1756-OA16 internal fuse

[Operaghost]

Designed obsolescence or just economics?

If I design a widget that will be built like a tank and last 20+ years, how much is that widget going to cost me to build? I'll need to use premium components to get that life span. And I will have to make sure I can get those components for the next twenty years so I can continue to support my product.

Then, my competitor builds a similar type of widget, but they opt to go the low-cost route, and thus their product will have a shorter life span of say 7 years. Their device sells for half what mine is selling for. Functionally the two products are comparable, but my product is beefier, so it is slightly larger along with being twice the cost.

Who is buying my product? No one. I am not price competitive and my product dies on the shelf. Hardly anyone thinks long term anymore. It is all about how much this will cost today. Everything is so short-sighted these days. Never mind you would eventually have to buy three of my competitor's products to match the lifetime of my one item. If it lasts 7 years great, because the person responsible will have moved on to something else and won't have to answer the questions about why they didn't buy the quality product when they had the chance. In fact, they were probably promoted for saving the company money. When in fact they cost the company money.

Yes, the PLC-5 was indeed a tank. It would still be running a lot of processes today, but lower cost and lower quality competitive devices entered the market and forced prices down. With that we accepted lower quality and shorter product life spans as the trade-off. I wouldn't say Rockwell or other big manufacturers purposefully design their product to only last 7-10 years, but it certainly is a consequence of the drive for lower costs.

After all this time, that old Kirby looks like a smart purchase.

OG

 

[parky]

It was a good purchase, although I think they were about £600.00 then so very expensive, nearly got one myself, had a cold call in the 80's with the chance to have a carpet cleaned (the Kirby was an all singing & dancing system even had a spray gun attachment & scalp massager), they guy demonstrated it, proceeded to clean a small patch of my lounge carpet, I reminded him that the offer was to "clean a carpet" made him complete it then told him I would think about buying one, I think he was not happy.
On the point of built to fail, I agree 7-10 years is ok as most want to employ the latest tech & most systems have a payback within that time, however, 3-12 months with very little use like those south eastern cheapies is definitely buyer beware.

 

[OkiePC]

The bean counters are not all that good at attempting to estimate the costs of downtime. Some processes can offset three times the cost of all the control hardware with one hour of lost production and wasted product.

I sure miss the PLC-5 hardware. There's nothing like landing sixteen 12 gauge wires on a module, snapping it to the card then latching a metal bar over the modules and locking them in place with 1/4" spring pins. Many folks claim they should all be made into boat anchors. I claim you could pull one out of the lake, blow it out, and put it back in service.

I know of one large corporation who is very unhappy with the reliability of Controllogix hardware and inability to get some of it with conformal coating which was standard on the PLC-5 gear they replaced with it. They'd keep paying $40000 for a 1785-L80E if they knew they could keep doing that indefinitely.