I bought a cheap elliptical / exercise bicycle. I didn't know if it would get much use. And if it did, then I could justify a more expensive unit. It quickly developed a clunk in the pedals. I disassembled the covers to inspect the drive, expecting to find the bearings were failing. The belt had a fixed tensioner, not spring loaded - the pedaling resistance was adjusted by a drum brake unit. I don't know how they assembled the tensioner - the belt was ridiculously tight. I had to struggle to unbolt and remove the tensioner - it was at the end of the adjustment for 'looseness'. After several minutes of pondering I re-routed the belt and re-installed the tensioner. The belt is now snug vs. piano string tight. And the clunk is gone.
Chris - I admire your tenacity in troubleshooting the problem. It seems that you should have been the design engineer on this mower. It also makes me wonder how much testing is done during the development stages for these types of products. It seems like this problem should have been recognized during product development.
Looks like another "Fixed by Clever Humans" column. I especially like how the author changed various dimensions, like distance from tensioner arm to bolt head and belt length. I agree with Nancy, he should have been the design engineer for this product.
I have found numerous opportunities to choose better bolts, knobs, transistors, resistors, capacitors, etc. on various pieces of equipment in my days. And certainly, in many cases, I could have written a better manual after spending only a few hours with a product. I could certainly spell better than they did.
We shouldn't expect perfection with most devices. They only had to meet spec for marketing. He was lucky to have a lift and to see the problem. I wonder how many of these were sold off on Craig's List to some unwary soul who spent a fortune on repairs never to be satisfied?
Yes, Ann, another "Fixed by Clever Humans" column. I do wonder, though -- did the manufacturer bother to test this design? From what I'm reading here, the design flaw could have happened on any or all of its mowers. Shouldn't they have picked that up in test?
For an item this expensive with only 7 hours of use, it surely would have been covered under warranty to troubleshoot the bad design. There may have been a technical bulletin explaining the issue that the repair tech could have reviewed.
Problem with a warranty claim, is you will only get the product repaired to the faulty design standard.
There are many times when I regard what I buy as not so much a product, more a set of parts from which to assemble something better.
I have a self-propelled Troy-Bilt walk-behind mower. In 7 years of ownership, I had to replace the rear drive wheels, the front axle, front axle support bushings (three times!), rear drive transmission, and four drive belts. The paint flaked off the inside of the deck years ago. To be fair, when it is working, it works well, but I have invested 50% of the purchase price to keep it running for the last 7 years! More evidence that the monkeys work for Troy-Bilt (and their parent, MTD)! I will NEVER buy a Troy-Bilt product again!
It seems like all the "Fixed by Clever Humans"--oops, I mean, "Made by Monkeys"--columns are about products that were never tested, or at least, never tested in any way that's relevant to their actual use.
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.