Re: [CAD_CAM_EDM_DRO] Re: Z axis drive

Both of my Bridgeports drive the knee for Z axis and they are in excess of 1000 pounds (knee, table, saddle, ballscrews, 2 servos, 2 mounts and vise). Getting 60 ipm Z rapids on both and use no assist whatsoever. 40 lb-in DC brush servo 2.5:1 reduction on a G320 Gecko. I ran one job recently on one of these that consisted of 1280 .875" reamed holes 3 inches deep in 1018 steel. Alot of pecking. The servo would have to rest every 4 hours to cool a bit. The Gecko would've run continually it seems. Great job Mariss..

During the retrofit and setting up the electronics, I had determined that drilling for prolonged periods would be out of the question. I was wrong.

Ron

skykotech <rick@...> wrote:

> Are you sure there isn't a counterballance system hidden in there
> somewhere? A hydraulic counterballance setup for a modest weight

like

> 1,000# can be pretty small and easily hidden.
>
> Without a counterballance system of some sort, any machine with a
> heavy head will cause a massive imballance in the servo load between
> up and down which I would expect would hurt performance.
>
> As someone else noted, without a counterballance the servo could end
> up driving in the up direction to move the head up, and driving in
> the up direction (just less force) to move the head down as the
> weight of the head backdrives the ballscrew.
>
> Pete C.
>

Ok, now I am curious. I will go check and see if indeed there is a
hydraulic cylinder or something that I have not noticed before. I
always assumed the little black box sitting on top of the ballscrew
was some sort of clutch or brake. I will snap a picture, maybe
someone will know from that.






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










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