Workshop practice
When everything fails the same way, the problem is not the parameters
You have tried three different strategies and the defect appears in exactly the same place. That is not bad luck: it is information.
There is a point in any technical job when you get stuck in a loop.
Something does not work. You change a parameter. Still wrong. Change another. Still the same. Try a completely different approach… and it fails in exactly the same way, at the same point, with the same appearance.
At that moment most people accelerate: more trials, more combinations, more time. That is precisely when you need to stop.
The signal
If two independent paths produce the same failure, the cause is not in the path.
It is almost a rule of logic. If the problem lay in strategy A's parameters, strategy B — with different parameters, algorithm and logic — would fail differently, or not fail. An identical failure means both inherit something from further upstream.
That “something upstream” is usually one of these:
- The model. An unclosed surface, a duplicate face, a reconstruction tolerance leaving a crack invisible on screen.
- The selection. All strategies receive the same incomplete geometry list.
- Workholding or the work offset. If the origin is wrong, all paths are equally wrong.
- The machine. Backlash, play, an axis not reaching where it says it does.
- The material. It is not what you think it is, or is not where you think it is.
None of those is fixed by changing feeds.
How to break the loop
When the signal appears, the question stops being “which parameter do I change?” and becomes “what do all my attempts have in common?”.
Then eliminate possibilities properly, not superficially:
- Change just one of the things above. Different workholding. A different origin. The same program on another piece of material. Another machine, if available.
- Run the simplest possible test. A plastic part, an air cut, a marker trace. Do not aim for the good part: aim to isolate the variable.
- Measure, do not look. “It looks right” is not data. An indicator is.
That takes more effort than changing a number and running again. It is why almost nobody does it first. But it is the only way to break the loop.
Why it is so hard
Because changing parameters feels like progress. Each attempt is quick, each is different, and the mind records activity as though it were progress.
Investigating the underlying cause feels like going backwards. You dismantle what was already set up, return to an earlier point and, for a while, do not even have another attempt running.
It is just as counterintuitive as stopping a line to fix a fault properly rather than keeping production going with a workaround. For the same reasons, it ends up cheaper.
The short version
Three different attempts. Same fault. Same place.
Leave the parameters alone. The problem is a layer further upstream, and that is where to look.
At 7Axis Industrial we solve industrial problems without an off-the-shelf answer. Much of the work is finding where the fault really is before deciding what to buy or manufacture.