Editing Instructions:ShopBot 3-Axis CNC Mill (section)

== Safety ==
===Fire Notice===
DANGER: FIRE. The ShopBot vacuum and dust extractor make it difficult to notice a fire until it has already started spreading. Always carefully plan cuts and monitor jobs closely.

If you notice any of the following:

* Burning smell
* Charring
* Tool damage
* Unusual Vibration
* Change in sound

STOP AND INSPECT THE DUST COLLECTOR FOR SIGNS OF FIRE. 

=== '''PPE''' ===
Wear:

*Safety Glasses (to protect against flying dust and debris).

*[[Hearing protection]] (to protect against noise greater than 85 dBa).

*Respiratory Protection (N95 dust mask or respirator) to protect against airborne dust when cleaning or running the equipment.
Do Not Wear:

* Loose hair
* Loose clothing (especially hoodie strings)
* Wired earbuds or earplugs
* Jewelery

=== '''Hazards''' ===
{| class="wikitable"
|+
!Hazard
!Causes
!Mitigation
!
|-
|Fire
|Friction from tools
Improperly installed tools
Overfilled dust collector
|Use correct feeds and speeds

Make sure the tool sticks out far enough

Do not leave the ShopBot unattended

Always check the dust collector before starting and empty if needed
|
|-
|Projectiles
|Workpiece shattering
Tool shattering

Tool slipping

Collision with fixtures and clamps

Debris in wood
|Check for cracks, knots, and debris in wood




Use correct feeds and speeds

Clean tool holder with compressed air

Program file to avoid collisions

Check that actual home position matches programmed home position
|
|-
|Entanglement
|Pinch points
Rapidly moving automatic equipment
|No loose hair, clothing, earbuds, hoodie strings, etc



Make sure tool has stopped before reaching in ([[hearing protection]] can make it hard to tell)

|
|-
|Noise
|Motor noise, vacuum noise, tooling noise
|Wear [[hearing protection]]
|
|-
|Inhalation
|Airborne dust
|Wear dust mask or respirator (minimum N95) while operating and cleaning
|
|}

[[File:ToolCrash.jpg|thumb|800x800px|left|Tool stickout]]
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===E-STOP===
In case of emergency, stop the ShopBot using one of three methods:

*E-STOP button on the remote. This will immediately cut all power to the ShopBot. The tool will spin down naturally. E-STOP is a good default option.

*Press the Spacebar. This will lift the tool up and apply the brake. This is a good option in less urgent situations, like needing to adjust the zero positions.

*Click the mouse. When the job starts, the mouse will automatically lock onto the stop button. Pressing any button on the mouse will stop the job in the same way as the spacebar.

===Common Problems===
Most issues are caused by:

* Improper feeds and speeds
* Improper tooling (especially low-quality tooling)
* Improper materials (particularly recycled materials with embedded nails or stones)
* Improper fixturing (workpiece comes loose)
* Improper programming/setup (offset mistakenly applied, not setting zeroes consistent with the programming, not avoiding fixtures)

=== Housekeeping ===
Empty the cyclone dust collector after every use. To empty the cyclone dust collector:

# Unlock the clasp.
# Remove the lid.
# If the dust collector is less than halfway full, scoop or dump the contents of the bag into an existing can. If it is more than halfway full, remove the bag and discard it the garbage can.

Empty the main dust collector when the dust has piled halfway up the viewing window. Check before and after use and empty if required. '''Overfilled dust collectors can start a fire.'''

Break down large pieces before putting them garbage bins. Round off sharp corners to avoid puncturing the bag and injuring the person carrying it.

After use, clean the equipment and surrounding area. Continue wearing your hearing and respiratory protection while you are cleaning up.

# Use a dustpan, vacuum, and broom to remove most of the dust from the table, and gantry.
# Use compressed air to clean the gantry. Focus on areas where parts interact: rack and pinion, spindle mount, motor mounts, etc.
# Clean the floor using a broom and dustpan, shop vacuum, or the dust collector hose. Make sure to clean under the ShopBot and the corners of the room. Replace the dust collector hose when done.
# Empty any garbage bins that are more than 75% full and replace the bag.
# Empty the dust collector if required.
# Return fab lab tools to their proper locations:
#* Tool holders on the rack
#* Collets in the drawer
#* Collet wrench placed beside locking fixture
#* Calipers, drills/impact drivers, squares, hand tools in the tool room
# Remove any personal tools, materials, and removable media from the room. The workbench should only have the wrench and locking fixture on it when done. Due to local fire code, do not store stock materials in the CNC room (fixtures are stored in the fixture cart - label with name and phone number)
# Turn off the equipment per shutdown procedures.
# Turn off the dust collector. If you are the last one in the room, turn off the room exhaust. The room exhaust is interlocked to the electrical system; turning off the room exhaust will turn off all equipment in the room.

=== Workholding Policies ===
Most profile cuts will cut entirely through the workpiece and into the spoilboard below. In order to cut all the way through the material without unnecessarily damaging the spoilboard, North Forge suggests programming cuts using the following formula:

'''Depth of Cut = Stock Thickness + 0.01”'''

This normally results in cutting all the way through the material without excessively damaging the spoilboard. Always measure stock thickness with calipers, never with tape measures or nominal dimensions.

If your cut penetrates deeper than 0.06” into the spoilboard, please stop and investigate. If the stock is set up correctly and the depth of cut is appropriate, the collet may be dirty or damaged and the tool slipping out, or the secondary spoilboard may not be perfectly parallel to the gantry (for example due to debris between the primary and secondary spoilboard, or issues with the underlying phenolic plenum).

Tips:
* Use a secondary spoilboard wherever possible.
* Zero to the spoilboard, not the top of the stock.
* Use conservative cut depths and nudge down as needed (for example, by using Z nudge function or manually tweaking z zero).
* Test toolpaths on a secondary spoilboard.
* Measure stock with calipers.
==== '''SCREWS''' ====
When using North Forge’s ''secondary'' spoilboard, it is okay to screw the workpiece in place. Do not:

* Screw into the main vacuum spoilboard
* Use nails to secure your stock to the vacuum spoilboard
* Use excessively long screws (ie long enough to pierce both the secondary spoilboard and the vacuum spoilboard).
* Use glue on the screw spoilboard or main spoilboard.

==== '''SPRAY ADHESIVE METHOD''' ====
It is also possible to use spray adhesive to secure the entire workpiece to the secondary spoilboard.

# Use sandpaper to knock down any high spots on the glue spoilboard (if required).
# Cover both the bottom of the workpiece and the appropriate part of the spoilboard with masking tape or painter’s tape.
# Spray both surfaces with spray adhesive (available at most hardware stores).
# Press the two surfaces firmly together and hold for 30 seconds.
# Test the hold by trying to move the workpiece sideways.
Do not use glue on the screw spoilboard or main spoilboard. Do not use screws on the glue spoilboard.

==== Other ====
Other workholding arrangements are possible, including vices, pins, clamps, custom fixtures, and the vacuum system.

If you are cutting all the way through a large workpiece on the vacuum spoilboard, BE CAREFUL. There is a high risk of damaging the vacuum spoilboard. It’s a good idea to test cut settings on a small workpiece and a secondary spoilboard.

The primary goal of workholding is to control the movement of the workpiece in three axes: X, Y, and Z. Always carefully check toolpaths to ensure they will not collide with any fixturing.

TIP: After a cut operation, the ShopBot will move to the “Z Safe height” before moving rapidly to its next position. When using clamps or other fixturing, adjust the Z Safe Height in the CAM software such that the Z safe height is above the clamp or fixture.