johnsmachines

I have several Proxxon tools, and I am happy with quality of these tools, which are mostly made in Germany.

One of my tools is a long necked angle grinder/ sander which I bought 2-3 years ago. It has not had a lot of use, but for small cutting, shaping, grinding and sanding jobs it has been excellent.

Recently I cast a 6″/150mm propeller in aluminium, and I was taking a lot of time in hand finishing it. Then I thought of my Proxxon long necked angle grinder. It takes a 50mm diameter flap disk, and it worked like a charm on the propeller. But the flap disk was a rather worn so I checked for replacements. And was a bit shocked to see prices of $AUD19 plus $AUD25 shipping PER DISK! F that!

So I hunted EbayAu and AliExpress but no joy there with the genuine parts.

But, I did find some 50mm flap disks at more reasonable prices, but the they were QuickFit attachments which would not fit the Proxxon. The had the same flap arrangement, on a hard plastic disk, but a plastic screw, replacing the centre hole.

Hmm. My Scottish ancestry kicking in. Can I modify these to fit the Proxxon grinder? Or make an adapter? That is a 2 start thread with an 8mm pitch. Would be tricky, but possible to make an adapter, but the flap disks would sit further away from the Proxxon safety guard. But MUCH cheaper at $AUD1.00 each!

So, as an alternative, I measured up the Proxxon spindle, 9.5mm diameter. And the retaining disk is 22mm diameter.

Modification Method: In a small lathe, I drilled a 9.5mm hole in the centre of the cheap flap disk which removed the plastic thread. The, used an old carbide boring tool to enlarge the hole at inner edges of the sanding flaps to 22mm, so the Proxxon retaining washer would fit. That’s it! Probably took less than a minute in total.

It worked perfectly.

n.b. The long neck Proxxon grinder runs at 13,000 rpm. I could not find a maximum rpm for the cheap disks, but time will tell. If you use this method, DEFINITELY USE EYE PROTECTION!