gang saws

[Tom Walz]

Thought you might find this interesting.

[Peter Quinn]

Is that for resaw? Looking at the site it looks like a gang rip circular saw resaw machine. I've used a regular gang rip before to turn wide boards into narrow boards, mixed results. One wide straight board goes in....twisted spaghetti comes out sometimes, so you wind up having to split over sized then reprocess each piece. Have you used that machine in the picture? What is it's purpose?

[Kent A Bathurst]

Double-arbor gang rip.

The pair on the left are used to make slats/boards for pallets out of low-grand hardwood.

Guessing from the photo that one can handle cants [their term for big honking slabs] up to 8" tall x 20"+ wide.

I can't get a good enough look a the blades ont eh outer [left] side of the setup - they might be spaced for wider cuts on the outside, but they might also be hogger blades. THe cants that are run for pallet stock are not sized to a reliable size - they come in over-size; the outer portion may vary widely in terms of wood v wane v bark - and anything out there they are just deciding to get rid of.

Gotta have 150+ HP motor running each arbor.

The interesting thing behind this: THey are giving up yield to gain speed of throughput. You can do the same thing with a multi-head horizontal bandsaw application - maybe 6 head in line, then take the unsawn piece and return it and run it though - gut that resaw runs much slower than a gang rip,and you have to make more than one pass. So - stick in a gang rip, turn more fiber into sawdust, but at a much higher production rate.

Also to note - because of the variability in cant dimensions, you can get a different # of boards out fo any given cant. BUT - you need the final width to be consistent. So - in front of the saw there is a one-head station called a sizer: Simply a one-head, overhead, planer on steroids - big honking motor. So - if you are running cants that are nominally 6", you size them first to get them all to 5-1/5", then slice them up.

The volume of waste - shavings and sawdust - coming out of that double-arbor gang rip at 100 LFPM is truly apocalyptic. You ain't never seen nuttin' like it. SImply amazing. And - it is common for it to be something like green red oak. So - not much in the way of a traditional dust collection system, because it is hard to pull green stringy ripped fiber via vacuum, and the volume is impossible. So - you would typically see the saw enclosure designed so that the waste drops down, out the bottom of the saw, onto a conveyor, that runs it out - either to a collection bin, or into a big dust collection port - like a gigantic floor sweep - that can then suck it away [because the waste is coming directly at it, not flying around inside the saw].

[Rich Engelhardt]

I have the hand powered version... :D :D

http://www.leevalley.com/en/images/item/Woodworking/Saws/variable_gangsaw1b.jpg