Allowable loco motor current draw before converting to DCC

[Toolbelt]

Well the good news is this old motor draws a little under 1/4 amp unloaded, 700 ma wheel spin and just about an amp when stalled. I had fully serviced the drivetrain prior to the test. The bad is the motor still growls like a Blue Box even though it's a good performer. I might play around with the flywheel balancing to see if that helps. If I put sound in this, I will likely have to crank the volume higher than I might otherwise.

 

[Smudge617]

I've maybe 15 BB Athearns, the only thing I check is the stall current as long as it's within the decoders limit I'll install and run it, so far I've never blown a decoder, at least not that way anyhow.

 

[Toolbelt]

I've maybe 15 BB Athearns, the only thing I check is the stall current as long as it's within the decoders limit I'll install and run it, so far I've never blown a decoder, at least not that way anyhow.

My current layout has cork track bed nailed to a 1/2" sheet of ply and the tracks are nailed through the cork into the ply. It doesn't have any supporting frame and has fold out legs screwed into the underside of the ply. It's creating quite a banjo effect I believe. My new layout will have a proper frame with solid legs, and 2" of foam plus cork roadbed glued to the ply. It should cut the noise down a bit, or at least I'm hoping so. My P1K RS-2 is silent in comparison so it won't cure the noise fully.

 

[bnsf971]

Well the good news is this old motor draws a little under 1/4 amp unloaded, 700 ma wheel spin and just about an amp when stalled. I had fully serviced the drivetrain prior to the test. The bad is the motor still growls like a Blue Box even though it's a good performer. I might play around with the flywheel balancing to see if that helps. If I put sound in this, I will likely have to crank the volume higher than I might otherwise.

Most of the noise is from the ball and spline driveshaft on the old Blue Box drive. The fix is to replace the flywheels and driveshafts with the updated parts with hex holes in the flywheels and one-piece driveshafts. Of course, by the time you do that, you are defeating the purpose of using the original stuff, cost-wise.

 

[Toolbelt]

you are defeating the purpose of using the original stuff, cost-wise.

I think I past that threshold just adding detail parts. Seems it's one thing after another when doing upgrades and conversions. I didn't start this process for financial savings but more because this old girl was 35 years old and sat in a box for 21 of those years. I'll be doing a quick conversion of my RS-2 (without sound), including a detail part or two, and after that it will be straight DCC from then on. Luckily I only have one more loco in mind for my layout.

 

[Toolbelt]

If I had some money to invest, I would develop a simple drop-in motor upgrade kit complete with drive shafts for the 100's of thousands of Blue Boxes still in operation.

 

[GGNInNScale]

I have a PowerCab on my n scale layout. I run up to 6 trains at a time, and may have 4-6 engines idling, all with sound on. All of my decoders are ESU LokSound. At most, I see about 900mA to 1A current draw. Most of my trains are ~6-7 cars due to length limits in the yards and passing tracks. Grades up to 2.5%. I have Kato and Atlas predominently, with a few ConCor E units, an Athearn FP45, and an Arnold U boat. The latter three are very heavy (relatively). Bottom line- you should be fine.

 

[bnsf971]

Off topic for this thread, but in the waning days of blue box kits, Athearn included plastic handrail sets colored to match the engines. You might be able to find a green set to fit your engine. Here's a link to similar handrails:

BURLINGTON NORTHERN GP50 RTR VERSION Handrail Set (Plastic Version) Athearn HO | eBay

PLASTIC HANDRAIL SET. BURLINGTON NORTHERN. READY TO RUN VERSION ONLY. DOES NOT FIT BLUE BOX.

www.ebay.com

 

[Toolbelt]

Off topic for this thread, but in the waning days of blue box kits, Athearn included plastic handrail sets colored to match the engines. You might be able to find a green set to fit your engine. Here's a link to similar handrails:

BURLINGTON NORTHERN GP50 RTR VERSION Handrail Set (Plastic Version) Athearn HO | eBay

PLASTIC HANDRAIL SET. BURLINGTON NORTHERN. READY TO RUN VERSION ONLY. DOES NOT FIT BLUE BOX.

www.ebay.com

Call me strange, but I like my metal railings, though I did have to play mad scientist by mixing a med green and white to get the right shade. They might be slightly chunkier but I have a habit of grabbing my locos where I'm not supposed to. lol

 

[kjd]

I haven’t kept up with this thread but wanted to say I’ve put decoders in lots of older blue box Athearn and never had a problem with the motor burning up the decoder.

I also prefer metal handrails to the crooked plastic ones.

If it’s not too late, BN painted walkways black. Unfortunately, back in the day, Athearn didn’t.

 

[Toolbelt]

BN painted walkways black.

Yes I have that on my to-do list and will try to paint it with the railings in place. I bought some 1mm Tamiya tape to hopefully get a crisp line at the hood edge.

 

[Canalligator]

I’m converting BB U-boats to DCC rather than replacing, because they’re custom painted for my freelanced road. See my avatar. I’ve done one so far. I just made sure the decoder had sufficient current capacity. Though I did buy a new F40, the old girl has a lot of hours on her.