The extrusion sample looks much better this time, but the extruder reckons that the imbalance of pressure around that hole will break the mandrel again very soon. They proposed a change in the profile of the rail to work around that. You can read about it in Harry’s Ulule update. I don’t mind the change, but I don’t understand why there was a problem in the first place. Some standard extrusion profiles (for example, the 4060 and 4080 profiles in the MISUMI HFS5 series) have holes just like the MakerSlide, with three webs meeting at one square core with a rounded fourth corner without a web. I would have imagined that this was a known problem with a known solution, not something that came as a surprise and required repairs and changes after the die was manufactured.
It is cold comfort to know that Bart Dring’s original MakerSlide, and later Inventables’, have been plagued by the same type of problem at one point or another. It only reinforces my opinion that the problem is common enough that it should have been foreseen and taken into account when designing the die.
We don’t know yet how much this change will delay the availability of the rail.