LarryEA Posted December 15, 2014 Report Share Posted December 15, 2014 (edited) It's a 40-690 Type1 Delta (Dewalt look-a-like). Had a switch problem and since I took the switch cover off the variable speed does not work. Dewalt Tech says I have to order new pc board and it comes with the variable speed control (potentiometer) My variable speed potentiometer (pot) wore out. (variable speed control) I don't want to spend $80 for PC Board just to get the potentiometer. I probably can jury rig a different pot but would like original equipment. Any ideas where I can get just the original pot? Edited December 17, 2014 by LarryEA Quote Link to comment Share on other sites More sharing options...
Multifasited Posted December 15, 2014 Report Share Posted December 15, 2014 If your only problem was the switch ,any chance you loosened some wire going to the mother board ,JUst one of the reasons I love my foot switch , amazingkevin 1 Quote Link to comment Share on other sites More sharing options...
amazingkevin Posted December 16, 2014 Report Share Posted December 16, 2014 Great detective work Carl,deductive reasoning !!!! Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 16, 2014 Author Report Share Posted December 16, 2014 If your only problem was the switch ,any chance you loosened some wire going to the mother board ,JUst one of the reasons I love my foot switch , I don't think so. All the wires are housed together as a cable in a tube running from front to back. Quote Link to comment Share on other sites More sharing options...
Sparkey Posted December 16, 2014 Report Share Posted December 16, 2014 If it's set up like the DeWalt check the wires on the speed control behind the switch. Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 16, 2014 Author Report Share Posted December 16, 2014 If it's set up like the DeWalt check the wires on the speed control behind the switch. Thanks, I checked those & resoldered. Next to check with meter to see if there is more 'juice' when you increase the speed. Quote Link to comment Share on other sites More sharing options...
Multifasited Posted December 16, 2014 Report Share Posted December 16, 2014 A cold solder joint is the single biggest electronic problem ,known to man ,any E.T. WORTH HIS SALT will tell you how many times they fixed elusive problems by just reheating solder joints ,never knew for sure which one it was but now it works !! Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 17, 2014 Author Report Share Posted December 17, 2014 Found my problem, now to get it fixed. My variable speed potentiometer (pot) wore out. (variable speed control) I don't want to spend $80 for PC Board just to get the potentiometer. I probably can jury rig a different pot but would like original equipment. Any ideas where I can get just the original pot? Quote Link to comment Share on other sites More sharing options...
Multifasited Posted December 17, 2014 Report Share Posted December 17, 2014 can you get any printed info off the oem to cross ref. , Quote Link to comment Share on other sites More sharing options...
Doug Posted December 17, 2014 Report Share Posted December 17, 2014 Seriously Larry, with a worn out old pot who knows what is next - I think you need a whole new scroll saw for your birthday tomorrow, not just a new pot. At our age you have to spoil yourself some as the opportunities are getting fewer and fewer. I am leaving the "pot" jokes to others. LarryEA and Wilson's Woodworking 2 Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 17, 2014 Author Report Share Posted December 17, 2014 Seriously Larry, with a worn out old pot who knows what is next - I think you need a whole new scroll saw for your birthday tomorrow, not just a new pot. At our age you have to spoil yourself some as the opportunities are getting fewer and fewer. I am leaving the "pot" jokes to others. Happy Birthday tomorrow Doug. Thank you and I would enjoy a new saw. I would still pursue to have this one work. Radio Shack has the VS Switch which I might obtain on my Birthday. Again, thanks and my best wishes to you. Quote Link to comment Share on other sites More sharing options...
JustLarry Posted December 17, 2014 Report Share Posted December 17, 2014 Larry Scroller on another forum had this situation back in March. Several of us helped him to find one. A couple of pots were located but not exact matches but might have worked. At the end he decided to order the pot/card combo. His thinking was if the pot went bad how soon before the old card could quit also. Links we used to locate pot/card under $80.00 in case the RS pot does not work. (Prices may have gone up by now) Black & Decker 5140101-32 CB & POT. | Ace Tool Repair $59.13Pc Board Assy - 5140101-32 - Industrial Tool and Supply $57.20DeWalt 286308-00 Circuit Board $57.20DEWALT - BLACK AND DECKER 5140101-32 - PC BOARD ASSY - Part Number 5140101-32 (DEWALT - BLACK AND DECKER ORIGINAL OEM). Smallenginesprodealer.com $50.72 Larry LarryEA 1 Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 17, 2014 Author Report Share Posted December 17, 2014 (edited) Larry Scroller on another forum had this situation back in March. Several of us helped him to find one. A couple of pots were located but not exact matches but might have worked. At the end he decided to order the pot/card combo. His thinking was if the pot went bad how soon before the old card could quit also. The old card may never quit, it does not have moving parts like the pot does. I would think the motor would be the next most possible. Thank you for the links. The lowest price I found was about $65 The Potentiometer is $3.49 at Radio Shack Edited December 17, 2014 by LarryEA Quote Link to comment Share on other sites More sharing options...
Around the corner Posted December 18, 2014 Report Share Posted December 18, 2014 Who sells the motor for the dewalt for the cheapest price Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 18, 2014 Author Report Share Posted December 18, 2014 (edited) Who sells the motor for the dewalt for the cheapest price I don't know and hope i never need to find out. I do think the replacement motor costs a heavy 50% of a new machine. The price at Ereplacementparts was upwards of $250. Edited December 18, 2014 by LarryEA Quote Link to comment Share on other sites More sharing options...
JustLarry Posted December 18, 2014 Report Share Posted December 18, 2014 The Potentiometer is $3.49 at Radio Shack Will you post the ID number for the Radio shack switch. Could come in handy. E-Replacement shows 270.38. Tool Parts Pro 229.37. Quote Link to comment Share on other sites More sharing options...
LarryEA Posted December 18, 2014 Author Report Share Posted December 18, 2014 Will you post the ID number for the Radio shack switch. Could come in handy. E-Replacement shows 270.38. Tool Parts Pro 229.37. Radio Shack # is 271-1716 This is premature because I havent been to Radio Shack to get it. I'll let you know if it is different # JustLarry 1 Quote Link to comment Share on other sites More sharing options...
Around the corner Posted December 18, 2014 Report Share Posted December 18, 2014 I found out this summer when mine died so I bought a new one after 15years.I was wondering cause if I can buy a used motor I will use the saw as a 2nd saw.Maybe someone has one that has a circuit board gone etc. I will keep looking cause the rest of my saw is still good.The repairman said it wasn't worth buying a new motor when you can buy a whole saw for almost the price of a new one.Thanks for the reply Larry. Damian Bfreeman 1 Quote Link to comment Share on other sites More sharing options...
Nichole Posted July 27, 2016 Report Share Posted July 27, 2016 Hi, My Delta 40-601's control knob stopped working correctly a couple of weeks ago and I just found this thread. Did that Radio Shack part work?? (I realize this is an 'old' post but it's the best lead I've found!) Thanks! Quote Link to comment Share on other sites More sharing options...
LarryEA Posted July 27, 2016 Author Report Share Posted July 27, 2016 Hi, My Delta 40-601's control knob stopped working correctly a couple of weeks ago and I just found this thread. Did that Radio Shack part work?? (I realize this is an 'old' post but it's the best lead I've found!) Thanks! Knob did not work......It ended up to be dust in the switch Quote Link to comment Share on other sites More sharing options...
Jim McDonald Posted July 27, 2016 Report Share Posted July 27, 2016 (edited) I got in on this thread really late--but: I spent 20 years at the Shack and would not have recommend that pot for motor use for a couple of reasons: #1 It is a linear pot and is not as accurate as an audio pot of the same rating (in ohms) #2 It probably would not handle the current and would eventually arc internally and either carbon up or weld itself at one speed. #3 There is no heat sink if it could handle the current. I understand the pot works with the circuit board to control speed, but somewhere in that line, there has to be some kind of resistance to slow the motor. Resistance equals heat. Edited July 27, 2016 by Jim McDonald Quote Link to comment Share on other sites More sharing options...
WayneMahler Posted July 27, 2016 Report Share Posted July 27, 2016 Jumped in late of this. Was thinking ebay but sounds like you got it worked out? Hopefully you did. Quote Link to comment Share on other sites More sharing options...
CharleyL Posted July 28, 2016 Report Share Posted July 28, 2016 (edited) The potentiometer needed for the DeWalt 788 is a 50 K ohm linear taper. Radio Shack sells one like it with the right physical as well as electrical size for just a couple of bucks, but the shaft on it is too long and there is no flat side for the knob D hole shape. I cut the shaft with a hack saw to make it the same length as the original, then figured out where the flat side needed to be by turning both the new and old potentiometer CCW to the stop. I then filed the shaft of the new potentiometer to create the needed flat on the side of the shaft to fit the D shaped hole of the original knob. Fifteen minutes and the saw was good again for about $3 and a little effort. Your Delta saw likely has the same speed board as the DeWalt. There is a huge amount of mis-information in this post. If you don't know the right answer, don't post at all. The electronic board takes care of the voltage control and speed of the motor. It electronically eliminates the "Heat" that would be encountered if using an old wire wound potentiometer in series with the motor winding to control the motor speed. The potentiometer used in these modern saws never sees more than a few milliamps of power, and therefore, does not get hot. Wire wound potentiometers for motor speed control went out with the dark ages and trolley cars. Modern electronic circuits like these speed control boards don't wear out. They sometimes go bad when a voltage spike in the power line damages them, but they don't wear out like an old mechanical machine. Most will be around and in perfect working condition until they are technically obsolete and scrapped. The Radio Shack 50 K Ohm linear taper potentiometer even looks like the original, except for the long shaft with no flat. A hack saw and a file make the only modifications needed. An AUDIO TAPER POTENTIOMETER is logarithmic, which means that it is non linear and increases resistance and an increasing rate as the shaft is turned. It WILL NOT WORK correctly for this application. Charley I'm a retired (EE) Automation Engineer Edited July 30, 2016 by CharleyL NC Scroller 1 Quote Link to comment Share on other sites More sharing options...
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