The large handle on the domino fence encourages downward pressure. When the part to be mortised is relatively narrow (see picture) the possibility of the plunging face of the domino tilting is a real possibility. This is especially so when the fence is fully down. Using the Bigfoot stabilises the whole process and gives a solid engagement. Without the Bigfoot any tilt means that the mortise is not perpendicular to the registration surface leaving the joint unusable in many cases.

Like Jiggy pointed out, the issue is to more fully support the front of the Domino fence and thus prevent rotational movement at the fulcrum point. Unless the BigFoot is clamped to the work piece, just adding the BigFoot will not prevent additional rotation of the DF 500. 

I really like the BigFoot for adding Domino's to a "field".

It got me wondering how its made. Assuming its carved out of a solid block seems like there is a whole lot of scrap.

Ya, that whole billet aluminum thing changed the manufacturing techniques for a lot of different everyday products. It actually made the products cheaper to produce than conventional manufacturing methods. It has virtually eliminated the castings & forgings used for most products.

I remember the first set of Boyd Coddington aluminum billet wheels. There was more aluminum machined out of the center hub of the wheel, than was left in the center of the wheel. I scratched my head and wondered how that made them a profit, but that was over 30 years ago and the billet train hasn't slowed down one iota since then. 

It got me wondering how its made. Assuming its carved out of a solid block seems like there is a whole lot of scrap.

It's made from extruded 6061 structural angle. It's obvious from the rounded edge. Little waste there. Likely the surfaces are ground flat at 90 deg. since extruded angles are rarely square.

@Michael Kellough – the DBF-45 BigFoot is machined from 6000 Series extruded Aluminum Alloy angle. There is very little material “waste” in this instance. A challenge with extrusions is preventing cosmetic damage to the surface in handling beginning with raw material, never mind all the handling in machining, anodizing and final assembly – don’t ask me how we know

Both faces are CNC milled flat and square – the only way to ensure angular accuracy.

“scrap” – aluminum is the easiest material to “recycle” locally and machine shops as well as fabricators regard scrap sales as another source of income (recovery). One thrifty operator even following the metals commodity markets to get top dollar for the aluminum scrap.

Hans

@Michael Kellough – the DBF-45 BigFoot is machined from 6000 Series extruded Aluminum Alloy angle. There is very little material “waste” in this instance. A challenge with extrusions is preventing cosmetic damage to the surface in handling beginning with raw material, never mind all the handling in machining, anodizing and final assembly – don’t ask me how we know

Both faces are CNC milled flat and square – the only way to ensure angular accuracy.

“scrap” – aluminum is the easiest material to “recycle” locally and machine shops as well as fabricators regard scrap sales as another source of income (recovery). One thrifty operator even following the metals commodity markets to get top dollar for the aluminum scrap.

Hans

@TSO_Products  Hans - I've used the BigFoot a few times now and really like it much better than the OEM plastic bracket. The surface on mine is not as shinny are some photos I see on others. Is it shot/vapor blasted? This rougher finish gives it a good - more secure feel.

Mike

I just ordered one this morning and can't wait 

@TSO Products I had a look at your only Canadian re seller and the number of items they carry is really limited. Is it your choice or their? From Ultimate Tools I usually save some BIG bucks. No shipping cost, no extra tax, no duties. For example they carry the GRS but not the parallel guides, and of course no BigFoot.

Discard my question if it's too politic.