I’ve used long reach tooling from Garr Tools.
Here’s some possibly workable options to look into from the Shapeoko wiki:
- http://www.ebay.com/itm/10pcs-3-175x42mm-Carbide-CNC-Router-Bits-Single-Flute-Spiral-Cutters-End-Mills-/291866010066?hash=item43f491e1d2
- GARR TOOL - Product Details Garr Tool Series 620MEDP#41030 1/8"x3x1" — excellent quality, long narrow bit w/ a long cutting length which makes workholding and fixturing much easier, and making through cuts (w/ a suitable number of passes) on 1" material feasible.http://www.carbidedepot.com/detail.aspx?ID=73347
- 3.175mm 2 Flute Spiral Bit Carbide End Mill Router 32mm CEL CNC Cutting Tool Sale - Banggood USA sold out-arrival notice-arrival notice Cutting 3/4" material with 1/8" Endmill - #9 by RichCournoyer
- Amazon.com Shapeoko3 2" depth HDPE - #4 by cod65
- Amazon.com
- Amana Let's cut 3" deep holes! - #2 by CNCInspiration
- Redline Let's cut 3" deep holes! - #3 by DanStory