Futaba 4PL Setup, Tips, Tricks & Help

[Charlie-III]

Have you checked the timing on your motors?

+1, if they have any timing in them (but 1 is reversed as it should be in a MOA) you will get different motor speeds. Most motors, unless ordered as a pair for a MOA, have some timing in them. This is fine until you reverse one motor. Then instead of "advanced" timing, it's actually "retarded" timing when both axles are driving the rig in the same direction.
When in doubt, set both to "0" for now.

 

[meffie]

Have you checked the timing on your motors?

+1, if they have any timing in them (but 1 is reversed as it should be in a MOA) you will get different motor speeds. Most motors, unless ordered as a pair for a MOA, have some timing in them. This is fine until you reverse one motor. Then instead of "advanced" timing, it's actually "retarded" timing when both axles are driving the rig in the same direction.
When in doubt, set both to "0" for now.

They are a matched pair of Broods I ordered specifically for my XR. The rear was reversed.

How do I set the timing? Is that a physical thing in the motors?

 

[Harley]

They are a matched pair of Broods I ordered specifically for my XR. The rear was reversed.

How do I set the timing? Is that a physical thing in the motors?

They should have been marked front and rear, and the timing should have been set correctly but who knows if he did it right or not.

There are physical marks on the cans that line up with a mark on the end bell. You can set them to zero timing to make sure that is not the issue.

 

[meffie]

They should have been marked front and rear, and the timing should have been set correctly but who knows if he did it right or not.

There are physical marks on the cans that line up with a mark on the end bell. You can set them to zero timing to make sure that is not the issue.

Roger, on it "thumbsup"

I'll let you know how that goes

 

[meffie]

While I assume this isn't Zero, not sure which side is, they are both timed the same it appears. Is there still a need to set them to Zero?

 

[Harley]

While I assume this isn't Zero, not sure which side is, they are both timed the same it appears. Is there still a need to set them to Zero?

I would set them both to zero and test everything out.

 

[Harley]

Zero is the first tick, just to the right of where they are set now.

 

[meffie]

Zero is the first tick, just to the right of where they are set now.

kk post back in a bit

 

[Charlie-III]

Both have timing, as Harley mentioned. The issue is it's advanced for one motor and retarded for the other motor (since one has to spin backward), thus the differences in performance.

 

[Harley]

Both have timing, as Harley mentioned. The issue is it's advanced for one motor and retarded for the other motor (since one has to spin backward), thus the differences in performance.

See you are making assumptions, remember he said one endbell is ROTATED 180 degrees.

 

[meffie]

Ok so I set timing to 0 on both motors. Same issue. The rear is still significantly slower than the front in forward. Same speed a-ok in reverse. Although it does seem as if the rear is spinning a bit faster forward now than it was.

 

[Charlie-III]

See you are making assumptions, remember he said one endbell is ROTATED 180 degrees.

Ummm....I got that (;-)), timing is related to the DIRECTION the arm spins, not the "wire color code".
Since the timing marks, in the pictures, are offset in the same direction, they are timed different between the 2 motors. One is advanced, one is retarded.8)
Think about it."thumbsup"

 

[meffie]

Ummm....I got that (;-)), timing is related to the DIRECTION the arm spins, not the "wire color code".
Since the timing marks, in the pictures, are offset in the same direction, they are timed different between the 2 motors. One is advanced, one is retarded.8)
Think about it."thumbsup"

So but now that they're both at zero, that shouldn't matter should it?

 

[Charlie-III]

So but now that they're both at zero, that shouldn't matter should it?

You are correct, I was responding to Harley.;-):lmao:

Since there is a "little" play in the brush hoods and we don't know the length of the brushes, there "may" be a slight timing difference between the 2 motors even with the static marks at "0", but not enough for most of us "mere mortals" to notice. This is due to cocking of the brushes in the brush hoods when the motor spins.

OK, not to be a PITA, have you swapped the ESC's or motors around to see if the problem follows? At least we would then know where the issue lies (since you stated all the radio set-up is correct.....)

 

[meffie]

You are correct, I was responding to Harley.;-):lmao:

Since there is a "little" play in the brush hoods and we don't know the length of the brushes, there "may" be a slight timing difference between the 2 motors even with the static marks at "0", but not enough for most of us "mere mortals" to notice. This is due to cocking of the brushes in the brush hoods when the motor spins.

OK, not to be a PITA, have you swapped the ESC's or motors around to see if the problem follows? At least we would then know where the issue lies (since you stated all the radio set-up is correct.....)

That brings up something.

When I was setting the timing to zero....I pulled the tops off the can without removing the brushes or the springs...

The rear motor, the brushes were touching each other.

The front motor, the brushes had a very big gap.

Meaning, when I put the motors back together, the rear motor I had to pull a brush to get it to seat, the front I did not.

So if brush length makes a difference, as that's what I'm assuming you just said regardless of if they still contact the comm or whatever it's called?

Sorry trying to learn all this crap.

 

[Charlie-III]

That brings up something.

When I was setting the timing to zero....I pulled the tops off the can without removing the brushes or the springs...

The rear motor, the brushes were touching each other.

The front motor, the brushes had a very big gap.

Meaning, when I put the motors back together, the rear motor I had to pull a brush to get it to seat, the front I did not.

So if brush length makes a difference, as that's what I'm assuming you just said regardless of if they still contact the comm or whatever it's called?

Sorry trying to learn all this crap.

Ding ding ding.....I believe we have a winner. It sounds like the front brushes are very worn, thus the way the motor reacts is different. It also affects motor timing.
I sorta willing to bet that if you swapped motors, most if not all the issues will follow the motor.
Doing a minimum of a set of new brushes front & rear will even things out.
Also making sure the brushes move freely in the brush hoods helps as well.

BTW, when removing the endbell, you should remove the brush springs & brushes 1st.

 

[WAM]

Question -- does rotating the endbell 180 actually change anything? Or does it just give you a new set of hash-marks on the other side of zero? (Because advance is now the other direction)

 

[meffie]

BTW, when removing the endbell, you should remove the brush springs & brushes 1st.

Yah I know that NOW

Ok so, after talking with Chris M about some wiring stuff, we talked about my situation with the motors.

He suggested based on my situation reseting the radio to normal on throttle and chan 4 (remember you guy's had me reverse them to make the wheels spin the same direction) and simply plug in my wiring backwards on both motors....

Guess what...It worked....

There's still a small variance in speed, Im guessing due to the little bit more worn brushes in the front, but otherwise the delay is gone, the motors are spinning the same direction, everything works, and the radio is set to normal all the way around.

All this time and pain, just needed to switch both motors, not just the rear, heh

Woot "thumbsup"

 

[Charlie-III]

Question -- does rotating the endbell 180 actually change anything? Or does it just give you a new set of hash-marks on the other side of zero? (Because advance is now the other direction)

providing you DON'T swap the motor wires????....yes, the "+" and "-" from the ESC are now 180* relative to the "north" and "south" magnets, instant motor rotation reversal.
Sooo....to reverse a brushed motor rotation, either rotate the endbell 180* or swap the 2 motor wires. Both do the same thing.
Timing is timing, it relates to "0" and the rotation of the armature.
Is you reverse the motor rotation you "change" the timing, not the degrees but the "advance" or "retardation".

Make a little more sense now?8)

 

[Charlie-III]

meffie, congrats on sticking to it, glad it's resolved. Get at least 2 sets of brushes, maybe even do a motor rebuild."thumbsup""thumbsup"