table crown in contractors saw- worth fixin?

I have a cheapie (well, it's belt drive so....) chinese 10" table saw that has a crown that I work around but am getting a bit weary of making adjustments depending on what I'm cutting. Anyone taken their saw to a machine shop and had the crown taken out....curious as to the dollars involved. Thanks in advance Pat
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patrick mitchel wrote:

I had a Chinese table saw once. If it had a crown, I wouldn't try to force the metal into being straight, I would beat it with a ball pien hammer until it was concave, then fill the depression with Alumi Lead (a type of bondo)and sand it perfectly smooth. Slime coat out the bubbles, and take it down to 400 grit. Another less violent method would be to heat spots of the crown with a torch, and then quench the spot with a wet rag, gradually shrinking the crown. After, use a sanding board to smooth out any little imperfections.
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I would get a piece of thick hardwood as long as the longest dimension of your table saw top. Joint one edge perfectly straight (use a friend's jointer if you don't have one). Place a thickness of index cards that is 2-3 times the height of the crown right on the center of the top's crown. Put the piece of hardwood across your table and over the crown (and cards), and clamp one edge. Now slowly clamp the other edge. Remove it and check the crown. Adjust the process until the crown is reduced and the saw is usable.
CI has a memory, so you have to experiment with how far you push it, because the crown will come back to a degree.
And all of this assumes you have made certain there are no root causes of the crown (like, the trunions were machined straight and stuff).
BTW, how far out is it?
You can PayPal the money I saved you to cgallery (at) yahoo (dot) com.
patrick mitchel wrote:

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Thanks for the reply , I bought the tablesaw new about 20 yrs ago and never bother to determine the root cause of the crown.I worked round the problem by always checking for square by making a final check before I made the cut (if it was a cutoff on the left side of the blade, I'd move the blade slightly to adjust for the slight crown, If a cut in half, the blade adjusted against the stop made for a square cut. If I lay a decent straight edge over the top, perpendicular to the miter slot, it has perhaps a 1/8" crown (shows about a 1/4" with one side of the straight edge held down). I haven't taken the saw apart to look at the trunnions. Was surprised to hear that cast iron is capable of being moved around a bit. Will play around a bit as I have some thick wall square tubing that I welded back to back for a homemade flattening jig that might prove useful in attempting to persuade the ci to move to where I'd like it to be... Thanks Pat
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