750W Milling and Drilling Spindle

This is an instruction how you can build your own Spindle. The Size, Power and Spindle Speed can be modified by using different Sizes of Extrusions as a spindle base and by using different motors, to modify RPM-Range and Power.

Materials used:

• 1x 750W AC Servo (https://www.omc-stepperonline.com/t6-series-750w-ac-servo-motor-kit-3000rpm-2-39nm-17-bit-encoder-ip65-t6-rs750h2a3-m17s)
• Claw Coupling D40L50 19/20mm (https://gtech-shop.de/Jaw-Coupling-D40L50-O40-Length-50-Alu-7075-19mm-to-20mm)
• 1x 50mm Extrusion 80x80S (heavy) I-Type Groove 8 (https://www.dold-mechatronik.de/Aluminum-Profile-80x80S-heavy-I-Type-Groove-8-719kg-m-Customized-Cutting-50-to-6000mm)
• 4x T-Slot Nut M8 (https://www.dold-mechatronik.de/Sliding-block-M8-with-web-I-type-groove-8)
• 2x 90x90x15mm aluminium raw stock for the spindle endplates
• 1x 65x65x4mm aluminium raw stock for the spindle bearing shield
• 1x 130x100x15mm Aluminium Raw Stock for the Adapter plate
• 4xAluminium Tube 12x3mm
• 2x Angular Contact Bearings 7004 AC (https://www.dold-mechatronik.de/Spindle-bearing-angular-contact-ball-bearing-7004AC-20x42x12mm)
• Collet chuck with straight shank C20-ER20A-100 (https://www.dold-mechatronik.de/Collet-chuck-C20-ER20A-100-straight-shank)
• 4x M6X80 DIN912 (https://www.dold-mechatronik.de/DIN-912-screws-with-hexagon-socket-stainless-steel-A2-M6x80-TG)
• 4x m3x8 DIN7991 countersunk allen bolts(https://www.dold-mechatronik.de/DIN-7991-countersunk-allen-A2-M3X8)
• 12x M8X20 DIN912 (https://www.dold-mechatronik.de/DIN-912-screw-with-hexagon-socket-stainless-steel-A2-M8X20-VO)
• 4x M8x25 DIN7991 countersunk allen bolts (https://www.dold-mechatronik.de/DIN-7991-countersunk-screw-with-hexagon-socket-stainless-steel-A2-M8X25)
• 1x Shim DIN988-20x28x0,2 (https://www.dold-mechatronik.de/DIN-998-Shim-steel-blank-20mm-d-D-28mm-H-02-mm)

Tools used:

• m8x1.25 Tap
• m6x1 Tap
• m3x0.5 Tap
• Tap Wrench
• CNC-Mill to machine the Aluminum Plates
• Allen Keys
• Press/Vise/ Hammer

Materials used in this Step:

• 2x 90x90x15mm aluminium raw stock
• 1x 65x65x4mm aluminium raw stock

Tools used in this Step:

• CNC-Mill / Manual Mill
• M6x1 Tap
• M3x0.5 Tap

Instruction:

First step is to machine all the required parts. This can be done with a cnc-router/mill. For Fixuring I used the masking-tape with superglue method (https://www.youtube.com/watch?v=e-coDYZCmEw).

Alternatively these Parts could be made on a manual mill.

Some holes require threads which you may need to make manually.

If you don't have access to this machines, you can order them from a CNC-Machining Services like Xometry.

Tapping of the required holes can be done by hand.

Materials used in this Step:

• 2x Machined Aluminium Endplates
• 2x Angular Contact Bearings 7004 AC

Tools used in this Step:

• Press/Vise/Hammer

Instruction:

Pressing in the Bearings in the bores. This can be done with a press. Alternatively you can use a vise or gently tap them in place with a hammer. Make sure to only apply pressure on the outer bearing race.

Note: I used non sealed bearings, which need to be greased before used. I applied the grease before I installed them.

Materials used in this Step:

• 50mm Extrusion 80x80S (heavy) I-Type Groove 8

Tools used in this Step:

• M8x1.25 Tap
• Tapping Wrench

Instruction:

Tap all eight holes of the Extrusion with an M8 Tap

Materials used in this Step:

• Tapped Aluminum Extrusion
• Prepared Aluminum spindle end plates with the bearings installed
• 8x M8X20 DIN912 socket head cap screws
• Collet chuck with straight shank C20-ER20A-100
• 4x T-Slot Nut M8
• T-Slot Nut M8
• spindle bearing shield
• 4x m3x8 DIN7991 countersunk allen bolts

Tools used in this Step:

• Allan Keys

Instructions:

Step 1: Mount the first aluminium end plate with 4 M8X20 socket head cap screws to the extrusion profile.

Step 2 (optional): if you have t-nuts which can't be inserted by inserting them in the groove by swinging them in, you need to insert 4 t-nuts to be able to mount the spindle backplate.

Step 3: Repeat Step 1, this time for the second end plate.

Step 4: Install the spindle bearing shield with the m3x8 countersink allen bolts

Materials used in this Step:

• Assembled Spindle Body
• Claw Coupling D40L50 19/20mm
• 1x Shim DIN988-20x28x0,2

Tools used in this Step:

• Allen keys
• Press/Vise

Instruction:

Slide the spindle through both bearings. Add a shim and the add the claw coupling. you can preload the spindle by pressing the coupling against the spindle shaft and then tightening the claw coupling. This preloading can be done with a vise or similar.

Note: the spindle bearing shield was not installed at the point when I took the photos.

Materials used in this Step:

• Spindle Body
• 1x 750W AC Servo
• 4xAluminium Tube 12x3mm

Tools used in this Step:

• Allen keys
• Press/Vise

Instruction:

Fit the Servomotor in the claw coupling. Use the 4 aluminium tubes to space the motor out to the right distance. Insert the socket-head-cap screws to tighten the servomotor to the spindle. Last step is to tighten the screw of the claw coupling to the shaft of the servo to be able to transmit power to the spindle.

Materials used in this Step:

• Spindle Body
• Spindle Backplate
• 4x M8x25 countersunk allen bolts

Tools used in this Step:

• Allen keys

Instruction:

If you have T-nuts which can be inserted after the end of the slot is closed, you need to insert them into the slot. Bolt the spindle backplate with the 4 M8 countersunk allen bolts.

Materials used in this Step:

• Spindle

Tools used in this Step:

• Allen keys

Instruction:

Now you can bolt the spindle to your machine using the last 4x M8X20 DIN912 socket head cap screws and tram it in. Then the only thing what is left is to wire everything up. Since wiring is depending on the actual used drive motor I am not going into detail how to wire everything up.

Congratulations you have made it until the end. Thank you for sticking around. Now you need to use your spindle for your desired application.The CAD-Files are available on GrabCad under https://grabcad.com/library/750w-spindle-1.