106 replies to this topic

[Leon]

When increasing the timing with a Rotor set-up, do you turn the endbell clockwise or counterclockwise? Thanks.

[Cheater]

Leon,

If you wish to advance the timing, you turn the endbell opposite the direction the arm turns. That's the way to remember it...

[Bill from NH]

Clockwise, Leon. Counterclockwise retards it. You can get about 5-7 degrees either way.

[Cheater]

Bill's right if the motor is assembled correctly, i.e. the north and south magnets are in their correct positions. But not all of them are... LOL!

That's why I gave a universal answer.

[Ron Hershman]

Even if the magnets are "backwards, reversed, or in a different position"... the comm timing remains the same

If you reversed the magnets in a "Rotor" set-up...... you would still twist the endbell clockwise to increase timing. And flip flop your wires when soldering them to the motor.

[Cheater]

I stand by my answer in post #2.

[Guy Spaulding]

Bill's right if the motor is assembled correctly, i.e. the north and south magnets are in their correct positions. But not all of them are... LOL!

That's why I gave a universal answer.

Changing the magnet positions will change how you hook up the wires, but won't change how to advance the timing.

Now, if you had an armature shaft long enough to put the pinion on the endbell side, and mounted the motor backwards, then you'll have to twist the endbell counter-clockwise to advance the timing. Of course, the available 5-7 degrees wont be enough to overcome the armature's built-in timing (typically 25-50 degrees), so the motor will be dog slow!

[Guy Spaulding]

Oops. Looks like Mr Ron beat me to the punch!

Anyway, twist the endbell clockwise, and the commutator segments reach the brushes sooner, hence timing is advanced!

[Cheater]

Changing the magnet position WITHOUT reversing the leadwire connections causes the armature to rotate in the opposite direction. Anyone disagree with that?

And I posted: rotate the endbell opposite of the armature's rotation to advance the timing. Anyone disagree with that?

Leadwire connections weren't even involved in this discussion initially.

[Guy Spaulding]

Leadwire connections weren't even involved in this discussion initially.

So who brought it up? (just messing with you, my old buddy. We're all right!)

[Cheater]

Like I said, I was trying to give Leon a universal answer, one that will work in every circumstance with every motor.

[Ron Hershman]

Changing the magnet position WITHOUT reversing the leadwire connections causes the armature to rotate in the opposite direction. Anyone disagree with that?

And I posted: rotate the endbell opposite of the armature's rotation to advance the timing. Anyone disagree with that?

Leadwire connections weren't even involved in this discussion initially.

Correct on changing magnets and not wires...leading to motor running in WRONG direction....still does not change the timing on the armature....it's static in this example.

If you took a Rotor motor as it comes off the shelf..... reversed the magnets and not the wires... it would run back wards...... the only way to get it to run straight.... would be to reverse the lead wires and again.... the timing would still be the same on the arm. Changing the position of the endbell will still advance or retard.

If you were to take the motor reverse the mags...making it run backwards and not changing the lead wires..... the ONLY way to make it run forward would be to "reverse" time the arm/comm.... the endbell would have no effect. The comm would have to be on the "other" side of the stacks.

Take a Puppy Dog motor in a inline car..........put the crown gear on the opposite side of the pinion from what is normal....change the wires and it will run forward.....BUT not fast enough and even if you could advance the endbell...... it's not going to work properly and will run very hot.

Again the comm is in a static/advanced position.

Now we know why P-S offers PD motors in both CCW and CW versions and the comms are timed for which direction the motor/arm/car runs.

Now if you had a arm/motor that had ZERO dergrees of timing ( which a Rotor motor is not ) that would be a different story and depending on the rotation of the motor/armature.....you could advance either direction, but would still have to change lead wires or mags to go forward.

Then there is the direction of wire when the arm is wound in regards to CCW or CW and timing, but let's not complicate the issue LOL

[Guy Spaulding]

Why not, Ron?

Let's throw a hemi-wound arm in the mix!

[Ron Hershman]

Why not, Ron?

Let's throw a hemi-wound arm in the mix!

LOL I wasn't going there....YET!!! LOL

Don't forget "inside or outside" firing as well.

[idare2bdul]

Oh go ahead and go for inside or outside firing!

[Cheater]

Too much info and yes, I am very aware that the actual timing is built into the arm, but that's not what Leon was wanting to know. And part of the blame for all of this needs to be laid on Parma and the other motor makers selling "adjustable timing" motors and endbells that really aren't that.

He asked a simple question and he got an answer to that question before you guys started dragging in other conditions.

[Phil Smith]

What is inside and outside firing?

[flem1959]

Don`t you dare say anything bad about Parma here or you`ll get put in time-out!

[Victor Poulin]

You guys are going to make poor Leon wish he'd never asked his question.

Leon,

As you can see, the guys here are very knowledgeable but also like to have a little fun?
If you think your confused now? Just give em a while

Vic

[Cheater]

Not saying anything bad about Parma at all.

The central issue in the little nitpicking session here is that motors are being sold as having "adjustable timing", when that is not exactly an accurate description.

[Ron Hershman]

Too much info and yes, I am very aware that the actual timing is built into the arm, but that's not what Leon was wanting to know. And part of the blame for all of this needs to be laid on Parma and the other motor makers selling "adjustable timing" motors and endbells that really aren't that.

Yes, they are "adjustable" timing motors.

There are two timings on a motor... comm timing and brush timing. Most endbells are designed to have "zero" degrees of brush timing in relation to the commutator.

While you can advance or retard the point where the "brush fires the comm" on the armature and in relation to the magnet tip length/width/height... it's better to put the timing into the endbell versus the commutator, but the advance of the endbell has it's limitations depending on the "height" of the endbell in regards to its position of advance or retard.

So while a Parma Rotor motor typically has 18 degrees of comm timing... advancing the endbell "CLOCKWISE" will increase the brush timing/firing position around 7 degrees.

Another thing that some think... a smaller comm diameter DOES NOT increase timing, but it does increase the "dwell" time of the firing of the brush in regards to the comm and this also can make a motor run faster than a larger comm.

Just think vertical versus horizontal brushes.

[Guy Spaulding]

Don`t you dare say anything bad about Parma here or you`ll get put in time-out!

Mike, are you saying that from personal experience?

[Cheater]

Yes, he is.

[Phil Smith]

Another thing that some think... a smaller comm diameter DOES NOT increase timing...

A smaller comm would definitely advance timing. An extreme example:Think of a 1" brush on a 1" comm. The brush would cover 180 degrees on the comm. So the smaller the comm is in relation to the brushes, the sooner the brush would contact a comm segment, thus advancing the timing.

[Ron Hershman]

Ummmm no....... you are changing the dwell and "duration" of firing the comm segment(s).... what you are changing is the firing point/time and duration of segment being powered.

You are NOT increasing commutator timing/position with brush size.

Again...horizontal versus verticle brushes......... just changing firing point/time of the armature/commutator.

Remember the comm position DOES NOT change.

Unless you physically change/advance the position of the comm in regards to the arm stack/blank.