Thread: Bulk cutting of 2" hook and loop sanding discs?

I would try cutting a sheet without grinding the teeth off. A soft edge on the sandpaper would not hurt.

One could make a hinged book from plywood with a predrilled hole in the top. Put however many sheets between the plywood , clamp and attach hinges.

Put the sandwich on the drill press and run down the spindle to fit the hole saw in the hole, clamp the open side and cut.

In the leather industry, there are 'clicker' dies. Hard steel, made to size, usually with some neoprene inside, and plywood backing. They are made for a table top hydraulic punch press. You may be able to find a leather shop that will let you use their press. I have 1/4 inch thick pipe sections, about 1 inch high. Use a 1/2 inch thick piece of plastic, set up 5 or so layers of abrasives, put a piece of wood on the metal, and use a 6 to 10 pound sledge hammer. No problem going through 5 layers, though you don't always strike level, so you may have to hit twice. The pipe is reamed out slightly on the inside, and a double bevel on the cutting edge (single bevel will tend to crimp over). Important to have punch board right over a table leg, rather than in the middle of the table. I don't see why it wouldn't work with a hole saw, but you would still want the wood over the metal, and you will have to remove the discs from the saw. I had tried arbor presses, but they don't hold up unless you have a really heavy one (5 ton or more), and the sledge is easier.

robo hippy

[. You may be able to find a leather shop that will let you use their press.

Pretty hard here with the OHS laws especially in Victoria where Ern is located. They have some of the toughest in the country.
But a good idea and ideal if you could swing it.

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The tricky bit is holding the multiple sheets in place while cutting, I haven't found an ideal solution for that yet

I have often wondered if a slow rotation of the hole saw rather than pounding it would not be better for multiple layers. I have done this with other materials but never with sandpaper and ideally have the abrasive side down when doing so.

Paul, good idea

For a trial I used a bit of Perspex on top ... gives the advantage that you can see to position the pack.

First run of 5 sheets, it was clamped on one side, hand held on the other. It did some walking but there was a good result. 2nd run: clamped both sides but the finer discs at the bottom got crumpled a bit on exit.

The Perspex is too thin; about 3mm. Double that or more would be better.

So the hole saw minus teeth and with the outside bevel honed with a diamond credit card is sharp enough to go into the melamine scrap on this table

The saw was $9 on sale at Total Tools (Preston, Melb.).

Added: the drill press was running at 250 rpm.

Update: this is going gang-busters

Takes about a minute to position, clamp, cut and extract. Stacks of 5.

Have found that sandwiching fine sheets between coarse, heavier-backed sheets, eliminates any crumpling.

Producing years' worth of discs, from #80 to #1200.

Originally Posted by rsser

Update: this is going gang-busters

Takes about a minute to position, clamp, cut and extract. Stacks of 5.

Have found that sandwiching fine sheets between coarse, heavier-backed sheets, eliminates any crumpling.

Producing years' worth of discs, from #80 to #1200.

sweet nice progress

Dave, I did give your suggestion a try out of interest.

Starting out with the muffler punch (pictured) it was clear that the outside had splayed. I was maintaining the bevel on the inside. So correcting the splay freehand on the grinder, I had at a stack of 5 sheets with MDF underneath.

The result was again not a complete cut, but the big advance was that it was only one thumping session for five scissor sessions So thanks.

The pipe must be stainless; the folds at the top are a by-product of many thumping sessions

...

If a beginner wanted to get into this game and had good hands, I'd recommend the punches Jim or the Sandpaperman stocks.

Cool to hear

The folds on the top look awesome

Cheers,
Dave

Nice bit of incidental art ;-}

So, after 14 stacks of 5 sheets each, the edge needs honing.

If you stack abrasive to loop/fuzzy side, very little migration. With the plastic punch board, they will cut all the way through. Having a wood pounding board over the metal prevents crimping. Cutter needs to be no more than 2 inches high. You could do a club purchase of a lot of abrasive, if you can get them to agree on which abrasive, and have a punching party. I used to pay my daughter 1 penny per disc to mark the abrasive grit on each one, as most of the abrasives don't have grits marked so that it will show up on every disc. They really should color code the grits.

robo hippy