Rapido LRC tight wheels.

[Alexpl]

Has anyone experienced tight wheels with their LRC coachs? Is there a fix?
Thanx in advance..
Alex Platt

[craigolio1]

I haven’t investigated mine too closely. Haven’t had time. But something is up. I think maybe the wheels are in gauge but the axle tubes aren’t centred so they may be rubbing on a bearing.

Craig

[dangerboy81]

I noticed a couple of potential problems, though I'm not sure just what is up for sure. I find the frame of the trucks is rubbing on the back of the wheels on some axles. I just kinda pried the frame away from the back of the wheel. I also lubed with an old bottle of graphite I have here. It was sold by Kadee to lube coupler pockets. I put a puff of that on the bearings and that helped immensely. I still feel they are too stiff, but they roll much better than they did.

[thomasjmdavis]

I noticed a couple of potential problems, though I'm not sure just what is up for sure. I find the frame of the trucks is rubbing on the back of the wheels on some axles. I just kinda pried the frame away from the back of the wheel. I also lubed with an old bottle of graphite I have here. It was sold by Kadee to lube coupler pockets. I put a puff of that on the bearings and that helped immensely. I still feel they are too stiff, but they roll much better than they did.

In that photo, there appears to be a lot (well, from an N scale point of view) of flash left on the truck frame- it looks like a larger bit is interfering with the back of the wheel in the lower right of the photo.  And perhaps also causing the bearings to fit too tight in the frame, distorting the ends of the frame and pressing them into the back of the wheels (apparent on both sides of the lower wheelset in the photo, the upper looks fine).  Either that, or the press fit on the bearings in the frame is just too tight by .001 or some such.

All that said, are those actually itty tiny ball bearings?

[dangerboy81]

Yes they are. I was surprised to see ball bearings myself.
I took these photos for a video I was going to make about it, but decided not to post.

[mmagliaro]

Hmmmm... Well, my experience with little ball bearings like that is that they are not as "free rolling" as you would think.  In fact, they are much worse than a pointy axle spinning in a bronze or Delrin cone-shaped hole.  In the photo you showed, the ends of the plastic frames all look bent outward and could still be rubbing on the wheel backs.  I think I would be inclined to not bend the plastic, but instead, file the outside faces of the plastic thinner so that the actual ball bearings races protrude slightly on the outside and the wheels run up against those instead of against the plastic frames.

Here's a photo that better explains what I'm trying to say.  I found this in another post on these cars over in the Product Discussion (which is probably where all this should be!)  Notice how on one side, the bearings stick out past the outside of the frame so the wheelbacks can never touch the plastic frame ("GOOD"), but on the other side, they do not and the wheels will ride against the plastic.  If you can push the bearing outward on the "Bad" side, I would think that would help.  I don't know if there is enough spread between the wheels to allow for this, however.  If there isn't, then filing the outside faces of the plastic frames will get you there.



---
How is the power pickup working?  It looks like they are depending on those brass "sleds" to touch the ball bearings, and I had disappointing test results with that in the past as well - meaning that the actual conductivity through a ball bearing race was flippin' lousy.

[thomasjmdavis]

@dangerboy81 - Thanks for the photo- a picture really is worth 1000 words in this case.

And Max beat me to the question about electrical pickup.

For me, this is "academic" because my modeling is focused on the mid 1950s, when there were no such thing as LRC cars.  But I do find the truck design interesting.  On the one hand, I think the use of ball bearings is cool, but I also think Max has a point- a ball bearing is not going to spin as freely as a pointed axle in a delrin truck frame. And on the bearings, I am very surprised that they did not use sealed ball bearings (although those might turn even less freely initially, depending what they were lubed with) as I would anticipate a lot of gunk building up over time as tiny bits of grit and dust find their way into the open bearing raceway.  Frequent lubrication a possible solution? 

[dangerboy81]

Oh I agree, a pointy pin, spinning in a cup is better, but as you can see, impossible to do in this case. I haven't had a problem with pick up, so far so good. I will take another look at mine to see what more I can do, but I do have them rolling "OK" now. I considered filing the truck frame a bit, but I kinda wanted to see what others are doing before I did something permanent. I will look for that other thread when I get a chance.

[mmagliaro]

I'd wager that a polished steel axle just rolling in phosphor bronze bearings (like steam loco drivers work) would work much better than this, and that would get you the inside-bearing truck.    All sorts of experimentation for this problem was done in a very long thread on another type of passenger car, but I can't remember what it was now.  You can get Bergeon bronze bushings in any thickness, bore, and diameter of the rainbow.

For example, here is one with a 1.5mm bore, 3.5mm OD, and thickness (width) 2.0mm.  They make a LOT of combinations.
20 for about 5 bucks.  If I could find ones that match what's in the car, I'd be really tempted to change them out and see how they do.
https://timesavers.com/i-9605155-48-bergeon-style-american-made-bronze-bushing-20-pack.html

[craigolio1]

I'd wager that a polished steel axle just rolling in phosphor bronze bearings (like steam loco drivers work) would work much better than this, and that would get you the inside-bearing truck.    All sorts of experimentation for this problem was done in a very long thread on another type of passenger car, but I can't remember what it was now.  You can get Bergeon bronze bushings in any thickness, bore, and diameter of the rainbow.

For example, here is one with a 1.5mm bore, 3.5mm OD, and thickness (width) 2.0mm.  They make a LOT of combinations.
20 for about 5 bucks.  If I could find ones that match what's in the car, I'd be really tempted to change them out and see how they do.
https://timesavers.com/i-9605155-48-bergeon-style-american-made-bronze-bushing-20-pack.html

It was @CNR5529 and I that did a whack of experimentation using bronze bearings.

He did the CAD design and had the trucks printed on Shapeways. I did a 7 car train. The results were better than. Athearn but not a home run. He then did a second design using a a lattice of bronze wires as a contact surface which by design, should have been better as in theory the axles were only contacting two wires at once. It was good but not really better than the bushings.

We shelved the project as our next plan was to try bearings in hopes that they worked better, but with the level of investment already into two different truck designs, decided to let Rapido do the R&D, haha. In comparison of the two, these new ones are not any better. I’m hoping to spend some time tonight tuning mine.

Craig

[mmagliaro]

Ah, Craig, yes, I remember now.  You did some really good work on that other car, and I remember the attempt with the bronze wires.
For the price of some bronze clock bearings (i.e. cheap), I think it would be worth buying some if you can find ones with the same OD and ID as what's in there (and a width that's at least close), so you could pop them in and see if they just "fix it".

[peteski]

Ah, Craig, yes, I remember now.  You did some really good work on that other car, and I remember the attempt with the bronze wires.
For the price of some bronze clock bearings (i.e. cheap), I think it would be worth buying some if you can find ones with the same OD and ID as what's in there (and a width that's at least close), so you could pop them in and see if they just "fix it".

If the wheelbase is the same, it would be even easier to use Kato Amfleet truck bearings (and wheelsets if the axle diameter is different).  To me that is probably the best design that can be achieved without doing some really esoteric stuff.

[craigolio1]

I’m not interested in re trucking these models.  Not at my own expense anyway. I’ll attempt to adjust them and if that doesn’t work ill take it up with Rapido.

Edit.

Had a chance to go over my cars. One car rolls fairly well so I decided to try and match the others to it.

I started by using the tip of a knife to turn the wheels. You can feel which ones drag more. On those I was able to move bearings a little hear and there. They now roll a tiny bit better but not great.

One of the cars actually has a bent wheel pin so it wobbles and locks the truck up after a 1/4 turn in either direction. That one needs Rapido for sure.

Regarding the frames bent out and touching the wheels. This is totally happening in places. After only a few laps there are wear marks on the frames. You can bend them out of the way but this will likely shift the bearing as well if you aren’t careful. The frame material is actually quite flexible compared to the typical plastics we see on trucks.

I’m deferring to Rapido.

Craig

[dangerboy81]

Let us know what they say/ suggest.

[craigolio1]

One will get new trucks for sure. But I have a feeling the answer won’t be readily available for the others.