories must give the same responses.
Once again, thanks for your help in sorting out my problem.
Best regards
Peter

Allan, I have now had the chance to fly the aircraft and the use of the flight mode switch and Mix switch has worked perfectly. Thank you for your help with this.

Peter

I'm trying to implement the same Throttle curve process for the D3 controller with my XG11. I downloaded your ThroCurves zip file. How does this work with the JR XG11. What is a .JRX file. Thanks in advance.

Hi Albabmg

I'm sure Allan will be along to correct me if I get this wrong!

If you download a Model Memory from the XG11 it creates a ???.jrx file and you can then upload this to another model memory or transfer to another XG11. So, the 2 .jrx files that Allan sent me I could download to the SD Card and then up load to spare memory slots on my XG11.

I use the 3 position FLAP switch as my FLIGHT MODE switch in conjunction with the 2 position MIX switch.

There are only 2 THRO Curves on the XG11 but that's OK since the only thing that needs to change between the four modes that the D3 is seeking is a change in idle speed of the motor. The THRO CURVE provides 2 of these and the 2 Program Mixes provide the other two.

For ground handling, the idle speed is zero and as you will have found the D3 stops the prop instantly so I only do this from the SPIN idle condition.

For Spinning, the requirement is for around 200-300 rpm

For Landing, the requirement is for around 400 rpm - I actually use the same rpm as for SPIN as otherwise the float is a bit too long for me.

For Aerobatics, the requirement is for around 1,500 rpm but you will need to change this to suit so that your downline speed is the same as your datum level speed.

So, I use the same throttle curve shape with the Aerobatic curve low figure moved up to provide the 1,500 rpm idle. This is unaffected by what happens in the next selection.

For Landing, I use the P MIX 1 to combine the THRO CURVE and to provide a landing rpm

For Spinning, I use the P MIX 2 to combine the THRO CURVE and to provide a spinning rpm.

I use the MIX switch to control both P MIX 1 and 2 but as both are MIX AND FM switch they act independently. You must set the AND button in the P MIX screen under SW SEL to get this argument to be active.

The .jrx files when loaded to your XG11 should be used with your FLAP switch set as the FLIGHT MODE switch - you do that using the SYSTEM LIST to access the DEVICE SELECT screen and under FLIGHT MODE select FLAP SW.

I have my FLIGHT MODES set as follows:

POSN 0 - SPIN
POSN 1 - LAND
POSN 2 - AERO(batics)

The MIX switch controls the 2 PROGRAM MIXs that provide Ground handling, Spinning and Landing idle rpms

With the FM SW at SPIN AND the MIX sw at 0 the motor is stationery.

With the FM SW at SPIN AND the MIX sw at 1 the motor rpm is set for spinning

With the FM SW at LAND AND the MIX sw at 1 the motor rpm is set for landing

With the FM SW at AERO it doesn't need either mix and the bottom of the THRO CURVE is used to set the aerobatic idle.

Does that make sense?

Incidentally, I fly the Debowski contra - Twin Motor Contra Rotating (TMCR) - that requires two D3s and while I initially used the Twin Motor setup to give individual throttle curves for each of the 2 outrunners, I ended up going with a Y lead to connect both D3s to a single motor output. That greatly simplified the set up and has proved perfectly reliable in over 200 flights.

Hi barnowljenx,

What a fantastic and comprehensive reply.
I have two F3a models both utilising Jeti Spin 99 controllers.
I want to swap out the Spin 99 controllers on both models for a D3 and a "VLV International equivalent" speed controller.
I believe both controllers are very similar.
I understand most of your clear and concise instructions so hopefully the setup for both models will be straight forward.
Thank you again for taking the time and effort to explain the process.
Cheers.
P.S. Also Thank you to Alan for his previous input.

Hi Albabmg

Pleased to help. The other thing you will find is that the D3 requires a different type of throttle management compared with a Spin 99. When I made the transition I found that I was using far too much throttle movement for the D3.

Cutting to the detail, from S&L flying at datum speed, I was applying far too much power and so I have now restricted my throttle stick movement for between 3-4 clicks up on the throttle ratchet that then provides sufficient power for a 45 deg upline and the same down for a 45 deg downline. For a vertical upline I will be at 4-5 clicks up but for the downline I use a fully closed throttle to activate the slight down elevator mix.

The downline speed can be adjusted by altering the idle rpm in Aero mode. Using this procedure, I am still really astonished at how easy it has become to fly at a constant speed. To cope with the new judging criteria of "constant flight speed within a manoeuvre" I use a couple more clicks of power when flying into wind and that seems to work OK.

There is another way of handling this and it is to limit the amount of full throttle so that a fully open throttle stick provides the power you have preset. I've not tried this as I like to be able to have that little bit extra power in a strong wind.

Adam Debowski says that the D3 is the fastest acting ESC on the market - he's not wrong! That means you need to be especially careful on landing to maintain the approach power till you have rounded out and are about to touch down. I closed the throttle during the round out as I would with the Spin 99 and the prop braking, that was instant, chopped the speed almost instantly and the aicraft arrived with a thump! So, be warned and do not close the throttle till you are about to touch down. I fly off tarmac and you can see the aircraft decelerate as soon as the throttle is closed on landing. Adam also says that you can keep the throttle closed, in Land mode, and dive at the spot you want to land on since the prop braking is so effective that the speed is well controlled. However, remember to move the power up by a 3-4 clicks as you round out or else the speed will bleed off too fast!

Stall turns are much easier to accomplish than with a Spin 99. As you know, unless the Spin 99 sees a fully closed throttle there is no braking whereas with the D3 the fact that it will hold whatever rpm you have selected with the throttle stick means that braking is there with the throttle stick at any position so that the prop rpm is maintained by the electronics. For the stall turn, as you close the throttle (1,500 rpm remember) the aircraft decelerates fast and then pushing to about 2 clicks of power gives you a well controlled stop before applying rudder and closing the throttle.

I have a Citrin with a Q80 and a D3 and the speed control that used to be such a problem with the Spin 99 is not almost as good as with a contra. I also use a 3 blade 21x13 prop that also helps with braking.

Finally, Adam tells me that the regenerative braking provides around 150 mAh of charge to the flight pack during a typical FAI P schedule. Apparently that is enough for an additional vertical upline.

Hope that helps you to make the transition from Spin 99 to D3. You will never want to use another type of ESC after that!

Perter

Hi Peter,

Great information. I have the D3 now set up. I will need to fine tune this weekend at our field, Hopefully all goes well.
I have stored all of your comments for future reference and possible tweaks as I fine tune.

Thanks again.

Brian

Good luck this weekend. Let us know how you get on.

How did it go Brian?