Over the past few years I have upgraded about 25 Hobbytown drive flywheel drive chassis with DC70 motors using the neodymium magnets from K&J. This is a very easy improvement that is worth time and money. It takes about 1/2 hour of time and about 2.00 for the magnets. The result is about 2 tenths of an amp drop in current from 6 tenths down to 4 tenths on average. I get more power, extremely good slow speed and much better speed control over the entire speed range.I used a stack of 1/2x1/4x1/8 magnets. If there is an air gap I have read that it is best to fill it .I use old xacto blades. break them with pliers and use the end that mounts in the handle. If you place the stack in and the motor runs in the wrong direction just flip the stack over to make it right. I started with the N42 magnets and then tried N52 I am not sure if I have noticed any apparent difference. I also did a couple of the smaller DC60? motors on the Hobbytown switcher drives and feel there are similar performance improvements. Of course the Hobbytown are outstanding drives and these improvements make them better.
I have a few more DC70 powered drives to do . I also have a couple of older nonflywheel drive Hobbytowns to do at some point,it will be interesting to see how these conversions do.
Ron High
The motor's assembled pretty tight. You might be able to get the original magnet out without disassembling, but it was almost easier to deal with the ball bearings. Assembling the motor without the magnet and putting it in last allowed me to get the BBs in place a lot easier, and then I could slip the magnet in.
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I know this is an old (2008) post. But my question is; can you remove the old magnet without disassembling the motor (and risking dealing with the bbs)? You imply as much by saying " I would recommend putting the magnet in after you've re-assembled the motor, since the BBs are slightly magnetic".
In any event..I note that 1mm bbs are available on the internet with either magnetic (steel) or non-magnetic (Tungsten Carbide) versions for fairly cheap.
Some great ideas out there to make old better than new! Thanks for the good info!
The PM-1 should have had a stronger motor given the size of the magnet and pole pieces, but I guess they didn't give them much of a charge. The large open frame motor in their steamers at the same time had a lot of torque.
I wonder if we're ever going to see can motors with neodymium magnets used in modern locos. They would allow for more torque in a smaller package, and are already in Slot and RC cars.
Nelson
Ex-Southern 385 Being Hoisted
sfcouple I've never checked the speed on my Hustler but back in the day it had to do 150 Scale Miles Per Hour. That thing just flew around my layout and at times would become airborne going around my typical 18" radius curves. But I digress.......
I've never checked the speed on my Hustler but back in the day it had to do 150 Scale Miles Per Hour. That thing just flew around my layout and at times would become airborne going around my typical 18" radius curves. But I digress.......
IIRC, when the Hustler first came out, MR clocked one at a top speed of 429 smph.
Good info there on the neodymium magnets. I did a conversion like that on an old Athearn metal RDC which was running slowly, drawing about 3 amps, and generally not doing well at all. The motor had a vertical armature, which drove a gear train in the single power truck. Two 1/2 x 1/4 x 1/8" neodymiums replaced the original Alnico magnet, and it runs great now. Low current draw, consistent speed range, very reasonable perfomance for a 55-60 year old model.
Keep up the good work!
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Gary M. Collins gmcrailgNOSPAM@gmail.com
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"Common Sense, Ain't!" -- G. M. Collins
http://fhn.site90.net
Darth Santa Fe!
This is an amazing post. For now, none of the information applies to my modeling but the knowledge and experience that you demonstrate are what I think great model railroading is all about.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Been working more on new magnets. I've done a few since my last update, but I'll just give one tonight.
The conversion is a Mantua MU-1 power truck, used in the metal Shark Nose and Talgo locomotive. A new magnet is practically a requirement to make it run well, since the old magnet is very weak and can barely move a load. The steel truck mounting plate used in the earlier metal Sharks makes the conversion more difficult, but it should be just like an MU-2 power truck for the rest. Due to a smaller amount of room for a larger magnet, I used a stack of four 3/8"x3/8"x1/8" magnets (could've used 1/4" thick magnets, but I didn't see them when I ordered). I suppose if some filing is done, a 1/2" cube could still fit. Because the magnet plates are held in place by a screw alone on these trucks, they should be glued in place with the new magnet.
And there's why it's more difficult to replace the magnet in the older Sharks. The magnet is strongly attracted to the steel plate, and even a large amount of weight can't hold it to the track properly. Now here's the fix:
I glued a hefty spring to the top of the magnets, and glued a piece of thick paper to the top of the spring for insulation. The spring effectively holds the truck right where it's supposed to be, and still allows free rotation. More than a quarter pound of lead over the truck helps too (I have an early model with no extra weight cast over the power truck).
And the results are totally worth it! It only showed a 9.6% drop in speed to 85 scale MPH and didn't improve low speed control, but there was a 40.5% drop in current draw to 0.22A, and the torque is significant! I would recommend this change to all owners of Mantua's MU-1 powered models!
I did not think much about the air gap. I will have to experiment a bit with increasing the air gap to see if that creates an improvement. I probably have the magnets to close to the armature. Original Mantua motors had a good sized air gap between the magnet and the armature.
If that works better I will try to take some picks to post.
Funny one!
Actually I used a good quality bar magnet that was marked N and S on the respective poles. I then labeled the poles of the motor and the poles of the new NEO magnets to make installation easy, no guessing.
Neo magnets have been used in slot cars for a while. What a great idea. I'll try on my Rivarossi Big Six. One thing, if you put them too close to the armature, they will probably use more amps. As I recall if you increase the airgap to a point, they will run faster.
John,
Here's my compass. I mark the pole he sticks to with an "S."
steamie 1. How do I determine the north and south poles?
1. How do I determine the north and south poles?
Oh, that's easy. Just keep your eye out for Penguins.... if you spot 'em, you're at the South Pole. If, on the other hand, you find yourself being eaten by a Polar bear, you know you've located the North Pole.
John
(And if you're surrounded by Eskimos raising their fists and chanting... ask 'em how was I supposed to know those weren't really lemon-flavored snow cones...??? )
I suppose every motor is different. My Mantua motor was improved quite a bit over what it was, and runs nearly as well as a quality can motor. When the old magnets do lose their charge, a new magnet is certainly cheaper than a new motor.
The recharging method from eHow would be useless for old open frame motors, because the magnetic circuit -- consisting of an alnico magnet, the pole pieces, and the armature -- is capable of holding more of a magnetic charge than the magnet alone, which is why manufacturers magnetized the assembled motor, and why these motors lose a major portion of their power when disassembled. I have a copy of a 1972 MR article on how to build a re-magnetizer from the filter chokes in an old CRT TV, but neodymiums have made that unnecessary, unless you want to keep a vintage piece original.
The rare earth magnets I put into the Mantua PM-1 motor in the picture above are a big improvement, but the motor speed still isn't as consistent as a decent can motor.
There are ways to re-charge magnets on your own but I don't know how feasible it would really be. A Bing search resulted in several ways, but a search on eHow resulted in this link: http://www.ehow.com/how_6751013_recharge-magnets.html.
Slot racing centers in the old days had equipment to re-energize magnets since the magnets needed it after a night racing due mainly to the effects of the heat, besides the car taking a beating. You could check to see if there is a slot racing center or LHS that could re-charge magnets. The advantage would be maintaining the same magnet shape and armature clearances.
Just my thoughts.
I tried this on a TYCO Rodgers 4-6-0 using 1/2 inch cubes, they fit great. I first tired a NEO 42 then tried a NEO 52. The performance is definitely better than the old magnets but not good enough in my opinion.
I found the top speed to be about the same with either but the NEO 52 seemed to have a little smoother power curve at the top end. I have not measuring equipment to measure the top speed so I just counted how many seconds the train took to make a lap around my circular test track and both seemed about the same.
I have one of the Rodgers 4-6-0 engines that I previously put a helix humper can motor in and have to say that the can motor performs much better. It has a much better speed range, starting off at a much lower throttle and easing up to top speed through the range. The top speed seemed comparable to the NEO modified motors.
One thing I've observed is that when using two rows of magnets, as in your Rivarossi ball bearing motor, the two rows have to be oriented NN - SS, since they are acting as a single magnet. Otherwise they will attract and cancel each other out, and any magnetic force in the pole pieces of the motor will be residual and weak.
Here's a shot of a PM-1 motor with twin rows of neodymiums. The individual magnets are stacked normally with opposite poles attracting, but the stacks are positioned in the motor with the same poles at the top and bottom.
I didn't pay attention to the original orientation, but it's easy enough to flip the magnets if it runs the wrong direction.
Modeling HO Freelance Logging Railroad.
Very nice write up. Thanks.
This helps a lot and should help anyone else who stumbles upon this thread.
I think I will try the N42 mags. If I can come across a spare motor cheap then maybe I could try a N52 also and compare them.
I will most likely update this thread with my results, but it may be a while.
Hi steamie,
1. I used the old manget as a reference to determine the poles. The opposite poles attract eachother, so when the magnets get stuck together, you know their orientation is the same. To make it easier, the old magnet should be marked before taking it out, and then the new magnet can be marked the same way once the poles are figured out.
2. The poles are at the top and bottom. The magnetism goes through the steel plates that wrap around the armature, so the magnet is in a way surrounding the armature like in a can motor.
3. I did use a 1/2" cube for the Mantua/Tyco motor. See the first part of my reply to know how to get the proper pole orientation.
4. I used N42 magnets. The N52 magnets would give even more power than the N42 and further lower the current draw, but they cost around 25% more. One thing to keep in mind as far as speed goes is that the stronger the magnet is, the lower the speed is.
5. I would personally do this before upgrading to a Helix Humper or Yard Bird motor. The Mantua motor is very well engineered. And with the stronger magnet, it runs about as well as a can motor. It's also only about 1/10th of the cost, since the 1/2" cube with a 3/16" hole is only $2.90.
And I'm sure I mentioned before, but never let the 1/2" cubes get close enough that they attract eachother together! When I let the two neodymium cubes go together, the force was so strong that one of them shattered!
Darth Santa Fe this is great info but I have a few questions.
I want to try replacing the magnet on some TYCO/Mantua PM1 motors so here goes.
2. Are the north and south poles at the top and bottom of magnet where the frame is or are they at the end of the motor and on the inside where the armature is.
3. I think you used a 1/2 inch cube for yours, how did you know how to correctly orient your cube?
4. Did you use N42 or N52 magnets and what would be the difference using the different strengthens? Which strength would give better top end, use less power, etc.
5. How would this compare to using a can motor such as the Helix Humper http://www.alliancelink.com/alp/photos.htm or a D8130 from Yardbirb trains http://www.yardbirdtrains.com/YBMotorIndx.htm. I know both of these have flywheels so that helps a bit.
Please elaborate a bit for my sake and others who may read this.
Thanks.
I missed this post the first time around, Darth. I was trying to find replacement magnets for the Athearn gold motors with the right dimensions myself, but all crescent shaped neodymiums for can motors I've seen have been for undersized motors in that line of small XMOD RC cars.
BTW, I saw a Dyson commercial the other night for their small canister vacuum, and they were touting the power of the neodymium magnet motor. Maybe James Dyson read this thread.
0-6-0 wrote: Hello Darth yes they are open frame motors they run but they are really slow. But that's not a big deal. They don't have the pulling power I think it should. They are kept clean . They are all metal f7a and one metal b unit that is not powered. It will pull 5 or so cars but if I put the b unit on it goes down to 2 cars.
Does it only have one powered truck? If so, you can increase pulling power by adding weight around, over, or near the powered truck. Also check to make sure the unpowered truck and dummy B unit are extremely free-rolling, because pulling or pushing stiff wheels is like dragging a hunk of lead around.
One was my dads from the 40s and we built it a year ago so the motor only has maybe 10 hours on it but it is 63 years or so old I would guess it would lose some power in that time. I will check out some new magnets and let you know how it works out. Or can I give the old magnets a recharge. Thanks Frank
The old magnet may have lost some power, but I wouldn't recommend recharging it yourself without a special tool. Can the armature turn freely? If not, check the brush tension, and make sure the bearings are oiled. You'd be surprised at how much noise and loss of power and speed can come from old, dry bearings.
Hello Darth yes they are open frame motors they run but they are really slow. But that's not a big deal . They don't have the pulling power I think it should. They are kept clean . They are all metal f7a and one metal b unit that is not powered. It will pull 5 or so cars but if I put the b unit on it goes down to 2 cars. One was my dads from the 40s and we built it a year ago so the motor only has maybe 10 hours on it but it is 63 years or so old I would guess it would lose some power in that time. I will check out some new magnets and let you know how it works out. Or can I give the old magnets a recharge. Thanks Frank
0-6-0, if your Varney trucks still have the open-frame motor, you can upgrade the power with a new neodymium magnet. All you have to do is measure the size of the magnet, and get one (or a stack) of the proper size. Just make sure it's magnetized the right way, or the motor won't run at all! As far as Lindsay drives, I don't have any experience with them, but I've heard they're an excellent design, so a simple cleaning and oiling should be enough to get them running again.
miniwyo, here's a link to a topic posted a while ago on making Athearn motors quieter.http://cs.trains.com/forums/1143504/ShowPost.aspx
Pathfinder, yes, the Hustler is a little faster now. The motor actually runs at a lower RPM now, but it also now has the torque to really get it moving!
With the stronger magnets, my little Hustler now has a lower starting voltage, draws less current, and has noticably higher power." border="0" />
Faster too?
RJ
"Something hidden, Go and find it. Go and look behind the ranges, Something lost behind the ranges. Lost and waiting for you. Go." The Explorers - Rudyard Kipling
http://sweetwater-photography.com/
Hello Darth I do not have a photo of the motor but I did find a web site that did it is
www.redehaas.dds.nl/Varney.htm
hope this will help Thanks Frank