Re: New Article Posted

Greetings all,

I have been reading all of the messages following Phil's post as
well as of Ballendos.

Both have recently introduced Stepper Drivers using the SLA7062 chip.

I am a customer of Dave's at Hobby CNC and until about an hour ago,
I was in the Yahoo Group "HobbyCNC", which requires you to be a
customer to join, and is the only method of getting tech support.

By the way, Dave's boards also use the 7062 chip, and it seems from
postings that Dave is insinuating that Phil and Ballendo/CNCResource
have stolen his design.

In an attempt to learn more, I posted a question on the HobbyCNC
group asking Dave to discuss what he sees as the advantage of his
board as opposed to these new competitors.

I also asked if Dave was supplying boards to Ballendo, since I
couldn't see inside the box and if he was indeed selling to them,
their complete system would be a known quality and a safe investment.

I was completely respectful and asked the question in the context of
an existing customer who is (now "WAS") willing to stick with
HobbyCNC even though Phil offers a pre-built solution for just a few
dollars more, and Ballendo a Plug-and-Play system at a very fair
price.

In any case, with no response or reply, it appears Dave simply
kicked me out of the HobbyCNC group. Guess he is afraid customers
will jump ship if they find out about affordable alternatives.

I do know for a fact that Dave is not particularly committed to
customer service. For instance, if you blow a 7062 chip, he sells
replacements for $15 (reduced to $12 just this week when I posted
that CNCResource sells them for $8.50).

Being that a great number of postings on the HobbyCNC group are by
customers who need replacement 7062s, perhaps Dave kicked me out
because I disrupted a major source of income for him??? I'm
guessing the $3 reduction is costing him a couple hundred a month.
At least.

Also, if you have a problem and ask specific, intelligent and
reasonable questions, Dave's answer is always to "reflow your solder
connections" with no adequate answer to the specific questions.
Other than the assembly instructions, the only thing Dave will tell
you is to reflow and set the Vref.

He won't answer about other potential test points on the board.
He won't answer about ground potential issues or state whether or
not optoisolation is necessary with his product even though at least
2 people in one week had board traces burn up when connected to a
PC.
He won't discuss failure modes or state a protocol or order of
accomplishing certain tasks to protect the board.
He has no interest in creating a FAQ.
Basically, if it isn't in the (meager)instructions or solvable by
reflowing the solder, once he has your money, you're out of luck.
Well, to be totally honest, if you ask questions he is somehow
incapable of answering, he might offer to buy back your board to
silence you, as NOT being a customer, he can turn off your group
membership and nobody would read about your problem with his design.

Note also that Dave refuses to provide schematics for his boards.
Anybody who buys a HobbyCNC board is easily capable of tracing out
the circuits, and with "Eagle" or similar, just by placing the
components and then making a few corrections on the Autorouter, you
can duplicate the schematic fairly easily and make your own board.
Hey, maybe some of the vulnerable "burning" traces could be beefed
up this way?

Interestingly, copyright law allows for replacement parts, or there
would be no such thing as Auto Zone or NAPA. I'm wondering how much
interest there would be in replacement HobbyCNC boards?...many have
burned when the SLA7062s explode.

Based on the recent postings on this, and I suspect other forums,
and the childish behavior of turning off a group membership for
asking respectful and appropriate questions he didn't like, I must
STRONGLY RECOMMEND that if you intend to be purchase a stepper
driver, skip Dave and instead patronize either Phil or Ballendo,
depending upon how you wish to complete your system.

Respectfully,

Tom








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

>
> Dave,
>
> Sure.
>
> Sense resistor value was as suggested by Allegro app engineer. You
> probably know Matt Honji?
> .2 ohm for "variable" usage over the range of the device.
>
> I've used everything from .03 to .68 ohm; depends upon the use and
> motors. (not what you're using<G>)
>
> Ballendo
>
> P.S. Suggesting that folks using .2 Rs means they've copied you

(at

> least that seems to be what you're implying about Phil? denies the
> fact that given a similar problem, and using the same device,
> talking to the same experts, it will be likely that some things

will

> match.)
> Should we assume that you've used Dale LVR-3's because Mariss

does?

> Or simply that from the sources "typically" used by small-scale
> electronics mfrs. this is the best value?
>
> BTW, we don't use the same layout, pots, caps, H/S or SIPs as
> HCNC...
>
> P.P.S. It's worth noting that in the new Allegro chips with

integral

> Rs, the value used is lower as the amperage goes up. Not really a
> surprise; but worth paying attention to at any rate. So now a

repeat

> of my question to you: Do you have boards for yours yet?<BG>
>
>
> >In CCED, "Dave Rigotti" <drigotti@> wrote:
> >Just looked it up...
> >Phil purchased a 4 axis driver board from us on October 30th,
> >2005. This explains the same value sense resistors we use. Not
> >sure what values Ballendo's version uses. Maybe he can tell us?
> >Dave Rigotti
>