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Power Cord Replacement
Posted: Wed Sep 18, 2013 11:43 pm
by rmingo
I need to replace the power cord on my 1958 vintage Mark V. The directions I downloaded off this site seemed like they might be a little more involved than necessary (copy attached). Has anyone replaced the power cord without removing belts and dropping the motor pan. The wire from the switch to the motor look to be in good shape so I would just be swapping out the common and hot on the switch and connecting the ground to the ground wire going to the motor.
Thanks,
Posted: Thu Sep 19, 2013 12:14 am
by JPG
rmingo wrote:I need to replace the power cord on my 1958 vintage Mark V. The directions I downloaded off this site seemed like they might be a little more involved than necessary (copy attached). Has anyone replaced the power cord without removing belts and dropping the motor pan. The wire from the switch to the motor look to be in good shape so I would just be swapping out the common and hot on the switch and connecting the ground to the ground wire going to the motor.
Thanks,
And how does the new cord get into the inside of the headstock?
A new strain relief will likely require removal of the motor pan.
The original cord had a small molded strain relief.
Posted: Thu Sep 19, 2013 5:21 am
by dusty
rmingo wrote:I need to replace the power cord on my 1958 vintage Mark V. The directions I downloaded off this site seemed like they might be a little more involved than necessary (copy attached). Has anyone replaced the power cord without removing belts and dropping the motor pan. The wire from the switch to the motor look to be in good shape so I would just be swapping out the common and hot on the switch and connecting the ground to the ground wire going to the motor.
Thanks,
You could do this without dropping the pan except that you need to connect the wires to the motor. Oh yeah, you could cut the cable and use inline spices. That way you can avoid disconnecting the drive belt and removing a small handful of screws. Yeah, it could probably be done but not to my Shopsmith.
Posted: Thu Sep 19, 2013 10:52 am
by Ed in Tampa
I did this a few years ago and it was simple. I don't remember the exact procedure but I know I did not remove any belts.
As I remember the biggest problem was the strain relief. I used 12 gauge wire instead of SS 14 gauge so the strain relief was tight. I remember using a file to file out the hole to allow for more room of the strain relief.
I think on the inside all I had to do was but spade lugs on the wires of the new cord. Pull the old lugs off the switch and shove the new cord in and plug on the lugs.
I can't remember but I think the electrical part took ten seconds and the strain relief took maybe 10 minutes.
If you are doing this do yourself a favor and use #12 wire. The machine will run completely different.
Posted: Thu Sep 19, 2013 11:36 am
by dusty
rmingo wrote:I need to replace the power cord on my 1958 vintage Mark V. The directions I downloaded off this site seemed like they might be a little more involved than necessary (copy attached). Has anyone replaced the power cord without removing belts and dropping the motor pan. The wire from the switch to the motor look to be in good shape so I would just be swapping out the common and hot on the switch and connecting the ground to the ground wire going to the motor.
Thanks,
Maybe I misunderstood. Where do you intend to connect the hot wire that comes from the switch? It currently is a wire in the power cord that goes all the way to the wall outlet.
Posted: Thu Sep 19, 2013 12:15 pm
by billmayo
You must have the power cord ground wire connected to the Shopsmith. I would believe the current power cord ground wire will be connected to the motor. I had to drop the motor pan to unconnect this wire. I have been shocked a few times when the ground connector on the plug had been removed. Many times if the run windings or internal wiring is shorted to ground (very possible with GE motor), removing the ground prong from the plug will allow the motor to continue to operate. When the Shopsmith motor trips the breaker on start up, some owners will remove the ground connection and the motor will then operate. I have seen over a dozen of these cases so they occur.
Please follow the Shopsmith instructions.
NOTE: Do not operate the headstock without the ground wire connected.
Posted: Thu Sep 19, 2013 4:26 pm
by JPG
Gotta chime again!
I agree with Dusty: dropping the motor pan is not a major undertaking.
Ed is giving good advice, but his was a later model with likely a heyco strain relief. Yer 50's model has a much smaller hole. You will need to decide how to replace the strain relief. I like a liquid-tite rubber bushing or a right angle 'BX' fitting, but they require enlarging the hole considerably.
Absolutely ground the motor, and make sure the headstock casting is also grounded through the motor mounting/pan etc.
I do not recommend just sticking a new cord through the original hole with out providing a strain relief(as you "implied' initially).
Posted: Thu Sep 19, 2013 7:46 pm
by algale
Ed in Tampa wrote:
If you are doing this do yourself a favor and use #12 wire. The machine will run completely different.
Ed,
Would you mind expanding on this thought? What gauge wire does Shopsmith use in its "stock" cord and what differences did you note by moving to #12 wire?
Thanks,
Al
Posted: Thu Sep 19, 2013 8:01 pm
by dusty
algale wrote:Ed,
Would you mind expanding on this thought? What gauge wire does Shopsmith use in its "stock" cord and what differences did you note by moving to #12 wire?
Thanks,
Al
The Shopsmith power cords that I can speak for were made using #14 stranded copper wire. While there are technical differences between #12 and #14 wire, I do not believe that changing from one to the other will produce any noticeable differences in performance UNLESS they are being used in an environment that is otherwise unacceptable. Aged outlets, loose connections, low voltage, long home runs, overloaded breaker panels are just a few items that are more likely (in my opinion) to cause performance issues.
For what it is worth, I have two Mark Vs running on #14 power cords, on 15 amp breakers and the power cords are longer than stock cords. I also, occasionally use an extension cord that is 20' long. I do sense some strain at startup when using the extension cord.
Posted: Thu Sep 19, 2013 11:16 pm
by rmingo
My apologies if I've replied twice. This is my first post and not quite sure how to reply. In answer to your question, I'm not replacing the wire from the switch to the motor, it looks good. Only the cord from the power outlet to the switch. And yes, I wouldn't use inline splices. I was planning on using a 12g extension cord cut to about 12'.