This old chestnut! Sport Tuned Motors - advanced timing or not.

[mtbkym01 4008]

24 minutes ago, sosidge said:

Because of the way that a sealed can motor mounts the brushes (pivoting in an arc rather than sliding in a straight line), as it breaks in, the "forward direction" gains RPM while the backwards direction loses it.

So this is normal behaviour of a broken-in motor.

The Sport Tuned doesn't have any advance in it -  or at least no more advance than any other sealed can motor. The brushes are in-line with the centre of the magnets on a new motor. You can see this just by looking at a new motor through the vents.

So you can run them in a reverse-rotation setup if you want.

(Source: I stripped down the motor in the blog post earlier)

Excellent, so I’m good to go with my Sport Tuned Motors in my Clod? New truck and new motors? Great news

**edit - how can @Juggular result with the new silver Sport Tuned motor be explained though, that had a significant speed difference between the 2 directions 🤔

[Falcon#5 594]

4 hours ago, Toolmaker72 said:

I’ve noticed no one has measured the wire diameter to determine the cross sectional area of the copper.  It’s all very well saying 23 turn, 25 turn, 27 turn, but unless you know the cross sectional area of the copper you can’t compare like for like and that’s before you start playing with the timing.  

https://fiveeight0sixsix.wordpress.com/2017/04/25/inside-the-tamiya-sport-tuned-motor/ - 'I ground off the tab that held one coil in place. There were 23 turns of 0.75mm wire wrapped around the armature.'

Going by that = 0.44179mm2

 

[Toolmaker72 507]

Now you can compare that with another motor.  Well provided the wire diameter is measured together with the amount of turns.

When I was a kid my dad explained how to make the motor spin faster.  Firstly with scalextric motors, then a bog standard 540 motor.  That was without changing the timing.   
Also the gap between the armature and magnet also plays a part.  So again for a direct comparison you need to know the gap.  I’m sure the smaller the gap, you get extra torque as well as rpm.  Well the old man made a hot 540 from a bog standard motor so I could wizz a hornet around to keep up with my mates technigold powered boomerang.  It did wear out quick,  well the standard bronze bearings got too hot and melted the rear plastic end bell.  So he went out and bought me a new motor that specifically had an aluminium end bell.   Over 34 years later I still have that aluminium end bell motor. 😊

[Juggular 4964]

12 hours ago, sosidge said:

The Sport Tuned doesn't have any advance in it -  or at least no more advance than any other sealed can motor. The brushes are in-line with the centre of the magnets on a new motor. You can see this just by looking at a new motor through the vents.

Thank you for suggesting that. That was a good idea. 

The brushes are mounted at different angles.  Magnet spacers and the windows are at the same point, but the brushes are mounted at an angle.  In the photo, it's only showing the mounting pin for the brush.  But the point is that they are at a different angle.  Which means the timing is different.  

This could explain 11% faster speed one way for Sport Tuned (brand new, unused before testing).  But the (used) 540 only had 2% discrepancy (which is a normal behavior, as you explained).  

 

[sosidge 624]

10 hours ago, Juggular said:

Thank you for suggesting that. That was a good idea. 

The brushes are mounted at different angles.  Magnet spacers and the windows are at the same point, but the brushes are mounted at an angle.  In the photo, it's only showing the mounting pin for the brush.  But the point is that they are at a different angle.  Which means the timing is different.  

This could explain 11% faster speed one way for Sport Tuned (brand new, unused before testing).  But the (used) 540 only had 2% discrepancy (which is a normal behavior, as you explained).  

 

That's really interesting, I didn't realise Mabuchi were manufacturing endbells with different advance for different motors, I'll have to take a closer look at that the next time I have a Sport Tuned in my hands.

[mtbkym01 4008]

14 hours ago, Juggular said:

Thank you for suggesting that. That was a good idea. 

The brushes are mounted at different angles.  Magnet spacers and the windows are at the same point, but the brushes are mounted at an angle.  In the photo, it's only showing the mounting pin for the brush.  But the point is that they are at a different angle.  Which means the timing is different.  

This could explain 11% faster speed one way for Sport Tuned (brand new, unused before testing).  But the (used) 540 only had 2% discrepancy (which is a normal behavior, as you explained).  

 

Hey @Problemchild, would you mind comparing your “budget” Sport Tuned Motors to this pic above and see where your brushes are? I checked my “non budget” versions to the stock silver cans and there is a slight difference I think, but not as obvious as this image above.

[mtbkym01 4008]

Additionally in those pics, you can see the power lead position aligns perfectly with the brush mounting pins, so this may be an easy tell tale too?

[kwkenuf 184]

I was going through an auction site this morning and came upon a brushed motor with adjustable timing...

https://www.ebay.com/itm/HobbyStar-540-5-Slot-Brushed-Crawler-Motor-Waterproof-16T-RC-Truck-1-10/174124621075

The specs claim up to 4S voltage (if I'm reading that correctly) and an RPM of 13,700 for the 16T version.  There are also 11T, 13T, and 20T versions.

I thought this was interesting. 

[Otis311 196]

15 minutes ago, kwkenuf said:

I was going through an auction site this morning and came upon a brushed motor with adjustable timing...

https://www.ebay.com/itm/HobbyStar-540-5-Slot-Brushed-Crawler-Motor-Waterproof-16T-RC-Truck-1-10/174124621075

The specs claim up to 4S voltage (if I'm reading that correctly) and an RPM of 13,700 for the 16T version.  There are also 11T, 13T, and 20T versions.

I thought this was interesting. 

Adjustable timing, while a novel idea, is nothing new. What's more interesting about those motors is the fact that they are 5 slot rotors vs the typical 3, they are skewed as well . That's a newer concept as far as RC motors go. It's a result of the demand for higher torque crawler motors.

[Toolmaker72 507]

1 hour ago, mtbkym01 said:

Additionally in those pics, you can see the power lead position aligns perfectly with the brush mounting pins, so this may be an easy tell tale too?

I was going to point that out.  The earlier plastic end bell motors used to have 3 notches cut into the back of the motor can. Neutral, +timing and -negative. 

[Toolmaker72 507]

37 minutes ago, kwkenuf said:

I was going through an auction site this morning and came upon a brushed motor with adjustable timing...

https://www.ebay.com/itm/HobbyStar-540-5-Slot-Brushed-Crawler-Motor-Waterproof-16T-RC-Truck-1-10/174124621075

The specs claim up to 4S voltage (if I'm reading that correctly) and an RPM of 13,700 for the 16T version.  There are also 11T, 13T, and 20T versions.

I thought this was interesting. 

Because these are 5 sets of windings the amount of turns cant be directly compared to a rotor with 3 sets of windings of the same amount of turns.  The 5 slot rotor will rotate slower than a 3 slot rotor with the same number of turns and with the same diameter wire used. 
As mentioned already, adjustable timing on brushed motors isn’t new but what made the Tamiya technigold motor so usable.    I’ve got an old Parma cyclone and kyosho gold with adjustable timing and as a kid it was like adding turbo boost at the top end 😊.  Lots of hours of running and adjusting for max speed or max battery life.  

[mtbkym01 4008]

Decided to grab a couple of the “budget” Sport Tuned as linked by @Problemchild earlier in the thread. I will be able to compare the timing on these to the stockers and the “non budget” Sport Tuned that I’ve already got. If they won’t work, then I can use them in other builds in the future.

[Problemchild 2149]

14 minutes ago, mtbkym01 said:

Decided to grab a couple of the “budget” Sport Tuned as linked by @Problemchild earlier in the thread. I will be able to compare the timing on these to the stockers and the “non budget” Sport Tuned that I’ve already got. If they won’t work, then I can use them in other builds in the future.

Will be good to have you experimental evidence based assessment vs my motor in hand assessment

JJ

[ChrisRx718 4470]

Whilst on the subject, are Tamiya Torque tuned motors zero timing? Ie. I can run one in a dual motor setup without anything being unhappy?

[mtbkym01 4008]

On 5/1/2020 at 9:50 PM, ChrisRx718 said:

Whilst on the subject, are Tamiya Torque tuned motors zero timing? Ie. I can run one in a dual motor setup without anything being unhappy?

I’ve never seen a Torque Tuned myself, so can’t answer

[Juggular 4964]

Out of curiosity, I tried to add magnets to the motor.  

Stock 540 silver can (old) showed 8800 RPM (at 3.7v).  

1 pair of slabs added: 9300 RPM (at 3.7v) Just 5% increase. 

2 pairs of slabs: 9500 RPM 

3 pairs of slabs: 9700 RPM (this would be similar to Torque Tuned because it's about 10% faster than stock silver can)  

4 pairs of slabs: 10100 RPM (I don't know why it went up by 400)

5 pairs of slabs: 10300 RPM  (17% increase after adding so much weight)

Didn't try 6 pairs, but assuming it jumps another 200rpm, it would be 10500.  

Above was without advanced timing.   

Sport Tuned was 11100 RPM forward, 9900 backward at 3.7v.  (Average of forward and backward =10500)  

These are fairly strong rare earth magnets.  I was surprised that it took 6 pairs to be as strong as Sport Tuned.  

 

Conclusion:  Just buy Sport Tuned; it's about 25% faster.  

 

[graemevw 823]

I wonder if they used better magnets in a sport tuned then? Dont suppose anyone has a new, opened sport tuned and silver cans and also has a motor flag?

 

[Toolmaker72 507]

3 hours ago, graemevw said:

I wonder if they used better magnets in a sport tuned then? Dont suppose anyone has a new, opened sport tuned and silver cans and also has a motor flag?

 

Magnets are the same, it’s down to wire gauge and number of turns.  

[Juggular 4964]

10 hours ago, graemevw said:

I wonder if they used better magnets in a sport tuned then? Dont suppose anyone has a new, opened sport tuned and silver cans and also has a motor flag?

 

I got 11500 RPM with 1 pair of magnets on Sport Tuned (as opposed to 11100 RPM).  It seems about the same amount of improvement as the silver can.   

But, I found a problem with adding magnets.  

I think it likes the same polarity, which might weaken the magnet inside.  It goes faster when the magnet seems to repel more. Which seems counter intuitive.  + to - and - to + is how magnets attach.  But that would only show a small increase, like 30RPM.  If I flip the magnets, it jumps 400rpm. (because of the steel motor can, it attaches either way)   

I'm wondering attaching a slab in the middle would break one magnet into 3 magnetic segments.  It could boost magnetism temporarily.  It's just my guess, but in the long run, I'm afraid this could mess up the magnets inside.  

6 hours ago, Toolmaker72 said:

Magnets are the same, it’s down to wire gauge and number of turns.  

I was nodding in agreement. Then I figured, "wait a minute, I should be able to test it." 

This pin was magnetized. (I didn't want to lose the pins, so I stuck them to a magnet)  One side of the pin should move when I get the motor closer.  Alternatively, I rolled the pin toward the motor too.  

Interestingly, Sport Tuned has much stronger magnets.  

It can affect the pin as far as an inch.  If I roll the pin, it would go from vertical to horizontal at about 3/4 of an inch.  

The pin wouldn't do that to the silver can until it got far closer.  Generally within about 1/2 inch to 1/4 inch.  

So the magnets must be different.  Quick Googling also showed that there are different grades in magnets depends on how they mix the ingredients when they make the magnets.  

Thanks to you guys, I'm discovering all kinds of things about 540 motors!  

 

[Toolmaker72 507]

Another thing to consider is how old or new the magnets are.  Magnets do deteriorate over time.  The 550 size motors have a metal sleeve which slides over the outside.  This keeps the magnets fresh for longer when the motor isn’t being used.  Higher end motors do use different types of magnet which give a stronger magnetic field to help produce a higher performance motor.  

[graemevw 823]

9 hours ago, Juggular said:

I got 11500 RPM with 1 pair of magnets on Sport Tuned (as opposed to 11100 RPM).  It seems about the same amount of improvement as the silver can.   

But, I found a problem with adding magnets.  

I think it likes the same polarity, which might weaken the magnet inside.  It goes faster when the magnet seems to repel more. Which seems counter intuitive.  + to - and - to + is how magnets attach.  But that would only show a small increase, like 30RPM.  If I flip the magnets, it jumps 400rpm. (because of the steel motor can, it attaches either way)   

I'm wondering attaching a slab in the middle would break one magnet into 3 magnetic segments.  It could boost magnetism temporarily.  It's just my guess, but in the long run, I'm afraid this could mess up the magnets inside.  

I was nodding in agreement. Then I figured, "wait a minute, I should be able to test it." 

This pin was magnetized. (I didn't want to lose the pins, so I stuck them to a magnet)  One side of the pin should move when I get the motor closer.  Alternatively, I rolled the pin toward the motor too.  

Interestingly, Sport Tuned has much stronger magnets.  

It can affect the pin as far as an inch.  If I roll the pin, it would go from vertical to horizontal at about 3/4 of an inch.  

The pin wouldn't do that to the silver can until it got far closer.  Generally within about 1/2 inch to 1/4 inch.  

So the magnets must be different.  Quick Googling also showed that there are different grades in magnets depends on how they mix the ingredients when they make the magnets.  

Thanks to you guys, I'm discovering all kinds of things about 540 motors!  

 

Im not surprised the magnets are stronger in the sport tuned.

The extra magnets on the outside might cause all kinds of issues. According to a motor builder i know its the field at the ends of the magnets that matters, adding smaller magnets will/may? Move the magnetic field? I dont know, magnetism confuses me 😂

But with an empty can and a motor flag you can feel how strong the magnets are, if there is a dead spot in the middle or not, and if the field is centered. Magnets not only loose power but the centre point moves which is also not good.

I was at my motor builders a couple of months back re zapping a load of old motors and we were talking alot about this kind of thing, not all the info went in though 😂

[waterbok 1282]

On 4/26/2020 at 10:50 AM, Toolmaker72 said:

I’ve noticed no one has measured the wire diameter to determine the cross sectional area of the copper.  It’s all very well saying 23 turn, 25 turn, 27 turn, but unless you know the cross sectional area of the copper you can’t compare like for like and that’s before you start playing with the timing.  

I disassembled a ST last week, 23 wires and .75mm, had the long pinion shaft

[Juictetin 10]

23 minutes ago, waterbok said:

I disassembled a ST last week, 23 wires and .75mm, had the long pinion shaft

Was this a black can or newer silver can?

[waterbok 1282]

6 hours ago, Juictetin said:

Was this a black can or newer silver can?

Old black one, it lost one of its brushes so I took a peek inside.

[Toolmaker72 507]

So reading this thread there doesn’t seem to be any comparisons to prove number of turns x wire cross sectional area being the deciding factor of a motors potential rpm.  
So I’ve measured the wire diameter on a couple of rebuildable motors.

a 19 turn stock motor

a 27 turn stock motor 

and compared to the latest post above with a black can Tamiya sport tune 23 turn motor.

With no load my 19 turn stock audibly spins slower than the 27 turn version.

wire measurements below.

After calculating the cross sectional area of the wires and then multiplying by the number of turns this gives the total cross sectional area of the copper per winding. Each of these motors has 3 windings so if magnets and timings were all the same the motor that would spin faster is the one with the lower total cross sectional area of copper per winding.

In this case my 27 turn motor actually has the smallest amount of copper surface area and does spin faster than the same brand, timing and can magnet 19 turn version.

What I’m trying to prove is that you can’t rely on a motors performance by simply referring to the turns per winding.  
The measurements I’ve used show the motor with the potential higher rpm for voltage is a 27 turn then the 19 turn then the 23 turn.  All being rotors with 3 windings.  
Of course adjusting the brush timing, magnet type and gap between the spinning rotor and magnet, brush carbon softness will all affect rpm and torque, but for arguments sake and all things being equal the number of turns within the motor does not say if the motor is a slouch or rev master  🙂.  Hope that makes sense