Loud knocking noise

[Fish]

I was cutting this afternoon and was at high speed. All the sudden I got a loud knocking noise and vibration, it got worse as time went on so I stopped.. I have a DW788 and I have heard someone else talk about this problem. If I go with a slower speed it will go away speed up it comes back.. Anybody remember what this was? I hope this isn't a major problem. I haven't taken it apart yet.

 

Thanks

Edited June 13, 2015 by Fish

[Scrappile]

Fish, have you read this?  http://www.scrollsaws.com/

 

Look in DeWalt tune up section.

Edited June 14, 2015 by Scrappile

[Ctutor]

Don't know but sounds exactly like what I experienced. The fix is reelatively easy. There is a video I think by the Gwanette woodworkers. You need to disasseble the Dw. It is easy believe me. Make certain you keep the various screws and bolts arranged so you can put them back the way the belong. I found that there are four screws that hold the eccentic at the back of the unit. Two of them were out and the third loose. The plate is just opposite the motor so you need to take most of the unit apart to get to the plate. Once everything is back together mine purrs now yours will also if that is your problem. you will need allen wrenches and star drives to dissassemble the parts. Tool me about 40 minutes actual time and about and hours to get up the nerver.  Darryl

[Ctutor]

Here is a link to the video I mentioned..    

[amazingkevin]

I was cutting this afternoon and was at high speed. All the sudden I got a loud knocking noise and vibration, it got worse as time went on so I stopped.. I have a DW788 and I have heard someone else talk about this problem. If I go with a slower speed it will go away speed up it comes back.. Anybody remember what this was? I hope this isn't a major problem. I haven't taken it apart yet.

 

Thanks

[Fish]

Thanks for the help. I messed with it all afternoon and still haven't got it to quiet down. There are no broken bolts or anything else I can find. it still only does it when it's going full speed. I tried adjusting both ways and neither worked. I'm missing something somewhere. I'll find it, thanks for the help.

[Ctutor]

Have you checked the adjusting rod  that sets the tension? You reach it through the switch. It might be hitting one of the fittings inside the top arm.

[Multifasited]

Polishing the Grove -slot also helps .

[WayneMahler]

Isn't amazing how you can ask for help and the villagers all gather around and pitch in

[Multifasited]

That video is a wealth of good info ! Save it for future info just in case !

[OCtoolguy]

Mine did the same thing. I was all set to do a total rebuild like the video but instead I just took the cover off one side and found the main shaft nut had come loose. Once tightened the knocking went away. I'm still going to do the rebuild.

 

Ray

[Fish]

I played with it some more. I got it quiet up to 7 but it starts all over if I try to go higher. The video is in my favorites. Thanks everyone for your help.

[OCtoolguy]

Mine is quiet up that far too but at 8 it starts to vibrate a bit. I found that part of it is in my table and the mounting of the saw. I am going to insulate under my table with some pipe foam rubber insulation. Once that is done, it won't vibrate any more.

 

Ray