OCtoolguy Posted March 29, 2015 Report Share Posted March 29, 2015 A question for those users of a DW 788. I never cranked up my saw to high speed until yesterday and when I did, I found that it vibrates quite a bit. I am afraid I might have built a vibration into my machine. I cut a couple of "knobs" out of cherry and glued them over the factory knobs. Of course, they are not balanced but I never gave it any thought when I put them on. Can any of you who have ONLY the factory knobs on you machines give me some idea of how smooth your saw is at full speed. If I have to I will take the additions off. It did make it a lot easier to tighten them when changing blades though. I will have a tough time getting them off if that's the problem. Can super glue be softened? Ray Quote Link to comment Share on other sites More sharing options...
Scrappile Posted March 29, 2015 Report Share Posted March 29, 2015 Acetone will dissolve superglue. In sure what your what it will do to the plastic on the knobs if you left that on. If it is nylon acetone won't dissolve it but it will dissolve plastic. I find it hard to believe that your knobs caused the vibration though. Is you saw on a real level spot? Can you add some weight to the stand it is on, like sand bags? Be very careful with those knobs. You over tighten the screws it will damage the threads on the aluminum clamps. Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted March 29, 2015 Author Report Share Posted March 29, 2015 Thanks Scrappile, I was thinking that too. The saw is on a factory stand at this time but I'm in process of building a nice heavy wood stand. It seems like the saw is just trying to shake itself apart when run at anything over about half speed. I had never tried to run it that fast before I added the wooden knob covers. They can't possibly have added that much weight. I'll fiddle around with them some more. Ray Quote Link to comment Share on other sites More sharing options...
LarryEA Posted March 29, 2015 Report Share Posted March 29, 2015 My suggestion is not a good answer but here it is. A customer told his car mechanic, 'I can't get my car into fifth gear.' The mechanic said, 'Then run it in fourth gear.' I doubt it is the knobs. Lucky2 1 Quote Link to comment Share on other sites More sharing options...
JustLarry Posted March 29, 2015 Report Share Posted March 29, 2015 Never run my clone at high speed. More at 3rd gear than wide open. I believe you are working on the vibration solution with that heavy wood stand. Four legged stands can be very hard to get set level on the floor. Just a little off of level and they will start dancing. I used to have problems with getting the blade holders tight and then loose until a posting on anti-seze compound popped up. Got myself a tube of that and with very little effort knobs are tightened and loosened. Larry Quote Link to comment Share on other sites More sharing options...
ike Posted March 29, 2015 Report Share Posted March 29, 2015 I agree with Larry I had a problem with ti;gating the blade until I used anti seize. I got a tube at the hardware stor for about $4 and it is enough to last a lifetime I don't see the nobs coursing any problems, I have a DW 788 and after about 700 hours it developed a problem I took it into the DeWalt repair shop and thy fixed it at no cost because it was still guarantee. IKE Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted March 29, 2015 Report Share Posted March 29, 2015 I had two dw788 's that vibrate over 5 on the speed dial.somethings wore out Tighten the stand bolts see that it's square to the floor ,check the saw mount (3) to see if they loosened up.I took one off the saw apart band re greased with Valvoline synthetic grease and it made the saw sweet as a kitten ,but still thee were two bearings i could not get to and the are in the upper and lower front end of the saw which is whee the vibration is coming from on two of my saws.I just keep the speed at 5 or less and I'm a happy camper, Just let me scroll! Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted March 30, 2015 Author Report Share Posted March 30, 2015 Thanks to you all. I don't know why I turned up the speed on mine but I did just to see how fast fast was. It seems that it starts to vibrate pretty bad at just over half throttle. Then it gets VERY bad. I don't think that the stand has anything to do with it. I have taken the saw off the stand and put carpet between the two. I'm building a very good heavy stand that will have three legs of 4 x 4 construction and will have an adjustable table that I can get the tilt I want. It will be heavy because the wood is too heavy for me to carry all at once. And it is dry wood. I'm going to check out all the bearings just because I want to. I'm not expecting to find any bad ones but it will make me feel better to know that they are all in good shape, As for running the saw at high speed,the only reason I turned it up was because of an article that I read about running the saw at a fast enough speed to help it cut thicker wood easily. At this point, I am only cutting BB plywood that is 5/16" so I don't need to run it very fast. I was just concerned at how much it vibrated when I did. I figured that if any of you more learned folks who have saws like mine have encountered this problem, you would be ready to help me fix mine. Thanks again to you all, Ray Quote Link to comment Share on other sites More sharing options...
Scrappile Posted March 30, 2015 Report Share Posted March 30, 2015 Well it would certainly worry me. When I had my 788 I ran it a full speed most the time. I run my Excalibur full speed most the time. That is the way I saw. You should be able to run at the speeds it was made for. If it is under warrenty, I'd have it looked at, if there is a repair place near. Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted March 30, 2015 Report Share Posted March 30, 2015 On the dw788 take the blade out ,then hold the top arm down firmly ,then lift up & down on the blade holder If it moves or has slack localize where the play is and you 'll find the vibrating culprit. While holding the top arm down repeat the same test for the bottom blade holder .Neither should have any slack or play.I had a broken bolt on the bottom blade holding mechanism. It never fell out but it was broken in two pieces.The top and bottom mechanism's is where i could not grease the bearings as they are pressed in.All the other needle bearings you can re-grease in the machine. OCtoolguy 1 Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted March 30, 2015 Report Share Posted March 30, 2015 P.S. i had the bottom blade holding mechcanism's 4 outside screws come loose to causing slack and knocking noise. OCtoolguy 1 Quote Link to comment Share on other sites More sharing options...
JustLarry Posted March 30, 2015 Report Share Posted March 30, 2015 Ray, this video will help you locate all the bearings. https://www.youtube.com/watch?v=KjgSKrlt7LE Larry OCtoolguy 1 Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted March 30, 2015 Author Report Share Posted March 30, 2015 JustLarry, I have watched that video before but had forgotten about it. I will watch it again. I was going to go through my saw as he did but hadn't had it in mind to do right away. I'm going to build my stand first and get the saw firmly sitting on something heavy and level and then see how bad it's out of balance. I did do the test as mentioned above and there is a little wiggle on the upper blade holder but not much. I'm going to thoroughly check out and lubricate everything at some point. Thanks to you all for all the suggestions. I'll keep you all updated as I go along. Ray Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted March 30, 2015 Report Share Posted March 30, 2015 JustLarry, I have watched that video before but had forgotten about it. I will watch it again. I was going to go through my saw as he did but hadn't had it in mind to do right away. I'm going to build my stand first and get the saw firmly sitting on something heavy and level and then see how bad it's out of balance. I did do the test as mentioned above and there is a little wiggle on the upper blade holder but not much. I'm going to thoroughly check out and lubricate everything at some point. Thanks to you all for all the suggestions. I'll keep you all updated as I go along. Ray Rick's Scrollsaw Rick's Scrollsaw http://www.toolpartsdirect.com/ http://www.scrollsaw...DewltTuneUp.htm Repairing a Scroll Saw - YouTube 2012-12-03 Scroll Saw Maintenance by Scrolling ... - YouTube DeWALT Scroll Saw Parts - eReplacementParts.com http://www.scrollsaw...-blade-problem/ “Preventive Medicine†for DeWalt 788 - Scroll Saw .. .2012-12-03 Scroll Saw Maintenance by Scrolling SIG (1h26m02s) - YouTube Hope this helps you some Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted March 31, 2015 Author Report Share Posted March 31, 2015 Hey AmazingKevin, you have outdone yourself. I will check out each and every one. Thanks so much for your kindness and interest. Ray Quote Link to comment Share on other sites More sharing options...
Sparkey Posted April 2, 2015 Report Share Posted April 2, 2015 I have a little vibration on mine on high. I don't cut above half but turned it up once to see how it was. Quote Link to comment Share on other sites More sharing options...
spirithorse Posted April 2, 2015 Report Share Posted April 2, 2015 Hi, Ray, I know you said you put some carpet down but, my humble suggestion would be to also temporarily clamp the dewalt to the bench with the carpet still there. I do not own a Dewalt but, just a couple quick grip clamps won't take too long to try out and may make an incredible difference. God Bless! Spirithorse Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted April 2, 2015 Author Report Share Posted April 2, 2015 Good idea Spirithorse. I'll give it a try. I do have a good heavy work bench. I was messing with it today and it does seem to have a bit of free play in the upper arm mechanism. I'm going to check it all out and try to tighten it all up. Thanks for your suggestion. Ray Quote Link to comment Share on other sites More sharing options...
ike Posted April 2, 2015 Report Share Posted April 2, 2015 When you have tried all the suggestions take it to a De Walt repair shop in your area-if it is on warranty if not it could cost you $$$ here in the Cincinnati area the cast runs $35 to $250. It will only get worse, Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted April 2, 2015 Author Report Share Posted April 2, 2015 Ike, it's long time out of warranty. It's a Type 1 and God knows when it was made. I'll figure it all out but for now, it works at low to mid speed and that seems to be ok. I'm not cutting anything very thick either. Thanks though. Ray Quote Link to comment Share on other sites More sharing options...
ike Posted April 2, 2015 Report Share Posted April 2, 2015 Ray there may be a nut connecting the motor to the arm that is loose. I hope this is clear i not sure what every thing is called. Quote Link to comment Share on other sites More sharing options...
dgman Posted April 3, 2015 Report Share Posted April 3, 2015 Ike, it's long time out of warranty. It's a Type 1 and God knows when it was made. I'll figure it all out but for now, it works at low to mid speed and that seems to be ok. I'm not cutting anything very thick either. Thanks though. Ray A type I is at least 12 to 15 years old! Quote Link to comment Share on other sites More sharing options...
ike Posted April 3, 2015 Report Share Posted April 3, 2015 I very welcome use High speed , i usually run at about #6. Mine did it last year and it finally started to vibrate at about #6 so i took it in for warranted work IKE Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted April 3, 2015 Author Report Share Posted April 3, 2015 I am going to go completely through it as the video done by Bob Brokaw showed. My question for you guys is, can I buy a kit from DeWalt that would have all the bearings/bolts/nuts that might need to be replaced? It would be so much easier to buy it all as a kit than to try to piece it all together in an order. I probably already know the answer but just in case I'm wrong, I hope they do. Ray Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted April 5, 2015 Author Report Share Posted April 5, 2015 Hey AmazingKevin, thanks to you, I found a fantastic 4 part video series on Youtube on start to finish repair for my saw. I downloaded all 4 parts and using Windows Movie Maker, I stitched them all together and made a complete movie of the series. I will be doing my saw in the very near future. A good Saturday afternoon project. All I have to do is round up all the required tools and parts. But, that's half the fun. Thanks so much for putting together that list of sources. Ray Quote Link to comment Share on other sites More sharing options...
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