Cutting straight line

[timelett]

Working on a Steve Good pattern that has a frame,the butterfly clock,I did ok cutting the top and bottom, but getting the sides in a straight line is a bit challenging. 

I was thinking about cutting two strips and attaching them to the sids.

[JTTHECLOCKMAN]

If I were doing a project like that I would have cut the outside frame on my tablesaw. I would get dead on straight cuts. The inside cuts is just a matter of practice to be able to cut a straight line. You could still trim it up on the tablesaw or use a belt sander. 

Edited November 27, 2025 by JTTHECLOCKMAN

[kmmcrafts]

One thing about doing long cuts that used to help me was making sure I have a brand new  blade at the start of these longer cuts. For me going straight was more about me wanting to "go faster" because of the longer straight cuts.. even circle cuts like ornaments is tough to do if there is not big details to do you kinda get bored and impatient and end up pushing the wood too much which will cause the blade to flex and wander. Most times I start a longer cut with a new blade even if the one you had been using wasn't that old or dull yet.. I also used to speed up the saw.. Now if you're having the opposite trouble where you feel it's going too fast for your comfort maybe a dull blade and slower speed is what will work for you. Some types of wood is real difficult because the blade will follow the path of least resistance so if there is a softer spot the blade will try to take that path into that soft area.  

[Scrappile]

What Kevin wrote works for me.  And, patience and not forcing the cut helps, me and is something I have to work at doing.  If, you can and have a long curve or straight line, switch to a bigger blade, easier to control, as long a  wider kurf will not hurt. 

[JTTHECLOCKMAN]

The one thing you can not control is grain pattern. Woods with heavy grain can veer the blade no matter what you try or how large a blade you use. It is flexible scrollsaw blade remember that. That is why I suggest elliminate 4 sides of cutting with scrollsaw blade. Should be a nice project when done. Good luck.

[Wichman]

To start I would like to get some definitions out of the way, it’s a bit technical, but it’s easier for me this way.

Blade width: the measurement of a blade from the front of the teeth to the back of the blade

Blade thickness: the measurement of a blade from side to side.

TPI: teeth per inch

Tooth to body of the blade proportions. Some blade styles have teeth that make up most of the blade and other have small nubs for teeth with a very wide body, this can have a marked difference in how tight a radius they will turn and alternately how well they resist following the grain.

 

When you are trying to cut straight lines or very gentle curves, you want:

A blade that has a greater width and has more back than tooth ( example: my favorite blade the FD Polar series has a small “back” then the FD Scroll Reverse blade, so the Polar will cut a very tight radius but the SR is easier when cutting straight ) I don’t know what blades you have on hand but you can check what you have.

Something to consider; because of manufacturing processes pin less blades are notably wider than pinned blades, it may be worthwhile to get a dozen pinned blades and experiment with them, just remove the pins and use like regular blades. ( For comparison the FD Polar #2/0 blade has a width of 0.023 and a thickness of 0.010, the Olson Pin End blade PRT427 has a width of 0.070 and a thickness of 0.010 so they have the same thickness but the Olson blade is three time as wide. Also, I just checked and the 0.070 is the width at the teeth, it’s even wider where the pin is.

 

When you are trying to cut a straight line, with, the grain and the grain is pulling the blade off the line, then:

More back than tooth

More TPI

Higher speed

Regular blade ( vs skip tooth blade )

 

And finally, you may want to consider the idea I floated a week or so ago and use a spiral blade and a fence. Practice makes perfect, but it only took me three cuts to get a good consistent cut. And FD has a spiral reverse blade to minimize chip out.

[timelett]

6 hours ago, JTTHECLOCKMAN said:

If I were doing a project like that I would have cut the outside frame on my tablesaw. I would get dead on straight cuts. The inside cuts is just a matter of practice to be able to cut a straight line. You could still trim it up on the tablesaw or use a belt sander. 

What I ended up doing is cutting two stripes on the table saw,I have a slider board and a zero clearance set up and I will  mend the strips to the finished cuts,I am trying to save the work already done.

[JTTHECLOCKMAN]

2 hours ago, timelett said:

What I ended up doing is cutting two stripes on the table saw,I have a slider board and a zero clearance set up and I will  mend the strips to the finished cuts,I am trying to save the work already done.

I understand what you are trying but you still need to straighten the edges on that you want to attach the strips too or they will not sit flat. If you do that then you may not need the strips. Very easy to do on a tablesaw. just use a square piece of plywood and attach the frame to it using double sided tape. Make one end as close to the end of the plywood that keeps the side of the frame looking staright. Probably would have to eye this or you can use a ruler. Once you have one side done use that against the fence and cut other side to match thickness of frame. The do the same for top and bottom. Maybe easier to do than explain but that would be my work around.  

[TAIrving]

What they said, plus keep the tension on the blade set tight.  A loose blade has a greater tendency to drift.