Xlracer

BTW

I previously had a problem with an astrotrac which I thought had a bit too much free play in the pivot bearing when I mounted a telescope on it, and returned it to astrotrac, who stated they found it to be within their normal parameters and OK. As the telescope was reasonably heavy, although claimed by astrotrac to be within the capabilities of the mount, and I intended mainly to stick a camera on it, for a shortly forthcoming trip to New Zealand I did not pursue the matter further with them, but I came to the conclusion that their engineering knowledge was a bit lacking since they clearly failed to understand how internal bearing clearance was the root cause of the problem, and made a straightforward modification that put an extra bearing in and that pre loaded both bearings which removed all play without increasing the driving torque required, and documented this on SGL for everyones information.  As I say if you think sorting problems out is expensive, try failure and all the publicity that goes with that.

Coming from a pre retirement background of employment as a senior QA engineer in the high tech electro optical  industry, the cost of quality argument seems a bit nebulous to me, either the product meets its specifications, or it does not. If it does not, in the UK at least, it is in breach of the Sale of Goods Act, which is the responsibility of the seller not the manufacturer. They can of course take the matter up with their supplier separately.

If it does not meet the criteria for which it was sold, in this case clearly as an accurate high precision imaging equatorial mount with specified accuracy criteria, it is not of merchantable quality, and must be replaced, repaired, or refunded by the supplier, its that simple. I was involved in a case in the past with a Cape Newise telescope where the supplier to her credit, did exactly that without demurr when the problems were quantified for her. The mantra  in industry in my experience is that if you think putting problems right is expensive,  try failures. There is clearly a concentricity issue between the effective pitch circle of the worm teeth and the mounting, which is a precision machining issue, and accounts for Meade telescopes having spring loaded worms as their accuracy is poor but dealt with rather cleverly by design, and accurate worm gears being expensive. However on modern CNC machines with effective sampling and inspection regimes, bad product like this should not get ot of the door, and represents a failure of the quality management system at Synta, irrespective of whether the gears are machined and assembled by themselves or sub contractors.