Drywall sheet is a simple product. A layer of gypsum between top and bottom sheets of fibre board.  The difficult part is in the manufacturing process.

The fibre board is supplied in large rolls.  A shaft is fitted through the core.  A standard procedure for most fibre board products.  The shafts generally have “strip fingers” which are pushed out by compressed air to grip the inside of the core.  When the roll has run out, the fingers are deflated and the core removed from the shaft, ready to be fitted into the next roll.
Most of the time, this process works well.

Unfortunately, every now and again, the fingers of the shaft don't retract and remain firmly embedded in the core.  This causes some major problems.

This dust presented breathing problems, the smell permeated a large part of the factory and it had the potential to trip the smoke alarms

This process needed a very steady hand, otherwise the angle grinder would cut through the roll and grind into the shaft.  This had happened often as the shafts were covered in knick marks .  These marks then needed to be cleaned up afterwards, but this did not always occur and so there was a danger of hand laceration plus the chance of damage to the finger extend/retract mechanism

But,  at the end of the day,  the cores needed to come off.  There was only a limited number of shafts so they had jo be removed promptly. The shop floor workers had to do the best they could with what they had.
This was obviously identified as a safety issue and I was given the job of coming up with a safe method of removing jammed cores.

I should comment here that the simple answer was obviously to prevent the cores from jamming on the shafts.
Why did they jam ?.  There were a number of theories,  the favourite being inconsistent quality of the core materials.  The plant was in constant communication with the suppliers and whilst the problem would go away for a while, it would always come back. There only needed to be one jam up for it to be a problem.

The bottom line was that we needed a safe and effective method to extract the cores, if (read as “when” ) they got jammed.  This must have been a common problem in the industry, but we never did find out how other companies managed.

This is how I solved the problem.
I won't go through the details because whilst the solution looks very simple (and it is), there was some trial and error involved.  But that is generally the case with engineering design.

The fabrication shown in the pictures evolved through a few variations before I got it right, so if I was starting again,  the unit would probably look slightly different.
My solution was NOT to “knock” the shaft through the core, but to hold the core and “pull” the shaft through.
I fabricated a stand for the shaft/core assembly with vertical fingers to provide a “stop” for the core.
There was an undercut on one end of the shaft which was used as a locator and guide for positional adjustment during the production process and
I fabricated a clamp to locate in the undercut. I then used a hand winch (come along) to pull the shaft out of the roll
This proved to be a very simple and safe method

If anyone has the same problem, feel free to use the concept.  If you need more detail,  please get in touch. - This e-mail address is being protected from spambots. You need JavaScript enabled to view it
The stand needed to be mobile,  but could just as easily be fixed in place