Traction

[Sasha]

I have so many questions but I have to start somewhere, so here's my first one:

If it's possible, how do you railroaders make your drive wheels gain higher adhesion?

[Desertdweller]

Be careful in what you buy for locomotives.  Pick locomotives that drive through both trucks.  Pick locomotives that are as heavy as possible, with robust motors.

If you are buying Diesels, avoid locos with traction tires.  Although these are supposed to increase pulling power, in fact they tend to bounce or be out-of-round, killing traction.  They also reduce the number of wheels picking up electricity.

Traction tires work better with steamers, as the number of drive wheels compared to Diesels is fewer.

If you like to tinker with locomotives, try to get them to run as smooth as possible.  This smoothness will aid traction.

Les

[jward]

diesels mostly run in multi unit consosts. therefore, adhesion is not as much of a factor as with steam. want to pull more, add another diesel.

that said, as a general rule, an sd40-2 with 12 wheels will pull more than a gp40 with 8, if they are of similar weight. and a dda40x with 16 wheels should outpull them all.

[Sasha]

Thank you for the replies.

The reason I ask is because I have 2 Spectrum DDA40Xs, one that I bought new about 2 weeks ago, and one that I bought new in 2001.  The older one has adhesion that would pull the bark off of a tree.  The new one has good traction, but nothing like the older one.  I have modified both of them to have all-wheel electrical pickup to go along with the all-wheel drive. I have inspected the wheels too, but I cannot see a difference between the 2 locomotives. I checked the U-joints and everything else that moves in the driveline to see if there was any slipping... no slipping anywhere.  It's all in the wheels.  When I apply power and manually stop the wheels, the motor stops on the corresponding driveline.

I wish I could figure out what makes the older wheels the superwheels they are.

[jward]

it sounds more like you have a weak motor. when you hold the locomotive in place by hand and turn up the power the wheels should spin. if they don't something is wrong.

[Sasha]

When I said I held it still, I meant that I applied enough downward pressure to stop the motor briefly.  It's plenty strong. It has more traction than my other models, no matter the make and model, but I'd guess only about half the adhesion of my older unit. If I merely stop the locomotive without downward pressure, the wheels spin like crazy.

[Jerrys HO]

Sasha,

I have never run DC but have a few DC engines that were given to me. There is a difference in speed. The link below is one I have found while learning DCC. It may help you understand a little better.

http://www.bachmanntrains.com/home-usa/board/index.php/topic,19731.0.html


Most of the loco's you described in you other post are exception puller's. I don't think on a flat layout without any grades you will need much more pulling power.

Jerry

[Sasha]

Thank you for the link, but it's not a speed difference, it's a difference in grip these two identical locomotives have.  The are both Bachmann Spectrum DDA40X models, numbers 6900 and 6926. Both dual-motored and all-wheel drive. One grips the track like mad, the other grips like my other locomotives.

I was just wondering if there was something I did for my first Centennial without knowing that made it adhere to the track so well that I could in turn do for my new one to match it.

[Sasha]

Alrighty - case closed.  I figured it out the hard way.  After thoroughly cleaning the wheels, I switched all 8 axles between my two DDA40Xs and tested them.  Having put the older wheels on the newer train, it now had the super-adhesion. The older locomotive with the newer wheels now just pulled like I expected it would.

I'm leaving them the way they are. The older locomotive is safely in it's Spectrum box and won't be touched unless I need it.