Some ways to make your engines' motors run better

[Darth Santa Fe]

Hello thanks Darth the rivarossis part helps out I have one that needs tuned up. How about something for my old Varneys ? I have 2 with the Lindsy drive 2 pulleys and a spring as a belt and it mounts to the rear truck. Thanks Frank

Do the drives look something like this?
Varney: http://hoseeker.net/assemblyexplosionvarney/varney2060kf31951pg2.jpg
(I couldn't find a diagram with the spring-belt drive)
Lindsay: http://hoseeker.net/lindsay/lindsay4wheelpowerdrive1949pg2.jpg

Do you have any pictures?

[0-6-0]

Hello thanks Darth the rivarossis part helps out I have one that needs tuned up. How about something for my old Varneys ? I have 2 with the Lindsy drive 2 pulleys and a spring as a belt and it mounts to the rear truck. Thanks Frank

[Darth Santa Fe]

I got some larger magnets for the Rivarossi motors, and the change was a success!

The new magnets are 1/2" x 1/4" x 1/8" thick, and fit the motor much better than the 3/16" cubes. All that has to be done to make them fit is to cut out some of the plastic endplate to clear the magnet, visible in the picture. Once the magnet is in, it should be glued in place to make sure it doesn't slip into the armature. Not only was this easier than the cubes, but it was also much more effective. My 2-8-4's speed dropped from 85 or 90 MPH to 70, and my 0-8-0 dropped from 120 to 105. Both engines draw 0.05 amps less at full speed. The torque is also much higher, so the motors are no longer under powered for the larger steam engines.

The Mantua PM-1 motor now has a new magnet that isn't shattered, and it runs even better than it did with the shattered magnet.

The Athearn motor experiment was a total failure, so now I'll have to look for some other use for all those 1/8" cubes.

[Darth Santa Fe]

I was looking at a burned-out Athearn gold can motor last night, and it looks like I may be able to fit some stronger magnets in it too. With the stock magnets, the gold motors (at least the ones before the RTR line came out) have less torque than a Mabuchi motor of half the size, so I'm going to see about getting more magnets so I can experiment. If it's a success, I'll post the results.

[Darth Santa Fe]

Just thought I'd share some ways to help improve the motors in your engines.

I'd like to start with some ways of switching out old magnets with newer, stronger ones. Stronger magnets will increase power, while reducing speed and current draw in most cases. All magnets used here are neodymium, which is the strongest type of magnet in the world, and were purchased from http://www.kjmagnetics.com/.

First up is an easy one.

Athearn's old silver motors are good runners, but they're very weak too. Changing out the old magnet with a stack of five new ones is pretty easy.

I found that 1/4"x1/4"x1/8" magnets were the best fit here, but as you can see, they were just slightly too long, so I had to bend the ends of the plates a little to make the motor go back together. With the stronger magnets, my little Hustler now has a lower starting voltage, draws less current, and has noticably higher power.

Next up is the Mantua/Tyco MU-2 power trucks.

The one shown here is actually Roco's plastic MU-2 clone, made for Tyco in the mid 70s. A 1/2" cube fit well in place of the old magnet, but the steel rivet has to be taken out first. I got the rivet out by drilling out the flared end of it. The steel plates that wrap around the sides will fall out without the rivet, but everything holds together fine once you put the new magnet in. My Tyco F7 now draws less than half the current it did before and has significantly higher power. It actually runs faster now too, because the old magnet was so weak the engine could barely move itself.

NOTE: Make sure your truck has the plastic mount, and NOT the steel-plate mount! The steel plate in older models is highly attracted to the magnet and will not allow the truck to turn!

Third up is Rivarossi's square motors.

This is one of Rivarossi's last ball-bearing motors before they switched to their can motors in the early 70s. The BB motors were some of the smoothest runners around through the 60s and 70s, but the magnets used in both them and the cheaper bronze bearing motors were too small for anything larger than a 4-6-2.

Here's the motor shown in pieces. Rivarossi used a lot of glue in the later BB motors, and it was a challenge to get the two screws holding it together unstuck. The magnet was also hard to get out, and it took large pliers to help me break the glue holding the magnet in. It would be best to set all the ball-bearings aside (15 total, except in the older ones which have 17) while you work on it, and keep a few spares handy (BBs are 1mm chrome steel). The magnet shown here was made using six 3/16" cubes, which had to be super-glued together to keep them from pushing eachother apart. I had to put a 1/32" thick steel washer on each side to bring it up to the proper 5/8" length.

And here it is all put back together. The BBs are a bit of a pain to put back in, and you have to make sure there's no debris stuck to them. I would recommend putting the magnet in after you've re-assembled the motor, since the BBs are slightly magnetic. Because the new magnet is much smaller than the old one, the improvements in running were minor, but still existent. I now think it would be much better (and easier) to use five 1/2"x1/4"x1/8" magnets stacked together with some of the motor housing ground away to make room, instead of using six small cubes glued together. The improvements would be much more noticable with that, and so much glue wouldn't be necessary.

Last is a Mantua PM-1 open-frame motor, which is what you'll find in most of their older steam engines. the process is basically the same as with the power truck, with the rivet being drilled out and a 1/2" cube in place of the old magnet. The magnet will fit better with a 3/16" hole going through the middle to make room for the rear bearing. With the new magnet, the motor's current draw decreased about 30%, the speed dropped a few thousand RPM, and the torque went up, I'd say, over 30%, making it strong enough for even Mantua's largest steam engines.

Now some tips on handling these magnets.
1. Never let them snap together! The larger magnets can and will shatter eachother! For example:
It's amazing that I even got the motor working with the magnet like that...
2. Don't put them close to electronic devices, like computers, cell-phones, credit cards, etc, or the device can be damaged.
3. Don't let your fingers get caught between two magnets, because you can get a really bad pinch if that happens!
4. When making a larger magnet by stacking small ones (like a 1/4"x1/4"x5/8" thick from five 1/8" thick magnets), make sure the polarity is through the thickness, not the length or width. Also make sure you get the polarity on the same ends as the old magnet, or your motor will runs backwards.

Now for another way to make a motor run better.

Some motors have too much tension on the brushes, making them run tighter, which will bring up the current draw and increase wear.

For brushes with leaf springs (or similar, like the coil springs with extensions on Rivarossi motors), bend the springs back a little at a time, and make sure it's the same amount for both of them. Keep doing this until the motor is running as freely as possible without reducing brush-to-commutator electrical contact. If you bend them back too much, you'll know it pretty quickly based on the motor's performance, and have to re-tighten them until it's just right.

For brushes with coil springs (like Athearn's black or gold motors), cut away a little of the springs at a time. If too much is cut away, stretch the springs back out until the motor is running properly.

Well, that's all I've got for now. I hope all this helps out some of you guys who want better running engines.