ROTARY
A medium rate of production.  Side or top loading into pockets.  The tooling becomes datum for the part.  Parts do not touch each other in this process, achieving better quality in flat and parallel.

                                        THRU-FEED  (Belt Feeder or Short Stroke Pusher) 
Normally produces the highest yield of parts per hour.  A belt feeder pushes each part end to end, forcing the part through the grind zone, wheels.  Part configuration needs to be noticed.  A triangular part is not conducive in this application.  The parts could/would ride up on the parts in front of, or in the rear, as pressure is applied (grind pressure).   The parts would have trouble at entrance and exit of the wheels, causing poor quality.

                         RECIPROCATOR / SWING ARM
Slower production.  Normally 1 to 3 parts at a time.  Normally manual load/unload.  Good for small lot sizes.  Easy changeover from part to part.  Also used for high stock removal.

                          LONG STROKE PUSHER FEEDER
The highest quality disc grinding application.  Loading one part at a time.  Pushing through the grind zone.  Similar in part path of a Thru-feed.  Normally very low stock removal.  Also a quality part coming in.  Used for .0001" or lower in flat/parallel.  Also micro finishes under 10 RMS.  The part enters at a slow rate, stock is removed.  Then, while between wheels picks up speed, creating flat/parallel then finish.  Normally NO head settings so the integrity of the wheels are perfect.

• This type of Grinder is used to grind one end   of a part.
   

• The part(s) are held by a belt.  When the carrier is empty, the belt is still held tight by the cylinder, when filling or full.  The cylinder gives to pressure.
   

• On a double or single disc machine, this style tooling does not allow the part to rotate.  A leading or trailing edge grind pattern is normal.
   

• This style tooling (a clamp style) is best for perpendicularity.
   

• The open vee or pocket allows for simple top load with the help of gravity.  Also simple gravity unload.
   

• This type tooling can be used on a Double Disc machine and also a Vertical.

• This is a typical Besly Double Disc Grinder.
   

• Loading on this style at the bottom.  Thus reverse head settings.
   

• Loading at the bottom allows for gaging to be done at the top, in a more open, cleaner area.  Gage setup is easier and more accurate.
   

• The center hole is smaller than that of the SH2 on the previous example.  Note the parts on these two examples break into the center hole.

• This style tooling takes the cable clamp style with open pocket and combines it with the conventional rotary carrier style.
   

• The carrier here uses open style pockets.  But there is no cable, belt to hold the part in place.  Instead we use a peripheral guide. 
   

• This style guide is fixed in place for the part being ground.  Clearance is held close to act like a full pocket in a normal carrier style. 
   

• The benefit here is the ease of loading and unloading.
   

• This style tooling can be noisy and is much harder and time consuming to set up from part to part.  Upon the O.D. being larger or smaller, the guide will have to be moved to hold the part in the pocket and not allow it to jam, bounce, etc.
   

•  Holding the part in a uniform manner is a direct relationship to the part quality.

• The Thru-feed Grinder is more of a workhorse.  It also has the highest thru-put on most applications. 
   

• The front on this machine is shown with a belt feeder.  There is also another example in this book of one that uses a sprocket/gear. 
   

• In this application, the parts are presented to the belt feeder either by a cylinder that shears the parts into the belts from a side stack of parts, or they can actually feed down a track and straight into the belts either by gravity or vibrating bowl, etc.
   

• The parts pass between the belts.  The belts create the feed rate and the pressure to push the parts into the wheels. 
   

• Due to the high rate, this machine is normally used for high stock removal by double or triple passing a part through the grinder to reach size. 
   

• One point to remember is there needs to be good surfaces on the parts to contact/push each other through the grind zone.  Round parts will still rotate, and this type part will have the best flatness and parallelism.  Square parts, rectangle parts, etc., will require a better machine setup to get better results due to the part not rotating.
   

• Gaging and size compensation manually is done at the back of the machine.

This style uses a Collet and Clamps on the ID of the part

"This is a very special Swing Arm style machine"

• A Swing Arm normally takes one part at a time.
   

• The parts are normally manually loaded and unloaded.  The part swings up and into the grind zone.  On many applications, the part swings into the center hole and then out.  It is done.  This can use a shear grind where all stock is removed at entrance.  Then a clean up or spark out occurs on the way out. 
   

• Other options are to swing the part in and out as you plunge feed the wheels to a pre-set size.  The wheels in this application are almost always flat, no head settings.  At the end of the plunge feed a pre-set amount of spark out passes can take place, going for finish, size, etc.
   

• Gaging is done after the cycle.  The machine can be compensated for size during the next cycle. 
   

• On this style machine it is very easy to reload the part and get a re-grind of high quality.  This is not so on most other models due to wheel load/pressure.
   

• This style machine lends itself to easy, fast changeover to other parts.  Even tooling pockets, vees can be easily changed. 

SDG2 Thru-Feed

SDG3 Rotary

SDG6 Thru-Feed

C & B
R242
Double Disc

1. Quill
2. Bearings
3. External Support
4. Spindle
5. Boot
6. Lubrication
7. Infeed Screw
8. Backlash Cylinder
9. Spindle Coolant
10. Encoder

Besly

1. Quill
2. Bearing
3. Pulley Support
4. Spindle
5. Boot
6. Lubrication
7. Infeed Cross Shaft
8. Backlash Cylinder
9. Spindle Coolant
10. Infeed Screw

Gardner

1.       Spindle
2.       Quill and Flex Cap
3.       Spindle Housing