pedestal grinders and other off-hand grinders session 6

Pedestal Grinders and Other Off-Hand Grinders

Session 6

Shop Tools and Techniques 2

Grinding

• Grinding is the process of removing material by the cutting action of individual hard and sharp abrasive grains or particles of a revolving wheel as they come in contact with the surface to be ground.


Grinding Wheels

• Abrasive Particles that are held together by a glue-like material called the bond.


Grinding Wheels

• Abrasives either Natural Occurring or Synthetic

• Natural• Emery• Corundum• Flint• Garnet• Quartz• Diamond


Grinding Wheels

• Synthetic• Aluminum Oxide• Silicon Carbide• Zirconia-Aluminum Oxide• Boron Carbide• Ceramic Aluminum Oxide• Cubic Boron Nitride• Diamond


Grinding Wheels

• Natural verses Synthetic• Synthetic Has replaced most naturally

occurring abrasives• Superior Hardness• Durability• Controlled Grain size• Controlled Purity• Controlled Shape


Grain Size•Grain Size determines the coarseness or fineness of the grinding wheel

Coarse Wheel Fine Wheel

•Ranges from 6 (very coarse) to 240 (very fine)


Bond Types

• Vitrified Bond• Most common (Clay or Feldspar)

• Resinoid Bond• Synthetic resins

• Rubber Bond• Flexible Bond

• Metal Bond• Electrically conductive wheels


Grinding Wheel Grade

• The degree of strength that a bond holds the abrasive grains in the bond setting.

• Grade A• Softest

• Grade Z• Hardest




• Hardness of Material• Hard Material – Soft Wheel

• Area of Contact• Large Contact – Soft Wheel

• Speed of Wheel• Higher Speed – Softer Wheel




• Machine Condition• Rigid Machine – Soft Wheel

• Rate of Feed• High Rates – Hard Wheel

• Operator Characteristics• Ram Rod – Hard Wheel


Grinding Wheel Structure• The structure of the grinding wheel is

the space relationship of the grains and the bonding material to the voids that separate them.

• Structure 0• Small Spacing

• Structure 12• Larger Spacing


Grinding Wheel Structure• Grinding Wheels are fitted with paper

blotters that act as cushions between the wheel and flanges holding them on.


Grinding Wheel Features

• Abrasive Type• Aluminum Oxide, Silicon Carbide, CBN,

Diamond

• Grain Size• 8 coarse to 240 very fine

• Grade• A – Soft to Z – Hard

• Structure• 0 – Close to 12 - Open


Grinding Wheel Features

• Bond Type• V – Vitrified S – Silicate B – Resinoid• R – Rubber E – Shellac M – Metal

• Diameter

• Width

• Bushing Size

• Shape


Grinding Wheel Manufacture

• The methods used in the manufacturing of specific grinding wheels are dependent upon the individual abrasive grain, the bond to be utilized and the particular application that the abrasive will be used for.


Pedestal Grinder

•. •

•The grinding wheels are mounted on a double-ended spindle and are held in place between two flanged disks

•Typically, a roughing or coarse grained wheel is usually mounted on one end of the spindle and a fine wheel on the other.

•A tool rest is provided for each wheel so that tools may be held or steadied while being ground


Pedestal Grinder


Pedestal Grinders


Pedestal Grinder Bases


Pedestal Grinder Accessories

Rear exhausted dust collection unit



Quench Bath Cup


Pedestal Grinder AccessoriesWheel Guard


Pedestal Grinder AccessoriesWhy you need a Wheel Guard



Spark Guard



A tool rest is provided for each wheel so that tools may be held or steadied while being ground



Eye Shield and Work Light



Dressing Tools



Tool set for removing and mounting guards, rests, and etc.



Spindle nut wrench



Spark guard and tool rest setting gage



Lockout lock and tag



Lockout hasps


Dismounting A Wheel

1. Turn off grinder

2. Lock-out and Tag-out grinder

3. Disconnect exhaust collector

4. Loosen and relocate Eye shield

5. Loosen and relocate tool rest

6. Loosen and relocate spark guard


Dismounting A Wheel

7. Remove wheel guard

8. Loosen wheel mounting nut

Right hand threads on right side

Left hand threads on left side

9. Remove Wheel

10. Inspect wheel for damage

Discard damaged wheel


Turn Off Grinder


Lock-out And Tag-out


Disconnect Exhaust Collector


Loosen And Relocate Eye Shield


Loosen And Relocate Tool Rest


Loosen And Relocate Spark Guard


Remove Wheel Guard


Loosen Wheel Mounting Nut


Remove Wheel


Inspect Wheel For Damage


Mounting a Wheel1. Clean Spindle shaft

2. Replace inner washer

3. Ring test wheel to mount

4. Install wheel on spindle

5. Replace outer washer

6. Tighten wheel mounting nut

7. Rotate wheel manually and observe


Mounting a Wheel8. Replace wheel guard

9. Reconnect exhaust collector

10. Relocate and tighten tool rest

11. Relocate and tighten spark guard

12. Remove Tag and Lock

13. Stand to side and restart grinder

14. Dress wheel


Clean Spindle Shaft


Ring Test Wheel


Replace Inner Washer


Install Wheel


Replace Outer Washer


Tighten Wheel Mounting Nut

DO NOT Over-tighten Nut!!


Rotate Wheel Manually


Replace Wheel Guard

DO NOT Over-tighten Nuts!!


Reconnect Exhaust Collector


Relocate And Tighten Tool Rest



Relocate And Tighten Spark Guard



Remove Tag and Lock


Stand To Side And RestartGrinder


Dress Wheel


Other Grinders


Other Machines


The End!!

pedestal grinders and other off-hand grinders session 6

Documents

shop tools

wheel grade

revolving wheel

fine slide

bond setting

open slide

larger spacing slide

techniques8 bond types