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SPSF posted:

Dumb question:  Aren't brushless motors prone to cogging at low RPM?

Most brushless motors I've seen are on high RPM applications: RC vehicles and Airplanes, weed wackers etc.  Except for a drill, but how long are you drilling something at a low speed compared to a train going around a layout at a low speed.

Historically, the major issue with synchronous or single phase asynchronous motors was that at 0 rpm they produced 0 torque. Thus, they were inherently not self-starting. Another motor was used to spin up the rotor and then disengage once the rotor was at speed. Asynchronous motors solved the problem by using 3-phase and such motors produce a tremendous amount of torque at 0 rmp as shown by the asynchronous motors used in a diesel electric locomotive. Synchronous motors with VFD the feeding frequency is so long that the motors can self start. For asynchronous motors, cogging has never really been an issue. For synchronous motors one can design the motor to have very strong cogging as in the case of a stepper motor or minimized cogging depending upon the application. 

My weed wacker has VFD. I can control the speed of the rotor by how much I pull the trigger, and as it says it is all digital so it is going through a VFD seed controller. 

Ever looked inside a cordless drill?  There is a fairly significant gear train, so the motor doesn't run all that slowly at it's slowest speed.  Same goes for jigsaws, never saw a circular saw that had ultra low speed, no point in it.

Besides, I suspect it "could" be done for model trains, the real question would be, is there something to gain?

Last edited by gunrunnerjohn

Ever looked inside a cordless drill?  There is a fairly significant gear train, so the motor doesn't run all that slowly at it's slowest speed.  Same goes for jigsaws, never saw a circular saw that had ultra low speed, no point in it.

LOL, yes I have. Corded ones too. And various types of saws.
Yes they have gear trains, so do most of the electric trains I've seen.
The motors in corded tools still run over a wide range of speeds and have lots of torque.

I don't think I've seen a variable speed circular saw.

gunrunnerjohn posted:

is there something to gain?

Since the question is singular, the response will be singular.

What is gained is what is eliminated. What can be eliminated by going to a brushless motor is the motor shroud that occupies most of the cab. What is gained by elimination of the motor shroud by adopting a brushless motor system is a completely detailed cab interior. 

This was fun, but time to do something else with life. 

Lou N posted:
gunrunnerjohn posted:

I say again, where are the O-gauge products if it's so simple?

Simple answer:  weed whacker=off/on/off/on

Model train:  infinitely variable from 2SMPH to 100SMPH and absolutely linear with no low speed aberrations.

And with due respect to Jim R and his vast knowledge, the commercial slot race setups and their associated controllers approach the operational method of:  off/on/off/on; or on/coast/on/coast.

Lou N

Sorry, Lou. Traxxas vehicles are radio control free-roaming vehicles. Not slot cars. 

The benefit of brushless motors in RC cars is speed. Using a realistic gear ratio for a brushed motor, most 1/10 scale RC cars top out at 35 mph. Brushless motors of the same model achieve 50 mph. 

That’s why brushless has blossomed so nicely in the RC world. 

I think the reason they haven’t found their way into the toy train world is, as John suggests, because there is no major benefit against the costs involved. 

From what I’m reading here, I’m not sure I understand why Lionel, MTH, Atlas or Bachmann needs to consider brushless. 

Perhaps those advocating their use could explain the great advantage specifically to toy trains.

Last edited by Jim R.

LOL Jim, I'm still waiting for the reasoning why that any of the major train manufacturers should consider brushless motors.  I certainly believe it's possible, but if MTH or Lionel saw the wisdom or a competitive advantage worth the engineering effort, I'm sure we'd see them pop up on new models.  The fact that we haven't suggests that they don't see any cost/benefit tradeoff, something that every company that want's to make a profit has to consider.

Brushed motors are still preferred in some RC vehicles, or so I have been told (I'm fairly new to this). My grandson's 1/10 scale rock crawler/off road RC truck has a brushed motor that will still run submerged. They also have very good performance at very slow speeds. They like to run these things slowly through anything that is muddy, awkward, or wet and deep. I have been told the brushless motors won't do water so well and won't run submerged, but we have never tried brushless, only brushed on the advice of others. Also, if you have any money left after all your train purchases, get into this hobby and you will be relieved of any extra funds in short order. 

gunrunnerjohn posted:

LOL Jim, I'm still waiting for the reasoning why that any of the major train manufacturers should consider brushless motors.  I certainly believe it's possible, but if MTH or Lionel saw the wisdom or a competitive advantage worth the engineering effort, I'm sure we'd see them pop up on new models.  The fact that we haven't suggests that they don't see any cost/benefit tradeoff, something that every company that want's to make a profit has to consider.

Here's some thoughts GRJ....

Mabuchi has multiple plants each making over a million motors a day.  Hing Lung does a Chinese knock off.  I have seen "380" size motors in the OEM market place for as little as 2 cents each.  The HO guys, who have a vast variety of DCC boards available to them, still use can motors. 

The three rail market doesn't need one more semi-reliable electronics board installed in their trains.  

And thanks Jim R for your clarification and insight on R/C motor usage.

Lou N

A little off topic, but boy is this an understatement

"Also, if you have any money left after all your train purchases, get into this hobby and you will be relieved of any extra funds in short order."

I always get a little kick when the usual bit**** and moaners write about the "high" cost of this hobby. All I read from these basement Barney's is that they don't get out very much. 

RTR12 is right on the money, with a similar commitment, this hobby is way less expensive then RC planes or cars.

Charlie

Lou N posted:
gunrunnerjohn posted:

LOL Jim, I'm still waiting for the reasoning why that any of the major train manufacturers should consider brushless motors.  I certainly believe it's possible, but if MTH or Lionel saw the wisdom or a competitive advantage worth the engineering effort, I'm sure we'd see them pop up on new models.  The fact that we haven't suggests that they don't see any cost/benefit tradeoff, something that every company that want's to make a profit has to consider.

Here's some thoughts GRJ....

Mabuchi has multiple plants each making over a million motors a day.  Hing Lung does a Chinese knock off.  I have seen "380" size motors in the OEM market place for as little as 2 cents each.  The HO guys, who have a vast variety of DCC boards available to them, still use can motors. 

The three rail market doesn't need one more semi-reliable electronics board installed in their trains.  

And thanks Jim R for your clarification and insight on R/C motor usage.

Lou N

I wanted to put a 😉 in earlier in my reply but I just figured out that my iPhone prefers that I start typing “wink” before it gives me the quick-click option. 

Charlie posted:

A little off topic, but boy is this an understatement

"Also, if you have any money left after all your train purchases, get into this hobby and you will be relieved of any extra funds in short order."

I always get a little kick when the usual bit**** and moaners write about the "high" cost of this hobby. All I read from these basement Barney's is that they don't get out very much. 

RTR12 is right on the money, with a similar commitment, this hobby is way less expensive then RC planes or cars.

Charlie

Some personal insight....

When I worked at Hobby House (late 60's early 70's) we were also the largest RC shop in Ohio.  We had a well to do clientele that were spending big $$$ on the first digital proportional radio gear for their planes.  We even had a board in the back room that kept track of field crashes.  Known as the Star Crashers, we had one guy auger in five planes in a year.  They laughed it off.

 And what I learned from the late Dean Bennett, Marketing Manager at Kalmbach:  the most expensive segment of model railroading is G gauge, especially the live steam part.  Also the most $$$ spent is in the Doll House category.  Many little old ladies like to recreate their childhood homes and he saw one purchase a grand piano for her doll house.  No music, no nothing but a static display.  Nine grand!

We are all in a very reasonably priced hobby by comparison.

Lou N

(Jim R: maybe you heard Dean tell some of those stories way back).

Jim R. posted:
C W Burfle posted:

Brushless motors seem to be common and relatively inexpensive in cordless power tools these days. I wonder whether Lionel or any of the other manufacturers will take a new look at using them.

And RC cars, too. At the hobby shop where I work part time, sales of the brushless motor version of Traxxas vehicles have ballooned in the past four years.

A brushless version cost about $100 more than the same vehicle with a traditional motor, but that’s not a problem for experienced hobbyists who want higher-end maximum speed out of their RC cars.

Just curious, does anyone still make reversing ESC's for brushed DC motors ? I was looking into upgrading some toy-grade R/C's (transit/intercity buses--not exactly a common sight) from their on/off style throttle+steering and recall having a tough time finding suitable ESC's for the plain-vanilla DC motors found in these.

---PCJ

gunrunnerjohn posted:
Lou N posted:
Mabuchi has multiple plants each making over a million motors a day.  Hing Lung does a Chinese knock off.  I have seen "380" size motors in the OEM market place for as little as 2 cents each. 

I don't know how you can make any motor and sell it for two cents!  That's totally insane, especially for a 38x sized motor!

End of Life; single shafted motors.  So you couldn't mount a flywheel.  Regardless, quantity pricing was previously under a dollar.  

And they were Mabuchi.  

Lou N

RailRide posted:

Just curious, does anyone still make reversing ESC's for brushed DC motors ? I was looking into upgrading some toy-grade R/C's (transit/intercity buses--not exactly a common sight) from their on/off style throttle+steering and recall having a tough time finding suitable ESC's for the plain-vanilla DC motors found in these.

---PCJ

Tons of DC reverse units available, you can buy them for as little at $15 direct from Lionel.  They also show up all the time in the for-sale area here.  I'm sure I have some in my parts box, send me an email if you're looking for something specific.

romiller49 posted:

When I saw the Odyssey motor under the Lionel tent many years ago I was amazed, but somehow, something got in the way of it. I wish Lionel would take another look. 

If I recall the general sequence of events, the complexity got in the way of it and then the electronic solution ("Odyssey System" rather than "Odyssey Motor") replaced it and that was that.   Lionel was shooting for functionality, so once they managed to get what they were after with the electronic boards (less a hiccup or 2, like "Odyssey Lurch" in very early engines), why would they waste even more resources chasing a solution that was hard or impossible to implement?  (or maybe even constrained by a patent on a previous product - I'm not familiar with that reference mentioned above)

gunrunnerjohn posted:

Looks like the whole motor to me!

That pic sort of looks like  a cartoon picture  of the motor with the post it on an actual physical shaft (black bar near the post-it).  

-Dave

gunrunnerjohn posted:
shawn posted:

Sure, would be better then a DC motor that fails and takes the electronics with it.

HUH?  How is that any better than the Odyssey motor failing and taking the electronics with it?  Note the driver board for the motor!

A01CD926-F061-4F62-9907-709D09A2E77E

"Brushless motors offer several advantages over brushed motors thanks to the design. Much of it has to do with the loss of brushes and commutator. Since the brush is required to be in contact with the commutator to deliver a charge, it also causes friction. Friction reduces the speed that can be achieved along with building up heat. It’s like riding your bike with the brake lightly applied. Given the same amount of effort from your legs, you’ll be slower. Conversely, if you want to maintain the speed, it will take more energy from your legs. You’ll also heat up your rims from the frictional heat. This means that brushless motors run cooler and more efficiently so they’re able to deliver more power.

The carbon brushes wear down over time. It’s what causes a spark inside some tools. In order to keep the tool running, the brushes have to be replaced once in a while. Brushless motors don’t require that maintenance. The combination of these benefits has another effect – a longer life."

Above, from a Makita article.

Plus, brushes aren't always used to contact the commutator on smaller motors. 

 

 

 

Last edited by shawn

There is also inertia involved when looking at new technology as well, companies are prone in many cases to stay with technology they understand and have a lot of experience with, and only switch when there is real reason to. So with a brushless motor, the question would be what is the advantage of a standard can motor...will it pull more, will it be more reliable, will it last longer, is it lighter (and is that even an advantage), is it cheaper? My dad told a story, he worked for Bell Labs in the 1950's, and in the early 1950's they were designing new generation amplifiers for use on long distance lines and undersea cables, if I remember the story correctly, and they were debating about whether to go with transister technology or vacuum tubes....and ended up deciding on vacuum tubes. While the transister being solid state had a much longer MTBF, generated a ton less heat, was smaller, you name it, they still went with transistors, and my dad's explanation was that at the time the operating parameters on vacuum tubes were pretty much known to the nth degree, they knew how much variance they would get, they knew their failure rates, they knew pretty much everything about them, and most importantly, the tubes themselves were common and plentiful; whereas transisters (at the time) were still pretty young (first operating transister was in 1948, this was maybe 5 years later or so), they hadn't worked out all the characteristics, were guessing on some of them, and they also were still not that plentiful...to us seems kind of obvious a transister would be better, but in terms of using it prob it took another 5 years or so before they got to that point I would hazard a guess. 

 

gunrunnerjohn posted:
RailRide posted:

Just curious, does anyone still make reversing ESC's for brushed DC motors ? I was looking into upgrading some toy-grade R/C's (transit/intercity buses--not exactly a common sight) from their on/off style throttle+steering and recall having a tough time finding suitable ESC's for the plain-vanilla DC motors found in these.

---PCJ

Tons of DC reverse units available, you can buy them for as little at $15 direct from Lionel.  They also show up all the time in the for-sale area here.  I'm sure I have some in my parts box, send me an email if you're looking for something specific.

I think you skipped a few words when reading my reply

To clarify, my question to Jim R. was regarding electronic speed controllers  (for radio controlled cars) with reverse. Many racing R/C speed controllers do not have a reverse mode, as this is disallowed in some (most? all?) sanctioned racing events. Many exist with just throttle+brake for this reason. Controllers with reverse are more for recreational R/C'ers, and are less common.

---PCJ

bigkid posted:

There is also inertia involved when looking at new technology as well, companies are prone in many cases to stay with technology they understand and have a lot of experience with, and only switch when there is real reason to. So with a brushless motor, the question would be what is the advantage of a standard can motor...will it pull more, will it be more reliable, will it last longer, is it lighter (and is that even an advantage), is it cheaper? My dad told a story, he worked for Bell Labs in the 1950's, and in the early 1950's they were designing new generation amplifiers for use on long distance lines and undersea cables, if I remember the story correctly, and they were debating about whether to go with transister technology or vacuum tubes....and ended up deciding on vacuum tubes. While the transister being solid state had a much longer MTBF, generated a ton less heat, was smaller, you name it, they still went with transistors, and my dad's explanation was that at the time the operating parameters on vacuum tubes were pretty much known to the nth degree, they knew how much variance they would get, they knew their failure rates, they knew pretty much everything about them, and most importantly, the tubes themselves were common and plentiful; whereas transisters (at the time) were still pretty young (first operating transister was in 1948, this was maybe 5 years later or so), they hadn't worked out all the characteristics, were guessing on some of them, and they also were still not that plentiful...to us seems kind of obvious a transister would be better, but in terms of using it prob it took another 5 years or so before they got to that point I would hazard a guess. 

 

This is very true. When I worked with Boeing (not for) developing a coating system that was first being used on the 767X (code name for the 777 then under development) Airbus was running full page ads in Aviation week touting the A340 and how the flying public would feel safer and more comfortable on an aircraft with 4 engines while flying over open water vs the two on the new 767X under development. Many in the industry and wall street analysts said it could not be done and would not get ETOPS even if the 767X eventually did fly. However, there was a very much can do attitude at Boeing at the time and defeatism was definitely not welcome. Wee, fly it did and now the A340 (a beautiful plane in its own-right) is gone and the 777 is one of the most successful aviation products put on the market and changed an industry. 

Eventually brushless motors will be used in not just O-gauge, but nearly all model trains. Marklin has already started it. The driver will be battery operation. While can motors can certainly be used with battery operation, to get any longevity out of the batteries will simply take a propulsion system that is more efficient than can motors are capable of. Of course "longevity" is subjective since some are happy with 3-minutes of operation while others are not happy with 3-hours. Also keep in mind that the "2-cent" RS380 can motors are terribly inefficient by even can motor standards.  To get maximum efficiency (70-75%) from a can motor takes ball bearings, high content silver silver-graphite motor brushes and precise balancing of the armature. By the time all that is done the can motor is as expensive if not more so than any other motor type and is still vastly less efficient than synchronous or asynchronous motors.  

Computers, phones, music devices, cars, trains, and even airplanes are migrating to battery operation. This is true for hobby applications as well. There are posts on this forum calling for battery operation of our O-gauge trains. Simply put, the majority of consumers want to cut the cord and to do that with our O-gauge trains will take something that is much more efficient that what we have now. 

Last edited by WBC
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