cutting long straight lines

[gilljc]

Can anyone give me some tips on cutting long straight lines with spiral blades? Want to cut portrait of glider and towplane, but would like to make it 20" wide, and my saw is 14". have had a practice, and have resorted to cheating where I can and cutting 'guide' with a straight blade then widening with spiral, but not always possible, and dust is turning blue in my shed every time a little 'bubble' appears in what should be a nice smooth line 

[scrollgirl]

I use bigger blades when having to cut long straight lines or long curves.  The larger blade is more stable and less likely to follow the grain of the wood as smaller blades do.  Also, when cutting, look about an inch in front of the blade.  For some reason this helps me follow the line better for cutting.

Good luck, Sheila

[EIEIO]

Straight lines are a lot harder than curved lines on a scroll saw. Make sure you have a high enough tooth count on the spiral so there are several teeth in the wood at any time - that reduces chatter. Then move like a glacier (slow) to get the feel for the blade/wood combination. Practice will prevail.

Keep your eyes on the line the whole time and make an effort not to think about anything else but cutting that line (if that's possible - St. Francis once offered to give a donkey to some guy if he could say the full Hail Mary without any distractions. The guy starts..."Hail Mary, Full of Grace,...will you throw in the saddle?")

Please post a photo when you're done.

[overfifty]

Good morning Gill. I also have issues using spiral blades. When I use a spiral blade I always make a primary cut with a small crown tooth blade. The spiral blade follows the cut without a problem. Cheers, Barry.

[GrayBeard]

Take it from someone who uses spirals almost exclusively...you ain't gonna cut long straight lines with a spiral blade!
When I need a long straight line I switch to a flat blade that will give a kerf about the same width as the spiral I am using.
Spirals are great for what they were designed for and that is cuts that would require twisting and turning the wood constantly, think 'portraits'.
Another thought is that the thicker the wood the easier it is to control the cut. Hence most of my work is with 1/8" or 1/4" wood but I always stack several to get a thickness of 1/2" to 5/8" for better control and smoother cuts.

~~~GB~~~

[UHMNL]

I have now a new spiral blade, what is a lot easier to control.
To stay on the line with a regular blade, you have to move the wood some degree to the right.
The blades have a burr on the right and will cut to the right. Never force the wood too hard into the blade, let the blade do the cutting.
Mike

[gilljc]

Hi, thanks all for your replies, all relevant and pretty much as I was thinking  posted pic on brag forum, used mach 3 blade for thin section of glider wing and two cuts with 2/0 for the wider part, but was getting drift towards the first line - should have stuck with thicker blade. in some places I started with a straight blade and then used Mike's new spiral blade, 2/0
got another pic in mind, this time more close up on glider landing - more blue air on way 
doing a Charles Dearing Labrador for a friend now, nice wiggly rounded lines.....

[Woodchuck]

 Best to use flat blades. Also when using flat blades, some people set to one side of the saw so when they push straight they are actually pushing  at an angle relative to the saw. Even for short distances that need to be straight, I change to flat blades, when I use spiral.

[ChuckD]

Mike, what is the new spiral blade you have that will cut straight?  
Other than than that I would pretty well do what GB says.  Flat blades then change.  No rules say you have to use the same blade all the way thru a project. This one took five different types blades.

[cdrover(Clyde)]

I am with Sheila, try to focus on there you want the blade to go, 1/2 inch ahead of where it is works for me. It takes a lot of practice and self discipline
not to watch the blade but ahead of the blade. I am reminded of something The Great One, (Wayne Gretsky) said in an interview when a reporter asked him about his success with hockey. Wayne said, "I try to predict where the puck will be, then I position myself there." Works for scrolling toooo.