Large Scale Central

Aluminum for Drivers and Wheels?

General Discussion
#1

Didn’t know really where to drop this question so I am posing it here. The conversation on Lasers and CNC has me about 99.999% ready to buy a table top CNC router. That led to a side conversation with Dan G. about cutting aluminum with them.

A project that I have been tossing around for quite sometime now with Kevin Strong requires a specific driver that if we want to be a rivet counting replica of the prototype is not available. That has led to many conversation with many people about milling the tires in steel and 3D printing the centers.

But this new conversation on CNC routers cutting aluminum makes me wonder if either an aluminum tire and 3D printed center, or an all aluminum driver, would be doable. If doable is it advisable? Is there any reason why it SHOULDN’T be used for that. And if it would make a decent driver, is there any reason it couldn’t be used for car wheels?

Curious what people might have to say.

#2

I would think that aluminum is too soft for train wheels.

#3

Well that was my original thought as well, but why? In what way would it be too soft? Are they going to wear out/get worn down? Car wheels are made from aluminum as are engine blocks and airplanes. I am not being antagonistic. I am genuinely interested in what “too soft” means in a practical sense and where the perceived failure will be.

#4

Car wheels are not in direct contact with the road. Aluminum engine blocks have steel sleeves for the piston holes and steel bearings for crankshaft.

Train wheels are in constant contact with the rails. I would think aluminum rails would create the least wear on an aluminum train wheel and stainless steel track the most wear.

#5

Devon,
I honestly don’t see why you couldn’t. It would take an awful amount of run time for them to wear down to a point were they would be unusable. However the flange would be the question as that is what is thin but I still think it would take a lot of run time. Check out the link below and you decide?
https://rrtools.com/product-category/track-tools/carts-dollies-push-cars/

#6

Thanks Joe. Thats more what I was looking for. And while I agree aluminum on aluminum would be the longest living.

I am only playing devil’s advocate because I raised the question in my own internal argument before posing it here. And given the weight of our trains and the honest amount of run time they see, do you really see a set of wheels wearing out?

I know I sound as if I have my mind made up and that I am disagreeing with you. At least thats how I feel it sounds as I am typing it. But I honestly am not doing that. I am just trying to hash out a personal opinion/understanding.

#7

and that is the flip side of my own internal argument when I posed the question. While aluminum is not steel, I would think it is at least as tough as plastic. And while we all love our steel wheels over plastic ones truth be told I will never run a train enough to wear a set out.

#8

I would think that aluminum drivers on an engine would be subject to much greater stresses and wear than wheels on a car being pulled along.

#9

I wouldn’t disagree with that statement. However, how much “more”? Do we really put that much strain on them that they would wear out? Unless people run theirs differently than I run mine, I can’t see me exerting enough stress to wear out a set of aluminum tires on a locomotive. I seldom see slippage that would causes excess friction. The weight of a locomotive is nowhere near enough to put stress on aluminum. I mean has anyone wore out a set of plastic Bachman 10 wheeler drivers. I would think aluminum would hold up at least as well and I can imagine anyone ever ran a 10 wheeler enough to wear them down.

Again only playing devils advocate here. I am not for or against either side of the debate.

#10

One area of concern, and rooster eluded to it, would be the flanges being the weak link. Where my concern there would be is rolling or some damage being done to the soft tip of the flange that may cause issues. But again if it were to happen it would be easy to file back into shape and I doubt would cause any long term problem.

#11

Does it HAVE to be aluminum? Why NOT cut brass?

#12

Fair question. From a practical standpoint brass would be fine. Aesthetically, unless we used white brass, it would not be prototypical. Of course this is a very minor point considering most of the driver/tire would be blackened and only the face would the raw metal been seen. And in most any case this would not be an issue for me. Certainly I would have no heartburn about it for rolling stock wheels. Even loco drivers I likely would not care about the color. But in the case of this one locomotive, it might be. I even cringed when I said that because I am not a rivet counter. But I do have grand plans for this one particular locomotive as a rivet counting project. That’s certainly one to consider and not at all out of the realm of possibility.

#13

There are many grades of aluminum from soft enough you could bend a 1/8 inch thick piece by hand (no tools) to armor plate for military vehicles. That said, what you would likely find at your local big box store is likely 6061-T6 which is a good general grade of aluminum.

There will be two different types of wear on rail car wheels. there is a compressive/slippage wear on the tire face that rolls on the rail head. Then there is a shearing kind of wear on the flanges where they rub against the side of the rail head. Flange wear will be significantly greater than tire wear. The second consideration is tractive effort. Aluminum rolling constantly on a harder smooth surface will over time somewhat polish itself, reducing tractive effort.

For manually pushed hand carts in prototype service I would agree aluminum is a good choice. It is far lighter than the steel or cast iron counterparts and will for practical purposes will last as long as the ferrous ones.

Personally, if I were going in that direction I would use the hubs from a cast iron pipe fitting to made tires for whatever material centers I was going to use. My choice for centers would be brass. The logic on the cast iron is it has the best coefficient of friction, and is harder than most of our rail materials.

My tuppence on the topic

#14

Thanks Bob this is exactly the sort of discussion I was hoping for. The problem we have had/still have is getting the right diameter driver tire in a ferrous metal . . . whether it be mild steel, stainless, or cast iron. Either it will cost a fortune to have them milled, no one wants to do it, or commercially made ones are not the appropriate size. Again this is a special deal where we are trying our best to get as close to prototypical as we can. Peter T has turned us onto some that would be very close and in all likelihood is the route we will go. But with the talk of CNC routers it made me wonder.

And the CNC router I would likely buy would not be suitable to cut steel or even cast Iron.

#15

Would these drivers be on live steam or electric? If electric, I don’t think aluminum would be the best for conducting electrical pickup. Also an issue if you use plastic inserts.

Thinking out loud
Steve M

#16

Battery RC. No power through the drivers

#17

Devon, if you are referencing a wood working router, even aluminum is going to be very hard on the bushings/bearings in the quill. I would not even dream of cutting ferrous metals of any kind on a router table, not to mention the safety hazard a broken bit would be.

Be kind to yourself and the tools and use metal working tools for metal work. Yes, I have seen folks use table saws and chop saws to cut aluminum, but just because you can does not mean you should.

#18

No Bob I am not talking about my wood working routers. I am looking at buying a table top CNC router that can be chucked with metal cutting pits to cut soft metals like aluminum and brass. This is how the entire idea came up.

#19

Well the 8" and 5" are both rated at the same weight capacity per wheel so how does that equate to a 3/4" or 1" wheel?

I’m thinking why not Devon… As I was told once… " You don’t know unless you try"

You are, you’re,your not gonna buy stock for the size you need at a big box store anyway.

#20

Oh if and when I do get the machine I will most likely at least try it. Whats the worst thing that could happen I wear out a set of drivers in a couple years and have to replace them? I certainly would give it a try.

So far no one has given me anything that would be a critical “no go” so far its just a wear issue and unless we try we won’t actually know.

Honestly I had a lot of people advise me against aluminum track for a lot of really good reasons. And so far I have experienced none of them .