RE: [CAD_CAM_EDM_DRO] where's the torque ?

Dave:

The "inches" in "ounce-inches" are related to the moment arm(or radius), NOT
the circumference.

A 296 oz-in motor will supply 296 ounces of force at a 1" radius. When used
with a 1.25" pitch diameter gear(I think this is what you were saying) it
will have a 0.625" radius(center of rotation to the pitch diameter circle),
so it will supply 296/0.625= 473 ounces of force at this radius.

Andy Wander
Verrex Corporation

-----Original Message-----
From: turbulatordude [mailto:dave_mucha@...]
Sent: Monday, May 16, 2005 12:08 PM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] where's the torque ?

I've been running thru the torque numbers for motors and seem to be
missing something.

A 1-1/2hp treadmill motor with 5,100 RPM has 296 oz-in torque.

On a rack and pinion. and using a 1.25" pitch, we can round the
distance per gear rotation to 4 inches. 1.25*pi=3.926, so 4 is close
enough.

When we calculate for a leadscrew, we come back to inches of table
movement. do we also do that for routers ?

I mean that we put on a 600oz-in motor, then multiply that by 5TPI to
get 3,000 OZ-IN that would mean 3,000 per inch, no ?

That would make the motor 296/4=74 oz-in if it were direct drive.
using 6:1 pulleys would then multiply that up to 444 oz-in. or 444 per
inch ?

The leadscrew moves 1 inch per 5 motor rev or 0.2" per rev while the
rack moves 1.5 revs per in. Gearing up to get 5 rev's per inch would
mean a 20:1 pulley to the 1:4 rack gear. If course that would
multiply the 296 by 5 for 1,482oz-in.

Since I've seen routers and plasma cutter run with much smaller motors
and much smaller ratios (3:1 on a 350 oz-in stepper) it seems I'm
missing something.

Anyone see my mistakes or what I've overlooked ?

Dave








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