Jig-a-rama

If you've spent any time around a shop, you've got a pretty good idea what a jig is.   Feel free to skip the next paragraph if short on time.  Or, if you are killing time at work (shame on you), read through it and post your improvements to it. 

So, here's my quick and dirty definition.  A jig is something you use to machine multiple parts with the same characteristic(s).  It is not to be confused with a pattern.  A pattern would be for creating multiple parts of the same size and/or shape, but would not aid in the actual application of tool to material.  Instead, patterns are used to trace a shape onto your material.  A jig is always combined with a tool to do its job.  Templates could be either/or, but I would say closer to the pattern end of the spectrum.

So, with that said, let's get back to jigging.  For a recent project, I had to create a tapering jig for my table saw.  There are a pretty wide range of ways to make a jig but something I have noticed is that there is a definite time/money/quality triangle that applies to building one.  In this example, I chose quick and cheap.  When it comes to jigs, that usually means it will do the job with the materials on hand, but wouldn't be something you want to be using 2 years from now.

For this tapering jig, I used scraps from around the shop.  There is a piece that rides along the rip fence of your tablesaw.  Then, hinged off of that, is a second fence that can be angled away from your normally perpendicular rip fence.  This fence has a sled for the part to ride on, as the entire assembly is pushed through and past the blade.  The result is a part that is angled slightly along the longest dimension.  There is a stop at the back of the sled to keep the piece in place and prevent it from kicking back.

I used a few scraps of primed MDF for the two fences, and had some concerns about them bending and bowing out of true.  Adding the sled to the blade-side piece seemed to square it up, so I did the same to the fence-side.  I made a U-shape that cupped the ripfence nicely.  Everything is glued and nailed together, except where I used screws to attach the hinges and the piece that locks down the taper adjustment.  The U-shaped runner works very well.  I like how it holds the fence true to the rip fence, much safer than a freely sliding assembly.

The taper adjustment will not last much past this project.  The materials I used just do not stand up to repeatedly having screws taken in and out.  You can see that the MDF is splitting where the screws go.  For the adjustment, I would use a threaded insert, or a t-nut that could be fixed in place, and yet be adjusted as needed.   If you look closely at the first picture, you can see I added a block of wood to hold the angle at a fixed distance from the ripfence. 

As time goes by, I will use this quick and dirty jig to model a better, more durable one.   I could buy one here also, though there is something fun about making your own, and using up those oddball scraps.  Solid maple fences and  replaceable plywood sleds, threaded metal inserts for adjustable points.  Nylon washers or runners to make it move smoothly.  It's enough to make me want to build just jigs. 

Temporary though the jig might be, it did a fine job helping me create these tapered black walnut legs for the desk.  I'm using them set at a compund 10 degree angle.  Pretty sweet, no?  Feel free to post any comments, or questions and if you enjoy the posts, please consider clicking the "Follow" button to get more updates from my shop.