[dgersh]

Thanks for explanation 300, that helps; and true, I didn't specify that the X12 is C-can, so only 16D by extension....

But the question really was: does the FK130 have as big a difference in startup and normal amp draw as some of these older motors?

Don

 

[Jimmy in Greece]

QUOTE Torque changes with motor speed, it generally gets less as motor speed increases. With increasing timing the torque doesn't fall as steeply as the motor speed increases. This means that at medium - high rpm, a motor with timing produces more torque (NOT less) than a similar motor with zero timing. In circuit racing the car spends a lot of the lap in medium to high rpm where timed motors give more torque than zero timed motors. The car spends very little time staring form rest when zero timed motor give more torque.
300SLR, You make a fair point but to go a bit further; The whole purpose of comm timing, as I understand it, is to reduce the inefficiency caused by the stator(magnetic) field being distorted by the rotor field as the armature rotates. By reducing this distortion through comm advancement the rpms of the motor increase. We don't use comm advancement, generally, to purposely change torque character.What you refer to as torque increase is in fact torque movement to a different rpm band. While it could be argued that this increases the torque in the (useable) range you don't use comm advance specifically to increase torque because it doesn't to any great extent. Torque can only be increased by changing wind character (size and/or number of turns), magnet field character (stronger field or reduced air gap), rotor (armature) charactor (diameter, length, arc radius of each pole, etc.), brush charactor (radius, width, material, etc), comm charactor (diameter and segment gap) and externally, gearing as torque multiplier/divider and to a lesser extent, tire diameter. Stronger magnets is a simple way to gain torque in a motor. But for our purposes we generally tune for torque at the axle by changing gears and when that isn't enough, going to a different motor altogether that has changes to one or more of the motor components listed above.
You assumption that comm advancement is desirable because motors spend much of their time in rpm areas where it is desired is a little misleading. On large tracks with long straights you may have a point but, on smaller tracks with tighter turns and on many rally circuits this may not be the case. It it far more desirable to tune for torque with gearing in this case. IMHO Am I too far off base here? Jimmy

 

[300SLR]

"Does the FK130 have as big a difference draw as some of these older motors?"
Are you talking about % difference or numbers of amps different.

Generally the difference in number of amps drawn is larger in higher current motors.

However, even the hottest FK130 (and other low end type motors) have much lower "free running" current than higher end modern motors. So the "free running" current is often a larger percentage different from the stall current in the hottest FK130 than in the higher end modern motors.

Perhaps I should explain I'm comparing free running at low voltage because some motors are likley to be damaged by free running at full voltage, indeed for higher end modern motors the makers generally don't give a RPM rating and quite a few warn you never to free run the motors on full voltage. I have done detailed measurements modern motors including modern C can and 16d motors, I don't know how the older versions of these motors compare.

 

[300SLR]

COMM Timing
Hi Jimmy - at the risk of going off topic ... OK lets go further into motor tuning.

Indeed there is no "one size fits all" set up that's best for all tracks. Part of the skill in tuning slot cars is changing things to work best on different tracks. Comm timing is one way to change a motor's characteristics, zero advance may well be best for some sorts of car/motor on some sorts of track, at the other extreme over 45 degrees advance is best suited for others.

Comm timing is but one of the "tools" in the motor tuners "tool box" - you've listed quite a few others in your post. I very skeptical about theoretical ways of calculating how much comm advance is best for particular circumstances. Everyone I've come across who's any good at motor tuning starts with experience of what works, then uses that knowledge to try and go quicker. Experience means what they learn form other tuners' experience as well as their own testing. A few come up with theories about why it works.

There are several explanations as to why comm timing makes a difference. One of them is to do with the current through the windings needing to reverse every half rev. The inductance of the winding means the current cannot reverse instantaneously. At low revs this doesn't matter but at high revs starting to changing early means it is nearer right more of the time. This is one way of explaining the practical observation that other things being equal, high timing arms go better at high revs and low or zero timed arms go better at low revs. Two illustrations of this are
A really high timing arm running backwards struggles to get up any significant speed, where as running forward it accelerates from rest very rapidly.
A zero timed arm runs out of torque to make the car go any faster at high revs, where as an otherwise identical high timing motor in an otherwise identical car has plenty of torque to keep the car accelerating to higher speed.

 

[Professor Fugly]

Hi Don,

QUOTE (dgersh @ 15 Aug 2016, 05:21) <{POST_SNAPBACK}>Hmm, much ado about nothing?

I'm starting to think so.

In fact, good question about these kinds of motors, with which I'm not familiar: do they draw as much extra current on startup as some other slot motors?

It's a wide range in the FK motor specs but generally, the same or more than an old FT13 or FT16. Less than any modern (1970s and up) C or D can motor.

The FK motor Poly-Neo magnets is where the additional current draw and torque output comes from.

For instance, when we were running X-12 powered (high-end production 16D size motors) 1/24 scale cars, they could draw something like 8 or 10 amps on startup, but that would drop to maybe 3 amps when running (figures off the top of my head, don't guarantee them, but that was the general spread). Don

 

[Professor Fugly]

QUOTE (300SLR @ 15 Aug 2016, 06:10) <{POST_SNAPBACK}>Yes X12 generally take a bit more current than the hottest FK130 motors. The Fox will take considerably less and the really quick slot car motors take considerably more current. It rather sounds like the motors dvd3500 is talking about are not the hottest FK130. The fastest production FK130 motors I know of are wound with 29awg, the same gauge of wire as a X12. The X12 has a shorter stack, less turns and better brushgear so takes a higher stall current. As with all slot car motors, the running current depends on how fast it is running, so current changes as it goes round the lap. The average running current is generally higher with an X12 Although an X12 arm would fit in a 16D, the standard X12 motor has a C can. C can motors are a little smaller and quite a bit lighter than modern 16d motors. They are usually built to the USRA spec which specifies minimum internal can dimensions, so the external size varies a bit depending on the can thickness.

Which FK130 motor model is wound with #29 AWG?

Thanks in advance.

 

[dvd3500]

QUOTE Hmm, much ado about nothing?

I'm starting to think so.

I dunno... they were not super BFFs or anything but it will be interesting when the next race happens how things go

 

[Professor Fugly]

QUOTE (dvd3500 @ 8 Aug 2016, 13:20) <{POST_SNAPBACK}>The Series is very strict. No magnets, all the same chassis, body etc. the only difference is tire radii (due to sanding), color of the cars and how many LEDs they have. They all have t have 2 in front and 2 in back with a gold cap so that when they do night races they can see the cars.

So the only real difference is maybe 2-3 grams of weight and the tires... Neither of f which would explain 1 amp me of pull (I am guessing.., it is all voodoo to me) And yes, he has been winning every race and by a margin of 1-2 seconds per lap.

Is that car:

A- killing you on the straights,

B - has better brakes and can drive deeper in to the turns,

C - kills you in the turns

all of the above?

 

[300SLR]

QUOTE (Professor Fugly @ 15 Aug 2016, 15:16) <{POST_SNAPBACK}>Which FK130 motor model is wound with #29 AWG?
The Trinity Evil 9 and Fast Ones Demon are both 60 turns of 29awg

 

[dvd3500]

QUOTE Is that car:

A- killing you on the straights,

B - has better brakes and can drive deeper in to the turns,

C - kills you in the turns

all of the above?

Yes


I don't race with the guys yet..I am too carp. I have only ever seen one race there so I can't be sure.

 

[Professor Fugly]

QUOTE (300SLR @ 15 Aug 2016, 11:34) <{POST_SNAPBACK}>The Trinity Evil 9 and Fast Ones Demon are both 60 turns of 29awg

We raced those.

Just spoke to the Evil one himself, Tony P. who I raced with in IRRA retro including the Evil-Flexi GT Coupe classes and we were team mates here in the Evil-9 GT-1 flexi enduro.

Tony managed Trinity since the beginning and Trinity was the importer of both the 'Evil-9' and relabeled 'The Demon'.

Ron Hershman owner of Fast Ones and Ernie Provetti owner of Trinity collaborated on the specs for these motors.

The answer I just got from Tony is 60 turns of 30 wire using a different slightly 'softer' brush material than the TSR-D3, Falcon 7, Hawk 7 or other FK130s run here in retro. The motor was not approved for IRRA retro due to the 60 turns as 65 turns nominal was the minimum allowed.

Without any reason to doubt Tony P. ... I have a call into Ron H. who created the spec to confirm/concur 60T/30W.

I built, painted, crew chiefed and Still have the Enduro Car

https://www.facebook.com/media/set/?set=a.4...mp;l=82f1d2a3f4

 

[Professor Fugly]

Just heard back from Ron Hershman - "60 turns of 30"

 

[300SLR]

QUOTE (Professor Fugly @ 15 Aug 2016, 17:46) <{POST_SNAPBACK}>The answer I just got from Tony is 60 turns of 30 wire using a different slightly 'softer' brush material than the TSR-D3, Falcon 7, Hawk 7 or other FK130s run here in retro. The motor was not approved for IRRA retro due to the 60 turns as 65 turns nominal was the minimum allowed.
Just heard back from Ron Hershman - "60 turns of 30"
The ones that appeared in the UK were 60 turns of 29. How do I know that?
The samples of the Trinity Evil 9 and Fast Ones Demon supplied by a UK importer were stripped and measured by BSCRA in 2013. They were not approved approved for BSCRA racing. The details of the strip down are on the BSCRA web site. The samples of Trinity Evil 9 and Fast Ones Demon were both 60 turns of 0.29mm diameter wire (approx 29 awg). The Falcon 7s measured were all 65 turns of 0.255mm diameter wire (approx 30 awg).

 

[acboother]

I produced a prototype that measured the current drawn and summed it as the car consumed it. Distinctly different approach to measuring the trigger position or voltage over time... or even peak current.

Basically this is 'fuel' consumption. A more powerful motor would use more fuel, faster.

Now set a limit on the amount of fuel that can be used -> this is the 'fuel tank'.

When the fuel runs out you can decide to do something - perhaps stop the car, make it go slow until a time period when the tank fills itself or something else.

Greedy motors run the risk of running out of fuel. Let them be used at the driver's risk/decision.

 

[Professor Fugly]

QUOTE (300SLR @ 15 Aug 2016, 17:23) <{POST_SNAPBACK}>The ones that appeared in the UK were 60 turns of 29. How do I know that? The samples of the Trinity Evil 9 and Fast Ones Demon supplied by a UK importer were stripped and measured by BSCRA in 2013. They were not approved approved for BSCRA racing. The details of the strip down are on the BSCRA web site. The samples of Trinity Evil 9 and Fast Ones Demon were both 60 turns of 0.29mm diameter wire (approx 29 awg). The Falcon 7s measured were all 65 turns of 0.255mm diameter wire (approx 30 awg).

Was it stripped to bare wire or measured with the Polythermaleze insulation still on? The correct tool for that kind of stripping is specific sized Clauss No-Nik. Not an Exacto knife or razor blade.

There was only one production run of 10,000 of these Trinity motors. One lot.

I have seen this http://www.slotcarracing.org.uk/motor/analysis.html

The word nominal also comes into play for both the bare wire and the insulation thickness.

I trust the word of the guys that put up the big "Evil Bucks" that know what they ordered... although, for what it's worth I Do Not trust the chinese at all.

AWG Size

30

full Spec-

http://wire-cable-tubing.wireandcable.com/...wire/item-14473

 

[Guest]

QUOTE (dvd3500 @ 15 Aug 2016, 16:17) <{POST_SNAPBACK}>I dunno... they were not super BFFs or anything but it will be interesting when the next race happens how things go
Please remember the first rule in competition: "the organisation is always fastest". If not rules will be changed until the first rule applies

 

[Professor Fugly]

QUOTE (Henk @ 15 Aug 2016, 23:31) <{POST_SNAPBACK}>Please remember the first rule in competition: "the organisation is always fastest". If not rules will be changed until the first rule applies

True dat... but we're told it's "in the best interest of the hobby"