My sweet gum cant is a parallelogram???

[kelLOGg]

A customer dropped off a sweet gum and some oaks logs. I sawed the gum first to approx to a 9 x 9 cant and noticed it didn't look square. Placed a carpenter's square on it and sure enough -  over an 8.5" span it was 0.25" off! on all 4 corners. What happened to my mill, I thought? I measured the height from the band to the bunk. It was constant to within <1/32" over the ~20" width. I measured the angle between the squaring arm and the bunks - again spot on.???  I wasted a good bit of the AM measuring and puzzling over this. I know sweet gum is interlocked grain and this was my 1st gum to saw. Wait til I saw the oak and then pass judgement, I said. Sawed the oak today and got square cants, as I expected. Not the mill (or me) - must be the gum.

Anyone had this problem w/ gum?
Bob

[isawlogs]

 The cant moved while you where sawing , or it was not up against the back supports before you sawed it , It happens, put it back on the mill and square it off , it probably has nothing to do with the log , operator error.  ;)

[Magicman]

Sometimes, especially with very large logs, you simply just don't get a square 2nd face opening.  Then, they are all off.  Could there have been a piece of bark or something under the cant when you opened the third face?  That will do it for sure.

I have a 12" square under my operator's seat that I will pull out in a heartbeat.   ;)



 

[paul case]

bark on the bunks is a big problem for me. i have gotten used to rolling the log back up some and clean them bunks off just about every log.  pc

[kelLOGg]

I slid the cant down the ramps to the ground to clear the bunks for the alignment measurements then re-loaded and re-squared the "cant" and got the same results. I did not look for bark stuck to the cant but if it was there it was stuck pretty good to survive unloading and re-loading. Maybe you're right, isawlogs, operator error - but I sure would like to know for sure. I'm going to put this one with the 40 cent error in my bank account, which also defied discovery, and eat it. After all, I was sawing 1.5 x 6s so it's not like it is going to be an eyesore.
Bob

[woodmills1]

is your clamp pushing out of square?

[WDH]

I don't doubt that the sweetgum cant moved that much.  My experience with the spiral grain woods has been worse than poor.  I have sawed a good bit of sweetgum, sycamore, and hackberry, and every time, the board quality looked OK green off the saw, but after some air drying, 50% of it was useless.

It just goes to show you the amount of stress that can build up in some trees.

[zopi]

Ya..prob over rotated the cant once...some thing you become very sensitive to on a manual mill...turning the bloody log back just sucks.

[kelLOGg]

The cant moved while you where sawing ,

... and the reason it moved is because there was some sapwood rot that was too insubstantial to hold the log against the stop! I am sure that is the reason. If I had not omitted that bit of info you guys would have figured it out before I did.
You're right on, isawlogs, even without all the information. I can let go of it now.
Bob

[Magicman]

I hates Sweetgum.   :-\

[WDH]

 :D

[Buck]

My clamp will push a cant out of square. I clamp it then back off a little and all is good. Each machine is different....maybe yours is quirky too.

[Left Coast Chris]

If your mill is a WM or cantilever head, run the head down close to a bed cross member and check the distance along the blade to the cross member.

I had some parallelogram sawing occur and sure enough the head needed adjustment after the round stock the head bearings travel on started getting a flat spot at the bearing contact.  Just one more possibility.

[ljmathias]

I think you got enough options now to pick one or two to live with... but the real problem with sweet gum is that, well, it's sweet gum.   >:(  I've managed to get a few boards off a sweet gum log that didn't turn into spaghetti, but not many.  It's definitely something you only cut if you're really desperate or you have too much time on your hands and are willing to take the useless boards and try to do something creative with them.... like burn 'em?  One good thing, though: when dry, the wood is incredibly tough.  Have fun!   :D

Lj

[kelLOGg]

The sweet gum was among WO all of which had rotted sapwood. The customer thought it was all WO which he was planning to use as trailer decking. I didn't know what it was until I started sawing but it did not look like WO. Well, it was sweet gum. When I delivered it to the customer I told him one of his oaks was a sweet gum.    he looked. "What did you do with it", he asked. "I sawed it", I said. What would you guys have done? saw it? or not?
I'm sure if I had notified him he would not have wanted to pick it up. and it's not even great firewood. So I continued to saw it.
Bob

[beenthere]

If the SG was in his log pile for sawing, for sure it would get sawn and you should get paid for it.
Unless he said just saw the WO in the pile

Is he fussing about paying you for the sawing?

[kelLOGg]

Beenthere, not in the least. He's more than a customer - close to a friend and a repeat customer. He's just 10 miles from me and I did not charge for delivery but he gave me a $20 "tip" which he called a delivery fee. (most of my customers "tip" me).
I just had second thoughts when I realized it was not what he wanted even though he delivered it. Maybe he'll find a use for it.
Bob