I just used some random clamps in the model from the sketchup 3d model library.
The basic idea being that I can clamp to the front, with the rails recessed into the hardwood edging that I intend to use on the table. This is just a mock up. The top skins on the torsion box will not extend to the edge of the table.
Right now its 3/8s mdf for the internal structure of the table with 1/2" or 3/4" MDF skins and 3/4" hardwood edging on the outside to improve durability.
I am going to check out a local plywood supplier this week and may adjust my designed based on what they have available.
I am curious on these and I am playing with some designs myself: Do you typically use some kind of sacrificial backing board with this? If not, do you see a lot of tear out?
Used a #251 downcut bit, and left a roughing clearance and took a finishing pass — nicely crisp joints which fit perfectly (if a bit proud — need to add a surfacing pass of the board ends).
Interesting how you have this designed but I have a couple of concerns you may want to take into account.
I am wondering if you clamp only at the top, will the momentum of a long piece make it difficult to keep it properly perpendicular? The clamping is system is attached to the torsion box, not the shapeoko frame so any movement of the Shapeoko on the torsion box would mess up the alignment. It would not take much misalignment to mess up the joinery.
I can’t resist sharing what my friend designed and built.
Perry built this for one of the Shapeoko in the SDFWA.org shop.
The video was used at one of SDFWA’s general meetings in San Diego.
Thanks for sharing this @TravisGood Do you have any more details other than the video? I can see whats going on here but just wondering if the spindle mount has been modified at all and what all is going on there. I found the JointCAM website and there are a few posts on the forums about jigs but nothing to the degree of finish as the one in the video.
This is pretty much exactly what I was thinking of but couldn’t find any real good examples of it so I was going through a little bit of development as a result.
I like how it cuts both sides of the joint in one pass…very clever.
To the points that @luc.onthego mentioned, I had considered the clamping apron. I will likely end up with something similar to what @TravisGood shared with a longer apron with t track down the front.
Also I fully intend to anchor the shapeoko to the table so that it cannot slide around. As I learned with my 3d printer, stability and rigidity go a long way towards accuracy. It goes for a lot of things actually. If you put more weight on a telescope than it is designed to carry then your accuracy will suffer as the mount struggles to maintain tracking.
So far thanks to everyone who has chimed in. I have a lot to think about
I built a fixture to allow vertical joinery on the SO3 as I’m not a fan of the mickey mouse ears joints that are common to horizontal joinery. I originally built it for JointCAM which is a very good software tool that helped me get started. I’ll continue to use JC along with other custom joints. Once you get started with vertical you will realize that the possibilities are endless.
Btw, the major challenge with the fixture was securing a tight fit on a platform that could not stick out beyond the front of the SO3 very far and use up the extra Y. If I were to do it again I might have considered using thinner alum. Also is the rigidity of the platform where we tapped 1/4-20 holes in the front of the SO3 and also the table that it was sitting on. That thing was not going anywhere. Here are some pics detailing the design and some interesting cuts inspired by Mirock.
@pcrutchfield Thank you so much for sharing these details.
This is very similar to what I was thinking about for my machine and while my drawing doesn’t show it, I was already considering a clamping apron down the front of the machine.
Not sure what you mean here. is there an aluminum plate between the vertical clamp board and the table/shapeoko?
Are you saying that you drilled and tapped the front frame to accept the large knurled nuts? It looks like there are 4 holes in the front frame, 2 on the bench edge, and two more that connect the vertical end supports of the clamp board through the bed of the vertical clamp board and into the frame of the bench. Also is the machine itself bolted to the table?
Would you be willing to share the CAD file? I’m curious about some of the construction. As I work through the design of my table I am going to plan for this kind of jig as future upgrade and if I make some design decisions now, it will make retrofitting the clamping apron on the front easier.
Since we are looking for the most possible Y clearance in front of the machine using .25 aluminum for the material mounting base (the apron) instead of .75 baltic birch ply would give you .5 inch more. You would have to think of another way to mount the t track.
Yes we tapped the front frame of the SO3. The fixture is bolted to the S03 and the table effectively bolting it to the table.
I’ll send you a STEP file that will keep you busy for a while…
Great video, I watched it last week, I will try to adapt your concept to my new Shapeoko bench and enclosure. I also want to make the jig a bit wider for making larger boxes
You may be faster than me, I have the cabinet half done and many other projects on the go so it will be a week or two before I get there especially since I do not have a need for finger joints in the immediate future.
My objection is that it requires that one secure the stock at a 15 degree angle, and seems to require one setup for each end of each board — 8 for a single box.