View source for JST JGD-125C Water Cooled Spindle

== Overview ==

A 5.5kW / 6kW Chinese water cooled spindle with an ER25 collet chuck. It is marketed for stone engraving rather than CNC routing.

== Wiring ==

Power inlet "WEIPU WS20" circular connector wiring:

{| class="wikitable"
! Pin
! Wire Color
|-
| 1
| yellow
|-
| 2
| blue
|-
| 3
| red
|-
| 4
| (ground)
|}

The spindle has male pins inside an externally threaded receptacle.

== Replacement Parts ==

=== Angular Contact Bearings ===

<pre>7007C T 2RZ HQ1 P4 DBL Z3X 131018044B</pre>

=== Deep Groove Bearings ===

<pre>SKF E2 6004-2Z/C3 15 260 K</pre>

=== Bottom Locknut ===

Doubles as a dust shield:

* 56.7mm OD
* 5.1mm thick (dust shield portion)
* 4x 3.5mm holes 3mm deep on a 44mm diameter circle
* must get past a 33.3mm diameter spindle nose before threading into place

=== Top Locknut ===

* 32mm overall OD
* 10mm thick
* M20x1.0mm threads on the ID
* 26mm OD / 22mm ID rim for bearing's inner shield
* 1.8mm clearance around the rim for the bearing's shield, as well as a shoulder with no threads on the inside

=== O-rings ===

The top cap with the water inlets have 10mm OD 1mm deep recesses with a 6mm ID hole for O-rings. Maybe for one of these?:

* [https://www.mcmaster.com/1171N144/ Square-Profile Oil-Resistant Buna-N O-Ring, 1.5 mm Wide, 7 mm ID | McMaster-Carr]
* [https://www.mcmaster.com/1171N181/ Square-Profile Oil-Resistant Buna-N O-Ring, 2 mm Wide, 6 mm ID | McMaster-Carr]
* [https://www.mcmaster.com/9262K628/ Oil-Resistant Buna-N O-Ring, 1.5 mm Wide, 6.5 mm ID | McMaster-Carr]
* [https://www.mcmaster.com/9262K595/ Oil-Resistant Buna-N O-Ring, 1.78 mm Wide, 6.35 mm ID | McMaster-Carr]
* [https://www.mcmaster.com/1302N037/ Oil-Resistant Buna-N O-Ring, 1.8 mm Wide, 6 mm ID | McMaster-Carr]
* [https://www.mcmaster.com/9262K166/ Oil-Resistant Buna-N O-Ring, 2 mm Wide, 6 mm ID | McMaster-Carr]

The bearing housing portion of the spindle has 8mm OD 1mm deep recesses with 4mm ID holes for O-rings. Maybe for one of these?:

* [https://www.mcmaster.com/9262K627/ Oil-Resistant Buna-N O-Ring, 1.5 mm Wide, 4.5 mm ID | McMaster-Carr]
* [https://www.mcmaster.com/9262K163/ Oil-Resistant Buna-N O-Ring, 2 mm Wide, 4 mm ID | McMaster-Carr] (verified)

=== Fasteners ===

==== Dust Shield ====

For holding the dust shield to the lower angular contact bearing retaining ring:

4x [https://www.mcmaster.com/91290a140/ Alloy Steel Socket Head Screw, Black-Oxide, M4 x 0.7 mm Thread, 8 mm Long | McMaster-Carr]

==== Lower Angular Contact Bearing Retaining Ring ====

For holding the lower angular contact bearing retaining ring to the bearing housing:

4x [https://www.mcmaster.com/91290A148/ Alloy Steel Socket Head Screw, Black-Oxide, M4 x 0.7 mm Thread, 12 mm Long | McMaster-Carr]

There are two M4-0.7 tapped holes 9.5mm deep for jacking the ring away from the housing, we used 25mm long screws.

==== Bearing Housing ====

Grub screws w/ teflon tape for sealing some water ports (manufacturing process side effect?):

2x [https://www.mcmaster.com/91210A310/ Alloy Steel Cone-Point Set Screw, M6 x 1 mm Thread, 8 mm Long | McMaster-Carr]

TODO verify the following:

For holding the bearing housing to the main spindle body:

6x [https://www.mcmaster.com/91290A232/ Alloy Steel Socket Head Screw, Black-Oxide, M5 x 0.8 mm Thread, 16 mm Long | McMaster-Carr]

==== Upper Angular Contact Bearing Retaining Ring ====

For holding the upper angular contact bearing retaining ring onto the housing:

4x [https://www.mcmaster.com/91290A228/ Alloy Steel Socket Head Screw, Black-Oxide, M5 x 0.8 mm Thread, 12 mm Long | McMaster-Carr]

==== Upper Rotor Bore Cover ====

For holding a lid over the upper part of the rotor to protect the floating bearings from contamination:

3x [https://www.mcmaster.com/91290A148/ Alloy Steel Socket Head Screw, Black-Oxide, M4 x 0.7 mm Thread, 12 mm Long | McMaster-Carr]

==== Spindle Top Cap ====

For holding the water inlet/electrical inlet cap onto the main spindle body:

6x [https://www.mcmaster.com/91290A256/ Alloy Steel Socket Head Screw, Black-Oxide, M5 x 0.8mm Thread, 35mm Long, Partially Threaded | McMaster-Carr]

TODO military connector screws?

== Online Resources ==

[https://www.aliexpress.com/item/1005001993140654.html JGD 125C Spindle Motor 5.5 KW ER25 Stone Water Cooling Cnc Milling Machine Spindle 380v / 220v 4pcs Bearing High Speed|Machine Tool Spindle| - AliExpress]