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neodymium magnets

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neodymium magnets
Posted by graymatter on Friday, September 8, 2017 11:18 PM

I descovered a safer way to 'pole push' a frieght car on an adjaecent track.

Still working on a way to turn it off.

Good thing I built a test track first

Thomas J SimpsonLaugh

 More details on video, This is a locomotive with an open frame motor that has neodymium magnets. The problem is these powerful magnets stacked up in the electric motor attrack ANY metal laying around the track, nails and screws and rolling stock with metal plates. The locomotive can pull or crawl up a grade without stalling. Traction is the limiting factor for the 4-6-2 on a grade.

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Posted by BNSF UP and others modeler on Sunday, June 3, 2018 8:58 PM

Soooo... you made a stronger motor using neodymium magnets?

I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.

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Posted by gmpullman on Sunday, June 3, 2018 9:05 PM

graymatter
The problem is these powerful magnets stacked up in the electric motor attrack ANY metal laying around the track, nails and screws and rolling stock with metal plates.

I followed the example of RR Mel and built a magnetic pick-up car. I was amazed at how much ferrous rubble it has picked up! Better here than in speakers and motors!

 IMG_7270_fix by Edmund, on Flickr

 IMG_7268_fix by Edmund, on Flickr

Thanks for sharing!

Ed

 

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Posted by BNSF UP and others modeler on Sunday, June 3, 2018 9:55 PM

Oh, whoops, I was way off.

I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.

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Posted by gmpullman on Sunday, June 3, 2018 10:25 PM

BNSF UP and others modeler

Soooo... you made a stronger motor using neodymium magnets?

 

Oh, whoops, I was way off.

No, you weren't off at all. Often, new "rare-earth" magnets will give an old Pittman or other open frame motor a new lease on life:

http://cs.trains.com/mrr/f/88/p/265702/3002771.aspx

My reply was in regards to the stronger magnets picking up stray bits off the roadbed, where a pick-up car can help mitigate the amount of ferrous debris left behind on the R-of-W.

Cheers, Ed

 

 

 

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Posted by doctorwayne on Sunday, June 3, 2018 11:25 PM

gmpullman
....No, you weren't off at all. Often, new "rare-earth" magnets will give an old Pittman or other open frame motor a new lease on life...

A friend gave me the brass locomotive, pictured below, because it wouldn't pull enough cars...

After replacing the magnets in the open-frame motor, I added some weight to both loco and tender, and gave it a new paint job.  Next time the friend visited, I stage a run-past with the loco easily dragging 20 cars of various rolling qualities and generally heavier-than-recommended weights. He was stunned, but declined my offer to return the locomotive to him, as he had already found a replacement (which I later modified in a similar manner).

Wayne

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Posted by garya on Monday, June 4, 2018 11:59 AM

graymatter

I descovered a safer way to 'pole push' a frieght car on an adjaecent track.

...

 More details on video, This is a locomotive with an open frame motor that has neodymium magnets. The problem is these powerful magnets stacked up in the electric motor attrack ANY metal laying around the track, nails and screws and rolling stock with metal plates. The locomotive can pull or crawl up a grade without stalling. Traction is the limiting factor for the 4-6-2 on a grade.

 

I've been replacing magnets in Bowser and Mantua Steam loco kits with neodymium "supermagnets."  I haven't had that happen to me yet, but I should probably experiment.  

I have had them suck up nails, screws, and a spare Kadee coupler or two while working on the loco on my bench...

Gary

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Posted by rrinker on Monday, June 4, 2018 5:29 PM

 I'd like to see how the brakes work when a strong magnet car rolls over a kadee uncoupler...

I don't use magnetic uncouplers so a magnet car wouldn;t cause problems for me. 

Just don't ask Gerry Leone how to pronounce neodymium Big Smile

                              --Randy


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Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by RR_Mel on Monday, June 4, 2018 6:15 PM

rrinker

 I'd like to see how the brakes work when a strong magnet car rolls over a kadee uncoupler...

 

                              --Randy

 

Randy
 
I haven’t taken a picture after applying the brakes, but it does happen.  I’ve had it derail a pair of 2½ pound E7s.  I push my magnet toting flat car at a creep and even then it can cause havoc.
 
The Kadee couplers are pretty good, I use the 118 Shelf Couplers on my E7s and haven’t broken one yet.  
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by emdmike on Monday, June 4, 2018 6:17 PM

The old Alinco magnets in open frame motors loosing thier strength was a known issue back when these were new.  Pittman and others advertised Remagnitizing services in old issues of Model Railroad and RMC way back when.  There just was not another option for the magnets back then.  These new magnets will restore the power those old motors really have. Most better quality ones will run smooth and quiet, with plenty of torque for slow speed crawling or starting heavy trains.  The motor will also run cooler and not foul the communtator as quickly with a healthy magnet.   Do this service to the motor, isolate the other motor brush and your ready to DCC it.      Mike the Aspie

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Posted by rrinker on Tuesday, June 5, 2018 5:47 PM

RR_Mel

 

 
rrinker

 I'd like to see how the brakes work when a strong magnet car rolls over a kadee uncoupler...

 

                              --Randy

 

 

 

Randy
 
I haven’t taken a picture after applying the brakes, but it does happen.  I’ve had it derail a pair of 2½ pound E7s.  I push my magnet toting flat car at a creep and even then it can cause havoc.
 
The Kadee couplers are pretty good, I use the 118 Shelf Couplers on my E7s and haven’t broken one yet.  
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 

 I have Kadees take the long plunge to the poured concrete canyon floor and not be damaged - there's a reason i use only real kadees in everything. Conversely, I've had new, still sealed P2K locos, when still Life Like, and they used those horrible plastic couplers, come out of the box with a broken coupler. I just recently picked up a pair of box cars with the new Proto-Max metal couplers but I haven't even taken them out of the box yet. Supposed to be pretty good - but I'll probably swap for Kadees.

                              --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by drgwcs on Tuesday, June 5, 2018 10:23 PM

Why am I thinking of the joke John Allen pulled with magnets in the end on two freight cars. It was intended to frustrate operators by not letting them uncouple. It was better when they repulsed though. He would advise the operator to corner the car on a siding so it would not get away. When they passed one another they would always derail.

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Posted by SouthPenn on Wednesday, June 6, 2018 9:49 AM
South Penn
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Posted by Southgate on Tuesday, June 12, 2018 3:59 PM

Has anyone used these magnets in the old Mantua-Tyco open frame motors, or just in the Pittman and other better quality motors? If so, how do they work in the Mantuas?  Dan

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Posted by garya on Wednesday, June 13, 2018 11:00 AM

Southgate

Has anyone used these magnets in the old Mantua-Tyco open frame motors, or just in the Pittman and other better quality motors? If so, how do they work in the Mantuas?  Dan

 

I did it with my Little Six motor:

It works ok, but it still takes some volts to get moving.

Unlike the Bowser/Pittman motor, which is bolted together, I had to cut off the rivet with my Dremel to get the old magnet out.  It took four of the magnets but didn't need shimming, so I used superglue to keep everything together.

The Bowser motors take 5 magnets and a shim:

Gary

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Posted by Southgate on Thursday, June 14, 2018 12:12 AM

Thanks, Gary. That helps to know. Where did you get your magnets?

I thought I'd do a little experimenting here. I ran a stock mantua motor, noted current draw and such, then I stuck a 3/8" cube magnet on the back of the motor just to see how it would run. After trial and error orienting the poles, it improved the smoothness of the motor, still about the same current draw.

When I removed the magnet, well, the little loco wouldnt run at all! I appearently demagnetized the original enough to pretty much kill what was left of it. I'll be buying some neo-mags pretty soon anyway.Tongue Tied  Dan

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Posted by garya on Thursday, June 14, 2018 3:12 PM

Southgate

Thanks, Gary. That helps to know. Where did you get your magnets?

I thought I'd do a little experimenting here. I ran a stock mantua motor, noted current draw and such, then I stuck a 3/8" cube magnet on the back of the motor just to see how it would run. After trial and error orienting the poles, it improved the smoothness of the motor, still about the same current draw.

When I removed the magnet, well, the little loco wouldnt run at all! I appearently demagnetized the original enough to pretty much kill what was left of it. I'll be buying some neo-mags pretty soon anyway.Tongue Tied  Dan

 

I did the same thing with the Mantua motor above.  Tongue Tied  I held some magnets near it to get an idea of how well they would fit, and killed the magnet.

I got my magnets from CMS Magnetics.  They have a variety of magnets and shapes.  I used 1/2x1/4x1/8 block magnets but look around and see if something else will work for you.

 

Gary

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Posted by NVSRR on Thursday, June 14, 2018 8:02 PM

I am having a bunch of ideas for magnets on a layout. Will have get a bunch and see what works

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An optimist sees the light at the end of the tunnel

A realist sees a frieght train

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Posted by Ron High on Friday, June 15, 2018 9:17 AM

I have used magnets from this company

https://www.kjmagnetics.com/

They have all shapes and sizes I use # B428 which is a 1/4x1/8x1/2  N52. The N52 is a rating of magnetic strength there also N42 which is a little less strong .The price difference is a few pennies for the higher strength.

I used these on Pittman DC 70 motors in Hobbytown drives . Benefits are more power even better slow speed control a slight drop in current draw,about 2 tenths of amp less. I have done this on about 20 Hobbytowns.

It is very important not to leave an air gap between magnets and pole pieces. A good way to fill this gap is xacto blades. Use some old blades and break off the end that mounts in the tool,unless you want the sharp end in your motor. Most of the time you only need one blade. Leaving an air gap will degrade the performance of your motor.

This is a good upgrade of an open frame motor will cost 2.00 to 3.00 and 1/2 hour of your time .

Ron High

 

PS if you find your engine is running in the opposite direction of other factory unmodified engines you will need to flip your magnet stack which will correct the direction.This is very obvious in DC only operation.

 

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Posted by BANDOJAMBO on Tuesday, June 19, 2018 4:50 AM

With a little know how one could even power a locomotive and even an entire layout with neodymium magnets and copper coils as there is not anything else required to produce usable electricity other then those two components.  There are tons of examples on youtube but nothing specifically tailrored to model railroads could be a good opportunity for someone looking to something truly unique.

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Posted by Jumijo on Friday, May 14, 2021 9:06 AM

I replaced the original magnet in an open frame motor with some small, round neodymium magnets, and the motor no longer worked. I replaced them with the original magnet and the motor still won't work. What's the issue and is it reversible? Did I kill th motor?

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Posted by Overmod on Friday, May 14, 2021 9:42 AM

You need to do careful troubleshooting, understanding how these motors work.

Presumably you used a permeable shim to match the thickness of the new magnet stack to the dimension of the old magnet.  This involves a certain loss of magnetic power... but is small compared to the absolute gain of the NIB stack.  Be aware of the direction of the magnetic field, and that the magnets you bought were end-polarized (the north and south poles have to stack in the direction between the open-frame pole pieces).

If this is right, you will have a solid 'magnetic circuit' through the frame, with the poles close to the armature ("minimizing the air gap") but never touching it.  The bearings should also be in line and free, and any end-play of the armature in the bearings should be carefully shimmed, although this can be a bit less important than getting the field correct.

If the armature rotates properly but the motor does not turn under power you have an electrical problem.  To diagnose this most easily, you should have a multimeter,  but even the cheapest ones available will do the job nicely.

First make sure you haven't damaged the armature windings or the connections to the commutator.  

Then make sure your brush connections are good -- and that a brush isn't quietly shorting to its holder.

Then ensure that the commutator is smooth and its segments aren't damaged, and that the brushes are dressed and properly sprung to provide running tension.  Even a small gap can keep the motor from running.

There is nothing mysterious or ornery about one of these motors, and you seldom need resort to incantations or sacrifice to get them turning.

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Posted by emdmike on Saturday, May 15, 2021 4:09 PM

Well written Overmod, well written.  The problem these days is most active modelers did not live in the "open frame motor" heyday.  When tuning and maintaining these was a common part of the hobby.  They have faded away to the maintaince free sealed Can type motor and Coreless motor.  And while those are nice, can be in short supply at times or expensinve. A fresh magnet stack and some easy maintance can make those old open frame motors run nearly as good and draw low enough amperage for DCC conversion, add in a Keep Alive circuit and your all set.  Most just need one of the two motor brushes isolated to be converted to DCC as the other brush was already insolated.  I have never isolated the whole motor, just both brushes.   Open frames are hard to kill unless run super hot with a weak field magnet.     Mike the Aspie

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Posted by Jetrock on Tuesday, May 18, 2021 10:25 PM
I've had good results adding neodymium magnets to Suydam interurbans with open frame motors, but in some cases the magnets are hard to reach without Dremeling out a rivet and I haven't worked up the nerve to try that approach with some of my brass. The bigger limitation with a lot of old brass interurbans is power pick-up off the track, typically each truck picks up power from one side only, and I haven't had the nerve to try to wire them for all-wheel pickup, but the new magnets do help and are a lot simpler/cheaper than a full remotoring. Although in the case of repowering some brass GE steeplecabs, I found using a newer Bachmann 44 tonner chassis (with circuit board removed to allow it to fit into the steeplecab chassis) produced better low-speed results, and had all-wheel pickup (plus you can get the appropriate sideframes via Shapeways.)
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Posted by rbturner on Wednesday, May 19, 2021 8:53 AM

I have used the super magnets too with good results.

I also experimented with 2, 1/2" cubes and old Alnico magnets that had gotten weak.

Using a compass to properly orient the magnets, place a super magnet on each end of the old weak one.

 

I am no expert but this process seems to help out the old motors a great deal.

Randy
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Posted by Overmod on Wednesday, May 19, 2021 10:56 AM

rbturner
Using a compass to properly orient the magnets, place a super magnet on each end of the old weak one.

And you can cut or grind the Alnico magnet to precise shim length, too...

I wonder if anyone has experimented with Cunife magnets as shims: they are soft enough to cut and so a little tapping on the stack would conform the contact without having to file a magnetic material.

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Posted by doctorwayne on Wednesday, May 19, 2021 1:15 PM

The sheet metal weights from freight cars come in varying thicknesses, depending on the brand, and are easy to add as shims once cut-to-size with a hacksaw or cut-off disc.

To easily determine which end-is-up for the stack of new magnets, simply bring it close, from above, to the old ones still in the motor - if the new stack is attracted, its orientation is correct, if it's repelled, it's upside-down.

I've re-done several locos with older open frame motors, and every one of them now pulls better, starts at a lower voltage, and offers much better low-speed perfomance, too.

Wayne

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Posted by Jumijo on Wednesday, May 19, 2021 2:07 PM

doctorwayne

The sheet metal weights from freight cars come in varying thicknesses, depending on the brand, and are easy to add as shims once cut-to-size with a hacksaw or cut-off disc.

To easily determine which end-is-up for the stack of new magnets, simply bring it close, from above, to the old ones still in the motor - if the new stack is attracted, its orientation is correct, if it's repelled, it's upside-down.

I've re-done several locos with older open frame motors, and every one of them now pulls better, starts at a lower voltage, and offers much better low-speed perfomance, too.

Wayne

 

Wayne,

Should the magnet's poles be oriented top and bottom or on each side of the frame? Does it matter?

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Posted by BroadwayLion on Wednesday, May 19, 2021 3:57 PM

YES, the LIOIN uses them powerful magnets to operat the siignals.

Problem was, I have put some of these magnets on the motor car and now they do not work as well.

 

When I get back up there again I will remove the magnets from the power car and put them on a car further away from the power.

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Posted by doctorwayne on Wednesday, May 19, 2021 4:50 PM

Jumijo
Should the magnet's poles be oriented top and bottom or on each side of the frame? Does it matter?

Sorry, but I'm not sure what you mean by "each side of the frame".  The magnets are stacked atop one another, and will only go together by the attraction of their opposite poles.  If the stack of neodymium magnets, when held slightly above the original motor, and is drawn towards the original magnets in the motor, then the new magnets should be inserted into the motor the same way. 
If you put the new magnets in upside down, the motor will still run, but in the opposite direction of what it normally did.

If you need to add to the height of the stack of magnets, in order to fill a gap between the magnets and the motor's frame, you can likely put it anywhere...atop the stack, beneath it, or within it, using a piece of steel of suitable thickness. 

On the motor shown below, the steel "filler" is atop the magnets...

While the magnets shown above are only half the size of the original one-piece magnet (which had a cut-out relief in its rear, in order to accommodate that screw), they make a surprising difference in the loco's performance.

Wayne

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