7X12 Import Band Saw not cutting straight, I found the problem!

[8ntsane]

Hello Guys

My 7X12 Import saw has been not making straight cuts for the last while. I had a chance to check it over tonight, and I was not impressed with the findings.
I had a few items to cut, so I figured Id have a look see, after the cuts. I had just dropped a piece of 2X2 metal on the table, and was just about to snug up the vise, I was lightly pushing down on the material, and I noticed a rocking motion.

I lifted it back out and expected some swarf under the material. Nope, it was clean. Under further investigation, I took a straight edge and layed it across the table. The top[of the table is bowed up in the middle! Crap! Looks like Im going to be tearing this puppy down, and get this ase mounted on the milling machine to re-cut the top. My guess is, it must be from excessive tightening of the vise that has caused this problem.

This saw is a Craftex, from the local Busy-Bee outlet. I bought it new back in 08
so Its had a few yrs on it. I havnt ever heard if this problem before, so if you saw just happens to not cut square, this is somthing to check. Its easy to over look this, but a straight edge told the story in short order.

Ahhhh, Another Damn job to do.

Paul

 

[Rbeckett]

Paul,
Before you go too far take a look at the 4X6 group at yahoo groups and follow there truing and tuning procedure. It is is the files section of there group. I did it to my 4X6 and it turned it around. Worth a look before you do the tear down anyway. Hope this helps.
Bob

 

[Tony Wells]

The bed of the saw table should be flat, but either it was a green casting, or is pretty thin. The clamping forces shouldn't have moved it very much. How much bow are you seeing?

 

[8ntsane]

Hi Guys

I checked it over again, its heaved up about .012 in the middle. Nothing much I can do , other than machine it flat. Once I get that sorted out, I,ll be taking a good look at the vise jaws to make sure they arnt tilted out of alignment. Should be a easy fix, just annoys me a saw built in 08 is outta wack allready.

I suspect that cranking he vise down tighter than needed has somthing to do with this, or the sliding vise jaw isnt 90 to the table, and not gripping the work well enough. I will look at the vise part after I get the table trued up.
The saw wasnt allways this way, I have had it since new, and have put alot of materials through it over the yrs. I just hope aftter the repair it stays true, and I dont find myself doing this a second time.
Paul