Re: [CAD_CAM_EDM_DRO] brushless servo drive?

and this;
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=3846354820
5" Sq. Brushless Servo Motor 1616 Oz-In

----- Original Message -----
From: Wm McNett
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Wednesday, October 20, 2004 11:55 PM
Subject: Re: [CAD_CAM_EDM_DRO] brushless servo drive?



Thanks, I see now that brushed is the path I'm going to take.

Bill

I'd seen some brushless on ebay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50924&item=3846335508
http://www.torquesystems.com/datasheets/brushless_servo_motors/bmr4400.pdf

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=50924&item=3847164728
http://www.torquesystems.com/datasheets/brushless_servo_motors/bnr3300.pdf

http://www.torquesystems.com/product_family_brushless.html




----- Original Message -----
From: Jon Elson
To: CAD_CAM_EDM_DRO@yahoogroups.com
Sent: Wednesday, October 20, 2004 10:38 PM
Subject: Re: [CAD_CAM_EDM_DRO] brushless servo drive?



Wm McNett wrote:

>What is needed to control a brushless servo?
>Brands?
>Gecko says "brush".
>
>
The Gecko 320 has 4 power transistors in it. The commutation is in the
motor. Standard brushless motors have 3 connected phase coils,
and so need 6 transistors to switch the current. The commutation or
sine-wave drive for these motors must be done in the drive, which
needs to know the exact motor position, ie. the relative position
between the magnets and the coils. Old-style brushless motors had
3 hall-effect sensors that sensed the location of the magnets, and signalled
the drive when to switch coils. Newer motors just have some kind of
encoder, not necessarily a standard A-B quadrature encoder with index.
They use this as a form of semi-absolute encoder to give both standard
encoder feedback as well as commutation information. All the manufacturers
have different, proprietary systems, which makes it VERY hard to have a
universal brushless drive.

I suspect this is a good part of why Mariss has not come out with the
Gecko brushless drive. I just worked on some Yaskawa drives and
motors, and they had yet another proprietary encoder scheme, and no
simple hall sensors or other obvious commutation scheme.

Jon



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]



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]