Dual fxr problem...
 

OK so I am building my first moa. I choose the fxr as i already one. I am using tekin 35t pros as of now, till I save up for hh. My tekin fxr and 35t i already had were only used about for about 5 fifteen minute runs. I have calibrated both fxr's and both have the same setup/programming. But when I go to accelerate the front engages first, add a little more throttle and the rear engages. And just the opposite in reverse. When I engage front dig with my 4pl the rear tries to turn in reverse instead of locking. Both the front and rear are set @ 100% with the radio. I have watched videos and searched and read but have yet to find an answer o this problem.... Any help, any, is greatly appreciated.....

Re: Dual fxr problem...
 

First question, XR10 or Berg axles.
Do you have a hotwire, or are you programming them via the buttons on the FXRs?
You will want different programs for the front and rear axles.
I always give my back motor a little more drag brake, to help control decents when in dig.
OK, so you engage front dig and the rear motor goes, but no front and it is in reverse? Correct.
Those are all settings in the 4pl. You need to switch to -100% on the dual rate and make sure the channel for your rear motor is listed in the d/r set up.
You are digging, just doing it with the wrong motor.
Think of it this way. You want to think about which motor you are turning off.
Also, are you setting it up for a rear dig as well?

If all else fails, go to an empty program, and start over.
I had to do that a couple times when programming my 4pk.
Once you get one you are happy with, copy it to program 1 and call it good.

When I engage front dig, the front works as it should. But the rear will try and creep in reverse instead of locking. When I use rear dig the front locks as it should. When I get home I will make a video to show the problem. Sometimes I am not good at putting things into words.

Re: Dual fxr problem...
 

Are you sure you don't have another mix activated?

Re: Dual fxr problem...
 

Sounds like the calibration was "not quite correct", throttle EPA's to 100%, all trims to "0".

Likely both motors have timing, in the same direction. This means one is "advanced" when going forward, the other is "retarded" when going forward.

Either set both to "0", or both to "a little advanced" when going forward. This means each motor will be twisted a different direction from the other. I would go ~1/8" from "neutral/no timing".

Positive. My 4pl was only used on my wraith. Plug and play. Nothing setup. I programmed it for dual ESC with harleys video. Step by step. At first when I would full throttle one ESC would light all the way up and blink, letting me know IRS wide open. The other would light up 5 LEDs. So I calibrated both to my radio and now the light up exactly the same but yet act different. I will be home in about 2 hours and will post a detailed video to show problems I am experiencing. I love moa and its crawling ability. But this issue sucks when I am in need of dig.

Re: Dual fxr problem...
 

OK....so back to motor timing based on your info.8)

How do I adjust motor timing. I haven't adjusted either motor and bought both brand new

Re: Dual FXR problem...
 

Brushed motor timing....there is a great sticky in this section, but......

On the motor end with the brushes, there should be 2 small screws ~90* to the 2 brushes.
----twist a wheel on one axle "in the forward direction", note which way the motor armature spins!
Loosen the screws ~2 turns.
You should not be able to twist the "endbell" (the part that has the brushes, brush hoods, ESC to motor wires, etc.)

"0" timing is when the centerline through the 2 screws is through the motor can vents/between the 2 magnets.

To advance timing for "forward", twist the endbell ~1/8" AGAINST forward motor rotation (armature rotation...the "spinney thing inside the motor").

Snug up the 2 screws.

Repeat for the 2nd motor.8)

"thumbsup""thumbsup"

NOTE: you could leave both motors @ "0"* timing, I usually set a little forward timing knowing I am giving up a little in reverse.

I'm a "motor hack", John Holmes & Eddie0 are the 2 best Guru's on this site.

PS, most motors come with "standard" advanced timing of a few degrees, but in a MOA one motor has to be reversed, thus it's the wrong timing.

Okay thanks for the input. I will try and time my rear motor after dinner as my front is the most responsive.

Oh yeah, since one motor has to be reversed on the xr, is it better to wire the motor reversed, or run that channel reversed

If 0* is when the top screws are lined up with the center of the cans vents. Then both of mine are set at 0*

Re: Dual FX-R problem...
 

You can do it 4 ways, all are OK:

-Reverse channel in TX
-Reverse that ESC (if it's possible) through programming
-Swap ESC to motor wires
-Loosen endbell & rotate 180*

Whatever works for you. I usually just swap the motor wires.

Since the timing is set at "0" for both, check brushes, gear mesh, etc. Maybe the settings in one ESC are a little different.

I tried with timing last night to no avail. After playing around and getting my meter out. I realized that the esc's are engaging at different time. This I don't understand as they both are using the same settings. I am going to try and calibrate both again today...

Re: Dual fxr problem...
 

On the TX, make sure the channels used have been set to:

Trim (including sub-trims) are 0
EPA's are set to 100%

Then, recalibrate the ESC's. Sometimes you can do both ESC's at once, sometimes you have better luck doing them one at a time.

Jumping on shirt tails here but same issue.. not explained at all..

Here's my issue and I'm baffled! Its my 3rd or 5th fxr smash. Its the first one I'm having this issue with.

I run a mt-4. I have changed out RX's, tested diff plugs in the rx, I have rotated the esc's on the motors and rotated the rx plugs in the rx.. calibrated an recalibrated... I have even changed which rx power wire was feeding my rx while my bec powers my servo direct.

The rear fxr, or second in line to get power, is starting second. The front motor is spinning and the rear esc didn't even start the lights moving yet. (I have replaced the rear esc as well)

Its not motor timing, cause it does the same thing weather its plugged into the front motor or rear motor(recalibrated between each move/change)

Its literally the esc, like its in a bind till it gets juice. Once it has juice, I can slow all the way down to the rig bein stopped. I can then ease back into throttle and its perfectly fine..

I set them up manually but set all 3 up manually. Could one of them need updated thru hotwire?

Next thing. I thought it was me, Until.. a friend told me his fxr was doin the same thing after he set it up manually. He runs a fxr an punk dig... . Starts up with a jump, then can be relaxes off of an crawled smooth..

Re: Dual fxr problem...
 

I would at least make sure they are running the same version of the firmware and also check the deadband setting on both.<<< shot in the dark.

please post your findings

e

Spot on friend, spot on..

I got a chance to hotwire them today. The 2 I was having "issue" with were firmware 28, the front one was 30.. they are all 32 now and working as they should!
Here when the firmware was done by tekin, a factory reset default setting of 34 was on the dead band. On firmware 32 the default was set at 20. No way to change that manually with the fxr's. :/

All good to go and perfect function now

Re: Dual fxr problem...
 

good to hear!

e

Sounds like the op is probably having the same issues. had 1 and bought a second 1 later.

Re: Dual FX-R problem...
 

This is one of my "cases" for CC ESC's. Plug them into the link, check firmware, then load a "saved profile" into each ESC.

To do the FX-R's, I have to screen-shoot the settings page & save as a "BMP" or "PNG" to review the settings. Not hard, just not as easy as the CC ESC's.

Glad you found the issue...oh wait, that means you'll drive better....ARGGGHHHHH!!:evil:

:lmao::lmao::lmao::lmao:

PS, good suggestion envious..."thumbsup""thumbsup"