Re: [CAD_CAM_EDM_DRO] Re: wrong guy, but have servo question.

Hi Wally:
All of the commercial conversions I have seen, mount a small Z axis
ballscrew to the quill.
This is probably the least offensive way out of an intrinsically crappy
situation.
The basic physics you are up against, is that an extended quill flops around
in X and Y, because it is cantilevered out so far.
This makes heavy cutting impossible, and accuracy a hit or miss affair,
depending on how far out the quill happens to be sticking.
Connecting the Z axis servo to the quill downfeed mechanism adds a
horrendous and variable amount of backlash to the equation.
I can't guarantee it, but I'm pretty sure you will be disappointed if you go
to all the trouble to make the mount, and then find you can't machine
anything to closer than boilermaker's tolerances.

Cheers

Marcus
-----Original Message-----
From: Wally K <cnc4me@...>
To: CAD_CAM_EDM_DRO@egroups.com <CAD_CAM_EDM_DRO@egroups.com>
Date: Monday, November 27, 2000 6:06 AM
Subject: [CAD_CAM_EDM_DRO] Re: wrong guy, but have servo question.

>Jon Elso wrote:
>
>> I used 200 Lbs force for the quill, as that is what the Bridgeport
>J-head's
>> overload clutch is set to on the power feed. I punched the wrong
>jog button
>> and brought a boring head down on my hand once, and it sure FELT
>like
>> 200+ Lbs!
>>
>> Jon
>
>
>Wally K. replys:
>
>Do you think the feed mechanism could be used for the Z axis on CNC.
>I think the little hand wheel on the side of the J head can be
>switched in to be manually turned to lower the quill. It would not
>be to hard to put a motor in place of the handwheel.
>
>Is this mechanism made for this kind of duty cycly.
>
>And how much backlash does it have.
>
>
>
>
>Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the

discussion of shop built systems, for CAD, CAM, EDM, and DRO.

>
>Addresses:
>Post message: CAD_CAM_EDM_DRO@egroups.com
>Subscribe: CAD_CAM_EDM_DRO-subscribe@egroups.com
>Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@egroups.com
>List owner: CAD_CAM_EDM_DRO-owner@egroups.com, wanliker@...
>Moderator: jmelson@... [Moderator]
>URL to this page: http://www.egroups.com/group/CAD_CAM_EDM_DRO
>FAQ: http://www.ktmarketing.com/faq.html
>bill,
>List Manager