China 3020 3040 routers

[w7bcw]

I have one of these routers, the 3020 and found out that movements on all the axii had some missing steps as has been reported
on this forum.
So I decided to do the filter cap mods as described elsewhere here but found that didn't help a whole lot since I still had missing steps
and after doing some more searching here found another mod adding a Schmidt trigger inverter chip from the opto outputs for steps to the drivers.
After this mod was done I found one of the axis was no longer moving in both directions so I must have zapped that driver chip.
Rather than replace the chip I decided to take some of the advise here and replaced the driver PCB with a Gecko G540. WOW what an
improvement, no missing steps at all !
So because of the way the Chinese driver PCB was designed and not using the guidelines for that driver chip as presented by the chip maker
some that decide to make the mods may find it may not help and others feel it did the trick but my opinion is replace that POS driver
with the G540 you won't regret it.

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[Alwaysintheknow]

I made the same replacement after fighting it for a year, runs like a champ now. May I ask what numbers you tuned your motors to, I'm using Mach3

Thanks in advance

[w7bcw]

12,700 steps per inch.
But need to increase the velocity from where I had decreased it. A bit too slow. I don't have
the acceleration or velocity numbers handy.

[shane94]

I just bought one of these Chinese 3040 machines and ordered the G540 as well. Is their a online "how to" to swap this over? Searched for awhile and cannot find it :/

[w7bcw]

I haven't found one either but it isn't difficult to make the replacement.
What I did was keep the power supply and spindle motor the same, mine was working ok and hasn't caused any
issues as of yet, I am not using the PWM spindle control or relay output to turn the spindle on/off. I used the cabinet too, I cut out the back side of the
cabinet and left an edge that is about 3/8" all around keeping the threaded holes
for mounting the cover. I then cut out a piece of 1/8" thick aluminum that mounts on the inside using #4-40 hardware, flat head screws up top
and pan head screws at the bottom. I also cut out reliefs for the cabinet screws that poke through when attaching the cabinet cover.
I mounted the G540 and spindle jack plus a 8 pin jack for limits and probe on the aluminum plate with the G540 above and other jacks at the
bottom. Along with the jacks is a fuse holder and a power cord grommet (power cord entry module would not fit). I re-used the X Y and Z 4 pin motor jacks
by removing the molex connectors and wiring jacks to the DB9's that came with the G540, this makes a short adapter (4 pin mic to DB9) that works fine and you
don't have to replace the motor plugs.

[w7bcw]

Oh forgot to mention that I mounted the fan inside of the cabinet at an angle that pushes air against
the back of the G540 for cooling.

[Fixittt]

The hardest part about the G540 is wirering the motors and not forgetting about the current limit resistor in the motor plug. G540 is a great stepper drive and a breaze to setup in mach.

[shane94]

I haven't found one either but it isn't difficult to make the replacement.
What I did was keep the power supply and spindle motor the same, mine was working ok and hasn't caused any
issues as of yet, I am not using the PWM spindle control or relay output to turn the spindle on/off. I used the cabinet too, I cut out the back side of the
cabinet and left an edge that is about 3/8" all around keeping the threaded holes
for mounting the cover. I then cut out a piece of 1/8" thick aluminum that mounts on the inside using #4-40 hardware, flat head screws up top
and pan head screws at the bottom. I also cut out reliefs for the cabinet screws that poke through when attaching the cabinet cover.
I mounted the G540 and spindle jack plus a 8 pin jack for limits and probe on the aluminum plate with the G540 above and other jacks at the
bottom. Along with the jacks is a fuse holder and a power cord grommet (power cord entry module would not fit). I re-used the X Y and Z 4 pin motor jacks
by removing the molex connectors and wiring jacks to the DB9's that came with the G540, this makes a short adapter (4 pin mic to DB9) that works fine and you
don't have to replace the motor plugs.

Thank you for taking the time to post that!