Bench Grinders

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Bench Grinders

Machine-default.png
Synonyms: bench top grinders, grinding wheels;
DE: Schleifmaschinen
Type: power sharpening tool
Material: metal (not aluminum)
Location: metal workshop
Access Requirements: bench grinder introduction
Tutors: Lukas
Similar (More or Less): disc grinder, files, sandpaper


Safety

As the bench grinder is not only a power tool but one with openly accessible spinning parts, precautions need to be made. Have a tutor show the machine to you before touching it!

  • never wear gloves and/or scarves, roll up long sleeves and tie back long hair so nothing gets caught
  • always wear personal protection, especially safety goggles and if necessary some ear defenders and a dust mask

Usage

  • after plugging the grinder in, turn it on and wait until it reaches its final speed
  • if you hear any rattling or other funny noises turn it off immediately and check whether something is loose or whether tiny parts are inside of the casing
  • grind whatever you want to grind by holding it against the stone wheel; make sure the piece is supported either by the little table in front of the wheel or some other structure
  • do not force your workpiece onto the wheel as that will produce a lot of heat; cooling your piece from time to time is always a good idea

Sharpening

  • approach the spinning wheel slowly so your workpiece doesn't catch on it!
  • when sharpening hardened steel make sure to keep the blade cool, otherwise previous hardening may be undone!
  • it's a good idea to press the blade firmly against the support to keep a consistent blade alignment
  • check the squareness of the blade often to be able to make corrections
  • keep in mind that the grinder itself is only for roughing out the blade geometry, for a truly sharp blade you definitely need to work with some wetstones afterwards


Brüder Mannesmann M1225-125

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Brüder Mannesmann M1225-125

Bench grinder.JPG
Synonyms: bench top grinder, grinding wheel;
DE: Doppelschleifer, Schleifbock,
Trockenschleifmaschine
Type: power sharpening tool
Material: metal (not aluminum)
Location: metal workshop
Access Requirements: Bench Grinder Introduction
Manual: Völkner.de
Tutors: Lukas
Similar (More or Less): disc grinder, files, sandpaper


This bench grinder from 1996 is used but still in decent condition; the wheels run true and quietly. The grinder is equipped with two different stone wheels with different grits (35 & 60); one for heavy-duty and quick material removal, one for a finer and more precise material removal that will leave a way nicer surface finish.


Maintenance

The wheels need to be "dressed" from time to time in order to produce nice straight edges and maintain stability. Apparently, it's possible to do that with nothing more than a few spring washers on a piece of threaded rod![1] We should try this before spending time and money on a more sophisticated tool.

Changing Wheels

After installing a new grinding wheel, set up a safety perimeter (let's say everyone leaves the room) and let the grinder run for five minutes. Only if that went well, without suspicious noises or visible signs of problems, should the grinder be used again.

Upgrade Ideas

For really sharp knives, we could turn an MDF wheel on the wood lathe and use that as the final "grit".


Triton TWSS10

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Triton TWSS10

Triton TWSS10.jpg
Synonyms: wet grinder, whetstone sharpener,
dual-purpose wet grinder/stropping wheel;
DE: Nassschleifmaschine
Type: power sharpening tool
Material: metal (not aluminum)
Location: metal workshop
Access Requirements: bench grinder introduction
Manual: Instruction Manual
Explosion Diagram
Product Sheet
Tutors: Lukas
Similar (More or Less): disc grinder, files, sandpaper


The Triton TWSS10 provides a stone for wet grinding and a leather stropping wheel. Please ensure you always empty the water and loosen the torque screw when you are done!

This grinder is slow moving and intended for the final sharpening passes, not gor quick material removal. It has a 220 grit "diamond wheel" (with a water bath) and a leather honing wheel. It may be nice to add a swiveling base under it so you don't need to pick up the machine to switch directions!

There are quite a few accessories available from the manufacturer. You can find them in the manual (page 8) as well as on the product page.

We should document individual accessories as we get (or 3D print) them.

Straight Edge Jig

We have a straight edge jig for flat irons like bevel edge chisels or plane blades.