Inside cuts

[scrollerbob]

I scroll names in 3/4 inch pine and I notice when I cut inside curves or ovals that the underside is bigger than the top side--I use a #5 blade why is this happening--I am using a Delta 788 and FD blades

[Jim Finn]

either your table is not level, or your blade is bending as you cut.  (Too fast a feed rate, or not enough tension on the blade,will cause this.)

[Multifasited]

You are bowing the blade,SLOW down your pushing too hard ,the blade must be able to catch up with the cut (cut a piece of scrap ,saw in make a 2' circle ,make the shape like a golf ball on a tee as you go to exit out the edge watch what cuts through first ,the top the rest is a bow and must catch up to exit smoothly,then look at your cut out will it slide out boths side or just one ,then look at the cut piece see any taper ,which way is it and where is it worse , the exiting at the edge gives you a grafic ,if you just break through the edge at the top ,stop the saw loosen blade clamps top and bottom remove the work piece with the blade still in place you will see what I am talking about ,now look to see if there is also some side bend ,from side pushing ! This is all part of letting your blade clear all the saw dust out of the kerf before oroceeding .smaller thinner blads are worse ,bigger thocker blade in thicker wood are more problematic 

[ike]

Let the saw do the cutting you just steer it. if your table is square with the blade this should cure your problem. Don't rush the blade.

[amazingkevin]

I've noticed that with the dw788 you can keep cutting with  no  blade tension at all.reason being is it is so gentile on the down stroke from tdc=top dead center.On chinese saw your blade will break when the blade is loose every time.Because on the down stoke from tdc its like falling off  a cliff, nothing gentle about it . Its either up or down like a sewing machine.Even though you start out with the correct tention as soon as you turn on the chinese saws it snatches the blade and give slack in the tension but you would never know it  till you have cutting problems like the curved cuts your having.

[browders]

I have the same problem. I have given up on cutting much in 3/4 or thicker stock. I'd like to cut 3D ornaments, but one side never looks like the other. I realize the problem is with me, I just can't seem to figure it out. Perhaps the slower feed will help. Thanks guys.

 

Jim

[me5269]

Quick way to check if your blade is square to the table:  Cut about 1/4" into the edge of a 2x4, back out of the cut, slide the 2x4 around to the back of the blade, the blade should slide right into the slot you just cut. if it doesn't adjust the table until it does.

I keep one next to the saw maked with which blade made the cut. Makes it quick to readjust the table back to 90*.

[NC Scroller]

Make sure you are working with a sharp clean blade.  Pine has a lot of pitch and combined with the fact you are cutting 3/4 stock it does reduce blade life.  If you are using the blade for more then 15- 20 minutes you are wasting your time.

[Multifasited]

all of the above is correct ,Rule #1 the BLADE  ANY BLADE even when perfectly straight to the table ,will bend (flex )opposite the forces applied.the blades center is flush with the table ,which is always the center of the (flex )the top and bottom are in the clamp and stationary ,the tention will automatically straighten from the tight tention you have set BUT HAS TO HAVE TIME TO CATCH UP ! thicker the wood the more time it takes ,side pressure has to work it's flex out after side pressure is removed and travels forward ,Table angle (planned taper is a different matter it is constant )However you can ruin that with side pressure by creating a bow  even in that .The BLADE IS THE BOSS ,Your just the steering mechinism ,Slow ,Steady and straight even on curves you only pivot while still going straight !Saw dust must have time to clear the kerf or it loades up the gullets (between the teeth) when that occurs your #7 blade becomes a wide space #2 ,Easy on the PRESSURE  ,CONTROL is what you are after !! 

[Kepy]

I keep an old credit card handy to check that the blade is square to the table.  I am usually reminded to check when a small piece doesn't drop out after cutting.  

[Multifasited]

Blade squareness is always important ,But the bow from too much side ward pressure will still allow pc to fall out bottom ,but not pull out the top.

the thicker the wood the more obvious the issue .stack cuts vary and don't match ,top smallest bottom bigest  cridical in areas where narrow spacing exists !!

[Multifasited]

The original poster ,must have faded into the shadows again !