Thread: clunk clunk clunk of wetstone grinder - why?

Two things I can think of straight off.

The wheel has not been properly trued and is not truely concentric with the spindle, cauing and intermittent cut. or

The drive system is motor shaft running against a largish wheel mounted to the main spindle inside the housing to provide the drive reduction. As you mentioned the large drive wheel is rubber surfaced, and the motor is spring loaded against the wheel with a substantial spring to provide drive friction. I'm thinking that the spindle being pressed against the drive wheel is creating an indent in the wheel while the unit is not in use, and the indent is causing the problem when the unit is operated. The indent probably recovers if the unit is in use for an extended period of time. A possible solution would be to rig a system that pulls the motor shaft clear of the drive wheel while the unit is stationary to prevent forming the indent.

Thanks Malb - you're absolutely right - not one but two resting place indentations on the rubber wheel.

I guess it doesn't affect functionality too much but makes for unpleasant operation - especially when it's brand new.

I'm not so sure that the rubber wheel will ever restore itself though - my mate's Triton never recovered...

I suspect that when switched off the wheel will frequently come to rest in that indentation, exacerbating the problem.

Cant say I have seen or heard this problem on a Tormek grinder.

Is there any way to dress these wheels to get the indents out or maybe it is an ongoing problem with too soft a wheel. or too much tension on the motor spring.

I agree Jim, it is either one or both of too much tension too soft a wheel.

I just got off the phone with Scheppach in Germany (luckily I speak Krautesian). They suggest I get in touch with my local distributor and get the rubber wheel replaced - this should not be the case.

I do harbour a suspicion that this is not uncommon on these rubber wheels though - I wait with baited breath.

Inspecting the underside I also noticed a bit of corrosion on the spring and tension bolt, suggesting it's been sitting in their warehouse for quite some time.

So I guess I'll take the whole unit back and get them to replace it - haven't popped it's cherry yet...

Unless some enlightened forumite is a rubber whisperer with a trick up his or her sleeve that they are willing to share on how to tease the indentation out.

Cheers

Ron

As you say still unused so back it goes and try one before you leave or get money back and upgrade to the Tormek

Took it back to Machinery House (for you kiwi readers). They suggested I take the shop demo model but when that wasn't sitting squarely on a flat surface I asked for a refund - their customer service couldn't be faulted and they complied straight away.

Bit the bullet, went down the road and bought a Tormek T7. Thanks for the support guys, I know I'll appreciate all the more in the long run.

Ron

I'm planning to buy one soon... Suggestions welcome

Originally Posted by Peter Benders

I'm planning to buy one soon... Suggestions welcome

All depends on what you want to sharpen.

The T7 has the advantage of beign able to use the blackstone wheel and also the new 4000g wheel for very fine sharpening of carving tools.