Re: Dro

At 12:31 AM 02/23/2000 -0000, you wrote:

>From: "Terry May" <tmay@...>
>
>For Art Eckstein,
> Art I read your post on the 9th about the servo motors you bought
>from Goldmine Electronics and thought it sounded good. I ordered some
>and just got them in yesterday. I'm am very interested in any details
>you care to share about your installation and I have a couple of
>questions right off the bat. First you mentioned getting bearings for
>the motor shafts from goldmine also, is this the bearing in their
>catalog numbered G1558 that they say has an ID of 7/32"?

Thats the bearings! But as posted earlier, it appears they have no more.
Also as I posted this week, the bearings in the motors have two different
OD's so if you are planning on useing them for your encoders, you will have
to have a stepped hole to accomodate the bearings or find another source
suitable. However if you can get these bearings, they have a 5mm ID like
the shaft of the motor. For new shafting, I ordered a 3' piece of 5mm from
MSC after I had gotten a 7/32" piece! Need a 7/32" dia drill rod about 35"
long:)

>It's the
>only one I saw in their catalog. My other immediate question is which
>colors on the encoder leads correspond to the A & B outputs on the
>Linsay schematic? My motors have red and black which I assume are pwr
>and grd and also blue and yellow leads.

Correct again, Red=+5V, Black=gnd, and the blue and yellow are the
quadrature outputs. Don't worry if you hook them up backwards (yellow and
blue that is) as the software can change direction if necessary (At least
using Steve's program)

> Again I would appreciate any info you may be willing to share. If
>you prefer to go off-list my email is tmay@....

As far as going off list, I will be happy to correspond with you or others.
I have shared with some, my "sketches" in Acad that I have for the building
of the blocks and also for the changes that I have made to the electronics
for this project. Hopefully, I can get some pictures made this weekend and
will be posting to my web site as soon as I can get the pictures made and
my web site re-generated. If all goes in accordance with the plan and the
plan works, that should be by the end of the weekend and I will post the
URL here for anybody that is interested.

> By the way if anyone else is interested Goldmine also has another
>motor with a physically smaller encoder but it is only 400 lines.

This is true, but to get finer resolution, you need either more lines, or a
smaller shaft diameter. As related earlier, I am now looking at physical
diameters of the shaft < 0.100 inches for a resolution of 0.0001 inches. So
if you were to use the 400 line encoder, (without some form of
multiplication of the signal), you would be looking at a diameter of
400/1000*0.100" or less than 0.04" in diameter and that would make a very
weak shaft and also very subject to slipping. Personally, I wish the
encoders had 2K lines!!

>Thanks
>Terry

OLDER THAN DIRT

Country Bubba

(Actually the inventor of Country and Bubba)