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Ajax DM-45 Spindle Bearings

Posted: Tue May 25, 2021 2:45 pm
by jottesen
I have a DM-45 CNC milling machine that I purchased from Ajax CNC about 15 years ago. The spindle bearings are failing and with Ajax CNC gone I'm hoping someone here may have documentation or experience with the BT-30 quill assembly in this machine. I converted it to belt drive a couple years ago so I know what is/was in the gearbox but I have not had the quill out. An exploded view of the quill and bearing numbers would be ideal but any information is appreciated.

Regards,
Jeff

Re: Ajax DM-45 Spindle Bearings

Posted: Tue May 25, 2021 6:45 pm
by jcsb
I might be able to help you with this, since I took the headstock off mine and made a new one. I have the quill on a cart and I'll take some pics tomorrow if I have time, otherwise Thursday.
John

Re: Ajax DM-45 Spindle Bearings

Posted: Wed May 26, 2021 1:36 am
by jottesen
Hi John,
Thank you, photos would be helpful. I'm also curious what you did for a new head as I am considering the same.
Jeff

Re: Ajax DM-45 Spindle Bearings

Posted: Thu May 27, 2021 7:50 pm
by jcsb
Hey Jeff,
I've attached the pictures of the spindle removal. At the top end of the spindle there is a tab washer that you need to bend the tab on. Then you can tap the nut loose and remove. The inner cone of the bearing should come right out. The other end where the tool holder would go has a nut retaining the other cone bearing. You should be able to tap it loose with a pin punch. Both retainers are normal right hand threaded. To remove the inner races you can use an adapter to press the small one out first then using a larger adapter press the larger one next.
Bearings:
35x72x17 30207
30x62x17.25 30206
John

Re: Ajax DM-45 Spindle Bearings

Posted: Sun May 30, 2021 4:35 pm
by jottesen
Hi John,
Thank you very much for the photos and the disassembly advice. It is a big help to know what to expect before tearing it down. Mine was leaking gear oil around the spindle for some time which likely washed the grease out but provided some lubrication. When I converted to belt drive I deprived the bearings of the leaking oil. Now that I know what to expect I can replace the bearings to get by until I build a new head.

I'm considering a belt-driven cartridge spindle with a new head and I'm curious if that is the path you chose.

Regards,
Jeff

Re: Ajax DM-45 Spindle Bearings

Posted: Mon May 31, 2021 11:15 pm
by jcsb
Yeah, I designed a headstock for it that would interface with the existing z axis. The picture shown is from last year when I originally installed a DMM 3 hp servo motor. Got going and then decided it was an overkill and put a 3phase 3hp motor and vfd.
John