dw788 problem

[Meducher]

Hello,

I just recently invested in a new dw788 scroll saw. My poor porter cable scroll saw was crying for a replacement. The saw has some impressive features but I'm running into a major problem with it and wondered if others have also.

I make free standing puzzles and cut 3/4" stock material mostly. I've tested cutting on several different hardwoods and its impossible to get a consistent 90 degree cut which is essential for puzzle making. I have tried different blades, different tension settings from the lowest to the max, adjusted the table several times....i've taken the entire thing off and replaced it 2 times. The blade is square to the blade prior to every test cut. I use ultra reverse #5 flying dutchmen blades for 90% of my work.

So any idea what is going wrong? I've exhausted every possibility I can think of. Its so strange considering my previous 2 low grade saws didn't have this problem at all. Any suggestions would help immensely.

[tomsteve]

too much pressure, or force, on the work piece can cause the blade to cut on a bevel. let the saw and blade do the work. i have a tendency(still) to try and work the saw too hard. i like to let off feed pressure occassionally just to make sure i'm not forcing the blade too much.

also it could be possible the blade is slipping in the clamps. i took an emery board and scuffed up the surface where the blade is clamped. i also clean the blade ends with some rubbing alcohol and scuff em up on my disc sander. just a little bit of scuffing and they hold good. i usually have the tension set at the 4 or 5 mark.

[NC Scroller]

Are you saying the blade and table are truly square? Have you checked the table to make sure the cast is flat (no high spots)? Are all the pieces off by the same? If all is flat and square it could be you. Make sure you feed the wood straight into the blade.

[Meducher]

Just did some more test cutting. The blade has been truly square to the table each time. I thought the blade might be slipping at first but the tension is still there (some tension would be released if it slipped correct?). The angle of the cut seems to change some but not significantly.

The last few pieces I just cut, I fed the wood much slower than normal. The angle was reduced but still there. I could slide the pieces out but the fit was very tight. I haven't checked to see if the cast is flat which i will do now.

I was wondering if the threaded bolts on the opposite side of the blade tighteners might need adjusting. You need an alen wrench to adjust them.

[handibunny]

For a clearer look at what's going on, try a test cut on a slightly thicker piece of wood, 1" or so. Draw a circle, about 3" in diameter, and cut around the perimeter. Check the sides of the circle against the blade to see if it is the same, bows out or in, or is angled. Then check your blade to see if it's still square to the table.

Those set screws opposite the blade tighteners will affect the left-right tilt of the blade, but if your blade is square to the table, they should be OK. Some folks have had problems with the front to back movement of the blade, but I've never had to look into that.

Sorry for your frustration. This is not what should happen when you try to upgrade!

[Jim McDonald]

From experience, I can tell you those blade adjusters are 3mm--just to save you "dry fitting".

[Meducher]

I'm thinking now it might just be me. I cut two puzzles out with no problem at all. Granted I was cutting at half speed to avoid any angled cut. I set the saw at a slightly lower speed and it seemed to help some. I changed the blade, started the third puzzle and about half the cuts were angled. I checked mid way through the third puzzle for squareness and the blade didn't seems to be off. I have noticed that straight cuts are fine but wavy cuts tend to be angled.

That's a great trick handibunny. I will give that a try.

To clarify I was cutting at half speed by feeding the wood into the blade. Then I adjusted the variable speed of the saw.

[Jim Finn]

I think what is happening is the set in the blade is wearing off and the kerf is then a little less, causing the too tight fit. I cut the outsides with one blade and always use a new blade on the interior cuts. If it is a large enough puzzle you may try changing blades part way through the interior cuts, as well. Using #7 or #9 blades may also help. Feed rate and pressure applied are important, as has been mentioned.