Re: [CAD_CAM_EDM_DRO] Re: Having problems with Lindsay design DRO... Could you please help?

Mike,
Just as a wild thought, did you use the transistor logic of Steve's
original design or ICs like I did?

When I was working on my design using ICs, I was advised by a couple of EE
designers to put "pull-up" resistors (I used 1K) on the inputs to my
buffers (the transistors are the buffers in this case) as the output of the
encoders is an open collector design. It might be possible the inputs to
the transistors are "floating" and causing the errors. I would not worry
to much about the speed of the computer as I am using a 486 DX 100 so that
should not be to much of a problem. For the power to the interface, did
you use an external power supply or internal from the computer? If
external is it "clean" and well filtered??? Did you use the 0.1uF bypass
capacitor as shown in "no_irq2.gif? This is another possible source of
noise on the line.

I am not an EE so what little I know in this area is purely by osmosis from
several people that I do know. One of the reasons that I went with the IC
setup was due to the problems I had getting the discrete transistors to
work in the first place:-{(

Another gentleman is also working on version 5 of Steve's program that will
give a beautiful "graphical" display on the computer and this will require
the use of the interrupt to minimize the error problem. Presently, I am
trying to find the time to get the board together and make it work. You
know how that goes though......so little time and so many projects that you
want to get done.

I personally like the program and find it very useful. At 11:33 PM 5/4/01,
you wrote:

>Well, I'm still stuck.
>I have adjusted the "Time" setting and it got a little better, but it
>still has alot of errors. If I go VERY slow, it will work fine, but
>that kinda defeats the purpose of the DRO.
>I have checked all the items mentioned, and they appear to be correct.
>I am using an old Compaq pentium 75 MHz PC.
>Could it be the cable between the black box and the computer?
>It doesn't appear to be damaged, but could this be the problem?
>I think a new cable will cost about $15. Should I just cut my losses
>and buy the pre-wired board from Camtronics and use the Kulaga
>software? (I really don't want to put $85 more into this if I don't
>have to.)
>
>Thanks for all your help.
>
>Mike
>
>
>
>
>
>--- In CAD_CAM_EDM_DRO@y..., "A. G. Eckstein" <axtein@s...> wrote:
> > Mike,
> > I also built my DRO using this system and my errors are low (so low
>in fact
> > that I have turned this feature OFF). You probably need to look at
>the
> > "TIME" function on the main menu and increase it. The program
>defaults to
> > 10 and I have set mine up to about 30 to minimize the error problem.
> > I used audio cable that has only one shield per cable and my
>longest cable
> > is approximately 5' long. Also, ALL grounds (electrical and
>shield) should
> > terminate at a SINGLE point to avoid ground loops. Also look around
>your
> > shop for something that may be causing spurious signals to get into
>your
> > system (fluorescent lights) etc that may be in close proximity to
>your
> > cables. Is your interface enclosed in a metal box (and grounded)??
> > Also look for possible poor electrical connections. Either
>mechanical or
> > solder joints can look pretty but be inferior when it comes to a
>good
> > electrical connection.
> >
> > Hope this gives you a good start on finding the problem, but if
>not; let me
> > know and we will try harder:-})
> >
> > At 11:34 AM 4/27/01, you wrote:
> > >Hello!
> > >I have built a DRO using the design provided by Steve Lindsay.
> > >I have used 360 cpi strips and encoders from US Digital.
> > >I have done my best to follow the directions provided.
> > >I did, however, not use the indevidualy shielded wire. I used a 4
> > >conductor with a single shield around the entire cable.
> > >It seems to have connectivity, but I get a huge amount of errors.
>I
> > >was trying to avoid buying the more expensive wire, but do you
>think
> > >this is the problem?
> > >
> > >Thanks,
> > >
> > >Mike
> > >
> > >
> >
> > Bubba
> >
> > OLDER THAN DIRT
> > Country Bubba
> > (Actually the inventor of Country and Bubba)
> >
> > axtein@s...
> > LaGrange, GA
> >
> > [Non-text portions of this message have been removed]
>
>
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Bubba

OLDER THAN DIRT
Country Bubba
(Actually the inventor of Country and Bubba)

axtein@...
LaGrange, GA

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