Rejects for Sale.

I don't normally grump about this topic, but like most of us I buy odd bits and pieces online - when buying from anywhere that isn't an established business my rule is only buy what I can afford to live without.

Sometimes I spot a 'too good to be true' bargain. Sometimes my fault, like the strap hinges that turned out to be sized for a jewel box rather than a guitar case.

Often turn out to be b-graded, like the R/C speed controller that had obviously failed due to problems with the original soldering but had been 'carefully re-worked' by an expert in hand soldering:

It works, but it's a moot question how many of those FETs are actually carrying their share of the current...

Yesterday I had four castors delivered, four for the price of one at the local DIY shed. One was looked solid - the centring bushes had been left out on assembly and the bolt tighted up until the side plates bent in and jammed the ball race. Cured with a length of ally tube and a couple of M6 washers, and a good price for a set of ball raced castors - but I assume the seller has got hold of a large batch that are cheap because an unknown proportion of them are QC fails?

And yesterday I dug out my insert tool for taking CCMT tips using the obtuse corner for a roughing tool. Again got very cheap ... and realised why I hadn't been using it, the thread wasn't deep enough for the screw to lock an insert in place. Fortunately I finally remembered where my M2.5 taps and die are (Q - why aren't they with all my other taps? A-I was planning to make a box for them) and the work of a minute to fix the toolholder. I was worried about breaking the tap in a hardened holder but it went through like a knife through butter. Probably EN1a... actually good news because at 12mm deep I can skim it down in the mill to make it consistent with my other tipped tools.

Moral, if you didn't know it already, if it's online and so cheap it looks to good to be true assume you might have to do some remedial work...

Substandard garbage is ok for the likes of us who can fix it but I think Trading Standards should come down much harder on people selling junk professionally rather than the odd attic clearout. I feel for the OAPs, children and people on desperately low incomes who buy cheap out of necessity and get stung.

Hi, one of my favourite bargain buys was from TK Max, it is a marble kitchen roll holder consisting of a curved tri-angular base and a 30mm pin. It was sold off cheap because the 6mm countersunk machine screw was missing, which holds the pin onto the base. Can't remember the price, but it was ridiculously cheap and I was looking for a holder anyway.

Regards Nick.

Edited By Nicholas Farr on 31/05/2019 11:51:47

Years ago I purchased a new toilet from a large building supply store. Got it home, unboxed it, and during a look-over I noticed a large hole in the ceramic under the rim all the way to the outside - a major leak if I had installed it, and not fit for use. Marked the hole with a red China marker, and took it back to the store. I exchanged it for a good one and took the new one home and installed it with no problems.

A few weeks later I was walking through the plumbing dept display and there on the shelf for sale was the defective toilet complete with my red China marker circle!

I wonder how many times they sold it and had it returned, or if some unwary person installed it and got a major water leak?

It should have gone back to the manufacturer or into the dumpster when I returned it, but someone or a few people in that store had no problem with trying to sell known-defective goods.

I remember picking up a centre punch from the car boot tool man for 99p..... I remember thinking how hard could it be to get a centre punch wrong..... I'll chance it for 99p.....

it lasted 20 seconds, blunt after the first hit, domed after the second and bent on the third...... I was only using a small tapping hammer!!

WOW, a lead centre punch !

Edited By ronan walsh on 31/05/2019 13:51:13

Bang good are an established business. Doesn’t make them any less of a shark where quality is concerned. I always say don’t buy from them unless you can afford to throw it away, if faulty.

Neil, time to 3D print some like these....

Originals are on Onshape at Tap boxes

Simon

I have been playing with digital humidity and temperature sensors and purchased some SHT10 Units off ebay, had a terrible time getting them to work so looked up the spec sheet and found the 10k resistor was missing off the board . I don’t know if this was a fault or designed that way but it sure would have saved me some hair pulling if the seller had have let me know. Ebay need to seriously clean up their act and sort out the sellers that say they are in your country but are really in China .

Another well documented issue is the inclusion of terminating resistors in Chinese "ELM327" OBDII car diagnostic interfaces. These are used to read fault codes etc on cars by interfacing to the CAN bus. This bus is terminated on each end by a 120 ohm resistor. As a resistor appears on the data sheet application typical circuit the Chinese include it. This results on 3 resistors connected to the bus and depending on other factors like cable length and number of bus nodes this can stop the bus working properly. Remving the resistor from tye interface fixes the problem. It's been known about for years but they keep fitting them.

Robert G8RPI.

Yesterday I needed a 8 x 1.25 mm die, I spotted a set of metric dies and holder at the local Challenge Garage, it was only $NZ10, so I bought it, commenting that it looked pretty rubbish. Got it home, found as I thought,the dies were unsplit, and what ever taper I put on the shaft it just would not cut. I took the Dremel with a fine cutting disc, and split the die, still no cut, had a look at the thread in the die, it was hooked over, same as a ***cheap die in another thread the other day. Got the Dremel out again with a cylindrical stone and ground the cutting edge, then back to the job, "it works". One other problem with the die is that there is only about 1 1/2 threads tapered on the lead in, and only just at that. By the instructions on the pack these dies are only ment for cleaning up damaged threads on bolts, not eor actual thread cutting. *** IT was Roy Garden, in what did you do today, on 28/05/19***

Ian S C

Edited By Ian S C on 01/06/2019 14:43:49