Vertical cut in thick hard wood - any suggestions?

[EIEIO]

I am cutting some toy cars. The body (see pattern below) is cut in one piece from a piece of 2"x2" red oak using a #5 blade on an EX-21 saw with the blade set perpendicular to the table. The upper arm position has been verified parallel with the table. The wood is actually an oak 1x4 ripped to two 1x2 then glued to a 2 x 1.625 with Gorilla wood glue.

The car shapes are all smooth curves. After cutting the outside shape or internal openings, the part will not come out of the blank in either direction until I cut around it to make some clearance. Looking at the final cut, the top and bottom surfaces of the cut look to be in line, but the center is bowed slightly, preventing the part from leaving the blank. This is not only in curved section, but also in long straight cuts such as the frame section under the pickup bed.

Any suggestions? There doesn't seem to be a way to tighten the blade on the EX-21, but if someone has a way, I'd like to know.

[Rapid Roger]

You are pushing the material to one side too much as you cut. The upper end and the lower end of the blade will remain in line but the center will bow a little as you cut. You might be rushing things a bit also and not letting the blade do the work and track vertically as it should.

Rog

[mlwmerk]

I Second what Rapid Roger said. 

I also have the same problem with only 3/4 inch red oak puzzles so I can imagine your problem with 2" red oak! 

Go slowly, don't push, especially around corners. 

You might try a # 7 or 9 size blade.  They will leave a bigger kurf, but from looking at the pattern, that should not be a big problem.

[Russ C]

I have had this happen to me before with thick wood and found it was the result of me trying to cut to fast and pushing to hard. 

[dunk]

I have to go along with the group, too much force, I encounter this all the time doing puzzles and cars.  With this thick of wood and species i'd move up to a #7 blade also.

[EIEIO]

OK - thanks. I'll try the bigger blade and a slower cut. I don;t think I'm pushing sideways, but I'll keep it in mind.

Anything on tightening the blade on the EX-21? Other than throwing the lever to the tension position, what else would control the blade tension?

[julief]

I have an older EX21 so I only have the one tensioner.  If you have the knob at the rear, tighten it up there.  I cut a lot of 2" thick stuff on my saw and if you can go with a little bigger blade that will help but you have to be so careful to slow down your cut (the feed - not the motor) to prevent that bow in the middle.

[EIEIO]

Here's something I noticed after this 1st posting - the top picture shows 2 trucks from the rear. They are both cut from the 2x2 that was made by gluing together (2) 1x2. On the truck on the right, the grain of the joined boards forms a 'V'. The truck on the left is opposite (I accidentally inverted the pattern on the 2x2). In the 2nd picture, from the side, the seat of the truck on the right is bowed up, while the seat on the left truck is bowed down. So I wonder if the blade is following the grain in the wood, which direction is different in the two trucks, and changed 1/2 way through the wood. Both trucks had the cut-out section stuck and I had to cut it apart to get it out.

[EIEIO]

I have an older EX21 so I only have the one tensioner.  If you have the knob at the rear, tighten it up there.  I cut a lot of 2" thick stuff on my saw and if you can go with a little bigger blade that will help but you have to be so careful to slow down your cut (the feed - not the motor) to prevent that bow in the middle.

Julie - I understood that the knob on the EX-21 is used to set the top arm parallel to the table. If it is adjusted when there is no blade loaded, then I think the tension lever will apply the same tension on the blade no matter where the knob is set. The knob could increase or decrease tension if turned after the blade is clamped in, but that would throw it off of parallel.

Do you regularly adjust that knob? I only change it if the arm has drifted down.

[julief]

I don't have that knob.  My saw is not equipped with it.  It is my understanding that you can "fine tune" your tension with it.  Maybe some of the Excalibur owners of newer saws can clarify or call Ray Seymore at Seyco.

[Toneman]

Mike sells some heavy duty FD blades that are great for thick hard wood. I have used them on 2" thickness pine and worked great, but, blade speed must be almost 100% and feed must be SLOW.

Tony,aka,Toneman

[Jim Finn]

I agree with those saying that you may be pushing too hard on the wood while cutting.  I have found that the heavy duty blades from Flying Dutchman are no better than their #5 Polar blades are.  They last no longer than their other blades, in my experience.  I like FD #7 Polar blades to cut thick wood.  Cutting through glue will dull the blade quickly also.