Re: BOSS5 to Mach2/Gecko

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