To all the DeWalt 788 owners

[OCtoolguy]

As I have said before, I have a Type 1 that I bought used. Today, I spent the day lubing all the bearings in it and found no bad ones. Not one. Anyway, I lubed them all with synthetic grease and put it all back together. I was hoping that whatever was causing my vibration would be fixed. But NOT! I'm pretty good up to and through the 5 setting but from there on up, it shakes like a dog that ate peach seeds. Anybody have this problem and what did you do to remedy it?

 

Ray

 

[Lucky2]

Ray, what is holding your saw in place, is your saw  on a factory stand? If you could find a way to fasten it down extra well, that might make a difference. Was your saw acting up, or giving you issues? If it wasn't I would never have taken it apart like you did, just to service the bearings. These saws are like most things, the more you take them apart the less they fight back together as tightly as they originally were. I used to service my little Delta saw like this, then the Delta maintenance center told me about taking the saw apart to often. 

Len

[Scrappile]

And yet, most the advice here says take apart re-lube the bearings, if I read it right, even on a new saw?

[OCtoolguy]

Thanks folks. My saw is attached to a very heavy stand that I made out of 4 x 4's and it sits on a piece of carpet also. I took it apart to try to remedy the vibration. I didn't cause it by lubing the bearings. I was following a very well done video on the subject and I did it just that way. I found no bad brgs. or sleeves and I put everything back in the same sequence it came apart.  The one thing that I changed I even went back and changed it back to what it had been set at. That change was to add one turn to the rod that controls the arm tension. I don't feel that I'm getting enough tension  on the blades so I wanted to increase that. Still no change. I have a vibration and I guess I will just have to stay under 5 until I can figure out what is wrong. 

Also, I wanted to service the saw because it's old. I bought it used, it's a type one very early. Then stand it came on was even a tubular one. Not like what they have now. It was junk. That's why I built the new one. Besides I wanted to sit down while cutting.

Ray

 

 

Edited October 21, 2017 by octoolguy

[EarltheScroller]

I also have a Type 1 that I bought new approx. 15-20 years ago. It has been a great saw but it does get to shaking pretty bad above 5 or 6.  I've tried the lubing, etc and nothing helps. But on the positive side I just haven't seen a need to use it above 5. It cuts plenty fast and certainly aggressive enough so I just stopped worrying about it. It's probably been that way for the last 10 years. I'm a top feeder (I think that's right...I keep the bottom of the blade attached all the time and loosen the top arm for all those inside cuts) and I find that to get really tight tension on the blade I have to push the top arm down till it quits moving, then attach the blade. If I just attach the blade where ever the arm stops it won't get tight. Don't know if that makes sense. 

[OCtoolguy]

3 hours ago, EarltheScroller said:

I also have a Type 1 that I bought new approx. 15-20 years ago. It has been a great saw but it does get to shaking pretty bad above 5 or 6.  I've tried the lubing, etc and nothing helps. But on the positive side I just haven't seen a need to use it above 5. It cuts plenty fast and certainly aggressive enough so I just stopped worrying about it. It's probably been that way for the last 10 years. I'm a top feeder (I think that's right...I keep the bottom of the blade attached all the time and loosen the top arm for all those inside cuts) and I find that to get really tight tension on the blade I have to push the top arm down till it quits moving, then attach the blade. If I just attach the blade where ever the arm stops it won't get tight. Don't know if that makes sense. 

You make perfect sense but I think if you are feeding the blade in from the bottom of the work piece that is what I would call a bottom feeder. Actually, cat fish and lawyers are also bottom feeders. Anyway, if you have the same vibration problems that I do and you saw is of the same vintage, well, I guess I will just live with it and start saving for an Excalibur or something of equal performance. I got a chance to experience an Excalibur last week and I can see why they get all the attention that they do.

Thanks for your input here Earl. I appreciate it.

Ray

 

[CharleyL]

Check the eccentric bearing on the end of the motor shaft, and the pivot bolt of the rocker arm. That whole section is a frequent source of vibration problems. The pivot bolt through the rocker arm frequently loosens if not assembled with Blue Loctite. on the bolt threads. On two occasions that I know of, this bolt broke in half. One of these saws was my type 1. The other was someone's saw on this forum, but I don't remember who's saw that it was. Any play at all in the bearings and mechanical connections in this area will cause vibration problems at higher speeds, but this area of the saw seems to be where I  have traced my heavy vibration problems to every time .  

I've only used speeds above 5 for cutting non ferrous metal. I turn the speed down when cutting wood to avoid overheating the blade and burning the cut edge of the wood. When cutting metal, the metal seems to absorb much of the heat and won't burn, so the higher speeds is possible.  I have had my 788 apart 5 times  since I've owned it and I bought it used, so it may have been apart before I got it. When properly done, this should not be a cause for saw deterioration. That Delta service guy was trying to get more business out of you or sell you a Delta saw..

Charley

 

[nrscroller]

HI all

Somewhere on this forum someone posted a fix for that problem of virbration. I did it to mine a long time ago and it fixed it. Do a search for dewalt vibration on this forum

nrscroller

[Fish]

My problem twice was the main  con rod assembly, the bearing, coming off the motor. Mine is a type 1 also.  I changed it out again and it runs nice quiet and smooth. I tried replacing just the bearing but it didn't work.  So I replaced  the whole piece.  Got it from ereplacement.com for $30.   

[bandaideman]

Looks like you got enough info on stopping the vibration. I would quit getting peaches so the dog won't eat the seeds and vibrate either or limit him to 5 or less pits. 

[OCtoolguy]

6 hours ago, Fish said:

My problem twice was the main  con rod assembly, the bearing, coming off the motor. Mine is a type 1 also.  I changed it out again and it runs nice quiet and smooth. I tried replacing just the bearing but it didn't work.  So I replaced  the whole piece.  Got it from ereplacement.com for $30.   

What did you finally find wrong with that connecting rod? I can't see anything wrong and the bearings are all in good condition. I'm going to go back through and make sure I didn't miss something. I don't necessarily want to run my saw at that high speed but I'm a nut about things not working right when they should. I gotta fix it.

 

[Fish]

I couldn't see anything wrong with mine either.    It was the last thing to try and after that I wasn't putting any more money in it.  I had taken mine apart  so many times I had to buy new lock nuts.  I put it together with only one side on so I could watch it and I ran it full speed the slowed down  over and over.  It won't hurt you saw just be careful at full speed.  After I put the new one on I tried it and it worked fine.   I still have a little vibration at 8 but not enough to bother you.  slower to 6-7 and it is as smooth as expected.   If yiu could just find the correct bearing you'd save a lot if money.  But it has to be an exact match.  I was careful not to over tighten the nut on the motor.     Good luck.  

[kmmcrafts]

I've heard that back bearing in the connecting rod is a common issue with these saws.. When I took mine apart after just three years of moderate use the bearing and sleeve ( the bigger ones ) was pretty dry on grease and had actually just started to hammer on the sleeve.. I only cleaned them up and added the synthetic grease.. The back end of my saw has the original bearings and sleeves in it still.. haven't taken the back of it apart since.. this has been about 5-6 years ago.. but it is now getting quite noisy back there and a higher speed.. ( around 7/8 to full speed on the dial ) Mine is a type 2.. Now.. I've had the front portion of my saw apart 2 times since that initial time when I had the saw apart.... 

I now have all new bearings and sleeves for mine.. just need to take it apart and plan to do a total rebuild with it this time.. howver that will probably have to wait until the busy holiday selling season is done..

On a side note... Brand new 788's are on sale at grizzly.com for $399 with stand and light.. I've been contemplating myself.. love my Hawks but if I need to do some rush cutting.... well... my comfort cutting is actually with my 788.. still sort of just using the Hawk as a playing around saw to hopefully one day get used to using it more.. I've been using it more and more.. and getting much more comfortable with it.. But when in a rush.. I still go to the 788..

   

[Chris Woodall]

I to have had this problem but the guy in the video showing how to do the lube job just happens to be in my woodworking club. He had me to take a T25 driver and adjust the center bolt on the top and bottom pivot arm where they come out the front of the saw. You have to make the adjustments while the saw is running. It will vibrate if it's to tight or to loose. Just keep adjusting till you find the sweet spot

[OCtoolguy]

16 hours ago, Chris Woodall said:

I to have had this problem but the guy in the video showing how to do the lube job just happens to be in my woodworking club. He had me to take a T25 driver and adjust the center bolt on the top and bottom pivot arm where they come out the front of the saw. You have to make the adjustments while the saw is running. It will vibrate if it's to tight or to loose. Just keep adjusting till you find the sweet spot

Thanks Chris, I'll give this a try. I was wondering about that too. Those two bearings were the toughest to remove and lube. Did you find that yours were too loose or too tight? I think I tightened them pretty tight but I'll give your suggestion a try today. Report back what I find. It does seem like the vibration/noise is coming from that area.

Ray

 

[amazingkevin]

On 10/21/2017 at 4:57 PM, octoolguy said:

What did you finally find wrong with that connecting rod? I can't see anything wrong and the bearings are all in good condition. I'm going to go back through and make sure I didn't miss something. I don't necessarily want to run my saw at that high speed but I'm a nut about things not working right when they should. I gotta fix it.

 

Link,Drive (286269-00) number 28 is the nut that comes off use loctite and put back on.click on the dw788 type 1 and picture 1 and look for nut 28.

Edited October 23, 2017 by amazingkevin

[OCtoolguy]

On 10/22/2017 at 8:39 PM, amazingkevin said:

Link,Drive (286269-00) number 28 is the nut that comes off use loctite and put back on.click on the dw788 type 1 and picture 1 and look for nut 28.

 

On 10/22/2017 at 8:39 PM, amazingkevin said:

Link,Drive (286269-00) number 28 is the nut that comes off use loctite and put back on.click on the dw788 type 1 and picture 1 and look for nut 28.

Kevin, that's not the connecting rod that he is talking about. The one I think he means is the one that has large and and a small end and is only about 2 inches long. It has two different sized bearings in it and looks like a connecting rod in an engine. It connects to the motors shaft and then to that vertical lever that drives both long arms that you pictured. It's number 82 in this pic.

 

 

Edited October 24, 2017 by octoolguy

[OCtoolguy]

On 10/21/2017 at 8:37 AM, Fish said:

My problem twice was the main  con rod assembly, the bearing, coming off the motor. Mine is a type 1 also.  I changed it out again and it runs nice quiet and smooth. I tried replacing just the bearing but it didn't work.  So I replaced  the whole piece.  Got it from ereplacement.com for $30.   

Can you tell me if that sealed bearing on the large end of the connecting rod is a pressed in bearing or is it just sort of floating in the rod? I just found that bearing to be "floating" in the connecting rod. I thought it was supposed to be a press fit. I'm going to do some more research but I thought I'd ask you seeing as how you have replaced both pieces. If it supposed to be a press fit, I'm going to try to shim the bearing with some paper and try pressing it back into the connecting rod. I also found some of the "racket" on the upper are out where the arm tension rod goes through the arm. It is hammering on one of the blade arms. I don't know how to explain it but in the diagram it is part number 10 and rod number 24 hitting together. I'm going to file the arm down a bit and give it more clearance. I have also filed down the under side of part number 80 to give it some clearance. I am going to get all the vibration and noise out of this saw yet. I would be curious to know if that bearing is supposed to float in the connecting rod though. Thanks for your help.

Ray

 

[kmmcrafts]

Believe the bearing is a pressed in bearing.. Also about that rod.. I think I've read somewhere about that and they mentioned to just turn the rod inward a turn or two.. Don't quote me on that though.. maybe totally different issue.. but I do remember reading about turning that rod in a couple turns to stop the thing from rattling... Think I read this on Rick Hutchins web site.. I found it years ago searching for "dewalt scroll saw tune up"

 

Edit to add link to the site..

http://www.scrollsaws.com/SawReviews/DewltTuneUp.htm

Edited October 27, 2017 by kmmcrafts

[OCtoolguy]

4 hours ago, kmmcrafts said:

Believe the bearing is a pressed in bearing.. Also about that rod.. I think I've read somewhere about that and they mentioned to just turn the rod inward a turn or two.. Don't quote me on that though.. maybe totally different issue.. but I do remember reading about turning that rod in a couple turns to stop the thing from rattling... Think I read this on Rick Hutchins web site.. I found it years ago searching for "dewalt scroll saw tune up"

 

Edit to add link to the site..

http://www.scrollsaws.com/SawReviews/DewltTuneUp.htm

Thanks. I have read that website many times and I have also done the turning of that rod both in and out. I was trying to get the tension on the arm increased and also to take care of the knock sound. After doing some real research this afternoon, I found that the two pieces that we contacting each other were the two that I mentioned above. Tomorrow, I'm going to remove some metal and give them the clearance they need. I did also find that the sealed bearing is not tight within the end of the drive rod. It moves in and out. I pushed it back in all the way and within a few seconds of running, it had walked it's way back out almost to the point of failure. Like I said, I'm going to try to tighten it up with a paper shim and press it back in to see if that fixes it. I did find the ereplacementparts part mentioned for the $30+ dollars. It is actually cheaper from DeWalt but by the time I add the shipping cost on, the two places are about the same. I guess I'll have to order a new one if my "fix" doesn't work out. I think it comes with new bearings on both ends so that's a plus. Little by little, I'm finding all the problems that need fixing. I sure hope I end up with a good usable saw when it is all done. I'm also going to bid on a used Hegner on eBay that may become my "second" saw.

 

Ray

 

[kmmcrafts]

5 hours ago, octoolguy said:

Thanks. I have read that website many times and I have also done the turning of that rod both in and out. I was trying to get the tension on the arm increased and also to take care of the knock sound. After doing some real research this afternoon, I found that the two pieces that we contacting each other were the two that I mentioned above. Tomorrow, I'm going to remove some metal and give them the clearance they need. I did also find that the sealed bearing is not tight within the end of the drive rod. It moves in and out. I pushed it back in all the way and within a few seconds of running, it had walked it's way back out almost to the point of failure. Like I said, I'm going to try to tighten it up with a paper shim and press it back in to see if that fixes it. I did find the ereplacementparts part mentioned for the $30+ dollars. It is actually cheaper from DeWalt but by the time I add the shipping cost on, the two places are about the same. I guess I'll have to order a new one if my "fix" doesn't work out. I think it comes with new bearings on both ends so that's a plus. Little by little, I'm finding all the problems that need fixing. I sure hope I end up with a good usable saw when it is all done. I'm also going to bid on a used Hegner on eBay that may become my "second" saw.

 

Ray

 

Don't know how comfortable you are with repairing things.. but rather than using paper.. you could try taking the part off the saw.. lay it onto a bench and use a punch and hammer.. you might try what I call pinging the metal in a couple spots to hold the bearing in place.. In other words you punch the metal ( in this case I think aluminum ) right near the bearing just enough to expand it outward toward the bearing.. just one or two spots of doing this would tighten up that bearing and keep it in place.. I'd do that before using paper.. should the bearing fail with paper in there it could set the paper on fire, LOL..

[hotshot]

The "Dewalt Doctor" in Atlanta has become very good at this.  It would be interesting to take of few of these loose saws to him to see how he handles the various things that go wrong.

-----Randy

[OCtoolguy]

2 hours ago, hotshot said:

The "Dewalt Doctor" in Atlanta has become very good at this.  It would be interesting to take of few of these loose saws to him to see how he handles the various things that go wrong.

-----Randy

That would a long drive for me Randy. I could buy a new saw for less. Ha!

R

[OCtoolguy]

4 hours ago, kmmcrafts said:

Don't know how comfortable you are with repairing things.. but rather than using paper.. you could try taking the part off the saw.. lay it onto a bench and use a punch and hammer.. you might try what I call pinging the metal in a couple spots to hold the bearing in place.. In other words you punch the metal ( in this case I think aluminum ) right near the bearing just enough to expand it outward toward the bearing.. just one or two spots of doing this would tighten up that bearing and keep it in place.. I'd do that before using paper.. should the bearing fail with paper in there it could set the paper on fire, LOL..

Thanks Kevin. I was thinking of that too. I'll give that a try. I just hope that it will all "tighten" up the bearing too as it seems that maybe the aluminum has stretched and allowed the bearing to float in the hole. That could set up some vibration so tightening it up by swedging the hole a bit may keep it from moving around. Thanks for all your help. It's nice to have someone who has been through it to suggest stuff.

 

Ray

 

[hotshot]

1 hour ago, octoolguy said:

That would a long drive for me Randy. I could buy a new saw for less. Ha!

R

Very true, but Kevin has a whole graveyard full of these.  Have you seen his videos on youtube?  I suspect you could probably reach out to him for advise via email.  If anyone is in the Atlanta users group, you might give us some insight.