40-690 blade movement - for and aft

[jscott2]

When my Delta 40-690, the DW788 clone, is cutting, the blade move back and forth about 3/32" as measured at the top of the table.  I find this causes the wood to move forwards and backwards, especially when I am sort of holding the wood back so it cuts more slowly.  The saw also seems to cut quite aggressively and gets away from me, especially in tight turns.

I've been playing with moving the lower rocker assembly forward, as mentioned in Rick's Dewalt tune-up section, and have moved it forward about 3/32 or perhaps 1/8".  The blade movement is down to about 1/64".  This has been done by removing the 4 screws that hold the lower rocker and sliding the rocker forward.  It's held now with a clamp - for testing.

Before I start slotting the mounting holes I was wondering how little blade movement is acceptable?  If the blade moves perfectly up and down, how does the sawdust get cleared out of the blade, especially for thicker wood. Is some back and forth movement necessary?  Am I wrong in thinking the back and forth movement make the saw cut more aggressively?

I will be very interested in your comments and suggestions.

Thanks,
Jim

[me5269]

Jim
I have the same problem with my 788, check you this post, it may help
http://stevedgood.com/community/index.php?topic=12502.0
mike

[jscott2]

Mike, I tried that http://stevedgood.com/community/index.php?topic=12146.0 and it did help get the blade more vertical to the table but I still have the back and forth movement that I don't like.

Thanks,
Jim

[dirtrider73068]

Most scroll saws are parallel arms, and will have slight blade movement to and fro, unless its the parallel link arms like the dewalt then it don't or shouldn't have that blade movement to and fro. I have a craftsman and the blade clamps are mount on the arm in a loose swinging action this enables the blade clamps to move to and fro but the blade stays straight up and down, but sometimes pending how the blade is mounted I will get the to and fro movement.

[Mainewoods]

Jim, the only saws that don't have forward and back movement of the blade is the Eclipse, because it doesn't use arms to move the blade up and down.

I also have the Delta 40-690, and had significant front/back movement.  I initially attempted the adjustments as indicated on Rick Hutcheson's site, but wasn't satisfied with the result, although it did diminish the movement a bit.  As I got to thinking about it, it made sense (to me anyway) to tilt the rocker assemblies toward each other.  I moved each one approximately 1/16".  I kept adjusting little by little, until it didn't seem to get any better.  Ultimately, I was able to reduce the front to back movement down to .022".  After that, the only problem I have with wood jumping around is when I'm using a reverse tooth blade and I'm not paying attention in a turn!