Large Scale Central

Aristo RS-3 and floppy axle positioning in general

Modeling Motive Power
#1

OK, since it stopped raining in Kalifornia, and after 2 weekends of spraying roundup and killing all the weeds on the right of way, I started going through locomotives on what needs updating, decoders, speakers, gauging, etc.

Got through all the USAT F3’s, all run great, all have dual speaker stereo sound, all have new centerset CamPac coupler boxes…

Got throught the GP7’s, same all run great, dual speakers, coupler mods.

Made a note that I need decoders in the S4, NW-2, and 44 tonner…

What was last in the cabinet? My old Santa Fe RS-3… and my database had a note about it running poorly and derailing.

Well, apparently I had put replacement motor blocks, the short-lived ones from Aristo that came with the stainless steel wheels. The flanges are too low, but heck, my trackwork is good, right?

The loco ran backwards, hmm, oh, I guess I swapped the motor blocks 180 degrees in the A frames, to put the floppy axle outboard… the loco derails on an S curve, wow, even the E8’s and SD45 run through it.

Check the track, dead level both directions… hmm… look at it more closely, on the lead truck, the 2nd axle is now the fixed axle. As it comes from the left turn to the 1 foot straight and then starts the right turn, the right wheel on the second (rigid) axle lifts as the loco swings to the left, comes up just enough to derail.

OK, so maybe it needs more weight, throw a couple of pounds on the top of the loco… WRONG! loco tilts to the left more, lifts the inner wheel on the lead truck more, worse derailment.

I’m stumped, dead level, and with a 1 foot straight, and no other locos derail there.

OK, so undo what you changed, put the trucks back with the floppy axles outwards, now no derailing in the S curve… yay, oops derails on a curve… ahh, next to a palm tree and a hump and crosslevel. OK, I can fix that, now it runs.

But here’s the point of the post: why is this thing so darn sensitive? I realize the RS-3 is a pretty long wheelbase, and perhaps 9.5 pounds overall is too light??, but why is this loco such a pain in the butt? Clearly it will now be between my RDC and RS-3 for the most picky on trackwork, but what have you guys learned about this loco and “rules” on the location of the floppy axles? These are latest gen motor blocks, BB and no lash screws. I just realized I did not check gauge, but this is happening on a curve and no issues through WR switches, so does not look like gauge issue.

So I’d like to hear experiences with the Aristo blocks and/or RS-3

Greg

#2

Easy one…,

Wheels are way under-gauge.

#3

Will check that Todd, not sure why it would cause derailments on track with no switches at point of derailment, but it needs to be checked and set for sure.

Thanks, Greg

#4

I have a RS3 with Revo/battery and I was having all kinds of problems with it derailing where other engines would not. Regauging the wheels helped but it is still finicky. I think the flanges are not as deep as my USATrains, this is my only 2 truck Aristo and as a result it is not as forgiving and more inclined to ride up on a switch or rise up if the track is not level.

I agree with Todd, check that gauge.

#5

Greg Elmassian said:

Will check that Todd, not sure why it would cause derailments on track with no switches at point of derailment, but it needs to be checked and set for sure.

Thanks, Greg

Let us know how you reset it. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-laughing.gif)

#6

I have an older RS3, I dunno what generation, and its one of my go to locomotives for all day flawless running. All I did was put sound in it and LED headlights.

As for what generation, it was the show locomotive for the ECLSTS 2005, the Western Maryland locomotive.

#7

and I just got the WM RS 3 2005 show loco, and am listening with interest to this thread…I found it derailed at a spot, but discovered the brake shoe had rotated down and caught the tie…

Jerry

#8

David, the older motor blocks with the axle tips in the journals tracked better in my opinion.

The newer ones basically are more rigid, since one axle is locked to the motor block.

Todd, if all else fails, widening the gauge can be accomplished by a small pie-shaped piece of brass shim stock a few thousandths between the axle and the wheel… works.

Greg

#9

Hi Greg,

If you remember, I have some operational-focused modifications on my RDCs. Most of mine are de-powered and have sprung sideframes (locomotive push-pulled). The cars not only track perfectly, but they even look better going over rough track (no tippy appearance). I used the FA/RS3 sideframes and trimmed off the brake detail to make them look more like coach trucks. On some of the newer ones I made little bushings to fit in the journals and trimmed the molded stops to allow full suspension. For wheels I used the PIKO 35mm ball bearing wheelsets and they plug right into the journals.

This year’s plan is to try powering some of the RDCs with one motor block and one full suspension truck. I’m hoping since I have super-free rolling BB wheels, that one motor block will handle 3 cars. If the Aristo motor block isnt up to the task I will use a USAT GP7 motorblock and 3d print a new sideframe.

Perhaps you could try this idea with your RS3…it may mean that you would run 2 RS3s with one motor block each to get the sort of pulling power you need.

#10

Greg Elmassian said:

Todd, if all else fails, widening the gauge can be accomplished by a small pie-shaped piece of brass shim stock a few thousandths between the axle and the wheel… works.

Greg

Show us how when you do yours. Hopefully we have the same generation/arrangement.

Thanks

#11

Will do Todd, really more along the lines of trimming the “pie shape” so there is no overlap as fitted between the tapered axle and the tapered hole.

Rocky, as this is a road switcher, and I have some grades, not powering one truck won’t work, but maybe I will go back to the old style trucks with the projecting axles to get a better suspension.

Also, remember these are the “reduced flange” stainless steel wheels, so that further exacerbates the problem. I might just fit standard wheels to it with standard flanges, but I like the SS wheels that do not rust. (the SS wheels will not go on the older axles, again differences in tapers, this makes a total of 3 different tapers used on aristo loco axles)

Will keep everyone informed, this weekend gauging will be checked/corrected.

Greg

#12

Greg,

Have you tried disabling the floppy axle’s ability to rock? Just jam in some cardboard or plastic. I know AC was thinking this design would have an equalizing effect, but in reality it doesn’t work! LGB trains also have no side to side give but they stay on the rails.

#13

Any updates?

#14

Nope, deep in the throes of QSI installs in an ABBBA PA-1 consist with special 4 speaker enclosures. Being really anal about track cross level and elevation change on a curve has mitigated the issue so far, but I’m not happy with the suspension system.

Please remember these had the very low flange Aristo stainless steel wheels.

I will investigate, and probably pull out my RDC’s at the same time, although they have the normal wheels.

Greg