The Radiusmaster II is the latest creation from the inventive mind of John Price. The original Radiusmaster was a innovative machine with five different wheels on one belt. John was recognized on the ABC television show "The New Inventors" for his invention. John has taken on board much of the feedback from the original Radiusmaster and made some performance improvements in the second version.
I was fortunate enough to pick up two of the new Radiusmaster II's from John's factory in Sydney. What an amazing workshop! John works with a small staff in making each of the machines onsite. His equipment and jigs are fascinating - presses and benders, mill, lathes and all kinds of jigs and fixtures to make the parts. Especially interesting was the old Radiusmaster on a 45 degree angle used for grinding the rubber wheels to size. A platen holds the wheels square against the belt, but the belt drifts across the wheel, ensuring no one part gets too hot to melt the rubber. You can see the man's inventive brain hard at work in the shop.
The two new variable speed Radiusmaster II's join an old Radiusmaster (fixed speed) and a variable speed Select-a-Rad in the workshop. I retired the two 72" D J grinders, so now I am on just one belt size for all my grinders.
What has changed?
The most noticable change is the off setting of the platen on the main casting. This allows cutting in on both sides of the platen. This requires a new set of platens.
The tracking mechanism has been strengthened and improved. This offers an even steadier tracking over the already excellent tracking of the original. Now you can really notice uneven belts as they wobble on the smooth tracking. Plunge cuts, ricassos all cut even smoother on the belts.
The new variable speed motor is fantastic. It ranges from 400 - 1600 RPM with a twist of the dial. The slower speeds are perfect for working with woods, or cleaning up delicate grinds after heat treating. I use the slowest speed with a trizac belt for putting on the final edge on knives, without risk of overheating the most delicate of edges. The faster settings remove material efficiently and cleanly. Pushing hard into the platen only has a minor effect on the speed of the belt. There is lots of grunt in the 1.5kW motor.
I also asked for the stands to be 75mm higher than the normal height. This small change makes a big difference for taller maker's backs, less bending over the belts.
John has changed the base boards from MDF to a steel construction. These allow the grinder to be moved around the workshop, while still providing a solid base. The bases as slightly narrower, resulting in sometimes needing to have your right foot off the base when grinding, because the belt is offset. A small block of wood under my foot should fix that. I use the bases because my workshop changes layout with different classes and it give me a flexibility. Other makers may not need a baseboard and bolt the machine to the floor.
The motor is slightly further away from the belt assembly. This isn't an issue except needing to adjust the hollow grinding jig to fit the new distance.
How does it grind?
Very smooth. The solid construction, quieter motor and strong tracking makes for a great grinding experience. I find the variable speed is great for the less confine students in my class build their confidence in using the machine. For me, I see an improvement in my grinds over the older model, smothers, crisper, cleaner cuts.
Is it worth it?
It lives up to its reputation as the "Rolls Royce" of linishers. The versitality, smoothness, solid construction all make for a better grinding experience. While you could make your own grinder for cheaper, the time you spend would not be worth it. I'd rather be grinding blades than trying to be a expert in grinding machines. For the serious maker an investment in a machine like this would easily pay for itself in a year with the increase in productivity. For me running classes, often with people not used to working with tools, the variable speed allows a greater level of success.
See John's website www.radiusmaster.com.au for more details.