DaveL322

Arnaldo,

Orders for NEU motors are placed through Castle Creations (in the US, and I believe they will ship internationally).
http://www.castlecreations.com/produ...motors/nm.html

The motor you want is the NEU-F3A-1, which is a 1513-2Y 1300 KV motor:
http://www.neumotors.com/Site/FAI_Motors.html

Other possible sources for the motor:
http://www.neumotors.com/Site/Where_to_buy.html

Regards,

Dave Lockhart
Team Castle Creations

tclaridge

Please help!
I have the Jeti 77 and am having a problem setting the throttle curve on my JR 12X. Sometimes it works, sometimes is doesn't, and I don't know why. I am wondering if I do something to trigger the autocalibrate that cancels out the throttle curve? Can anyone add some insight on how to use the Jeti 77 and a throttle curve on the 12X?

PS I've tried rebinding and setting both curves the same, but I still get full throttle even though I've adjusted the high point down to 80%. Then, every once in a while, the throttle curve "kicks in" and works fine. I use a watt meter to watch the amps, so I know when the curve is working, and when it is not. I also watch the monitor screen on the 12X, and the thottle setting is following the curve correcting, but the Jeti is stilling pumping out full throttle. Is the esc reprogramming the endpoints?

woodie

If you have a standard Jeti 77 then it is possible you are resetting the end points. Since the standard Jeti 77 it does not have end point adjustment and uses an auto-end point function, the Jeti 77 (and 90) default to a 1.8ms being high throttle when powered on. If it sees a higher ms input from the receiver , then it resets the high end to that higher ms end point. This has the affect of changingmid range throttle settings when it resets the high end. So, if you turn on the receiver, do not do a full throttle run up to set the high end, then mid range throttle may seem a little high at take off. There are 2 fixes for this. First, do a 3-4 second full throttle run up before take off to reset the high end setting for the ESC, then it will not change on you during flight. Second, have someone tell you what the % end point setting is for 1.8ms from the JR transmitters and reduce your high throttle end point to match that. If you do this, the ESC will never see anything higher than 1.8ms and never reset the high end during flight.

Anyone know what the JR throttle end point % is for 1.8ms?

Hope this helps
Woodie

tclaridge

It is a Jeti Advanced Pro Opto. Another data point on the throttle curve issue: When I set the throttel curve for a maximum of 50% or lower, the throttle curve works fine. I also do not get that full throttle at the half-way point on the initial throttle up. If I just go to 55% on the max value for the throttle curve, it seems to ignore the throttle curve and still give full power. This seems very strange.

2Sunny

Hi Tony,

I had similar issues with my setup.

First I hooked up a Spin Box to determine what the throttle pulse signal output of my 12X was in ms. Then I used the ATV function on the 12X to limit the low end to 1.1 and the high end to 1.8. Then I created a throttle curve on my 12X. The curve worked fine as long as I kept the midpoint above 65% or so. When I tried to reduce my midpoint lower than 65% the power response would become irregular presumably because the Jeti was somehow "resetting" the curve during the flight. I have no hard data other than to say when I went below 65% my power usage changed by more than 10% meaning half throttle was much higher than before and that I could duplicate the problem again and again by shifting from a high midpoint to a low midpoint on my 12X. In the end I came to the conclusion that the Jeti 77 Advanced Opto Pro is a "sport" esc and meant for folks who will not be playing with their throttle curves, but rather simply going out and flying a 3D machine or something. In addition I did email Jeti but never got a response. Today I run the Castle 80 HV instead and although I still think it's "noisy", it seems to be perfectly controllable and virtually bullet proof for F3A usage. I know that's not much of an answer, but just thought I'd share my experiences.

Joe

woodie

I doubt the Jeti 77 is resetting any curve during flight unless you exceed the 1.8ms full throttle default. As far as being a 'Sport' ESC, I guess it is all in how you look at it. The Jeti-77 is a 'plug and play' ESC that doesn't have some of the bells and whistles of newer ESCs like programmable brakes and fixed end points, however it has sure brought home it's fair share of trophies including several District Championship trophies here in D7 so I guess that proves the point that it ain't the plane/radio/prop driver that determines the winner..... ;-) I actually recommend the simple Jeti controllers to people just getting into epattern because they are 'simple' and it eliminates confusion over 'settings' once you get your throttle end points set correctly.

OK, hopefully the following will help.... These settings are for a standard (not Pro) Jeti/Hacker 77 but I can't imagine the Pro being much different.

Here are my ms settings for my Jeti 77 from my 14MZ. Below is a picture of my throttle curve. I used to fly linear/linear for the TX and ESC but lately I have changed the throttle curve in the TX to be a little more aggressive on the bottom end. It ramps up a little more steeply from idle then slowly flattens out by the time it reaches mid throttle (on the TX, not the ESC). The vertical lines in the picture represent % of throttle stick in 25% encrements from -100% to +100%. The left side at -100% throttle is 1.15ms which is a slow idle, the right side at +100% is 1.8ms (full throttle). The vertical lines from left to right represent:

-100% 1.15ms idle
-75% 1.20ms
-50% 1.33ms
-25% 1.43ms
0% 1.52ms mid stick position
+25% 1.59ms
+50% 1.66ms
+75% 1.72ms
+100% 1.80ms full stick, full throttle

These percentages and ms readings are with throttle cut off, when I turn throttle cut 'on', the -100% position is 1.006ms.

Woodie

wattsup

My Feedback: (1)

Woodie, thanks for setting the record straight. As you and I had agreed in an earlier email "It doesn't matter what you build or buy, you've still got to fly it!" The numbers and graph from your transmitter should help alot of pattern flyers who cannot afford the "latest & greatest with all the bells and whistles" but want to pursue e flight. I too have one of the Jeti 77's and have never had a complaint or problem with it. Talk to you soon____Everette

tclaridge

Woodie and Joe, thanks for the info. I was looking to create a curve just like that, but instead of full throttle at the top end, I wanted to scale back to about 80-85%. (What I am trying to do is scale down the thrust by 80-85% because my plane seemed to go too fast on the up lines, and I want the stick to be at full up during a vertical climb.) My guess is that if I set the full up throttle joystick position to something less than full power, the Jeti would scale the top end back to full throttle.

2Sunny

Actually, according to Jeti the throttle adjusts automatically to your personal throttle usage based on the maximum and minimum signal that the esc is presented with hence the need for folks to perform full throttle run ups on the ground prior to takeoff. I had a curve similar to yours and was very happy with the performance of the Jeti until I began trying to adjust the midpoint at which time there were dramatic changes in the performance of the planes power setup in terms of throttle position, speed, and mAhs used. Without a doubt the Jeti 77 Advance Opto Pro is a great esc capable of performing well in an electric F3A plane. Tony's question was related to anamolies regarding his curves output based on changes in throttle curve input, and I can validate that problem but was unable to solve the problem and did not receive any response from Jeti as to how to solve the problem I experienced. Of course it begs the question as to whether the problems I experienced are related to imagination, other components, lack of experience, lack of understanding or maybe just maybe I had a problem, understood what my problem was but have been unable to find a solution.

tclaridge

2Sunny, problem and mystery solved! It took two throttle curves and a watt meter to figure it out. I posted my solution on the other thread:

http://www.rcuniverse.com/forum/fb.asp?m=9861148

woodie

This is true IF you exceed the default full throttle setting of 1.8ms. If you do that, the controller will reset the full throttle ms setting to whatever it saw as the highest ms seen from the RX. IE, if you set full throttle to 2.0ms on your TX/RX, arm the controller and do a full throttle run up, the ESC resets the default full throttle ms reading from 1.8 to 2.0 ms and every point in between is also reset proportionately so you now have a new 'line' from idle to 2.0 in the ESC.

I don't mean to drag out this explanation but I know it is confusing. It took a while for us to figure it out and only got there when Jeti responded to me describing how the stock Jeti 77 managed the throttle settings. When Jeti added fixed end point capability in it's latter ESCs, this became a non issue because the ESC would never reset end points.

On a stock Jeti 77, if you don't do a full throttle runup, take off, do a few maneuvers before you exceed 1.8ms then go to full throttle at 2.0ms, the ESC then resets to 2.0ms for full throttle. The throttle response will not feel the same because the ESC is working with a new range and you will notice idle is off a little bit also. The power you had a mid throttle previously will now be lower. The RX is putting out the same signal but the ESC has 'reset' to a higher/broader range. This problem had us scratching our heads for a while trying to figure out why settings were changing in flight. That is why I set the full throttle output from the RX to 1.8ms so it will never trigger a 'reset' in the ESC. I don't really like to do full throttle runups on the ground so I use the default of 1.8ms on the stock (non Spin) Jeti ESCs.

Joe, if you limited the throttle to 1.8ms at full and it worked but you then can't set the mid range, I guess I don't really understand the problem you are describing. Are you saying you increased or decreased the ms output from the rx by changing the midpoint of your throttle curve and it dramatically changed how the motor ran? What was your midpoint ms setting when it was working correctly and what was it when the ESC was not doing what you expected?

Woodie

woodie

Great, hope it works out for you. Seems a little complicated but what ever works, right? Perhaps the software coding of the Pro vs stock Jeti 77s is different. I may have to pick one up to play with.

Woodie

tclaridge

I wish Jeti had documented the "full throttle reset" procedure in their documentation. It would have explained the behavior and avoided a lot of trial and error. Also, the two-curve solution is is the only way to get a throttle curve with the top end less than 100% full power. But at least it works!

Woodie, I did set my throttle ATV limits to be 1.1ms on the low end, and 1.8ms on the high end. The initial run up still did NOT follow the throttle curve set in the Tx. Actually, I tried a lot of other values, and no matter what I picked, the Jeti scaled the whole curve only after full throttle was reached. So an initial full throttle run up is ALWAYS required, regardless of you throttle ATV settings on the Tx. Otherwise, the endpoints don't get set, and your midpoint will be different before/after full throttle. This may be a function of the Jeti Pro to be more robust regardless of the Tx throttle range, but it should have been documented.

tclaridge

Just to finish off the subject, I built the curves to get the linear response I was looking for. Results are posted on this thread:

http://www.rcuniverse.com/forum/fb.asp?m=9862826

johncoulouris

Hello guys,

would the Jeti Spin 77 opto be enough for Hacker C50-14xl for 10s F3A setup ?

Thank you,
John

tclaridge

Probably. You gotta choose your prop correctly. There is probably a burst rating on the Jeti that is higher than 77 amps too.