Re: [CAD_CAM_EDM_DRO] Knee for z-axis control?

Using the knee or the quill for Z are both acceptable methods. many on here seem to think if the knee moves it is somehow independent to X and Y positioning. All 3 axies work together. The knee is similar to a tailstock on an engine lathe. If it is repositioned it doesnt lose it's X and Y position, if it does you need another lathe or replace the bedways. That is just an inherent quality of any well made machine tool. Thay are accurate throughout. As I've mentioned my machine uses the knee for Z and I have no positioning errors at all with it, Some of the fixtures I build involve "ganging" Atlas-Copco nut-runners together for in plant assembly operations anyway, when I gang these together I use an aluminum block of all different configurations and cut .845 radial troffs across it that the guns lay in and then are secured. To machine these I stand the block up and and use a long 1" finish mill and semi-circle toolpath climb-milling that advances .200" -Z on each go around. Sometimes
these troffs will be 3 or 4 deep or accross the block. After the troff is machined it looks like a mirror and it is smooth as silk. Z is not moving the X and Y around at different Z heights as some have suggested if it were I would not get results like that.

Ron


pondindustrial <pondindustrial@...> wrote:
Hi all,

I will be retrofitting my Bridgeport mill soon and know that some
have used the knee for z-axis control. Does anyone here have any
experience with this method? If so, what should I take into
consideration if I decide to go this route? The mill has a 9" X 48"
bed.

Is a counterweight to offset some of the lifting load preferable?
Did you use the original acme screw/nut, or retro with a ballscrew?
What would be a reasonably sufficient drive in terms of motor torque
and gear reduction?
What are the pros & cons of using the knee opposed to the quill?


Thanks, Eric




Addresses:
FAQ: http://www.ktmarketing.com/faq.html
FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/
Post Messages: CAD_CAM_EDM_DRO@yahoogroups.com

Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@..., timg@...
Moderator: pentam@... indigo_red@... davemucha@... [Moderators]
URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO

OFF Topic POSTS: General Machining
If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble.
http://www.metalworking.com/news_servers.html

http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list.

NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........
bill
List Mom
List Owner


Yahoo! Groups Links







---------------------------------
Do you Yahoo!?
Yahoo! Mail - 50x more storage than other providers!

[Non-text portions of this message have been removed]