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For making timbers for timber framing you should not quarter saw the logs.This would be for any timber 5x5 or larger.You need to have the center of the tree in the center of the timber for strength.Jim Rogers
Jimdad07,Looks like you did a pretty good job making your mill. Have you fabricated any other forestry/farm equipment?
The thing you need to avoid at all cost is having the "pith", the centre of the growth rings, anywhere near the edge of a beam or board. It will warp, twist, bow, or check... possibly all of those at once.There are 2 ways of dealing with this. Heart centred. This means you keep the pith centred in your beam, and this balances the stress that's naturally in the tree, or is caused by the tree drying. This will be most common with smaller logs, where you have now way of cutting the sizes you need without including the pith. So then you would saw off some outside boards for other uses, and leave the central beam.OR Free Of Heart This means that the piece is cut well away from the pith, juvenile wood and the small growth rings near the centre. This should give you a piece with straight even grain, that should be stable and probably stronger then heart centred. Of course you need MUCH larger logs to be able to produce these, usually big softwood Dough Fir or similar.Quartersawn relates to a sawn board, and how the growth rings are orientated. Looking at the end of the board, if the growth rings are near 90deg to the board, then it's Q-sawn. If the growth rings go across the wide dimension, then it's flat sawn. 45deg is Rift sawn. It doesn't really apply to beams as they are more square in dimensions. An 8x8 doesn't have a "flat" side to reference the grain fromIan
One way to deal with those big logs is make a ground (or bolt on) track for your mill head to ride on.
If you are a newbie to timberframing, and really need to build over the winter and spring, you need to get up to speed quick. In that case I'd recommend that you partner with a timberframer to help you design, cut your project, while teaching you at the same time. Another option would be to hold a workshop at your place with a good framer who has held workshops before. You will learn in the workshop, while working on your project, and having other students there to offset the cost of the event.
Jimdad, I am assuming here when you say "poplar" you are refering to "Tulip Poplar" or "Yellow Poplar" and not "Popple" which is a regional term for Aspen. Aspen should not be used for framing. Yellow Poplar is a strong and light wood and frames well if you can get it to dry correctly and stay straight. That said it is very prone to wide, deep checks. If you are doing boxed heart framing this is not that much of a concern as the check never passes through the heart but with the way you are sawing, the check could split the timber clean in half. Twisting is also an issue. Try to verify that there is no spiral in the bark of the trees you select. I once cut some braces out of poplar that were not boxed heat and after they dried, you could split them in half by hand. Just a few wood fibers were holding them together. Poplar is noted for making good siding. With logs that size you might want to cut the outside off for siding until you reach the size timber you desire wich would be boxed heart center and good for timber framing.
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