Posted: Jan 11, 2010
Updated: Dec 23, 2013: Added note about clamping the hubs in a vise
Review: Oneway Balancing System
A simple idea yields big benefits
$63 from Craft Supplies USA, $69.50 from Lee Valley (NOTE: you must get the correct version for your grinder, not all vendors carry all versions)
Apparently making grinding wheels is difficult. Even premium brands are lumpy, warped, and (most important) out of balance.
Even if you use a dressing tool to make the wheel perfectly round, it can still be out of balance because of variable thickness and uneven density. And an unbalanced wheel can make grinding an unpleasant, difficult, and perhaps even dangerous task.
The Oneway Balancing System uses a simple, elegant method to perfectly balance a grinding wheel in just a few minutes. The kit contains the balancer, which is just a piece of sheet metal with a bearing attached, and special hubs and parts to balance one left-side and one right-side grinding wheel. The hubs are made for a particular size arbor and wheel opening, although the kit comes with spacers for wheels with larger openings (the red plastic tubes). There are no spacers for the arbor, you must get the the correct kit for your grinder's arbor. You can buy individual hubs from Oneway for additional wheels, but at $32 + shipping each, you may as well buy additional full kits.
Wheels are balanced by replacing the wheel's hub with one of Oneway's special anodized aluminum hubs. Each hub is threaded for a specific side of the grinder, make sure your get it right or the hub may come loose.
The instructions tell you to clamp the hub in a vise while tightening the other side. Make sure you do this. I recently spent several hours emailing back and forth with someone whose hub kept coming loose when he tightened the grinder nut. We finally determined that he hadn't put the hub in a vise and consequently hadn't gotten it tight enough.
Three bolts attach to the hub and act as balancing weights, like balancing a car tire.
Once the wheel is on the balancer, you adjust the balance bolts so they're evenly spaced with one bolt at the top. This bolt marks the "light point" of the wheel (the heavy point is at the bottom). You then slowly move the other two bolts toward the light point, which shifts the balance point towards the middle of the wheel. Eventually, the off-center bolt weight should counteract the off-center wheel mass and give you a wheel that stay put no matter what position you place it, i.e. it's now balanced.
Note that if the wheel is badly unbalanced the weight of the three bolts may not be enough to counteract the imbalance. Oneway doesn't address this in the instructions, so I sent an email to tech support. Their prompt answer said that it's possible to add more bolts or more washers to the current bolts. However, they suggested that if the wheel is that severely unbalanced you should just exchange it for another one.
Once the wheel is balanced, that's it! You should never have to do this again for the life of the wheel.
One other source of vibration can be the stamped steel arbor washers, they're not exactly a high-precision item. Oneway provides high-quality machined steel washers to replace these as part of the kit. The outside stamped steel washer is replaced by the Oneway hub itself.
(You may notice in the last photo that I use Oneway's Wolverine Sharpening System. However, the Balancing System is completely independent and doesn't require the Wolverine at all, it will work with any grinder.)
The difference in grinder performance with well-balanced wheels is phenomenal! My grinder is a fairly nice Jet 1hp running Norton 3X wheels, but it still vibrated to the point that the stand would slowly rotate on the floor. After using the Oneway Balancing System, the grinder runs wonderfully smooth and I get a better finish on my tools because they're easier to control while grinding.
It's a bit pricey, but in my estimation gives great value.