Building a slab saw

Advice and images on creating a contraption for chopping bundles of kindling. January 16, 2002

I am considering building a slab saw to chop bundles of kindling. I have a 10 hp tefc saw-arbor motor, a #2 starter, and a semi-auto plastic strapper.

The trouble is, I've never seen one before so I don't know how to proceed. Does the saw move or the slab(s)? Conveyer to advance the slab? Is some sort of clamp for the wood required?

My slabs are typically small softwood (larch).

Forum Responses
I have a Rainier hydraulics chomper that uses a shear to cut firewood. I bought it to process slabs, and it does a fine job. Now if I could just get more customers. I think your desire to bundle is probably going to give you a more marketable product.

From contributor J:
One of the first things I built myself, when I was starting out in the sawmill business, was a slab cut-up table. I saw one at a logging equipment show and they wanted $1200 for it. I wasn't going down that road.

I made three sawhorses and a table that looks like a ladder without round steps. I used 2x4 oak for the runners and cross blocks. These cross blocks were added directly onto the runners. The spacing was 2' on center. On top of these cross blocks I mounted a roller. I got 7 or 8 of these at the local woodworking tool and supply store for about $6.95 to $9.95.

Next I built a special bracket stand to hold a chain saw lumber maker. You know, one of those things that you clamp onto your chain saw bar and slide down a 2x6 to rip logs into lumber. I mounted that to this special stand and at an angle to hold the saw up out of the way when not cutting slab. Then I added a fence to the front edge of the table to stop the wood from sliding off as being cut, as the chain saw would pull the wood towards the operator. To the top edge of this fence I pounded in roofing nails with the heads spaced out 16" from the chain saw bar.

To use this cut off table, I would drop a piece of slab onto the table, slide it over under the chain saw bar until the opposite end lined up on a nail head. Then cut off a piece shorter than 16". This waste piece would drop into my backhoe bucket. Then slide, cut and drop. When the bucket is full, it's dumped directly into the dump truck for hauling away.

I'm lucky to have a bark mulch guy near me who has a tub grinder and will take my entire slab, with no disposal fee. But he doesn't want long lengths. Now he will take four to six footers. I only use the cut off table to cut hardwoods to save for my own stove or to sell.

The total cost was under $100 for rollers and chain saw lumber maker. I had the lumber for the saw horses, stand and table.

Make it safe for anyone to use.

From the original questioner:
Contributor J, I like your resourcefulness! Too often we just make do without a tool because there isn't one suitable for our production size or budget. This inhibits our efficiency, which is usually in the toilet already.

I was thinking of some kind of adjustable stop for piece length that would retract as the saw engages. A table on the out-feed side to support the pieces, and a little rack to slide them into that would hold them for bundling.

My slabs are tiny so I think I'd stack a few on there before cutting the length. This, I think, means I will need a hold-down of some kind. A 3" nylon strap and spring over the slabs next to the saw, I think. A foot pedal could bring the strap down as well as the length stop.

Another thing I need to watch for is keeping sawdust and bark flakes out of the guts of the strapping machine. This might be the limiting factor for my plans.

I take it that the saw is on some sort of a pivot like that of a wood processor.

From contributor J:
Years ago when we first started, we had a piece of wood sticking out on the drop side to use as a measuring stick to make all the correct length. This worked but got in the way of the backhoe bucket and pile in said bucket. It continually broke off. Once the first end is cut with the other end on a nail head mark, then all others cut will be of the correct length. We place the slab on the roller with the sawmill cut flat side down. This makes it easy to slide or roll over to the next cut.

An out-feed table or bundling station would work for you. You'll have to make one up and try it. I use a plastic strap on my grade stakes and it works well with a little metal buckle. This could be something you could use to hold your bundles together. Then you might need a handle of some sort.

Below is another shot of the table with the saw and backhoe bucket.

To the original questioner: Instead of using the strap, you might use a role of plastic like they use to wrap rolls of cloth in for shipping (about the same as the plastic used to wrap produce). It comes on roles about 18 inches wide. Put a couple of U shaped saw horses under the off-feed side of the slab cutter, and wrap it in plastic after it is full.

To the original questioner: I have done something similar. I use a swing saw for cutting the much smaller materials for bundles of kindling. I build a jig to hold up to enough for three bundles. The jig is 1' x 1' open ended. Materials are cut 16" long. I lay bailer twine beneath where the materials are laid and when each jig is full, I tie each bundle with two pieces of baler twine and join them to make a handle.

Each bundle goes for $5, which is equal to 22 bundles per rik, 66 per cord and $330 a cord. I move up to 10 cord a year if I want to, otherwise the small stuff goes into the chipper and I sell the chips for $10 yd delivered or $8.00 yd u-haul.

The larger slab wood goes into a jig that holds 1/4 cord of the material and is designed to be picked up with forms and dumped into my truck for delivery. The jig is designed so that I can cut it every 16" or 32" depending on the customer. I use most of the material myself for heating my kiln with a Taylor Stove or for the house, which is also heated with a Taylor.