What's new
What's new

Replacing HRT-210 motor

Aero Garage

Mar 14, 2023
I have an older (white with red logo) Haas HRT-210 with the brushless sigma 1 motor and very little use despite being a 12 year old unit.

Here’s the short version, I was getting servo overload alarm so I opened it up. The input shaft/worm gear on the rotary will turn very freely and smooth, but the servo motor shaft/pulley is very hard to turn by hand. Rotary was making a gravel mixer noise just before I got the alarm, so I presume the motor internals have grenaded.

I have the yaskawa part number right off the motor, SGM-08U2HA12. They’re all over eBay for like $500, can I just order a new one to drop in or is there anything special about the Haas part (at nearly $2k!)
Does the “O/N number” have any significance or do I just need to match the SGM-part number?

Will I need to swap the encoder I currently have or should any motor with that number have the correct encoder on its back?

As for swapping the pulley, induction heater and a gear puller are the first things to come to mind…


  • FD4970E9-6498-42C4-AF53-296A4B3D54B5.jpeg
    1.3 MB · Views: 7


Hot Rolled
Dec 11, 2013
Alberta canada
If it’s the same servo designation it should be drop in.
I’ve swapped between 2 different hrt160 before.

I’m betting what happened is the permanent magnet that is wrapped around the rotor has cracked and delaminates from the shaft.
I’ve actually gotten away with dismantle and re epoxy the broke bits to the rotor. Still running that servo today with fantastic results. Was a real trick to take apart tho. (You do t
want to loose orientation of the encoder to the rotor. And the magnet fragments make it hard to slip out.

(11pm on a Saturday job that was due Monday. Very happy with the result several hundred run hours later, shockingly)