This is a relatively new development. My battery powered Aristo RS3 is riding up on my LGB 16000 switch frogs. Other engines USAT are OK.
I checked the wheel gauge against a USAT and the Aristo is maybe 1/32 of an inch narrower. I ran the engine backwards and it had the same problem.
This is my only Aristo road engine and compared to my USAT the flanges seem shorter on the RS3.
What can be done about this problem?
Like USA Trains the Aristo-Craft half axles are pushed into sleeves on the drive gear. Ignore the brass tube repair.
Altering the back to back wheel gauge may solve your problem.
Using the assembly method in this repair article may help.
http://ovgrs.org/the-trains/repairs/usa-trains-diesel-repairs/
Set the back to back correctly, measure with calipers, try 1.575"
But, the old style wheels are similar to the above, the newer types are wheels on tapered axles, and you have to shim the wheels out, since they are normally undergauge…
Greg
Perhaps provide a water feature to keep the frogs off the track… Sorry I couldn’t help myself (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-sealed.gif)
I know! Those pesky frogs causing problems along with the chipmunks, squirrels, rabbits, turkeys, cats and my cocker spaniel that likes to chase those critters, My RR is more like a zoo.
I wonder if the hot Summer sun has done something to my switches and the combination of the low flanges and tight gauge has this engine derailing? This wasn’t happening last year.
I will check out those wheels as suggested. Thanks guys.
Todd,
Have you run the loco through an offending turnout as slow as you can while watching it up close? Since it is only the RS3 that is doing it, something has changed in a truck or trucks. Sideframe dragging? They are real close to the rails to start with.
This is an (wheel) undergauge situation, the back to back is so “tight” that the wheels cannot stay on the rails when encountering guard rails/wing rails.
Can you explain what is actually happening? Did you measure the back to back yet? Can you take a picture similar to the above?
Greg
Greg Elmassian said:
Set the back to back correctly, measure with calipers, try 1.575"
But, the old style wheels are similar to the above, the newer types are wheels on tapered axles, and you have to shim the wheels out, since they are normally undergauge…
Greg
I just looked at a new motor block and it is the same as Paul shows and adjusted the same way and yes has tapered wheels.
Richard
Update: I don’t have a digital caliper but I do have a basic slide one.
I compared the RS3 to my S4 wheels spacing and the bad news is they were the same but the good news was I found a busted pickup wire on the S4’s truck so I resoldered that.
I then remembered that I have an Aristo B unit so I measured them against the S4 and the RS3 and the spacing was the same. The B unit has new wheels so I measured at the flange and it was close to 38mm. I measured the RS3 and it was 37mm. I bought this RS3 used and have been running it often after custom painting and installing a battery with Revo. I actually think the wheels are worn to the point that they can’t negotiate through the switch frog.
I then took the track powered B unit outdoors and ran it at different speeds through one of switches that is derailing the RS3 and it was fine and went over it without a bump.
Does the worn wheel/ flange theory make sense?
If it has tapered wheels, it cannot have projecting axle tips as Paul posted (and that picture is a USAT axle).
If it has the tapered fit wheels, then there are screws in the center of the wheels.
“new style”:
Old style with axle tips that go into sideframes:
Anyway, virtually all Aristo locos have incorrect wheel back to back, the picture below shows a result of insufficient back to back setting:
The wheel tread is lifted from the rail head.
The worn wheel theory does not make sense, you would have to wear off a huge amount of metal, since it’s the back side of the flange for a fair distance “in”.
38 mm is 1.5" too tight… 37 mm is way off… and you need to measure not at the tip of the flange, but the flat back of the wheels.
Still would like to see EXACTLY what you mean by cannot negotiate through the frog… I have shown you one example. If you try creeping through the switch and taking a picture it should show if you have tight gauge, bad flangeways, bad wing rails, bad wheels, etc.
You took it inside and it was fine, so you could start by comparing the 2 switches, the gauge through each, but the RS-3 is a touchy beast, there is not a lot of flexibility in the pivoting of the trucks, and many people will cut off the bolster rib on one end to help.
Greg
Just a quick question Todd How free are the trucks on the RS3 is there any binding? when you check don’t just let it hang put pressure on it and try to turn.
Richard
Greg Elmassian said:
If it has tapered wheels, it cannot have projecting axle tips as Paul posted.
If it has the tapered fit wheels, then there are screws in the center of the wheels.
Almost all Aristo locos have incorrect wheel back to back, that picture is an Aristo motor block.
The worn wheel theory does not make sense, you would have to wear off a huge amount of metal.
38 mm is 1.5" too tight… 37 mm is way off… and you need to measure not at the tip of the flange, but the flat back of the wheels.
Still would like to see EXACTLY what you mean by cannot negotiate through the frog… I have shown you one example. If you try creeping through the switch and taking a picture it should show if you have tight gauge, bad flangeways, bad wing rails, bad wheels, etc.
You took it inside and it was fine, so you could start by comparing the 2 switches, the gauge through each, but the RS-3 is a touchy beast.
Greg
Paul’s example is not about the axle tips but how the axle is pushed into the gear and that is how I and Paul adjust, push in or pull out.
Richatd
Thanks Richard, I was focusing on something else, the different motor blocks and their incarnations in the RS-3.
The RS-3 has the reputation for being finicky on track, as the articulation of the motor blocks is limited, many people removing one of the bolsters to sort of make a “3 point suspension” as is often recommended for rolling stock.
I did update my post above a bit, and recently I was running mine, which has the Aristo stainless steel wheel motor blocks, and those have reduced flange depths and mine was derailing quite a bit. Swapping the trucks so that the “flexible axle” was on the outer ends, as opposed to nearest the fuel tank made a huge difference. I had a cross level issue that my other locomotives took in stride, but the RS-3 with the more rigid motor blocks with reduced flanges did not like.
Greg
update:
I have the old style trucks with the axle tips.
I took the RS3 back out to run it through one of the known trouble spots and it passed through just fine at different speeds. I then took it to a another switch and the rear truck rode up and derailed.
I then took just a wheel set, made sure it matched the width of the RS3 wheels and carefully ran it through the LGB 16000 RH switch. I think what is happening is that the longer wheel base of this aristo truck which is approx 4" compared to a USAT at 3.5 is pushing the wheels to the Left rail on the switch as the engine is going through the Right tangent. Pushing the single wheel set at the same width as the RS3 wheels through the switch had the right wheel contact the brown plastic guide opposite the frog, causing it to lift and try to go straight when it should be going right and derailing.
This is a new development. The USAT engines go through Ok. The Aristo B unit with the same wheel spacing goes through ok.
It must be a really fine adjustment that needs to be made by pushing the wheels out a bit so when the truck jogs to the left due to the forward momentum the right wheel will not contact that plastic guide.
My RS3 is a PITA to run so it’s been years since I’ve run it. I think it has to do with the side frames and the way they interact with the axle.
OK, if the wheelset has the back to back correctly set (not yet satisfied), then perhaps the flangeways are not right, but it sounds like your back to back is still too tight, just like the first illustration I posted.
37 and 38 mm are out of nmra spec… you want to be at 40 mm… actually the target value is 40.005 mm
Greg
The back to back is 36mm on the RS3. I measured 3 types of metal wheels on my rolling stock, a Bachmann Climax a NW2 and they are 37mm. The RS3 is tighter than the average but my USAT GP38 which also has a longer truck wheelbase like the RS3 is also 36mm. The wheels on the GP are smaller in diameter but they also have the deeper flanges.
What is weird is that all the wheels on the RS3 have this 36mm and it ran fine over all these switches last month. I don’t know what has changed.
Now to figure out how to remove these axles and spread the wheels a mm or 2.
Todd you don’t have to remove any thing but you should find a Harbor Freight and buy a caliper under $20 from them and 2 straight screw drivers that are the same and will fit between the back of wheel and motor block.
Richard
That’s in my opinion a little dangerous, as you can “cock” the axle in the “gear castings”…
Richard, when you do this, you are pulling against one wheel and this can (not will) produce undue pressure in the wrong places.
Todd, please set the back to back to possibly at the NMRA minimum… your unmodified switches are a bit “sloppy” on the flangeway widths, but you CLEARLY have an out of spec problem.
This page has the specs, and the references to the NMRA and G1MRA standards.
Greg
I still think this is really odd how this engine has been fine all last season running over LGB and Aristo switches without issue and now it is having problems wit the LGB ones of all things. Maybe when I open up the motor block to spread those wheels I will find a axle issue but all 4 wheel sets measure the same on the back to back so I don’t think it is a cracked gear problem unless all 4 are broken which is unlikely.
I still do not know what has changed to make this RS3 such a problem except it has the lowest flanges of the fleet.
Thanks for all the info Guys.
