setting idle on electric model
 

I am using a 14 MZ, and have to adjust the throttle trim before each flight to get the idle where I want it to be. IS there a better way to do this may'be put it on a switch?


TIA

RE: setting idle on electric model
 

I'm using the throttle trim, can't see what's wrong with using it. What else are you going to use it for?

RE: setting idle on electric model
 

I use the throttle cut function on the 14MZ assigned to a switch . I set the throttle cut 'on' setting just low enough to arm the ESC and when I flip the throttle cut switch 'off', the motor goes to my selected idle speed without touching the trim at all. When I am ready to kill the motor, I just flip the throttle kill switch back 'on'.

Works great every time.

Woodie

RE: setting idle on electric model
 

Hey Woodie can you exapnd a little on how you set it up, what function you went into on the 14 to get it done?


TIA

RE: setting idle on electric model
 

I use something similar to Woodie except I use the slider on the left side (LST) to be my throttle trim. That way I can adjust it quickly and easily without having to use the digital trim.

RE: setting idle on electric model
 

Here is how I do it

http://www.futaba-rc.com/team/team-tip-004.html

Leaves the normal trim level intact for coarse adjustments and allows fine tuning etc to be done by a slider/dial etc.

RE: setting idle on electric model
 

Another way is to copy your regular flying condition to a condition called startup, assign it to a switch, give it the highest priority. Set the startup condition throttle curve afr to 100%, make it seperate, set the normal condition throttle curve to 85% or whatever needed to get the idle you want, leave it grouped. Use the startup condition when arming the esc, switch to your regular flying condition when ready to go.

RE: setting idle on electric model
 

The Jeti Spin ESCs have the ability to set the actual pulsewidth as parameters both ways. Then you get all values fixed and don`t have to arm the ESC with full throttle each time. Combined with an "idle-up"-setting would give you both idle and cutoff as you prefer every time...

RE: setting idle on electric model
 

Specific to the Jeti Spin 99…

At what point does the brake come on? Is it any time the motor RPM is exceeding requested RPM or does it only come on when the throttle stick is in the off position?

If the latter, then will not setting up an idle effectively disable the brake?

My last ten or so flights have been with the brake off and I don’t really see the need for an idle (or the brake!) RPM never drops below 1500 according to the data logger.
…although I did flop a stall turn or two :eek:

RE: setting idle on electric model
 

Scott

I have always been taught that the brake on an electric motor is only for gliders. For pattern and sports you want the brake off so that the prop idles when you cut the the throttle.

RE: setting idle on electric model
 

Brake comes on at the off position so your right, you won't be able to use an idle. Some manuevers its nice to have, if you don't want it to activate just stay a click or two above the off position. I've got mine set pretty weak, just so the downlines are constant speed. 45 lines I don't let it activate.

RE: setting idle on electric model
 

OK, here's how I do it.....

But first, a little info on the Jeti 90 and Jeti 77 ESCs (non Spin version)

The default end points for the non- Spin Jetis are approx 1.1 ms for low and 1.8 ms for high throttle. I set up my radio so the default is not disturbed during a flight. When I say 'disturbed', the Jeti 77 and 90 will reset the high throttle ms setting to anything it sees over 1.8ms. So if your ATV on high throttle goes to 2.0ms then the Jeti will reset to 2.0ms at full throttle and expand the overall range of throttle throw. It does not increase the power to the motor, it just expands the range of throttle 'throw'.

Because of this, and I hate doing full throttle run ups or immediately after take off to set the high end ms setting, I limit my ATV on the throttle to never exceept 1.8ms. I have a Jeti programming box that reads the ms timing of a channel and that is how I determined where to set my ATV. This seems pretty consistant across 2 radios and 2 Jeti ESCs.

If you like to do full throttle runups (or you have Jeti Spins which are programmable for end points) then you can ignore my comments on high throttle ATV.

My throttle ATV settings in my 14MZ are shown in one of the attachments below. HIgh throttle ATV is at 73% and low is at 99%. The 99% setting is low enough for the Jeti to 'arm' (you have to be below 1.1 ms for it to arm). This is also with my throttle cut switch 'on'. The 73% high throttle setting is 1.8ms timing, equal to the default setting in the Jetis.

The second attachment is my throttle cut screen. I use the Throttle Cut (Linkage Menu) to set this up. I assign my throttle cut switch to SW-B but you can use any switch convenient to you and not currently used for something else. I have used SW-B for so long I don't want to 'switch' (pun intended). You can see the settings on the attachment below.

So I plug in the ESC with the throttle cut in the on (kill) position, the ESC beeps several times indicating the cookies are done ;-) and when I am ready to start I flip the throttle cut switch off and the motor starts at idle. You may need to play with your throttle trim a little to get the idle where you want it but after that, you don't have to touch the throttle trim. Same everytime.

Woodie

RE: setting idle on electric model
 

Thanks guys for all your help. I finally got it to idle without adjusting the trim everytime. Turn on 14MZ--- hit throtlle cut, trun on plane, take throttle cut off bump throttle up a tad and viola; motor runs on low rpm:D

RE: setting idle on electric model
 

I recently tried to set fixed end points on my Jeti Spin and couldn't get it to arm in the airplane. I thought I had it figured out when using a pulse generator. If I turned the system on with a pulse width above the 1.0 msec I had set, and then dropped it to less than 1.0, it would arm. I couldn't do it in the plane. I gave up and went to auto low end and fixed 2.0 msec on the high. Seems to work.
What is the trick to get the fixed low end to arm? You mentioned something about arming with full throttle?

Jim O

RE: setting idle on electric model
 

Hi Jim,

I has similar results trying to set a fixed low point. I emailed Jeti and their response was:

For low stick position it is necessary to set longer impuls - if you measure 1.095, set 1.12 - 1.15
There are some differencies due to mechanical construction of sticks and temperature.
For high stick position set shorter impulse - 1.90 or 1.85

RE: setting idle on electric model
 

Thanks Scott,

I reset the fixed low end to 1.1 and now it arms every time. However, it doesn't actually start until some higher value. I suspect the clock in the Jeti is not accurate but it doesn't matter as long as everything works. The Spin 99 does not start as smoothly as the Hacker/Jeti 90 and seems to have a lot of hysteresis between start and idle. In other words after it starts you must back off for a slower idle. Once set, you can almost see the blades.

RE: setting idle on electric model
 

Jim, I experienced the same thing on my Spin 75. Took a little more than idle to get it started then you could slow it down again. My Jeti 77 is very predictable on start (smoother than the Spin) and idle is the same each time..... Must be something in the softward of the Spin controllers.

Don A

RE: setting idle on electric model
 

I have noticed something else with the jeti 90 and the hacker C50. If the prop comes to a stop it will not start up again unless the idle is brought all the way down. Luckily the prop is unlikely to stop while flying even at idle but it may occur on the runway. I may have something set up strange but this has been my findings. As long as the prop is still moving even if by wind it will restart but once it stops totally I have to lower the idle first.

Anyone else find this?

Stuart

RE: setting idle on electric model
 

I have noticed the same thing with my Jeti and Hacker A60 - not a big deal at all.

RE: setting idle on electric model
 

Interesting to hear this. I thought it was my inexperience with the setup. I also had the motor "freeze" where it would not startup again until throttle was brought all the way down. I also find it interesting that the Jeti non-Spin effectively recalibrates itself if it sees a pulse width greater than 1.8ms. I have been having a hard time smoothing out the throttle response and it seemed to me that it was always changing. Since I have just started running mine (as of last weekend) I am still climbing the learning curve and figured that it was my inexperience rather that component "features".

I have been struggling trying to get smooth throttle response with my Jeti 90 and Axi 5330. The only way I can explain it is that it seems "notchy", and seems to jump from one level to the next without smooth seamless transition. Once again, that may just be my setup.

Steve

RE: setting idle on electric model
 

Back to the original question. I believe it is a good idea to set the trim before each flight. Here is how I do it. Transmitter is a 9ZAP. I enable the throttle curve and use the left slider as the throttle trim control. On the throttle curve screen I set the low to 80% and that allows the low trim to go to the extreme position set by the ATV and AFR. I set it up to get the following PPM pulses out of the receiver:

low trim - .922 msec
medium (beaper sounds) - 1.000 msec
high -1.175 msec

High throttle -2.000 msec

Motor is Hacker C50 14XL
ESC is Hacker/Jeti ) O-90 set to auto start and auto end point
Battery is TP5300 10s4p

Start up sequence:
Turn on transmitter with throttle stick low and trim lever low. (.922 msec)
Plug in arming cable
Turn on receiver, ESC arms

Slowly increase throttle trim (left slider) until beeper sounds. Come up another 3 or 4 clicks( about 1.035 msec) motor starts at reasonable idle.
Push throttle to full power and bring it all the way back slowly. Reset the idle. One click either way.
Taxi out and take off. I have found this to work consistently, flight after flight. Therfore you could put it on a switch.
Before landing, I bring the trim back to the mid position (beep). This turns the motor off but it does not stop the prop. I very seldom have it stop on the runway and almost always am able to turn around and taxi back. It will stop if you come to a complete stop for a few seconds but seems to windmill as long as the plane has forward motion.

If one had the competition ESC with a setable brake it could be engaged with this setup. In fact I borrowed one last year and found it quite effective especially on landing. Just bring the trim back to slightly less than the start position with the slider or a switch and then it will engage when the throttle stick is pulled all the way back.

Today I duplicated this setup in my Abbra with a Dualsky 6360 and Jeti Spin 99. It seemed to work exactly the same with a smooth start. After touching up the trim it idled smoothly at 420 rpm. Top end yielded 5750 rpm on an APC 22x12 at 63 Amps and 34 volts according to the watt meter. The ESC readout had it at 61 Amps.

Hope to fly it this week. I doubt that I'll need the brake but I may play with it.

Jim O

RE: setting idle on electric model
 

Good info Jim,

I was wondering why my motor wouldn't shut down all the way on landing approach. I guess that's just normal. It did seem, however, that the idle is too high after flying and that I had to drop throttle trim all the way in order to slow down enough for landing. Maybe I am just landing too hot and it is free wheeling too much. I'll have to watch it closely.

RE: setting idle on electric model
 

Hi Steve,

Happy you are thinking about pattern again. Yes, I found out that the electric motors are easily driven by the forward speed of the plane and really need a brake to slow down rpm wise. Without a brake the best you can do is turn off the motor and let it free wheel. With a light airplane this should work fine.

One thing I didn't mention is to be sure and set the failsafe to turn the motor off if you go into failsafe.

Hope to see you at a contest this year, Jim O

RE: setting idle on electric model
 

Hi Jim,

I've got a lot to learn.....

I've already set the fail safe to shut down (I think it is about 840ms pulse width now). My first eye opener was when I was testing this beast in my garage and the throttle was reversed.......

I'm hoping to make it to Hemet in August. I don't think I will be ready for Riverside in June, seeing as how that is only a couple weeks away and I still haven't flown the sequence yet. I've got at least one more IMAC event that I need to take seriously so I can have a chance to qualify for the shootout. After that, I can focus on pattern.

I love the power of the AXI/Flightpower setup but I am having trouble smoothing it out and getting it to shut down when I want. I should probably start a new thread on this topic but I have also seen a big difference in throttle performance between my flight packs (both Flightpower 5350 F3A packs). That is driving me nuts.

RE: setting idle on electric model
 

I saw this behaviour on my Jeti 90 Acro/C50 14XL this weekend, when I set idle on a switch to activate brake only in some maneuvers. When idle is too low it seems Jeti 90 doesn't have good "sincronization" or something like this and makes the prop to stop (a friend has a MasterSpin 99 and have better idle). When this happens then you have to thottle back and accelerate to have it runing again. In the air it doesn't seems a problem but is not a nice thing to hear this in the pits, it looks like the gear is going to break ;)

RE: setting idle on electric model
 

I reset the endpoint to be below 1.7ms and set the low end to turn on when my 9Z slider just passes the "beep". Worked great. Throttle curve is pretty close to the one Woodie shows. It works pretty good. I am happy. Just flew my first complete P-07 sequence, now I can start practicing.

Thanks

RE: setting idle on electric model
 

I tried the logrithmic curve on the Spin 99/DualSky combination and at first thought it was worse as far as rough startup. However I can see if you start it aggressively it will always start in the right direction so it might work better for geared motors. Then I tried the exponential curve. It is the softest start of all but will start in the wrong direction some of the time. However it has by far the best idle and smoothness coming off of idle. I had it running at 200 rpm. Almost as good as my new ceiling fan. I don't know what that curve looks like so I guess I'll have to map it if I get a tachometer working.

Jim O

RE: setting idle on electric model
 

I tried to fly with the expo curve today and knew I was in trouble when it took 1/3 throttle to taxi out. The flight was terrible. It was like flying a two stroke with no mid range power. I might be able to compensate for it with the throttle curve in the transmitter but didn't try today. The idle was great and I only used 2694 mAh for the Master's sequence but it is not the way to go.
I went back to linear on the next flight and thought I heard a couple of cutouts during the flight. On the third flight I heard something on the bottom of the Figure M that sounded like something broke. I throttled back and landed okay but it looks like there is still something wrong with the Spin 99s. Is there any success stories with the Spin 75? I really like the data logging feature on the Spins.

Jim O

RE: setting idle on electric model
 

Data logging is nice to have - reliability is even better, Jim. Stick with the regular Jeti's and stay away from the Spins until they can fix their problems.

RE: setting idle on electric model
 

Okay fellas, I have a got a new spinn after the last one stop running. This one will not idle below 780 for the life of it. I have tried everything from using end points to fixed to logorithmic to linear; nothing works. Do you guys running the spin have any thoughts?


TIA

RE: setting idle on electric model
 

You don't need to set an idle with electric.

RE: setting idle on electric model
 

Jim,

I ran the Spin 75 for awhile but was having some of the same issues you describe with rough start up as well as the idle not being consistent. While I liked the data logging features, I found the volt and amp readings to be unreliable, rpm seemed fine. I did like the programmability features like acceleration, timing, etc. I played with timing from 20 to 30 degrees and funny thing, I ended up at 24 degrees as the setting I thought ran best all around. Guess what, 24 degrees seems to be the default setting on the Jeti Opto Advance 77 and 90 so in my case, the timing programmability didn't buy me anything but I still got to play with it ;-)

I also had a problem with the motor hesitating in the air as I did throttle ups for verticals. I thought I could hear it happening and the Eagle Tree Data Logger proved it was happening so I finally gave up and sent it back, traded it in for a Jeti 77 Opto Advance. I had an early version of the Spin and I would assume there were some programming, recording issues to be worked out. I kept the programming box since I assumed I would end up buying another Spin when the bugs were worked out and I liked some of the features in the box like pulse width and servo test so I kept it.

I also tried exponential for one flight and went back to linear. I use throttle curve on the transmitter programming to shape power response and am happy with that.

How's that Dualsky working out for you? Mine runs great and a couple other guys up here are trying them out. Jerry B is also runnng one now. Mine pulls about 65 amps on a 20x13 and I have all the vertical and speed I need for a 11 lb plane. Can fly the P07 sequence at under 3500 mah at 150 meters and large maneuvers.

Don

RE: setting idle on electric model
 

Don,

I just wrote a long response and it was rejected by RCU. Must be a setting on my new computer. Let's see if this gets through.

Jim

RE: setting idle on electric model
 

Here we go again. I was just thinking of starting a new thread on the Spin to see if anone is happy with them.
My original did not work well on the bench. Rough starting and many cutouts at all speeds. I sent it back and got a new one. The new one didn't seem to cutout but was still rough starting. I flew it in my Impact with a Hacker C50 for one flight. It was too hard on the gearbox during start up.
I then put it in my Abbra with the Dualsky and flew about 15 flights. It worked at first but didn't start and idle as well as I'd like and that is why I was fooling with the curve. The expo was neat on the ground but no good in the air. I went back to linear.
On flight 12 or so I thought I heard a cutout. This continued and then on the last flight I heard a noise that sounded like a rough restart. I landed and put in my Hacker Master 0-90.

The Master 0-90/Dualsky combo works great. Starts at 200 to 400 rpm and you can leave it there. I use from 3000 to 3500 mAh per flight on TP5300 Prolites. I'm running the 22x12 and having no heating problems.

I don't understand why they can't make the Spin work as well as the Master 0-90 and have all the added features.

A little shirter this time, Hope it goes through.

Jim

RE: setting idle on electric model
 

140 flights and no issues with my Spin 99. Setting are:

Manual brake 12% initial, 68% final (prop just stops as plane is touching down.)
21 degrees timing (was running 25, plenty of power with 21 and a few less amps.)
1.0 sec acceleration
Slowdown cutoff
Initial point auto - on
End point 2.0 (output pulse measured at 1.93...Jeti says to be less than measured for high stick but full throttle was reached too early)
Auto inc end - off
Expo throttle curve (12Z transmitter, 3 point spline, point 2 at -17, +22 rate)

I fly with an idle up set for about 400 rpm (once motor is running...just flipping on idle up will not start the motor.) I went the idle up route because a few times early on, after an extended down line, it would make an awful noise on throttle up if I got into the throttle too quick.

Scott

RE: setting idle on electric model
 

Scott, glad to hear you are having good luck with your Spin. I will probably get another when the 'normal or usual' feedback on them is positive. I was an early buyer and I suspect some of my issues have been resolved at this time.

Have you checked M, Amp and Volt data recordings against a known source? My logged RPM data was ok, but Volts and Amps weren't even close.

Don

RE: setting idle on electric model
 

Thanks for the feedback Scott. I will try the 21 degree timing and a longer acceleraion settings. The noise I heard was probably the same as yours as I was at the bottom of a fig. M getting back on throttle. I thought something broke.

Jim O

RE: setting idle on electric model
 

I picked up this controller last September so I imagine it's one of the earlier ones as well. I found the logging to be of little use since it's a min or max value. Temp and max RPM are good to know, but V and A aren't that useful (or accurate as you say.) Errors are good to know and fortunately I haven't recorded any yet! Besides, you just can't beat EagleTree! Here are two recent flights, first was TP5000-10SX, second was TP3850-10LSX, A60-20S, 17x12E, master's sequence.

RE: setting idle on electric model
 

I'm running the Spin 99 with AXI 5330 FAI and TP 5300's. I didn't like the 1second throttle and back that down to .3 sec. Linear throttle. I've played with timing and can't tell a huge difference...I'm between 23 and 25 degrees (24 default). I'm flying a DX7 so throttle curve isn't available. I just initialize the ESC with the throttle trim pulled back about 15 clicks, then click the trim up to near neutral. If you click it up far enough to actually start the motor, it will be a little too fast for "idle". but there is a range where the motor will continue to run once started by stick movenment just before it starts from trim movement where it idles well.

The only issue that I've had with the ESC is the "horrible noise after extended downline" that someone else mentioned. I'm guessing that it has something to do with the windmilling prop being driven faster than the esc can keep up with, but I'd sure like one of you smart guys to tell me what it is and how to fix it. I haven't used the brake, and perhaps that would prevent overspeeding.....?

RE: setting idle on electric model
 

Hello again folks,
I put the Spin back in my Abbra with the Dualsky 6360 and have flown 11 more flights. I've had no cutouts or big noises in the air. I've tried timing from 21 to 24 degrees and acceleration from .5 to 2.0 seconds. The big problem is starting especially the first start of the day. It wants to run backwards. I try bringing the idle trim up slowly and bringing the stick up fast. Neither works. The best compromise is to set the idle trim where I know it will idle after it starts properly, and then start it with the stick. Sometimes it still wants to start backwards and it won't stop by bringing the stick back but only when the trim is also pulled back.
I could defiinately feel the lag in acceleration with it set in the 1.5 to 2.0 second range. The change in timing was not significant as far as I could see but the low timing and slow acceleration seemed to conserve energy. I used less than 3000 mAh on all flights that consisted of just the masters program. With many extra maneuvers I was still under 3500.
I guess one could get used to it but after seeing how great the Jeti/Hacker Master 90-0 works I'm not completely satisfied. I failed to mention that I've had the brake turned off through all of this. I guess I should try it to see if it affects the starting.

Jim
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