VMC 1300, adjustment procedure to eliminate play in toolholder collet/spindle/drawbar assembly

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neilo
Posts: 3
Joined: Mon 02 May , 2022 18:31 pm
Hardware/Software: VMC 1300 , Turn 270 , Router 2600. VR-Milling-V5, VR CNC Turning, etc

VMC 1300, adjustment procedure to eliminate play in toolholder collet/spindle/drawbar assembly

Post by neilo » Mon 02 May , 2022 23:39 pm

The school where I work has a VMC 1300 mill that has started producing very poor finishes, ie. chatter, ( see attachments ), so while troubleshooting I found some vertical and lateral play when the toolholder is inserted in the spindle. When the pull stud is removed from the toolholder and inserted into the spindle, it can be seated with no lateral or vertical play. Is there a documented procedure about how to go about adjusting the drawbar so that the toolholder is pulled higher and tighter into the spindle ? Any suggestions and direction would be appreciated.
Attachments
facing endmill chatter.jpg
facing endmill chatter.jpg (554.27 KiB) Viewed 4612 times
facing endmill no chatter.jpg
facing endmill no chatter.jpg (395.12 KiB) Viewed 4612 times

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Steve
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Re: VMC 1300, adjustment procedure to eliminate play in toolholder collet/spindle/drawbar assembly

Post by Steve » Fri 06 May , 2022 9:04 am

The tool should be pulled up tight in the taper of the spindle so there should be no movement once fitted. Could you remove a pull stud from a toolholder and check it fits in the taper correctly?

All that could cause a tool fitted with the correct pull stud to be loose would be that the springs are not correctly under tension as these pull the stud and the tool into the taper.

Has anyone done any work on the spindle?

I attach the diagram for a VMC 1300 which is much the same. I will also include some photos.

To remove the drawbar there are two nuts at the top that need to be removed VMC/0113 and VMC/0111 then the drawbar will fall clear of the spindle. Note there are four ¼” bearings that will fall out when the drawbar is removed. These should be stuck back in place with grease when refitting.

There are only a couple of things that could cause the tool to be loose:

VMC/0106 the collet that holds the 4 bearings should be fitted so that 4 threads are left visible on the drawbar and then this is locked in place by a grubscrew.

There are 44 springs in the spring stack and these should be fitted in opposite directions to each other. The first locknut (VMC/0111) is screwed down clamping the springs in place so it is 10.5mm below the top of the spindle then locked in place using a grub screw accessed through the hole drilled in the spindle. Then the second one (VMC/0113) is screwed in level with the top of the spindle and again clamped with a grub screw.
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johnparker
Posts: 19
Joined: Mon 16 May , 2016 20:18 pm
Hardware/Software: VMC 1300 Pro

Re: VMC 1300, adjustment procedure to eliminate play in toolholder collet/spindle/drawbar assembly

Post by johnparker » Wed 22 Feb , 2023 19:33 pm

Steve, What's the best way to remove the drawbar rocker VMC/073 to get access to the drawbar locknuts? It looks like the rocker pivot has a sort of clip retainer - can I just ping this off?
Attachments
Rocker.png
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johnparker
Posts: 19
Joined: Mon 16 May , 2016 20:18 pm
Hardware/Software: VMC 1300 Pro

Re: VMC 1300, adjustment procedure to eliminate play in toolholder collet/spindle/drawbar assembly

Post by johnparker » Wed 01 Mar , 2023 21:07 pm

Just a note to say I serviced my VMC 1300 Pro drawbar using the info supplied and it cured by lose tooling problems. I made a spanner from an old imperial socket to turn the nuts. When replacing the drawbar, not the orientation of the flat on the bar and the indent in the spindle so you can slide the bar up. My Pro has 5 balls in the drawbar.
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