Dayton Drum Switch Modification

Canuck75

Active User
H-M Supporter Gold Member
Joined
Jan 1, 2014
Messages
233
I posted this information as an addition to a previous thread, which probably caused it to be buried, so will repost it here to highlight a simple cure for that "live lead" when using the common Dayton drum switch in a 220V setup.

Two years ago I opted to use a 4-way house wiring switch to give me a reverse capability on my King PDM30 (RF 31 style) mill which made sure all power to the motor was killed when in the "OFF" position. This did the job but was an extra switch to operate. A proper cure has always been in the back of my mind.

For whatever reason, I had a look at that unused Dayton switch again the other day and realized that there was a solution I didn't see before.

Within the housing there is room for another set of contact arms on the end of the mounting bars down at the bottom, and also room on the end of the control shaft for another single row rotating contact plate. This was a EUREKA moment! It would give a way to totally cut the power from both leads in the OFF position. The existing configuration of the Dayton gives an easy way to switch the Red5 and Red6 leads for FWD and REV and to break the one "line" lead in the OFF position, now, the new contacts would give a way to break the other "line" wire in the OFF position, but also making it "hot" in either the FWD and REV position.

The Dayton moving copper parts are mounted on a non-conductive ferrule with 3/8" square shoulders and a 1/4" square bore to fit the control shaft, plus non-conductive spacers as required. To accomodate the extra contact plate on the end , I made a ferrule with a 3/8" square shoulders on both sides and 1/4" square bore, a spacer with a 3/8" square bore, a copper contact plate, and 2 brass contact arms with copper shoes riveted to them. The contact arms are .050" thick made from brass bolts. All the copper bits are from flattened out 1/2" copper pipe. A little milling was required on the back end of the non-conductive mounting bars to provide a flat spot to mount the new arms. Since the new arms and rotating contact plate took up some of the original space available for wires inside the box I added a small addition on the back of the Dayton to give some extra room. A total of 7 wires plus a ground were routed from the motor to the modified drum switch. The sketch shows the wiring arrangement I used.

This a solution for the "live wire" problem without having to buy more expensive switches or having to use contactor blocks. Also, there are no safety issues with this mod since the new parts are insulated/isolated equally well as the original switch parts.

Hope some of you might find this useful.

Canuck75

IMG_7439.jpg

IMG_7453.jpg

IMG_7457.jpg

IMG_7462.jpg

IMG_7465.jpg

img291.jpeg
 
Back
Top