Posted on 23 Comments

I have been puzzling over these for a a little while and have created some sawdust…

I have been puzzling over these for a a little while and have created some sawdust over this problem. The solution eludes me.

I need a foolproof easy way to be able to do repeatable 30 degree  bevel cuts on a board so that the resulting shape on edge is a rhombus, all sides are the same length.

Using a board planed down to 1.25" x 5.5" x 3' for instance. I imagine having the fence on the left to facilitate safe and easy bevel cuts. My issue comes from after the first cut how to adjust the fence over the width of the board plus the kerf to arrive at the next position.

Any help is greatly appreciated. 

23 thoughts on “I have been puzzling over these for a a little while and have created some sawdust…

  1. As all sides should be the same, the distance between fence and blade should be the same as the width of the already cut surface.
    So you could use the cutoff (in theory) as the spacer for the fence. In practice that won't work as the one side is sticking out a bit. Would be much easier to describe if the edges in the picture were numbered/named.

  2. Not sure exactly, but I would suggest spacers a little thicker than your 1.25 boards. You could use one spacer for the first cut and a second spacer twice as wide for the second cut. The third cut could use both small and double spacers. Another solution might be easier. Cut the strips slightly wider and make a jig to feed them twice ( 2 faces ) through your planer.

  3. Here my idea explained. Name the cutoffs in this picture from left to right with a through e. Then on each piece name the edges 1 through 4 starting with the right facing edge going counter clockwise.

    When you cut off part a you can use it as a spacer, with edge a1 as the spacer laying flat (as it should have he same length as edge b2) and edge a2 facing the table saw blade. Corner a12 should fit right in the angle of the table saw blade.

  4. So the cuts would be numbered right to left. 1,2,3, and 4. The first piece is the small cutoff that is the right triangle on the right. My issue is that I have no method of moving the fence over accurately (read as thick as the board is + saw kerf). Or even figuring out a proper spacer to add to the fence.

  5. Updated image. Somehow unable to replace image above:

  6. The solution is to start cutting from the other side and never to move the fence which stays fixed at the width of each cut.

  7. +Pablo Lattes Hmmm, I like it.

    Can you comment on my further thoughts?

    I then end up with a fairly sharp edge that butts up against the fence. I think becomes prone to binding against the fence?

  8. I would think the bottom edge touching the fence is good enough but if you are worried about it, you can clamp a fixed piece of wood to the fence with the complementary angle. Let me know what you end up doing.

  9. +Pablo Lattes I like that option, thanks!

    I suppose that using a zero clearance insert will also help.

  10. +Pablo Lattes Yeah, I have seen similar jigs for doing strips, etc. My real issue is getting the accuracy of the width of the cut to match the thickness of the board, which I think your first suggestion does admirably. Since I can set the fence by placing the board vertically between the fence and the blade with the fence on the left.

    My only further concern is that the piece by the fence is fairly narrow and prone to pinching against the blade. I bet if I use a helper like the gripper, it would be the best method.

  11. For the sake of safety and control you might want to consider making some test cuts on a bandsaw with wide, sharp blade.

  12. so last night I tried what +Pablo Lattes suggested. I put the fence on the left, set the width of cut to match the thickness (this is much harder than I thought) placed a block of wood in such a way that the wood would stay flat and a bevel cut board to hold up against the edge to help keep it against the fence.

    I worked reasonably well. since the width I was shooting for on this particular run was close to 1 3/8" there was just enough room to have this work. I imagine that going with something in the 7/8 range would be much touchier and I don't know that I will try it with such narrow boards, yet I am trying to get to that range.

    +Christopher Osgood I have tried getting my band-saw to do such a thing. My band-saw accuracy leaves a lot to be desired especially at such a steep angle.

    AS part of my experimenting with thinner pieces of wood through a thickness planer, but I noticed noticeable rounding of the surface because of the uneven support because of the overhang. If there was some clever way to attach several of these rhombic strips together I might be able to get down to a much thinner rhombus strip.

  13. Thanks for the update! I can see that it would get very difficult (next to impossible) with narrower strips.

    If you have $400 dollars to spend, perhaps you can buy an accurate enough fence as the Incra one.

    What are you trying to make?

  14. +Pablo Lattes Assembly type puzzle. I need to further cut the strips into same thickness cubes or double cubes. So a bevel cut yet again with the stock sitting on the edge of the rhombus.

    Yet another problem.

    I need to figure out some elaborate jigs for repeat-ability here.

    This is not a new idea. Just a puzzle I have not seen in 20+ years.

  15. Make longer pieces and cut to length? Access to a multi moulder would be nice.

  16. I ran one years ago at a cabinet shop I worked at. It has steel rollers that feed stock in and then multiple heads with cutting blades. They are used to make all sorts of mouldings.

  17. I would love to have access to real machinery to do what I want… I think even a more accurate table saw would be marvelous.

  18. My only other suggestion would be if you're setting the fence up opposite use a finger board to hold down your stock and to help prevent a kickback.

  19. Probably more trouble than its worth… Have you thought about building a jig for a surface planner? 

  20. I have thought about it. So far I have stalled because of time and camping. Thanks for the thought.

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