Re: BOSS5 to Mach2/Gecko

Evening Brady,

I did alot of research into the project and would be glad to share all
of the information that i have, I will gather all of the schematics
for the "return energy dump circuit" as well as anything else as far
as power supply calculations and part numbers for the stuff i used.
i wasnt an electrical genius before i started the project and i'm
still not, but it is a task that can be done if you take your time
and use this group for any questions.there is another site that has
been created for gecko drives, you may want to investigate that site
for further information about power supplies and related stuff. i
have to say that i am really glad that i bought geckos, not because
of their price but because the owner of the company always had time
to talk to me personally and helped me to understand what was
happening and how to correct it. that in itself is unheard of by any
other company that i have ever dealt with.as far as the full or half
or micro step settings go, i tried them all. i'll have to check my
notes to verify which worked best but one thing that i do remember is
this. in talking with mariss of gecko drives we came to the
conclusion that the bridgeport steppers of that vintage may not be
able to provide a really smooth "unsteppy like" motion at lower
speeds because of the motors inherent characteristics i believe the
term he used was "linearity".the gearing on the mill was left as it
was from the factory, belt driven, stock ratio.

I'll e-mail you the stuff sunday night, any other questions feel free
to ask, i'll be glad to help.

Jeff















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

>
> Thanks for sharing the info, Jeff.
>
> I am not opposed to going the Gecko route with another power

supply.

> Would you be willing to share your power supply plans with me? I

had

> a book on power supplies...and no lie, the dog ate it! Sounds like
> your PS would be perfect for my machine as well. Also, info on
> the 'return energy dump circuit' would be helpful too as I am no
> electronic expert. I am willing to compensate you for your sharing

if

> need be, off-list.
>
> I do CNC routing and CNC plasma cutting and I want to take some of
> the 3D router files that I have and run them on the BP. I can't do
> that right now with the factory setup.
>
> Thanks!!!
> -Brady
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "ja_erickson"
> <ja_erickson@y...> wrote:
> >
> > Evening All,
> >
> > I have been doing my Boss5 retrofit project for some time now and
> > have done exactly what you want to do with the exception of the
> power
> > supplies. i built my own 72 volt/7 amp toroidal power supplies

and

> > used gecko g210's with pretty good results. I rewired the

original

> > bridgeport steppers to run in "half winding" which will provided
> more
> > low speed torque. according to my bridgeport manuals the original
> > steppers were designed for 68 volts and 6.8 amps which is right

on

> the
> > upper side for the geckos. I was concerned about it until i spoke
> to
> > the owner of gecko drives and he assured me that 72 volts and 7

amps

> > would be alright for the 201/210 series. he also warned that it
> would
> > be WISE to incorporate a "return energy dump circuit" in order
> > to protect the drive against any "returned energy" from the

motors

> > during sudden stops.neither the drives or the motors ran hot so
> fans
> > for the drives were not needed.the campbell breakout board is a
> must
> > have item becuase it really provides alot of interfacing in a
> > relatively small footprint, well worth the cost. motor tuning

with

> > mach2 went really smooth, just dont expect the machine to move

like

> a
> > new c.n.c., the machine would lose steps if the accelerations

were

> to
> > great and i think i could achieve 60-80 i.p.m. reliably.however
> there
> > was a problem with the system in the end where any feedrates

below 4

> > i.p.m. were very steppy, by this i mean you could put your hand

on

> > the table and actually feel the motors step. i couldnt have that
> > because i was afraid of tool marks on the workpiece. i talked

with

> > the owner of gecko drives and he helped me all he could to

rectify

> > that situation but we couldnt get rid of that steppiness. if that
> > situation doesnt bother you then i wouldnt hesitate to retro it.
> >
> > Jeff