Budd Car Speed Problems

[Neil Poersch]

Hi again everyone,

Another RMT problem. I recently received a second Budd car in addition to one received about six months ago. I had intended to run the two cars together in a lash-up mode. However I have found that the new Budd car is about two to three times as fast as the older Budd. In other words when I place both Budds on the same track at the same voltage but operating seperately, the new car will run much faster than the old car. I have checked the old car for lubrication or electrical problems and can't see anything obvious.  I am concerned about running the two cars lashed together due to the significant speed differential. It seems to me that running in this mode would put strain on the motors and traction tires.

Has anyone else had this problem?

Thanks again in advance,

Neil

[rlplionel]

I think your concerns are justified. Have you contacted RMT about this problem to see if they have a solution?

[phillyreading]

I second what 'rlplionel' mentions as it could be a voltage differance from the circuit boards to the motors on two differant production runs of the Budd cars and this 'will affect' long term running of both units.

Also have to watch this on diesel engines when putting two or more motorized units together.

Lee F.

[brianel027]

Unfortunately this is an inherent problem with the truck mounted DC can motored locos from any maker be it Lionel, K-Line or RMT. The motors which are made by Mabuchi are decent operating motors, but are not precsion like a Pittman. I have noticed this between the same types of locos made by the above mentioned. I have K-Line S-2's that run at different speeds. I've even noticed that sometimes two differing trucks on the same exact loco can run at different speeds, which also adds to the "growl" noise these locos naturally make especially on tight 027 curves.

With my K-Line locos, I have enough of them, that I have swapped motored trucks from one loco to another to improve operation. I've also ripped out most reverse circuit boards, run my layout on DC current and have noticed a distinct improvement in running from these locos. Some of the better runners have their traction tired removed. All my Lionel Industrial Switchers have been modified, improved and all are now minus traction tires and pull just as well if not better.

If it's any consolation, I have bought identical Lionel locos with the same exact open frame AC motors, done maintenance and notice that some of these run at differing speeds for no obvious explanation.

You could call RMT and see if they have any suggestions. Even if they were to go as far as to replace the "Buddy" with another one, you could very well end up with the same situation. Nothing against RMT. These truck mounted DC can motored locos are decent running and pullers, but this "problem" or drawback in just common with all of them. One of the compromises for budget priced trains.

I just checked the RMT website and found no mention of it, but you might check the "Buddy" for a "series-parallel" switch if they have one (on the underside of the unit). Some of the last K-Line can motored locos came with a switch for the motor wiring... having it set to "series" will make the loco run slower on the same exact current as another set on "parallel."

As a final note, I have the somewhat similar version K-Line made Budd car RDC's. I've swapped out one motored truck for a dummy one and have one motor in each car. If I decide to run them single, with the weight I've added, there's enough pulling power to pull several Lionel short 11 inch passenger cars.

[lionelsoni]

There's a difference in how permanent-magnet ("can") motors and traditional series-wound universal motors handle speed.  The can motor wants to run at a speed proportional to its voltage.  If it is forced to run slower (as by being heavily loaded), it will draw lots of current.  Likewise, if it is forced to run faster (as by another motor), it will source lots of current.  Unless well matched or wired in series with each other, they are not very suitable for use in multiples.

The series-wound universal motor will never source current and will simply pull somewhat harder if slowed down or pull less if speeded up.  It is the same general type of motor as the traction motors in all but the most modern prototype locomotives; and they are of course well suited to being used in multiples in both prototypes and models.