Model Engine Maker

Help! => Mistakes, muckups, and dangerous behaviour => Topic started by: Farmboy on July 25, 2012, 11:16:11 PM

Title: Wrong thread
Post by: Farmboy on July 25, 2012, 11:16:11 PM
Not sure this is the right place to post this, but it was certainly a mistake, just not mine.

When I bought my new SIEG C4B lathe it was a replacement for my little-used Unimat SL, so a huge step up in power and rigidity. A few practice pieces showed it to be more than adequate for anything I am likely to do with it, but when I used the power feed the result was very poor with the drive slipping intermittently.

After much head-scratching and dismantling I eventually discovered that, while the leadscrew had a left-hand thread, the half nut was right-handed! You can imagine they didn't engage very well  ::)

It took a fair bit of correspondence and some photographs to persuade the supplier (Axminster) that I knew what I was talking about, and a good deal more time waiting for the replacement parts to be shipped from China. To be fair, Axminster offered to replace the machine but by then I had completely stripped, cleaned and re-assembled it and mounted it on my home made stand so I opted to wait for the bits.

Once the correct parts were installed it was a whole different experience and my initial doubts about my purchase quickly disappeared as I cut a few practice threads with ease.

I doubt if this is a common fault, but something to think about if you have a similar problem.
Title: Re: Wrong thread
Post by: Farmboy on July 29, 2012, 12:24:11 PM
I forgot to mention that Axminster gave me a generous discount on my next order to compensate me for the inconvenience. (no connection, just a satisfied customer - eventually)
Title: Re: Wrong thread
Post by: BillTodd on July 29, 2012, 12:32:47 PM
Quality control - what quality control? !!!

How on earth could that happen?