Charlie E Posted November 13, 2018 Report Share Posted November 13, 2018 I've run into a problem with my Dewalt 788 type 2. I guess it's about 6 years old. I was using it today and after a couple of hours it decided not to come on. After lots of checking I found it will start if I move the arms myself but it runs very erratically, suddenly speeding up-slowing down. I took the brushes out and one of them had a little build up on it. I cleaned both but it made no difference. I'm still suspicious if they may just be worn down, not making good contact since manually moving it makes it start. I admittedly know very little about motors so that may be ridiculous. I tore it apart several times but as I don't know anything about electrically trouble shooting it I didn't accomplish anything. Just wondering if anyone has had this problem and resolved it. OCtoolguy 1 Quote Link to comment Share on other sites More sharing options...
tomsteve Posted November 13, 2018 Report Share Posted November 13, 2018 had a type 2 some time ago. it started doing the same,then started running at an extremely high spped- like it had a massive shot of nitrous. my landlord at the time owned an electric shop. asked him to take a look at it. turned out the windings shorted out. however, there could be a problem in the circuit board in yours. OCtoolguy and Charlie E 2 Quote Link to comment Share on other sites More sharing options...
kmmcrafts Posted November 13, 2018 Report Share Posted November 13, 2018 Mine does something similar to this when it's cold out when i first start it in the morning.. but once it run for 10-15 seconds clears right up... I figured it's probably not to good for it to run that way so i got to where I'd heat it up with a heat lamp for a few minutes before turning it on... Another possibility is the bearings are dried out of grease and dragging the motor down.. OCtoolguy, Charlie E and tomsteve 1 2 Quote Link to comment Share on other sites More sharing options...
Charlie E Posted November 13, 2018 Author Report Share Posted November 13, 2018 46 minutes ago, tomsteve said: had a type 2 some time ago. it started doing the same,then started running at an extremely high spped- like it had a massive shot of nitrous. my landlord at the time owned an electric shop. asked him to take a look at it. turned out the windings shorted out. however, there could be a problem in the circuit board in yours. Thanks. I've done a little more research and I'm betting the circuit board/potentiometer. OCtoolguy and tomsteve 2 Quote Link to comment Share on other sites More sharing options...
Charlie E Posted November 13, 2018 Author Report Share Posted November 13, 2018 28 minutes ago, kmmcrafts said: Mine does something similar to this when it's cold out when i first start it in the morning.. but once it run for 10-15 seconds clears right up... I figured it's probably not to good for it to run that way so i got to where I'd heat it up with a heat lamp for a few minutes before turning it on... Another possibility is the bearings are dried out of grease and dragging the motor down.. Thanks. I greased all the bearings a short time ago to quieten it down, which did help with the noise level. I've done a little more research and I'm betting the circuit board/potentiometer. Now to decide whether to spend $80ish on an educated guess. OCtoolguy and tomsteve 2 Quote Link to comment Share on other sites More sharing options...
NC Scroller Posted November 14, 2018 Report Share Posted November 14, 2018 Hope that is your issue because a new motor will cost almost as much as a new saw and I think a new motor only carries a 30 day guarantee. tomsteve and OCtoolguy 2 Quote Link to comment Share on other sites More sharing options...
Charlie E Posted November 14, 2018 Author Report Share Posted November 14, 2018 17 minutes ago, NC Scroller said: Hope that is your issue because a new motor will cost almost as much as a new saw and I think a new motor only carries a 30 day guarantee. Yeah, no way I'd replace the motor. Not sure what their angle is jacking up the price of a motor like that. Sure wouldn't motivate me to buy a new Dewalt if a motor is what I needed. I have really enjoyed my saw but I've had to make several repairs on it and I'm already researching for when it's time to replace it. This hobby has been so good for me I'm not afraid to invest a bit more next time. tomsteve, NC Scroller and OCtoolguy 3 Quote Link to comment Share on other sites More sharing options...
OCtoolguy Posted November 14, 2018 Report Share Posted November 14, 2018 If you like that type of mechanism, check out Excalibur, King, Seyco and Jet. They all use pretty much the same geometry. Charlie E 1 Quote Link to comment Share on other sites More sharing options...
tomsteve Posted November 14, 2018 Report Share Posted November 14, 2018 11 hours ago, Charlie E said: Sure wouldn't motivate me to buy a new Dewalt if a motor is what I needed. I have really enjoyed my saw but I've had to make several repairs on it and I'm already researching for when it's time to replace it. This hobby has been so good for me I'm not afraid to invest a bit more next time. in my opinion, and from experience with my type 2, changing brands is a good thing here. santa brought me an EX 16 4 years ago. dc induction motor- cant be beat.although i dont think excalibur is the name of the saws any more( i think its king,seyco, and/or some other name), it it well worth the extra money. its been a workhorse. had a problem recently with the VS control and the thumbscrew finally stripped out, but thats a wear part i would expect to wear out eventually. its still been worth the money. some day im gonna use the tilting head and do some compound cutting. OCtoolguy and Charlie E 2 Quote Link to comment Share on other sites More sharing options...
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