manufacturing cost 2

[autoguru]

I wonder what might be the difference in manufacturing cost between the following 2 roller chains.

The two chains are identical in everything except the second chain is 30% wider than the first. So they both have the same chain plates, same construction, but the roller, bushing, and pin on the second is 30% longer than the first.

Will it equates to a 30% increase in price?

Thanks

 

[autoguru]

I don't think the needle bearings are worth it for its cost. Even though it may decrease the pin wear rate, (by a lot?), the chain will still die when its fatigue life ends.

Usually a normal chain only has a life of 15000 hours under ideal lubrication condition and installation. They needs to be replaced once the elongation reaches a certain limit. But this "needle bearing" design can increase the wear life drammatically so the chain will be limited by its fatigue life.

I'd like to find out more about fatigue life calculation. Do you think a chain can last 50000 hours if there are no pin wear elongation?

Thanks

 

[mloew]

There seem to be two conversations going on here: Price vs. Cost and chain engineering and costs. I really like the Price vs. Cost portions as this is typically not seen by the average engineer. I suggest that DReimer (to whom I gave a

) start a new thread.

Best regards,

Matthew Ian Loew


Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[autoguru]

While the needle bearing joints can extend the life of the chain drammatically, it'll do so at a very expensive price. For example, it might be 3 times as expensive as a regular chain.

That might not be cost effective if the machine only last twice as long as a normal chain. Normal chains can last up to 15000 hours if everything is ideal. For a machine that has a life of 20000 hour, clearly it's not worth it to get a chain that cost 3 times as much.

So my question is, what are the lives of common industrial machines that uses the chain drive? such as pumps, fans, compressors, ect... (in hours).

Thanks.

 

[GregLocock]

Jeez, for a guru you seem to be asking an awful lot of questions.

Typical lives for production machinery are 10000-80000 hours, although the latter is probably unrepresentative.

We still use some pre-war presses, albeit extensively refurbished.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[autoguru]

But those hours can be extended almost indefinately if there are rebuilds (repeatedly)?

I do ask a lot of questions since I'm curious but also because I need the answers.

 

[ischgl99]

Autoguru, noting can be extended indefinitely, there comes a point where the rebuilds are too expensive and it would be cheaper to buy a new machine.

Whether the needle bearing chain is expensive depends on your application and what you are comparing it to. How much does it cost to replace the cheaper chain? If minimizing elongation is a vital part of your selection process, then the higher price for the chain might be insignificant when you compare the alternatives. This company would not be selling this chain if someone did not recognize the value of it. Just because it is more expensive does not mean it is not the better value.

For a car company looking to do things cheap and make money on spare parts and repairs, the needle bearing chain is probably not worth the cost, but to the end user who must do the maintenance, it might be worth much more.

 

[DReimer]

Mloew,

Thanks for the star - my first!

I'm not sure I'm qualified to start a whole thread on this subject. I just took a business course a few years ago and we spent a few hours on marketing. Given that I'm pretty cynical about marketing I found the pricing strategies the most interesting and relevant to me.

mbensema: this is one of the things vendors can't seem to grasp with oem companies (like the one I work for). We're not interested in chain with 10 year service life. We just want something that will outlast our warranty! Ditto for so many other types of products - these guys need to sell the end users on this stuff so that they will demand it in the machinery they buy.

Dean

 

[ischgl99]

"these guys need to sell the end users on this stuff so that they will demand it in the machinery they buy."

That is exactly what I tell our salesmen

 

[autoguru]

Back to the original topic. I'm still talking about the manufacturing cost. (not the sales price)

How much would adding a small idler sprocket add to the cost of a chain drive?

Thanks

 

[dwt]

"How much would adding a small idler sprocket add to the cost of a chain drive?"

However much the idler sprocket cost plus mounting/attaching hardware.

 

[autoguru]

Let's say it's a chain drive with a ratio of 3:1.

It's often said that the sprockets are cheap and chains are expensive.

For sprockets, the smaller one will be cheaper.

The idler sprocket will be about the same size as the small driving sprocket but it's not really under any load, therefore I think it can be made more cheaply.

Therefore my rough guess is that the idler sprocket will add no more to 5% of the cost of the drive. But that's only my guess.