Dewalt SCMS owners: check the belt tension

[Paul F Franklin]

I have an older Dewalt 708 12" SCMS that has served me well for many years. But lately it has seemed to lack power and the blade brake was not working well. And then it started making an ominous noise and the blade took a couple seconds to get to speed. I had previously replaced the switch and the motor brushes, so I was pretty sure that wasn't the issue. Turns out the belt between the motor and blade arbor was a little loose. My bad, but I had never checked it. It's a simple adjustment. One T25 bolt removes the belt cover. Then there are 6 T25 bolts that mount the motor on sliding bosses; those need to be loosened. Finally there is a T25 jack bolt on the back of the carriage that adjusts the tension. Tighten the belt, tighten the motor mounting bolts, put the belt guard back on, and you're done.

I did inspect the belt and it was still in good condition, just a little loose. The motor and blade arbor pulleys are only about an inch in diameter, so they don't have a lot of belt contact area. After tightening the belt, all is well: full power, blade spins up instantly, and the brake works well again. And no ominous noise; I think that was the squealing and shuddering of the belt slipping when the blade brake engaged.

Thought I'd pass this on for those driving a dewalt.

Alas, the reason I looked at it right now is because I thought (or perhaps hoped) if it was toast I would swing by the Hartville Hardware tool sale this week and pick up the Bosch Glide I've had my eye on. Oh well....

[John C Bush]

Perfect timing. Have the same saw and it's starting to develop the same symptoms. No blade brake and blade appeared to be slipping on heavy cuts. 20 years of hobby use and have been wondering
if brushes need attention. I do notice a bit of arcing when I hit the trigger but powering up has seemed WNL. Thanks for the tips.

[Jim Becker]

Checking the brushes at the same time is a good idea as that can also affect braking, in my experience.

[Mark Bolton]

Its not unwise on any belt driven saw to keep a spare belt. I always keep one spare on hand for the two bosch sliders we have. On the bosch's they are a cogged belt and Ive had them get loose and someone gets a blade pinched or some other issue and strip a few teeth off the belt and your in a pinch waiting on a $10 belt.