Table Saw / Router Table Fence Extension

Description

This is a simple to build table saw fence extension using relatively cheap and readily available 2060 aluminum extrusion.  This is a great addition to a compact table saw like the Dewalt 7485.   The fence extension quickly and easily clamps on to your saw's existing fence.  

The fence shelf pieces allow you to extend the infeed or outfeed surfaces of your saw.  The standard sized t-slots in the aluminum extrusion provide ample connection points to secure tools like featherboards to the fence.  

The bottom fence shelf contains a recess so you can support it from the floor with a cabinet jack if needed.

Print Settings

Fence spacer

The fence spacers need to be pretty strong.  I printed mine with 50% infill, supports, and oriented with the dovetail groove up..

Fence shelf

The fence shelf needs to be pretty strong and rigid.  I printed mine with 50% infill, supports, and oriented as it is in the model.  It seems to work ok as is.  However it takes a long time to print and uses a lot of filament.  After printing this I realized it would probably be faster to set the shelf on one of its sides ( L side down ), set the infill low to 15%-25% and then add 4-5 80%-100% infill ribs for strength.  I've included the ‘Fence shelf with structural ribs’ model below with this suggestion.

Featherboard

The featherboard is largely a copy of @design8studio's design.  Follow the printing suggestions for that design: https://www.printables.com/model/172907-featherboard-for-woodworking-no-supports-needed-wi.  

Additional Hardware 

• 2x 2060 1000mm Aluminum Extrusion 
• 2x m5 nuts ( for featherboard attachment, optional if you don't want a featherboard )
• 2x m5x30 T-Slot bolts ( for featherboard attachment, optional if you don't want a featherboard )
• 8x m5 T-Slot nuts ( for fence spacer and extrusion attachment )
• 8x m5x8 hex socket bolts ( for fence space and extrusion attachment )

Assembly

• Drill 4 evenly spaces access holes through one of the 2060 extrusions.  These holes should be drilled in the center of the t-slots through the 20mm side of the extrusion as opposed to the 60mm side.  See photos.  I used a 4.5mm bit to drill the holes.
• Collect the two 2060 extrusions on the 20mm edges using 4x m5 t-slot nuts ands 4x m5 hex socket bolts.  Use the access holes you drilled in the previous steps to insert an Allen wrench to tighten the hex bolts.  Make sure the two extrusion pieces are perfectly aligned.
• Use 2x m5 t-slot nuts and 2x hex socket bolts to attach each fence spacer to the 20120 extrusion piece you assembled.  The fence spacers sit on the 120mm side of the extrusion that will be between the existing table saw fence and the extrusion ( away from the saw blade ).  There is text on end of the spacers.  This text should be up when the the fence extension is attached to the tables saw.
• Press a 20120 endcap into the each end of the 20120 extrusion assembly.  You can gently hammer the endcaps fully into place.

Use

• Use 2 Microjig dovetail clamps to clamp the fence extension assembly to your existing fence using the dovetail slots in the fence spacer pieces.  The fence spacers are precisely sized so that when the fence assembly is attached it is 2" from the existing fence.  This should make positioning the fence from the blade pretty simple.  Dovetail clamps are strong so be careful not to over tighten or you could damage your existing fence.
• Use 4x m5 t-slot nuts and 4x hex socket bolts to attach the fence shelf to the 20120 extrusion assembly.  You can use the shelf as an infeed or outfield extension.  Or go nuts and print 2 and have an infeed and outfeed extension.
• Use 2x m5 nuts and 2x m5x30 T-Slot bolts to attach the featherboard to the saw side of the extrusion.

Future improvements

• The fence spacers are designed to work with Microjig dovetail clamps.  It might be nice to make them work with another type of clamp.
• I can see that having a featherboard sit away from the fence would be useful so I'd like to remix this design to work with my 20mm t-slots.
• The fence spacers only have bolt holes for the top and bottom t-slots.  It might be more convenient or flexible to have holes for all 6 t-slots.

Disclaimer

Using power tools is dangerous.  Using any power tool  with this design is probably even more dangerous.  Use this design at your own peril. I assume no liability for any injury or damage that occurs while using this design.