Locomotive weight/speed

[DakotaLove39]

I'm wondering if there is a way to reign in a Loco's speed on the track? My BB SD9 screams past my P2K GP38 on the track, yet the P2K is superior when it comes to slow running. In typical Athearn fashion, the SD9 doesn't take off until about half power (This is on DC currently).

I've watched a few videos on how to improve slow speed control specifically on Athearns, but I figure after I do that this thing will still haul kiester around the track like a drag car, and perhaps even more so than now.

The loco is also ridiculously lightweight compared to the P2K. Should I be adding additional weight to it, and will this have any beneficial effect as far as speed control and unit traction?

Also, anyone know where to get nickel steel wheels for these BB engines? The ones this unit has REALLY like to pick up crap, and I'm wondering if they just don't contact as well. I will also be purchasing an SW7 from another user on friday, and the first thing I want to do with it is replace the iron wheels with nickel steel ones.

 

[jeffrey-wimberly]

You can get nickel silver wheels from Athearn. The SD9 used the same wheels as the F7 and many other other Athearn locos. For slowing it down, one word - resistor. Adding weight is simple. Glue some lead sheet to the top of the inside of the shell.

 

[Selector]

This sounds like an unhappy confluence of perhaps two or even three problems. If the loco doesn't move until quite a bit of juice is applied to the rails, it has an inefficient or defective drive system. It might be the motor, in which case remotering might be the best solution. Gearing is also an option. You'll want a further reduction to the final gear axles of maybe another 20-230% over what is extant in the locomotive at present.

 

[DakotaLove39]

.. Yeah I don't think I'll be diving into gear ratio alterations just yet. If re-motoring is required, would an entire drive assembly from a P2K SD40-2 or some other six-axle be good enough, or should I try to match up with their SD9 drivetrain? I suppose I can just find replacement internals from an Athearn RTR. They're still using the same motor and flywheels in their SD40-2's.

Also Running Bear, I have plenty of self-adhering automotive wheel weights I bought from my work. They're little squares about 2mm thick that are measured in 1/4 oz increments. They've been great for weighing my freight cars properly.

I was really only asking if it was beneficial. If it sounds like this thing's motor isn't performing like it should, then I might want to hold off on the weight for now..

How about I clean this thing up and lubricate it before we call it a dying motor though?

 

[D&J RailRoad]

I had been using enough weights on my locos to the point that I used a router to cut a shallow slot in a piece of wood to make a mold. I bought fishing weights and melt them down then pour the liquid lead into the wood mold. I can stock up on the weights and store them till needed and cut them to fit what I need.

 

[bnsf971]

You can look into Ernst regear sets for Athearn diesels as well. If you are going DCC with it anyway, I would install a decoder, like a Digitrax DH163AT, and do some CV tweaking. CV2 and CV5 will be your friends. You can also load speed tables with that model decoder, further refining its running quality.
Northwest Short Line also makes nickel wheelsets for that engine.

 

[DakotaLove39]

You can look into Ernst regear sets for Athearn diesels as well. If you are going DCC with it anyway, I would install a decoder, like a Digitrax DH163AT, and do some CV tweaking. CV2 and CV5 will be your friends. You can also load speed tables with that model decoder, further refining its running quality.
Northwest Short Line also makes nickel wheelsets for that engine.

See that just rams it home for me even more. Athearn is the Chevy of model railroading. Although I hadn't anticipated such a large aftermarket.


DCC is still a big questionmark. I have no permanent layout and no club to go to so I can't justify in my head the money spent on all the stuff for DCC.

 

[nwdrummer379]

Hey Dakota, Who manufactures those weights you speak of?

 

[DakotaLove39]

Hey Dakota, Who manufactures those weights you speak of?

Looks like a company called "Perfect Equipment"? I bought these from the CarQuest I work at. It's a box of 30 strips, each strip has 12 1/4 oz weights on it.

If you have a CarQuest Auto Parts store near you, go there and ask for part number 100360 wheel weights.

Using these, all of my cars are either perfectly balanced or within 1/8th oz difference (and I don't think I can easily cut these things in half..)

I should point out they're also made of lead, so in Cali-fear-nia you might have some trouble getting them?

 

[nwdrummer379]

I gotcha, I seriously think the engines I got from Brad's big ol' sale there. They're attached to the inside top of the shells. They say "1/4 oz. 7 gm" so that's gotta be it. I wonder if Napa will have these.

 

[DakotaLove39]

I gotcha, I seriously think the engines I got from Brad's big ol' sale there. They're attached to the inside top of the shells. They say "1/4 oz. 7 gm" so that's gotta be it. I wonder if Napa will have these.

Napa is pretty good at carrying everything CarQuest does. I would think they'd atleast have one box of them. They should be able to cross-check the part number I put out.

 

[psychobeagle12]

I had been using enough weights on my locos to the point that I used a router to cut a shallow slot in a piece of wood to make a mold. I bought fishing weights and melt them down then pour the liquid lead into the wood mold. I can stock up on the weights and store them till needed and cut them to fit what I need.

Hey I just thought of a good idea. If anyone shoots flintlock rifles and ever casts their own maxi-balls they would make nearly perfect barrels for loads in about a .45 caliber I think! Just run the lead through a Lee bullet mold and then cut the top down flat instead of the semi-pointed tip. Should make good barrels and weight... I'll have to give that a try I think

 

[sd24b]

I'm wondering if there is a way to reign in a Loco's speed on the track? My BB SD9 screams past my P2K GP38 on the track, yet the P2K is superior when it comes to slow running. In typical Athearn fashion, the SD9 doesn't take off until about half power (This is on DC currently).

I've watched a few videos on how to improve slow speed control specifically on Athearns, but I figure after I do that this thing will still haul kiester around the track like a drag car, and perhaps even more so than now.

The loco is also ridiculously lightweight compared to the P2K. Should I be adding additional weight to it, and will this have any beneficial effect as far as speed control and unit traction?

Also, anyone know where to get nickel steel wheels for these BB engines? The ones this unit has REALLY like to pick up crap, and I'm wondering if they just don't contact as well. I will also be purchasing an SW7 from another user on friday, and the first thing I want to do with it is replace the iron wheels with nickel steel ones.

Dakota
I have many Athearn blue box units that I run with my P2K's. I first installed constant lighting which reduced their start voltage, then removed several coils from the motor springs. Added 3-4 ounces of weight. I changed the wheels on my GP38-2's (NWSL). But found that their tractive effort was reduced significantly. Also make sure your motor shafts are as close to level as possible Phil

 

[DakotaLove39]

Dakota
I have many Athearn blue box units that I run with my P2K's. I first installed constant lighting which reduced their start voltage, then removed several coils from the motor springs. Added 3-4 ounces of weight. I changed the wheels on my GP38-2's (NWSL). But found that their tractive effort was reduced significantly. Also make sure your motor shafts are as close to level as possible Phil

I've heard about clipping the springs just a bit to reduce friction on the armature, But I wouldn't have any idea on how to level out the driveshafts, did you just lower the motor a bit?

If you repeated this again, would you have left the original wheels?

 

[PMac]

In addition to the Automotive Parts stores, Harbor Freight carries 1/4 and 1/2 oz tire weights (steel, not lead) with two sided adhesive tape already applied to them.

 

[diburning]

Pennies will give you the best weight to cost ratio, especially if you use pennies from 1981 or older although even newer pennies are still more cost effective than buying weights.

 

[DakotaLove39]

Pennies will give you the best weight to cost ratio, especially if you use pennies from 1981 or older although even newer pennies are still more cost effective than buying weights.

Id prefer to put all my pennies in my change jar for later purchasing of beers.

 

[sd24b]

I've heard about clipping the springs just a bit to reduce friction on the armature, But I wouldn't have any idea on how to level out the driveshafts, did you just lower the motor a bit?

If you repeated this again, would you have left the original wheels?

I tweaked the bottom clips. And eyeballed the drive shafts for alignment. Phil

 

[sd24b]

I've heard about clipping the springs just a bit to reduce friction on the armature, But I wouldn't have any idea on how to level out the driveshafts, did you just lower the motor a bit?

If you repeated this again, would you have left the original wheels?

I changed out the wheels on 3 GP38-2's with NWSL wheels. I noticed a decrease in tractive effort and the wheels got dirty as fast as the Athearn sintered iron wheels. I've not done any more Phiol

 

[johnpenn74]

Locomotive & Car weights

Forum Members,
Does anyone actually have cars are weighted prototypically? Does any actually gear weight locomotives so that they pull what the real would be able to pull?

I work in live steam where the physical weight of the cars and the grade on the track can stall you if you bite off more than you can chew. It it myunderstanding that NMRA recommends so much weight per inch, I am wondering why not have the actual scale weight of the car, and the scaled horse power of the locomotive on the model railroad.

Is NMRA RP 20.01 arguable out of date?
Does the grade and friction of locomotive drivers to rail work where this is feasible?

John P
Atlanta