In the picture, I've got 2 aluminum bars and a couple of plastic cam clamps to hold down 1 1/4" x 1 1/4" balusters for milling slots and pockets. None of the milling comes in from the sides, only the top. I've been having some minor issues with slightly warped wood and not being able to hold features in place due to not being able to clamp completely along the length. As part of my move to a LEAD 710, I was thinking about making a table out of 20x80 extrusion. Probably mounting a spoilboard on the table and facing it, with some pockets cut out for fixturing as needed. I'm thinking replacing the bar aluminum with a piece of 20x20 extrusion held down with angle brackets to the table on the non-contact side. Using maybe 4 or 5 cam side clamps, with another free-floating piece of 20x20 extrusion to distribute the clamping force without leaving dents on the wood. My thoughts are that this would hold the baluster and straighten out minor side warping while milling to keep the features in their proper locations between the edges. The slight warping won't be a problem for assembly of the finished product if the features are located correctly. Am I missing anything? If this picture doesn't help that much, I can take a better one an post it with a piece in place for the current machine.
You still risk slight rolling of the 20x20 when pressure is applied with the brackets located on the back side like that. I would suggest using a 20x40 set flat and having the screws drilled through the body of the 20x40 with the anchor nuts in the track below.
I was thinking of using a lot of these: Black Angle Corner Connector But your comment is well taken. I could use the 20x20 and drill through like you are suggesting for the 20x40, but I think I'll go with the 20x40. Thank you!
...What's wrong with one of those vises? Even if you have to slot all the way through, 2-3mm of replaceable spoil material (and more on each side to protect against jaw marring) shouldn't be a huge problem. They look big enough to get a solid grip along a decent length of the blank. Or just replace your plastic cams with metal toggle clamps. You could fit far more of them in there than just two, since they cam vertically, not horizontally. Add some angle brackets to the back side of the aluminum bar to stop the screws from rolling over under pressure.
Sorry, I thought you were talking L type angle brackets. Yes BACCs are a good solution but still the possibility of lifting the front edge. Typically on a connection like this I will use a blind connection. I drill a 4mm hole through the center web of the upper extrusion to where I can poke an allen wrench through and tighten a screw with a washer set in the lower channel of the upper member into a T-nut set in the upper channel of the lower member. This creates a truly immovable and inflexible connection.
The vises are too short (4" and 6" and the 6" can't actually fit anything larger than about 5" with the guide rods on the ends), given that the parts are up to 30" long, and are also so long they won't fit oriented along the X axis. Also, since I do have a slight warpage issue with the wood, I really want to be able to clamp along the full length. I hope this picture gives a better idea of what I'm working with. The part in this picture is 27" long and walnut, so pretty spendy if I screw it up. No worries. I appreciate the suggestion, I've dealt with some clamping issue in the past and completely understand what you are talking about. I've got more than enough T-nuts and I'm probably going to put a screw in about every 50mm to 75mm along the length. I'll make sure to post pictures of the finished fixture. I'm still waiting for a couple of parts i forgot to order to be able to assembled my LEAD 710, and I'll order the extrusion pieces now too. I've also decided to wait until I finish this current project (braiding frame) as it is for a friend with terminal cancer and I want her to be able to enjoy it as long as possible, so I'm making it with my old working setup. Thanks again for the help!
