Re: cheap retrofit with the Allegro UCN5804B chip

keizer.peter <keizer.peter@...>

Hi Walt,

Thanks a lot for your reply.

I've also contacted the original poster of this idea, Gelandangan, and he
also replied to my mail. I've asked him in which way he used the chip
and he came up with this reply:

That post was made almost a decade ago! I have not used the F1
controller for 8 years now.
Ok, what I did at the time was to figure out the point where the native
motor driver of the F1 gets its pulse signal (connectors x34, x35,
x36).and use the UCN5804 chip's output to feed to it.So in effect, I
get the PWM of the native driver, yet using the Step/Dir translator of
the 5804 (5804 is not a PWM chip).To do this, simply wire the outputs
ABCD of the 5804 to the corresponding connector inputs ABCD of the
respective F1 connector input.
Now days, I use Gecko Drives to drive the motor, and I have replaced my
motors to much larger/stronger 300 ones.
Good luck!Gelandangan"

It seems like the way he used it is a bit different than the way you
described. But we'll sort that out.
I'll send him an email to ask whether he used it "plug and play" or the way you described it.
I'll also ask him if he's willing to contribute to this thread because it makes it easier to read for other people if all the information known about this subject is in one place.

Thanks a lot guys for helping me out!I really appreciate it.I'm looking
forward to test is as soon as my chips are delivered and i'm also
looking forward to make a tutorial for others!


p.s. i've also replied to the thread at EmcoF1Mill group.

--- In Emco_cnc_users@..., "cncwannabe" wrote:
> Peter,
> You should be able to find schematics in the files section of this or the F1 group. I'll summarize what you will find.
> There is a six pin connector for each axis on the F1 Stepmotor board. They are designated X34, X35, and X36. The pin #'s and labels for each axis are:
> Pin Signal
> 1 5V
> 2 GND
> 3 C
> 4 D
> 5 A
> 6 B
> The ABCD signals match the UCN5804B data sheet.
> You may need to add 5V pull-up resistors to the outputs of the UCN5804B. I don't know if the Stepmotor board provides them. Hopefully it doesn't have pull-downs. You may also need to provide an intermediate buffer (CMOS inverters would do) to provide some noise margin due to the Darlington transistor outputs of the Allegro part. You want the logic zero output to be well below 0.8V.
> The EMCO system uses the "two-phase drive sequence" described in the data sheet.
> Good luck with your conversion.
> Walt
> --- In Emco_cnc_users@..., "keizer.peter" wrote:
> >
> > Hi guys,
> > While searching for a cheap (an temporary) way to retrofit my F1 (and
> > maybe also the 5CNC) machines i found this old message here on the
> > beard:
> > "Hi
> > Funny, this seems to be the first post :)
> > A little background on my experiences.Okay, I own a F1 CNC mill for
> > about four years now.The native programming for the F1 is in a word
> > SUX.So, I look around and found the company WelSoft,its
> > and looked at their Wellmillconversion board. Simple
> > thing methinks, butgodalmighty aint they expensive!!!So, I do a little
> > research on the way the wellmillconnected to the emco. Having a circuit
> > diagram forthe F1 helps a lot :)
> > Lo and behold, I came up with a design that worksfor the past 3 years.
> > I use Allegro's UCN5804B chips for step/dir control,TurboCNC from DAK
> > engineering for the Gcode to Step/dir translator,DeskProto for STL to
> > GCODE translator andSolidworks for design.
> > If anyone need some help...
> > Gelandangan."
> > I have searched in google, i have read basically every message up here
> > and also the EmcoF1Mill group.But i couldn't find any good explanation
> > of how to do this.
> > It seems that it's possible to actually use the Emco stepdriver board
> > and the original drivers.Then you just hook up the machine to your pc
> > and use it with Mach3 or whatever and use it like that.
> > Is there anyone that knows how it works or can be done?
> > I've already ordered 3 of those chips on ebay, since they're very
> > cheap.I wasn't sure whether i needed 1 chip per axis, or one chip per
> > machine.
> > I hope one of you guys can help me out!
> > Thanks a lot in advance!
> > Peter Keizer.
> > (I'll be posting this same question in the EmcoF1Mill group.If we can
> > figure out how it works, i'll make a nice tutorial of it so others can
> > do it as well.)
> >

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