The small branches of a tree can be quickly bucked into sticks that contain several pieces of firewood. Stacking these sticks into a specially designed frame allows them to be safely, quickly, and efficiently cut to final length with a chain saw.
Gather some basic parameters for your frame. How long would you like your firewood? Theoretically my stove can take 16" pieces but I find 14" pieces are much easier to work with. Cutting shorter pieces is more work so you don't want to make them shorter than they need to be. But firewood that doesn't fit in the stove is useless.
How many pieces of firewood should be included in each stick? A tree can be quickly bucked into sticks that contain several pieces of firewood. The longer the sticks the less time required in the field. However, long sticks are more difficult to transport and they don't stack as tightly into the frame. The longer your sticks the longer the frame needed to hold them. I make sticks 3-5 lengths of firewood long. For me that is 42", 56", or 70" long. A measuring stick with these lengths clearly marked is very handy.
How long is the bar on your chainsaw? The bar needs to reach all the way through the stack of sticks. I have a small electric saw with a 14" bar. My frame is 10.5" inside dimension. The saw runs on the outside of the 1 ½" vertical. This provides 2" extra bar on the opposite side of the stack.
How tall do you want the frame and how low do you want to stoop when cutting the bottom of the stack? My frame is 46 inches tall. The top of the upper cross-pieces (which is also the bottom of the stack) is 18". This provides easy loading and a convenient work height. The dimensions of your frame will impact the length of construction materials needed. If you are using second hand material as I did, that might figure into your thinking.
The frame should be made out of sturdy 2x6 or 2x8 material. I used rough 2x8s recovered from some gates found in an old dairy barn. The backbone of the frame is the two longitudinal planks that run the length of the frame. Calculate their length by multiplying the length of your firewood by the number of pieces you want the frame to hold and subtract about 4" to provide clearance at the ends. Remember that a frame three pieces long can effectively hold sticks up to 5 firewood lengths long. Simply center the sticks and cut the two outside lengths first.
The verticals form the box to hold the firewood sticks. They extend past the longitudinal pieces to form the legs of the frame. Verticals that are about 48" long work well. The upper and lower cross pieces tie pairs of verticals together. The upper cross-pieces form the bottom of the stick box. The maximum length of the cross pieces is dictated by the length of your chainsaw' s bar. Bar length minus 3.5" is a reasonable length.
After collecting your materials and cutting them to length it is time to screw the entire frame together. Use #10x3" deck screws or similar heavy duty fastener. Fasten pairs of verticals together by attaching two upper cross pieces. Align the pairs of verticals. Center each pair one firewood length apart. Clamp the longitudinal plank into position under the upper cross-pieces and screw into position. Add one lower crosspiece at each end for added strength.