duke2a10 Posted September 6, 2014 Report Share Posted September 6, 2014 I have a DW 877 and when I go to high speed my saw starts to vibrate and make funny sound. I can still cut but I have chatter. At low speeds it sounds good and cuts good. Any help. Thanks Quote Link to comment Share on other sites More sharing options...
jellis Posted September 7, 2014 Report Share Posted September 7, 2014 Mine did that and I took it the Dewalt shop and they had to rebuild it. I am just glad it still under warranty. When it started just kept saving till I got enough to buy the EX-21. Joe Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted September 7, 2014 Report Share Posted September 7, 2014 Mines have been doing that for over a year, but only over the #5 on the speed control .So I leave it at 5, no biggie.Then recently the bolt broke on the top arm but didn't fall out .i replaced that with a m4 -8? Bolt from the big box store, But more importantly a year ago I regretted everything with car synthetic grease and thins are still working. I need the bearing where the broken bolt is but i think it needs to be pressed out . i can't chance it and be out of a saw even though more damage is incurred with tolerances getting bigger.This will be my second dw788 for parts if need be when it dies Take the machine apart and you can grease all the bearings except two which are in the top and bottom of the arms in front that hold the blade mechanism.That was the biggest improvement and lasted a year easy of hard non stop scrolling 3/4: plywood. Quote Link to comment Share on other sites More sharing options...
duke2a10 Posted September 7, 2014 Author Report Share Posted September 7, 2014 Thanks for the help Quote Link to comment Share on other sites More sharing options...
JustLarry Posted September 8, 2014 Report Share Posted September 8, 2014 This link takes you to information on "fixing the DeWalt knock": http://www.scrollsaws.com/SawReviews/DewltTuneUp.htm Larry Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted September 8, 2014 Report Share Posted September 8, 2014 I just remembered one time my old dw788 type 1 knocked anything above 5 on the speed. It ended up being a nut on the connecting rod that comes off the motor.It goes on the side of the connecting rod you cant see. When you find it you'll need to put loc tite on the threads to stop that from happening again. After i repaired that it ran wide open quiet and smooth as a kitten.There's only a few things that cause a knocking sound so google exactly what you want to know and it will come up.I drilled a hole oposite where the nut goes for ease off replaceing it.About a 1" hole to where i could look in see where it goes add loc tite and install the nut. the saw comes apart easy but tedious,and time consuming to go back together. Jim Finn 1 Quote Link to comment Share on other sites More sharing options...
ike Posted September 25, 2014 Report Share Posted September 25, 2014 (edited) Mine was doing that and I had to run at #5. I usually run at that speed but every once in a while I need a high speed so I took off the side and looked . Nothing was ok so I put it back together and the vibration stopped, so I think that one of the nuts was a little loose or tight. You could adjust that with out taking the side off.do not tighten too tight Edited September 25, 2014 by ike Quote Link to comment Share on other sites More sharing options...
Jim Finn Posted September 26, 2014 Report Share Posted September 26, 2014 ...... It ended up being a nut on the connecting rod that comes off the motor.It goes on the side of the connecting rod you cant see. When you find it you'll need to put loc tite on the threads to stop that from happening again...... I did the exact same thing on my DeWalt and then sold it. Quote Link to comment Share on other sites More sharing options...
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