Blade slipping

[Dennisfm56]

Ho Folks,

What's the best way to dress the set screws and thumbscrews to help with blade slippage? I currently use a piece emery cloth. I'm wondering if I'm just making the problem worse. I have the Pegas clamps on a Delta and have replaced both the screws and thumbscrews that I purchased from Dennis Knappen (ArtCrafters). Thanks

[TAIrving]

Dress the ends of the blades (where the clamp clamps) in addition to the clamps.  They come from the factory with a light coat of oil which causes slippage.  

[Dennisfm56]

1 hour ago, TAIrving said:

Dress the ends of the blades (where the clamp clamps) in addition to the clamps.  They come from the factory with a light coat of oil which causes slippage.  

I always put the end of the blades in a solvent that should remove the oils. but dressing the blades won't hurt. Thanks for the tip.

[JTTHECLOCKMAN]

I run 220  grit sandpaper across the set screws as well as the ends of both sides and both ends of the blades. Has worked well. Over time though setscrews become rounded from constant pressure. I take them out and hit them on my grinder to flatten. If you have the screws that have the movable pad then skip that step and just touch with sandpaper. 

[RangerJay]

I use an alcohol swab to remove the oil followed by roughing up with 220 grit sandpaper - they are both needed.  Not sure why this is but I only need to do the lower end of the blade.  Should add that this seems especially important when using spiral blades.

 

 

 

Edited December 6, 2025 by RangerJay

[BadBob]

I never clean my blades, and I've never had an issue with them slipping on any of the scroll saws I have owned. I keep spare parts for my EX-21 and Pegas saws for several years and have never had to replace them.

My saw is not running every day, so maybe I am not working it hard enough. 

[Roberta Moreton]

I drilled a hole in a 1/4” piece of wood and this is where I screw in my thumb screw to be sure it is straight and flat when I sand the end.  The sandpaper I use is attached to a flat surface as well. If you put a hex key in the set screw to hold it straight you can sand it as well. 

Edited December 7, 2025 by Roberta Moreton