Re: [CAD_CAM_EDM_DRO] Re: Check my math and reasoning....

Brady,

Just one more question. What is the name plate voltage on your stepper
motors?

Bob Campbell
Bob@...
www.campbelldesigns.com
Breakout board
THC board sets
CNC router plans
Stepper Motors
VisualMill Basic

----- Original Message -----
From: "braidmeister" <braidmeister@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Monday, June 27, 2005 5:28 PM
Subject: [CAD_CAM_EDM_DRO] Re: Check my math and reasoning....


> Thanks Bob. What would be the result of running the larger ampacity
> supply (@70v) over one that had less amps for the steppers?
>
> Drives will be 202s for the steppers and 320/340s for the
> servos...same 70v requirements just different ampacities.
>
> -Brady
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Robert Campbell" <bob@c...>
> wrote:
>> Brady,
>>
>> You need to separate the calculations for stepper motors and servo
> motors.
>>
>> I would suggest that you build two power supplies. One for the
> stepper
>> motors and one for the servo motors.
>>
>> One of the limiting voltage factors will be the drivers that you
> are going
>> to use. The Gecko drives have an 80 volt limit. I would keep it at
> about 70
>> volts.
>>
>> I would recommend that you look for 100 volt capacitors. You can
> always hook
>> them in parallel to get more capacitance.
>>
>> Bob Campbell
>> Bob@c...
>> www.campbelldesigns.com
>> Breakout board
>> THC board sets
>> CNC router plans
>> Stepper Motors
>> VisualMill Basic
>> ----- Original Message -----
>> From: "braidmeister" <braidmeister@y...>
>> To: <CAD_CAM_EDM_DRO@yahoogroups.com>
>> Sent: Monday, June 27, 2005 5:04 PM
>> Subject: [CAD_CAM_EDM_DRO] Check my math and reasoning....
>>
>>
>> > OK gang,
>> > I am trying to piece together my power supply and have a few
>> > questions regarding the rated voltage for a capacitor. I am
> finding
>> > that most use 50v caps and they are cheap and available...I am
>> > wondering at this point if I am missing something...here's where
> I am
>> > and where I want to go with the PS:
>> >
>> > I am running Sigma N42 motors on the Bridgeport and the manual
> says
>> > that they are 6.8A. I would like to build a power supply with
> enough
>> > juice to power these 3 steppers AND an 11A Servo for the 4th axis
>> > down the road. I will eventually need to run 4 of these 11A
> servos @
>> > 70v ~ so I am thinking why not just build one supply and be done
> with
>> > it?
>> >
>> > Right now I have 2 50v (what decal says on each...but advertised
> as
>> > 55v when I bought them) 800VA torid transformers. I bought 2 at
> the
>> > time so that I would have enough amperage to run the 4 servos. Now
>> > comes the question of capacitors...I need caps are rated by
> voltage
>> > after being rectified, right?...In this case at least 80v...not
> 50v,
>> > right??? I searched around on here and didn't see any reference to
>> > this.
>> >
>> > So...If my math is correct, I will need (using the servo motor
> draw
>> > as a guideline) Assuming 50v rectified to 70v by the 2 torids:
>> >
>> > 44Amps * 67% (from Campbell's pdf) = 29.5A
>> >
>> > C= (80,000 * I) / V)
>> > (80000 * 29.5) / 70 = 33691 uF
>> >
>> > Could I get away with 3 P10653-ND from DigiKey? They are 12,000
> uF @
>> > 100v +/-20%.
>> >
>> > Did I do my math right...or am I missing something???
>> >
>> > Thanks!!!
>> > -Brady
>> >
>> >
>> >
>> >
>> > 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@a...,
>> > timg@k...
>> > Moderator: pentam@c... indigo_red@q... davemucha@j...
>> > [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
>> >
>> >
>> >
>> >
>> >
>> >
>
>
>
>
> 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
>
>
>
>
>
>