This Viewer Jig in actually made from…………..CONCRETE?!?! Let’s check it out:
I once thought of patenting this thing, instead, I leave it to you to air it if you wish. It’s also an expose’ on making tools out of concrete! This miter jig consists of concrete with polypropylene fibers for added strength. It describes a perfect 45 angle and the ‘table’ (piece of Corian on top) is at a dead 90 to the work. This, as seen, can even be used with material that is not flat. The work is clamped via cams. One routers the 1st pass on top of tape. Feeding the router in a way as to prevent tear out. A 2nd pass is done freehand with the tape removed. The idea is to not blow through the perimeter. This needs be done to only one of the meeting miter surfaces. With a second router (plunge) on a sled, and without moving the work, a spline slot is cut. This ensures that the two miters line up perfectly.
19 Responses to “Concrete Miter Jig – Viewer Jig”
That looks really heavy and unwieldy. If it works though…
Wow. It’s a very nice jig, butt as a woodworker, I’d probably build it from Baltic Birch Plywood.
Not knowing much about concrete, how does one form it so the table supporting surface is exactly 45 degrees to the bed?
I’m not an engineer by any stretch of the imagination, but here are some general observations which may not be very accurate. It looks like you have other tightening cams on the bench top. May I assume these are for different wood thicknesses? I noticed that your router sled is adjustable laterally by loosening 4 bolt nuts. Would it be better to replace the nuts with some knobs such as Rockler sells for jigs to make loosening and tightening quicker? I see you’re using wood shims between the stock and the cams. Do you think something like a strip of UHMW would be a suitable substitute, although that may be too slippery? You’d need only a single strip.
I’m only guessing on the “C†clamps at the corners of the Corian top, but I assume the blocks they clamp down act as stops for the router sled. Could these be replaced with bench style clamps mounted to the Corian? As far as the what looks like a Kreg extra large face clamp, perhaps a large Kreg bench clamp mounted underneath. Of course you would need to mount it somehow on the concrete part, or mount it to something else mounted to the concrete form.
I may be way off on these things, so please disregard if so.
At this stage of my life I want things lighter not heavier.
Ok, concrete is a new twist. I have seen some pretty good stuff made from concrete (I used to work with a construction testing company). I guess the only question is…why? I am impressed but I am not running out for a bag of quickcrete the next time I need a shop jig.
I’m confused with the choice of using concrete over plywood as the jig material? I would think that with the time involved in building a form for the concrete, pouring it, finishing it, and whatever else needed done, you could have made 3 very stout jigs out of plywood. And all this just to cut a miter? Am I missing something?
hmmmm…
Well, it’s interesting and “out of the box”. Several good concepts in there. Don’t understand the material though.
Another thought. Since this jig is obviously heavy and massive, it might be a good idea to mount it on something more permanent so you wouldn’t have to lift this thing to the vise each time you wanted to use it.
I think concrete makes perfect sense. Like cast iron on a jointer bed, it provides enough weight to dampen vibration and provide a solid, stable surface for precise cutting. And cement is a lot easier to cast in a home workshop than is iron.
But you must cut a lot of miters to warrant such a heavy jig.
DD
Concrete – that would be heavy but it would be sturdy. Wouldn’t mind seeing a short video of this in action. The useage of something would have to be easy for it to be on someones wish list….
This is a very interesting concept. Though I would have to add steel toed boots to my list of shop safety equipment!
This looks like overkill to me but it does seem to work. Interesting choice of material.
WOW!
They made ships out of concrete! I have not seen any lately. the form is probably made of some sort of wood, or did you use fabricated iron? One place I worked, we made a large optical turning machine, basically a large vertical lathe using granite. Extremely stable stuff in its own right, As I recall the foundation was prestressed concrete
“But I’Much Better Now”
I noticed that you have two coffee cups in the same pattern as my wife’s country apple Corell pattern. Do all creative woodworkers gravitate toward the same commercial dinnerware styles or have you been seeing my wife on the sly? :) Also, how do you get your wife to let you take the kitchen stuff out to the shop?
About the jig; I think plywood would be a better choice, but it is certainly an interesting idea. Probably worth the exploration. The best advantage that I see is the solid mass should eliminate any vibration, which could mean smoother cuts.
I am still trying to see why I would want to use this jig. What is the advantage. Maybe the pics are not giving me the full picture. I do all my mitering on the saw, DEAD ON. Hmmmm
Great use of alternate materials in the workshop.
Lately I have been working with a friend on concrete projects. A table top is setting up now, and the legs have already been cast.
Also working on making a concrete geodesic dome… hopefully it will be a workshop for me when it is done. 20′ dia, not big but should be fun when done. … A real ‘man cave’.
I agree with many others on this one. Its an interesting expose on the use of alternate materials, and a conversation piece. But I do not see any significant advantages over plywood.