2/8/12

Routing the Saddle Slot in the Granadillo Bridge Block

When we last saw our granadillo bridge block, the saddle slot marks were laid out and waiting to be cut.

I bought the Stew-Mac router jig for this job (and future projects yet to materialize).  So let's have at it.

After a lot of pondering, I came up with this method of routing the slot.  It's not perfect, but it worked.

There is a piece of pine clamped vertically in the Workmate which acts as a guide.  With the router against the guide, I could determine where it would cut as it ran down the guide.  I made that mark on the blue tape. Oh, and I used the 'longer' side on the router jig.  I felt that I needed more surface to run against the fence.  That's why it seems to be on an angle. 

Then I used double-sided carpet tape to hold the bridge block down to the Workmate and cut the slot.

Here it is in action.  I wound up marking the first cut on the bridge with tape, since I wanted to make sure it was square.

After the first cut, I just shifted the bridge block outward a tad (how precise) and made a pass.  The bit I have is small diameter - it took three passes to get the width I needed.  Next time, I'll be more confident, and will use a wider bit.

I also made each pass quite shallow - maybe just a millimeter or so.  It took three or four passes, but it worked, and I didn't get any tear out.

Here's the slotted bridge block.   It's not absolutely clean, but I can easily clean it up with a file.  The main thing is that it's square and the nut blank I'll be using fits very tightly into the slot.

I'm pretty pleased with it.  Clearly I can fine-tune the method (I'm thinking I can make a proper jig to adjust the cut more accurately next time), but I didn't ruin my nice piece of granadillo!

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