cast alum vs cast iron

[diesel85]

Not a fair comparison. A tractor is supposed to be heavy. A chainsaw and flashlight are supposed to be light.

My Dolmar chainsaw is made from mostly cast magnesium. Talk about light, but it's also a brittle material. I've had it for about a year now, curious to see how it will hold up for many years to come.

 

[Gary Fowler]

Since when is a tractor supposed to be heavy?

A real tractor is designed for pulling and when pulling, weight is your friend. Cars are made for speed and weight is your enemy.

Some of the E type "tractors" are basically lawnmowers with some tractor features (FEL) added on for use in yard maintenance. They are made to be lighter so they don't damage the yards as much. In yard maintenance, aluminum is better than cast steel but it is not so good when it comes to dragging a load, however, you can always ballast up with liquid or steel weights.
Depending on the alloy, aluminum might be stronger than a cast steel frame or axle housing.

 

[Industrial Toys]

Sure, the aerospace industry uses alloy castings and some of the most expensive equipment on the planet does as well. But this should not be confused with the "cheapest possible" type alloy castings used to make many consumer products.

 

[ultrarunner]

My opinion: It depends on design and material used. There are times when cast aluminum is stronger than cast iron and vice versa. No one ever talks about compacted graphite iron much... bring best of both worlds -- lightness and strength. But expensive.

One of the reason the Model T and early Model A's were so robust is the liberal use of Forgings...

Around 1930 the Accountants at Ford stared to substitute stampings in place of forgings and the stampings are not even close when it comes to strength...

 

[LD1]

As others said it all depends on the end game.

Aluminum in general is about half the strength of steel. But its also about 1/3 the weight.

So pound for pound aluminum is stronger.

They can design aluminum to be just as stong as cast iron, but its going to be a bulkier part. And the only real advantages are heat displacement and weight. Neither of which is critical on an actual tractor. Which is why most still use iron.

On the E-series, I think the intent was to make a lighter machine. For yard and gardening type work. Mowing, pulling a tiller, etc. Where weight (and traction) arent primary objectives.

Cast aluminum is more expensive. But its also easier to machine. So dont know if that had any effect on deeres decision

 

[Industrial Toys]

I will never forget when I was working in a stamping plant for Honda. Paging systems. Anyway, I saw how they carefully crafted a rear end out of stampings. Until then, I would have assumed all rear ends to be cast. I'm not even sure what vehicle that would have been used on in the early 90s.

 

[buickanddeere]

How does the cost of an ingot of aluminum cost vs cast iron? The cost of melting and pouring? The cost of machining?

 

[Ivan49]

How does the cost of an ingot of aluminum cost vs cast iron? The cost of melting and pouring? The cost of machining?

I don't remeber the cost but most aluminum is melted at a plant and then trucked to the casting plant. They use to add alloys to the aluminum to make it as tough as cast and it was in many cases a smaller finished part replaceing several cast steel ones. Most of the castinga are not iron but steel. I have machined 100's of them for the auto ind over the years and I have been to many casting plants casting alum. steel and magisem

 

[goeduck]

A real tractor is designed for pulling and when pulling, weight is your friend. Cars are made for speed and weight is your enemy.

Some of the E type "tractors" are basically lawnmowers with some tractor features (FEL) added on for use in yard maintenance. They are made to be lighter so they don't damage the yards as much. In yard maintenance, aluminum is better than cast steel but it is not so good when it comes to dragging a load, however, you can always ballast up with liquid or steel weights.
Depending on the alloy, aluminum might be stronger than a cast steel frame or axle housing.

Weight is NOT always your friend, which is partially why Kubota designs tend to the lighter side. To your point you can ballast up a light tractor but you cannot unballast a heavy one. I have soft soils with a high water table and at this time of year the heavy tractors rut the fields up. Weight is not my friend. There are many threads in this so we can get back on subject if that is okay. Cheers.

 

[TMGT]

My Dolmar chainsaw is made from mostly cast magnesium. Talk about light, but it's also a brittle material. I've had it for about a year now, curious to see how it will hold up for many years to come.

I have 2 dolmar's, you'll be fine, there's a reason Home Depot uses them as rentals.

As for the aluminum, I've been inside the Kubota B series rear axles, very well designed and whatever alum alloy they use is pretty tough stuff.

I'm also in the group that needs a light tractor that can be ballasted when needed. It's used for multiple duties from lawn aeration and mulch spreading to clearing brush and trees and moving pallets of firewood so a heavy machine couldn't do everything I need.