DW788 Lifespan?

[sdguy]

I've got a DW788 that I've had for three or four years, and I use it mostly to cut stand-up puzzles. It's been a great saw for me, but lately the blade bending is worse, and on 3/4" thick puzzles, that means your pieces won't pass through cleanly.

I've had issues with this kind of thing before--sometimes it's due to me being too aggressive with the cutting, and I do cut a lot of challenging woods (wenge, bloodwood, bubinga), which doesn't help. Lately, however, I think my problems are due to blade tension. When I first started, 4 was pretty tight. Then 5. Then maxed out. Then I went in and tightened the tension bar by turning it a few turns, and that helped for a while, as did pushing down on the top of the blade holder, but now it's really loose again, and there's nothing left to be gained from the bar no matter where I have it set. I literally can't get the blades tight enough to make a straight cut.

So. . . is this the end for my saw?

[Hawaiilad]

When I owned the same saw I remember that happened along with lots of other problems. That and many other reasons is why I gave up on the saw. I remember even cutting off the ends of the blades thinking they might be to long. Of course I ran into a batch of problems with 5 different saws... I kept taking it back to the store and exchanging for another one until the store ran out. I gave up and bought a Hegner, and yes I love this saw.

[NC Scroller]

I have a Dewalt type 2 with over 1,000 hours on it and going strong. I did once have to adjust the tension bar one time. When you do put a couple drops of loc-tite on the nut. You should be fine.

[tgiro]

Might be a problem in the type 2. My type 1 was made in 2001. I bought it, used, three years ago. I have done some adjustment & tuning and the blades are tight somewhere around 1 or 2.

They do sell parts for type 2's. You might check with Rick Hitcheson @ Rick's Scrollsaw. He has a wealth of info on the mechanics and maintenance of the machines.

[handibunny]

The 788 in my community woodshop started showing problems after about 3 years, related to tensioning the blade--it just would not tighten up enough. I tried the usual fix of turning the bar, but there was something broken in the back. It was sent out for repair, and the repair person obviously did not know the saw. It came back usable, but you have to crank the tension up to maximum to make it workable. There must be a fix, and parts are available, but there is a definite shortage of competent repair people for the saw.

Fortunately, I now have my own shop, and own a Hegner. Sorry I didn't buy it sooner.

[JimSawyer]

I guess I got lucky. I've had my 788 since 1998 with no real problems.
Once I had to reset the angle gauge, but I think I owe that to the fact that I have my table slightly angled so much for inlay work. And once I had to tighten the screw for the tensioning knob. It was simply loose.

I can't complain about 14 years of faithful service....

[oily]

I have a Dewalt type 2 with over 1,000 hours on it and going strong. I did once have to adjust the tension bar one time. When you do put a couple drops of loc-tite on the nut. You should be fine.

Use BLUE loc-tite Not the red!!!

[Jim Finn]

I had the same experience that Hawiilad had and also went to a Hegner. I found when cutting stand up puzzles that after cutting the outside of the puzzle I install a new blade to make the inside cuts, Super sharp blades help a lot with those.

[shadowfx97]

Your blade may be slipping in the the blade clamps. At the tips of the tightening thumbscrews (top and bottom) there are flat plates; these plates should turn freely. If they don't, try to work them loose manually. Another thing to try is to lightly sand these tips; after much use, they tend to become too smooth to grip the blade firmly. Also, blades often have an oil apllied at the factory as a preservative to keep them from rusting. It's a good practice to wipe them top and bottom section of the blade with mineral spirits--or simply lightly rub each section with sandpaper before you install it. If you determine that the thumbsrew tips are the cause, you can order replacements online for not much money. I would try these steps before thinking about factory repair or a new saw. I've had a 788 for twelve years ; I has to loosen the tips once, and since I've started sandpapering each blade, there has been no trouble.

[sdguy]

Thanks for the tips, all.

Blade slipping has been a sporadic problem, too, although I have already learned the trick about wiping the oil off the blade, scuffing the ends with sandpaper, and I have already changed the thumbscrews and scuffed them, too. Pretty frustrating. I don't know exactly, but I'm thinking the saw has somewhere between one and two thousand hours on it.

Hegner, huh?

[tas2181]

Sounds like you may have wore down the tension wedge or the plate that causes the upper arm to raise when tensioning.

The tensioning system is quite simple. When you move the tension lever it pulls on the rod connected to the tension wedge which is pulled forward pushing up the upper arm. This upper edge of the wedge rides against a plate that is angled in the upper arm.

I would first check to see when you move the tension lever if the arm raises.
You can easily do this by releasing all the tension on the upper arm. (No blade installed) Use a ruler to see how much the blade holder moves up when you move the tension lever to full tension. This should raise the upper arm about 1/4 inch or so.
If it doesn't, I would assume the wedge and/or the plate needs replacing.

If the plate is worn with a groove from the wedge you may be able to just turn it over to make it work. If the top edge of the wedge is worn you will probably have to replace it.
Another possible problem could be the bushing on the end of the tension rod could be worn. You should be able to tell that, if there is some slop in the tensioning lever before it starts to raise the blade.

[Jim Finn]

Thanks for the tips, all.

Blade slipping has been a sporadic problem, too, although I have already learned the trick about wiping the oil off the blade, scuffing the ends with sandpaper, and I have already changed the thumbscrews and scuffed them, too. Pretty frustrating. I don't know exactly, but I'm thinking the saw has somewhere between one and two thousand hours on it.

Hegner, huh?

I replaced my 788 ,after 20 months, with a Hegner. It is a very expensive move but it is a great saw. I find the Hegners cut just as well as the DeWalt, no better, and the blade changing is a little harder on the Hegner. The thing the Hegnar has above many of the others is that it is durable, while others are not.

[ubgoofy2003]

I have the type II 788 & have had it about 3 yr. I have had to tighten the tension screw once & it works about the same as it did before it loosened up. I adjust the tension about 4 or 4 1/2. Works fine for me. I've had good luck overall with my saw.

[sdguy]

Captain Impulsive struck. I ordered a Multimax 18V. Getting kind of excited about it, too.

[baggetta]

I had my 788 for about a year (bought January 2, 2011) and about two weeks ago it died. I used it quite regularly every day, but I expected it to last longer. Brought it to my local repair center which was backed up on repairs and not really into repairing scroll saws, so it seems. I finally called them today and they said they didn't get to it yet, but would check it out today. They called back a couple of hours later with the "good" news. The motor died and would have to be replaced to the tune of $319. They needed another 3 weeks before they could get to it and said they weren't sure about my warranty, so I should check with another repair center some 40 miles from my home.
So I did.
The manager there was very good and said he thought it was still under warranty (although a first person I spoke to said the motor was only guaranteed for 1 year). He offered to pick up the machine from my local shop, bring it to their distant shop and repair it and will return it to may local shop, so I won't have to make the journey. I hope this all comes to pass.
In any event I decided that if I get the 788 fixed I'll use it for a back up in case I need it in the future. Called Seyco and ordered a new Excalibur 21, and should be here by the end of the week. I'm looking forward to giving this a run.
Happy sawing.
Al B.