won't scroll straight

[Bruce Horn]

I have a Craftsman 20" Professional, garage sale find, that doesn't track properly. When I try to cut a curve it wants to stay straight. The tension is tight and the blade is thin, 12tpi. The material is 3/4" pine. Any thoughts?

[Bill WIlson]

Could be a few things or a combination, thereof.  Have you had the same problem, cutting other types & thicknesses of wood?  Have you tried different blades?

Many scroll saw blades have a bit of natural drift to them.  It's a result of the manufacturing process.  Most scrollers eventually learn to compensate accordingly.  If the amount of drift is extreme (and I have no idea how to objectively measure what "extreme drift" is), the blade might be twisted or be otherwise defective.  Also, pine is notoriously hard to cut.  The different densities within the grain can cause the blade to be hard to control.  Try a different wood and a different blade.  If the results are the same, then the problem may lie elsewhere, but eliminate the simple factors first.

[Sycamore67]

What blade are you using?

[Wichman]

19 hours ago, Bruce Horn said:

I have a Craftsman 20" Professional, garage sale find, that doesn't track properly. When I try to cut a curve it wants to stay straight. The tension is tight and the blade is thin, 12tpi. The material is 3/4" pine. Any thoughts?

I see that you are new here, how much experience do you have on the scroll saw?

To test the blade tightness, pluck the tightened blade like a guitar string, the blade should "ping" and not "plunk". Dull blades will not want to turn either. 

[Bruce Horn]

Thanks all for responding. I have a bit of experience. The blade "pings" like a guitar string. I have cut the same wood on my 16" Delta and have had no issue. The drift is extreme, as in I turn the wood but the blade still goes straight. It is a pinned blade, so it may not be tight in their seats. I did discover tonight that the bar connecting the upper and lower arms has a hole slightly out of round, introducing slight slop in the vertical motion, so maybe intermittent loss of tension?

[Sycamore67]

What Brand blade are you using?  The type of blade..skip or reverse?  

 

[Bruce Horn]

Thanks again all for your input. It turns out to be the connecting rod holes being out-of-round.  I couldn't find a replacement so I made a new one. It weems to be working well now.