CAD CAM EDM DRO - Yahoo Group Archive

Re: motor sizing vertical slide EDM

Posted by tomp-tag
on 2006-05-12 14:41:05 UTC
Mariss,
Your's are alway more complicated ;-)
(math & physik challenged here )

>Message 7
> From: "Mariss Freimanis" mariss92705@...
> Date: Thu May 11, 2006 8:54am(PDT)
>Subject: Re: motor sizing vertical slide EDM
>
>TomP,
>
i f a = v/t then the 40 mS is the t
and i was just looking at the linear acc of the driven axis
never looked much at the motor ( rotary) itself
>Not quite sure how to reconcile "15Krad/sec^2" with "40mS response
>time" and "8X acceleration that I stated".:-)
>
arrg radian ( tomp looks up radian... think it's like 56 degrees or so yeh?)
yeh 57.295, angle subtended by circumference equal to the radius....
so 15000rad/s^2
is near 262 revs/sec^2
meaning, a blurr, and a real kick when it accelerates... ok
>I use 15Krad/sec^2 as very respectable acceleration goal on a
>servomotor. This reflects a very good motor torque to inertia ratio.
ok, so it's a cap
>This value is motor-bound in that all mechanism acceleration rates
>will be limited to or below this value.
>
2"/sec = 120"/min ok
I'm thinking I can direct couple now
looking at R+W http://www.rw-couplings.com/
>You said the goal is 2"/sec on a 5TPI screw (600 RPM) reduced from
>the motor's 3,000 RPM via 5:1 reduction.
no more 5:1 see above, just truncate the top rpm and take the slow
speed response and full torque at lower velocity range ( whatever's
left over after getting the best slow speed response )
>
Yep, the acc time would be 1/2 my design limit ( thats good )
(I hoped for 40 and you say 20, kewl )
>Using that accel rate, the motor will take 21mS to reach 3,000 RPM.
>The linear velocity will go from 0 to 2"/sec in the same period of
>time if I understand your mechanism correctly.
>
this math is all new to me..
v = 120"/min
t = 21ms = .021S
a = v / t
= 120 / .02
no, in seconds.. ( inches per seconds and acc time in seconds.. )
= 2 / .021
= 47.61904761904762 ???
anyway, the same magnitude area where you were..
>Solving for "a" (a = v / t) gives 95.5"/sec^2 or 0.249 G (G =
>384"/sec^2).
>
but it seems to be .126G ( 47.5"/S^2 / 384 )
huh? what happened to the 9G slam we had yesterday??
>The power needed to accelerate a 700lb mass at 0.25G to velocity of
>2"/sec is only 39.5 Watts, the energy invested is only 0.83 Joules.
0.83 joules! ???
1 joule = 1 watt second
= 100V at 1 amp for 10mS
ssome magnitude problems here (likely on my end )
but the jist is
the motor I suggested before is WAY outta line, right?
>
>Mariss
thanks
TomP

Discussion Thread

tomp-tag 2006-05-10 11:11:08 UTC motor sizing vertical slide EDM Graham Stabler 2006-05-10 15:02:43 UTC Re: motor sizing vertical slide EDM Mariss Freimanis 2006-05-10 16:23:36 UTC Re: motor sizing vertical slide EDM Marcus 2006-05-10 19:53:52 UTC Re: [CAD_CAM_EDM_DRO] motor sizing vertical slide EDM tomp-tag 2006-05-11 06:51:51 UTC RE: motor sizing vertical slide EDM tomp-tag 2006-05-11 07:58:55 UTC Re: motor sizing vertical slide EDM Marcus 2006-05-11 08:09:42 UTC Re: [CAD_CAM_EDM_DRO] RE: motor sizing vertical slide EDM Mariss Freimanis 2006-05-11 08:54:51 UTC Re: motor sizing vertical slide EDM Graham Stabler 2006-05-11 09:34:00 UTC Re: motor sizing vertical slide EDM tomp-tag 2006-05-12 14:05:31 UTC Re: motor sizing vertical slide EDM tomp-tag 2006-05-12 14:41:05 UTC Re: motor sizing vertical slide EDM tomp-tag 2006-05-12 14:43:19 UTC Re: motor sizing vertical slide EDM tomp-tag 2006-05-12 14:46:08 UTC Re: motor sizing vertical slide EDM tomp-tag 2006-05-12 14:46:27 UTC Re: motor sizing vertical slide EDM tomp-tag 2006-05-12 14:52:24 UTC Re: motor sizing vertical slide EDM Graham Stabler 2006-05-12 15:22:22 UTC Re: motor sizing vertical slide EDM Mariss Freimanis 2006-05-12 18:06:56 UTC Re: motor sizing vertical slide EDM Jon Elson 2006-05-13 09:27:37 UTC Re: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM Graham Stabler 2006-05-13 12:59:52 UTC Re: motor sizing vertical slide EDM Marcus 2006-05-13 19:27:50 UTC Re: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM wthomas@g... 2006-05-13 20:21:17 UTC W.E.T.??: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM John Dammeyer 2006-05-13 23:00:01 UTC Bender question wthomas@g... 2006-05-14 00:10:27 UTC W.E.T.Re: [CAD_CAM_EDM_DRO] Bender DRO question some OT ballendo 2006-05-14 04:18:30 UTC Re: Bender question (long reply) Wayne Weedon 2006-05-14 05:34:23 UTC Re: W.E.T.??: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM turbulatordude 2006-05-14 06:17:23 UTC Re: Bender question (long reply) John Dammeyer 2006-05-14 10:39:39 UTC RE: [CAD_CAM_EDM_DRO] Re: Bender question (long reply) Marcus 2006-05-14 12:39:51 UTC Re: W.E.T.??: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM ballendo 2006-05-14 14:00:33 UTC No add photos button?!? wasRe: Bender question (long reply) Graham Stabler 2006-05-14 14:06:44 UTC No add photos button?!? wasRe: Bender question (long reply) ballendo 2006-05-14 14:16:20 UTC 3-in-1 back gauge photos at DIY-CNC was Re: Bender question (long reply) ballendo 2006-05-14 14:18:12 UTC Re: Bender question (long reply) John Dammeyer 2006-05-14 14:54:29 UTC RE: [CAD_CAM_EDM_DRO] Re: Bender question (long reply) ballendo 2006-05-14 14:58:49 UTC OT thank you re No add photos button?!? wasRe: Bender question (long reply) Jon Elson 2006-05-14 15:02:32 UTC Re: W.E.T.??: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM ballendo 2006-05-14 15:22:20 UTC Re: Bender question (long reply) ballendo 2006-05-14 15:33:56 UTC Re: Bender question (long reply) ballendo 2006-05-14 15:38:28 UTC ELS? was Re: Bender question ballendo 2006-05-14 15:45:06 UTC W.E.T.??: [CAD_CAM_EDM_DRO] Re: motor sizing vertical slide EDM wthomas@g... 2006-05-14 17:14:45 UTC Re:W.E.T. [CAD_CAM_EDM_DRO] Re: Bender question (long reply) John Dammeyer 2006-05-14 19:59:30 UTC RE: [CAD_CAM_EDM_DRO] ELS? (long answer) BobWarfield 2006-05-15 15:47:52 UTC Re: Bender question ballendo 2006-05-15 16:52:29 UTC Re: Bender question wthomas@g... 2006-05-15 22:22:35 UTC W.E.T. [CAD_CAM_EDM_DRO] Re: Bender question tomp-tag 2006-05-16 14:48:18 UTC Re: motor sizing vertical slide EDM