Newbie: how much vibration is normal for DW788?

[jplacy2]

Hi Folks-

 

I decided to jump into scroll sawing with both feet, and purchased a lightly-used DW788.  I had the seller fire it up prior to the purchase, and to my untrained eye, all seemed well.

 

Fast forward a week and a little more experience watching videos, and now I'm concerned there is a problem with the saw rattling/vibrating a bit more than it should.  Problem is, I have no baseline for comparison to know what is "normal."

 

Please check out this short video, and focus and periodic "bumps" and rattles visible in the air nozzle.  Especially at higher speeds:

 

https://www.youtube.com/watch?v=kLBxPC9gi_I

 

In your opinion, is what you observe considered typical, or could the "bumps" be considered a sign of a bigger problem?

 

Thanks for your advice!

 

Jim

[JimErn]

With the caveat that I do not have a DW, the concern I have is the periodic catch sound when it is running.  Odd noise IMO, it is periodic and the frequency does change as you change speed, but I can not imagine what would cause it since it is not every stroke, or stroke cycle

[fredfret]

I suspect a loose bolt/nut. Take the side cover off and look for loose parts. Dewalt website has the parts breakdown showing how everything goes together.

Fredfret

Wichita, ks

[hawkeye10]

I bought a new 788 from Woodcraft and it sounded just like yours. In my opinion there is something wrong with it. Here is a long video ( 1hr and 26 min) on how to fix your DW 788) but a good video. He will show you how to fix it and where to buy the parts cheaper. So don't go off the deep in thinking you have been taken to the cleaners. Remember mine was brand new.

 

[jplacy2]

Thanks for the suggestions. Hawkeye10, since you had a similar issue, what solved it?

[hawkeye10]

Thanks for the suggestions. Hawkeye10, since you had a similar issue, what solved it?

I bought it new at Woodcraft and returned it and bought an EX 16. I love it.

[amazingkevin]

Hi Folks-

 

I decided to jump into scroll sawing with both feet, and purchased a lightly-used DW788.  I had the seller fire it up prior to the purchase, and to my untrained eye, all seemed well.

 

Fast forward a week and a little more experience watching videos, and now I'm concerned there is a problem with the saw rattling/vibrating a bit more than it should.  Problem is, I have no baseline for comparison to know what is "normal."

 

Please check out this short video, and focus and periodic "bumps" and rattles visible in the air nozzle.  Especially at higher speeds:

 

https://www.youtube.com/watch?v=kLBxPC9gi_I

 

In your opinion, is what you observe considered typical, or could the "bumps" be considered a sign of a bigger problem?

 

Thanks for your advice!

 

Jim

wish i could help . don't have speakers and can't watch movies.I've done lots of work on dw788's

[Sparkey]

Jim your video wouldn't play for me. I have a DW 788. Mine sounds like my wife's sewing machine. I can hear it run but no rattling or clanging. I would suggest checking all of the bolts and nuts including going in inside and checking the bearings.

[jplacy2]

Okay, I think I have a winner.  I wanted to post this follow-up in case some other newbie stumbles across this thread in the future.

 

Three things addressed the problem:

 

1.  The lower rocker assembly was pretty loose.  I found it required some very careful tightening to get just right.  Too tight caused binding, too loose caused knocking.  This didn't solve the "bump" but it did quiet things down.

 

2. I opened up the saw, and tightened everything I could.  Particularly the "con rod" assembly.  Nothing was exceptionally loose, but I was still able to get just a fraction of a turn on some of the bolts.

 

3. It turns out the previous owner hadn't used the saw for "years" in his words.   After making the above adjustments, the "bump" was better, but still there.  I let the saw run for 30 minutes straight at about #6 speed, and it gradually seemed to get better.  I'm no mechanical engineer, but it seems plausible that any machine which sits for a long period of time will need to "wake up" a bit.

 

Thanks to those of you who offered suggestions!

 

After video:

 

https://youtu.be/dzJz4iqF7V4

[tomsteve]

glad ya found some solutions.

something to consider, iffen ya haven't read or been given the suggestion yet:

have some rubber insulating  pads under the saw when ya bolt it to your bench.