- Joined
- Feb 2, 2013
- Messages
- 3,625
I purchased a beautiful Hercus ARH lathe a few years ago.
https://www.hobby-machinist.com/threads/hercus-9-workshop-lathe-model-arh-serial-15548v.24143/
i love this machine, but the original owner didn't wire the drum switch for direction.
it only ran in the spindle CCW direction ,whichever direction the drum switch was switched.
being a threaded spindle, the direction of operation was just fine for turning.
i didn't see an urgent need to make the motor bi-directional.
Something changed in me the other night,
Suddenly i felt the necessity to correct the problem that didn't really bother me before.
but whatever it was, the dragon had to be slayed before i could rest easy once again.
I went to the shop and took the drum switch off the lathe, noting the wiring arrangement
to my surprise, the drum switch was just being used as an off/on switch,
there was one jumper wire installed, but no other wires were present.
the drum switch is a Square D Class 2601 Type:AG-1
the motor is a Dayton - thermally protected, split phase, 56 frame, 1/2 hp, 115v single phase, 8.4Amp, 1725 rpm motor
i am glad i got this bug in my head,
the old wire insulation from the drum switch to the motor was crispy and crunchy.
as i removed the wires the insulation mostly flaked off
After seeing this, i was determined to do things differently....
there are many ways to achieve the end.
this is the way i did it.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
if you are not comfortable with electrical circuits, consult qualified personnel before attempting service of any type of equipment
The 1st step:
was to construct the control circuit wiring diagram to make a unidirectional motor, bi-directional with a drum switch
here is what i came up with...
the control circuit consists of 6 conductors and a ground wire.
the motor start leads are in effect brought back to the switch for directional control, then the wires are returned to the motor terminals.
by swapping the M2 and M3 leads in relation to the start leads, reverses motor direction.
The 2nd step:
was to figure out what wire to use for the project.
working with the given parameters, the motor pulls 8.4 amps by the nameplate.
I chose 14 gauge THWN oil resistant White wire, here is why..
i went to the local box store and looked at the different selection of wire, and cord
they did't have 7 wire 14 gauge SOW cord.
i had some liquidtight fittings and flex conduit already at home, so i figured i'd just use THWN, instead.
i looked at the wire selection and the pricing was ridiculous, to be mild.
here is what i found,
50 ft feet of 14 gauge THWN was $20
100 ft was $28
500 ft was $40
i ended up buying 500 ft of White THWN, just out of principle- now i have plenty
White wire can easily be marked with permanent markers for easy identification.
Note: Stranded THWN wire no matter the color, is made to the same specifications- the only difference is the jacket color.
you may choose any color, as long as you mark or otherwise identify the individual wires
(i would not recommended using green stranded wire for power circuits- it could too easily confused with a ground wire)
The 3rd step:
was doing the work (my favorite part!!!)
i cut the liquidtight conduit to length
i cut the wire into 7, 3 ft lengths and pulled the wire through the conduit
i marked all the wiring with colored ink bands for easy identification
i wired up and mounted the drum switch
then secured the conduit and fittings into the switch and motor
i made the connections as per the diagram
it was tight work getting all 6 conductors and the ground under the cap, but it all fit!
The 4th Step:
i plugged the power in and gave her a test run.
Sheila now runs forward and reverse
thanks for reading!
https://www.hobby-machinist.com/threads/hercus-9-workshop-lathe-model-arh-serial-15548v.24143/
i love this machine, but the original owner didn't wire the drum switch for direction.
it only ran in the spindle CCW direction ,whichever direction the drum switch was switched.
being a threaded spindle, the direction of operation was just fine for turning.
i didn't see an urgent need to make the motor bi-directional.
Something changed in me the other night,
Suddenly i felt the necessity to correct the problem that didn't really bother me before.
but whatever it was, the dragon had to be slayed before i could rest easy once again.
I went to the shop and took the drum switch off the lathe, noting the wiring arrangement
to my surprise, the drum switch was just being used as an off/on switch,
there was one jumper wire installed, but no other wires were present.
the drum switch is a Square D Class 2601 Type:AG-1
the motor is a Dayton - thermally protected, split phase, 56 frame, 1/2 hp, 115v single phase, 8.4Amp, 1725 rpm motor
i am glad i got this bug in my head,
the old wire insulation from the drum switch to the motor was crispy and crunchy.
as i removed the wires the insulation mostly flaked off
After seeing this, i was determined to do things differently....
there are many ways to achieve the end.
this is the way i did it.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
if you are not comfortable with electrical circuits, consult qualified personnel before attempting service of any type of equipment
The 1st step:
was to construct the control circuit wiring diagram to make a unidirectional motor, bi-directional with a drum switch
here is what i came up with...
the control circuit consists of 6 conductors and a ground wire.
the motor start leads are in effect brought back to the switch for directional control, then the wires are returned to the motor terminals.
by swapping the M2 and M3 leads in relation to the start leads, reverses motor direction.
The 2nd step:
was to figure out what wire to use for the project.
working with the given parameters, the motor pulls 8.4 amps by the nameplate.
I chose 14 gauge THWN oil resistant White wire, here is why..
i went to the local box store and looked at the different selection of wire, and cord
they did't have 7 wire 14 gauge SOW cord.
i had some liquidtight fittings and flex conduit already at home, so i figured i'd just use THWN, instead.
i looked at the wire selection and the pricing was ridiculous, to be mild.
here is what i found,
50 ft feet of 14 gauge THWN was $20
100 ft was $28
500 ft was $40
i ended up buying 500 ft of White THWN, just out of principle- now i have plenty
White wire can easily be marked with permanent markers for easy identification.
Note: Stranded THWN wire no matter the color, is made to the same specifications- the only difference is the jacket color.
you may choose any color, as long as you mark or otherwise identify the individual wires
(i would not recommended using green stranded wire for power circuits- it could too easily confused with a ground wire)
The 3rd step:
was doing the work (my favorite part!!!)
i cut the liquidtight conduit to length
i cut the wire into 7, 3 ft lengths and pulled the wire through the conduit
i marked all the wiring with colored ink bands for easy identification
i wired up and mounted the drum switch
then secured the conduit and fittings into the switch and motor
i made the connections as per the diagram
it was tight work getting all 6 conductors and the ground under the cap, but it all fit!
The 4th Step:
i plugged the power in and gave her a test run.
Sheila now runs forward and reverse
thanks for reading!
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