Re: Servos and Controller boards

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo" <ballendo@y...>
wrote:

> Tom,
>
> I think many would (and do) say the same thing about building a cnc
> machine...
>
> (Why build when I can buy a perfectly good one for a great price?)
>
> I hope your reply doesn't keep folks from trying. After all, if
> everybody only did what was "economical", we'd still be buying
> expensive CNC machines.
>
> We are the recipients of MANY folks who "work for free", and I hope
> that each one of them continues to find learning and sharing a
> worthwhile exercise, so that one day we can have as many servo
> options as we now have for steppers...
>
> Ballendo
>
> P.S. As "list mom" of the DIY-CNC group, I've heard a few "reasons"
> given in answer to the recent thread about posts at CCED. And

they're

> NOT all about moderation... Many have told me that they are
> frustrated by: asking a question for technical advice, only to get

a

> reply for a commercial product to buy. We're trying to build NEW
> options, NOT just continue with the old ones... (And "money" is NOT
> the only motivation.)
>
>
>

I did not make that post glibly. I would be the first one to
recommend that building vs buying is an indivdual choice. You noticed
I said "I would not attempt it". I have done closed loop controls
with servos and spent a good many years working with switching power
supplies that require loop calculations (that seldom are right). I
have had a top of a plastic TO220 FET embed itself in my forehead.
It's a mix of digital and analog design skills. The newer chips are
all SMT and make a hobby level design a challenge for anyone.

If someone posted and asked about designing and winding their own
stepper or servo motors what would you advise? Each person has to
evaluate their skill level and decide if the effort (and probable
failure) to build something that can be purchased for 65 bucks is
worth the "learning" experience.

I think there is a subset of the membership that lives vicariously
through the actual builders and can dream up all kinds of interesting
engineering projects. Like I have said in the past some of
these "projects" are solutions looking for a problem.

If someone is looking to dive into the guts of doing a power servo
design they should slide over to the OSMC (Open Source Motor
Control). There you can rub shoulders with guys that have already
tackled the problem of DIY servo controllers, brushless DC (BLDC)
controllers and AC servo control.

One of our responsibilities (sounds noble huh!) is to help guide the
new persons through the maze. Part of that is to take our experience
and keep people from heading off down a rough road and maybe loose
them as part of our community. We have people here at all levels in
the multitude of skill sets needed to build their own CNC machine.
After reading hundreds of posts about something as simple as an
unregulated power supply and the all the calculations, I just get the
drift that the electronics design skill set is not possessed by the
majority of the builders. Maybe we need a "star" rating system like
they do on DIY TV. Building your own power supply is ** while
designing a closed loop servo for power control is *****.

I could go on and on but I have to go now. I am working on building
my own blender. I am on a limited budget and the commercial blenders
are too expensive; besides I need the learning experience and I have
a CNC mill that I can turn parts out on and show my wife why I spent
all that time building it :-O