Without the sheet of ply on your drawing, it was hard to tell the distance between the edge and the leg. If itās a 1 foot (meaning legs are spaced 6-feet apart) I agree that it should be ok. I was thinking it was more like 2-feet (legs 4-feet apart) and I started to get concerned.
Thought soā¦ I was worried myself but didnāt know if it really mattered or not. Technically, it could always be braced by a piece of steelā¦ do we know just how much bowing will occur when the sled is at the top? Regardless, I see merit in your design of offsetting the top beam rather than the mounts. Because the stress is all on the top beam, and the connection between the top been and the leg is just to hold up the top beam, can it be supported by a single threaded rod rather than blocks? Something like this:
I ask because that would facilitate a design that allows the beam to be moved in and out away from the leg to accommodate different thicknesses of wood.
I think I added an extra block (accidentally) in the overhead view drawings. Last night, the plan was a 2x4 top beam stood proud of the legs, a piece of 3/4-inch ply, then another block of 2x4. In the drawings I just posted, I had another piece of 2x4 between the ply and the top beam.
I like the look of that, but I would be worried about the threaded rod enlarging the hole in the leg over time. Might not be a problem, though, especially if something like 1/2" rod were used giving a solid bearing surface. Another good aspect of that idea is that it still lends itself well to using either lumber or unistrut for the top beam.
One issue I do see is in the implementation of lag bolts through the long axis of a 2x4. Having drilled holes in that manner to mount my unistrut, I can say that it is not really the easiest thing to do without a drill press. Given that the stock design is meant to be built with a minimum of tools, getting accurate holes drilled to hold up the top beam with lag bolt might be pretty difficult.
I would imagine that if it did become part of the stock design, the hardware (all-thread, nuts and washers) that would need to be included with the kit.
That was how I was reading your drawing. That puts the sprocket about 3-1/4" from the front face of the top beam, so, with a 3/4" back board and 1/2" spoil board, only about 2" in front of the work plane. Add to that the 3/4" work piece and the sprocket is only 1-1/4" in front of the front surface, which may cause problems for balancing the sled. I suggested taking out that piece of 2x4 blocking, but perhaps leaving it in and mounting the motor to the outside of the bracket is actually the way to go.
The more I think about it, the more I like threaded rods/bolts for the offset. But I think ot would need pre-made mounts (metal or pre-drilled chunks of wood to be glued/screwed to the top 2x4 of the frame)
With a drill press itās not too bad, but I did find that ripping the edge off the short piece of 2x4 that I used did make it easier (mainly to stand the piece up, but also to be able to drill through without having to buy a special long drill bit).
no matter which kit, the chain needs to be at the balance point of the sled (Ā± an inch or two) a sled with an external z axis will have more weight further from the sled, so the chains should be higher.
With the stock sled (no triangular setup) I have the chains mounted to the second to highest hole in the bracket with a 1/2" sled and that is about a half inch to an inch too low when the sled is on the 1/2" backer board. I plan to add an 1/4" spoil board and then the height of the work piece which will likely usually be either 1/2 or 3/4 stock, so that should put the chains right into the sprocket plane. Total distance is 5-1/8" from the framing member. If you added in a thicker spoil board and sled, then yeah, 6 inches easy.
Yeah, that was my point earlier
In the absence of a hacksaw, the extra could just extend out the back (or front if is avoided the chains).
In which case it would likely be sized appropriately
Yeah, I was thinking the distance was going to be shorter. Iād be worried with my original design to have the mount extended out that far from the beam.
And for those that are building from scratch or redoing their frame, get a hacksaw (they are cheap enough)ā¦
