[Rimbaldo]

Hi! I've got a friend in my country that has an unused Gecko G540 driver that he wants to sell, but it's revision 4, not the latest, 8. What are the crucial differences on them? I'll use it in my Sieg X2 mill that I'm converting to CNC, so I'd like to know if this revision 4 would be ok, or are any flaws corrected in next versions that would make it not a good purchase.

Thanks!

[CoAMarcus]

Rimbaldo,

The main difference is the trimpot being located on the motherboard so you don't have to adjust the drives with the small trimpot that was on the G250X. Aside from that, we massaged the short circuit protection to prevent false positives and changed out the fuse from 7A to 10A in the process. Nothing too major and it will work just as well as a REV8 once it is adjusted for smoothness with the G250X mounted trimpots.

[john-100]

I would give Geckodrive a call to be 100% sure

looking at the manuals for the two versions

G540 REV-8 - Stepper Drives - Motor Control Manuals - Support Geckodrive

http://geckodrive.com/gecko/images/c...4%20MANUAL.pdf
http://www.geckodrive.com/images/cms...8%20Manual.pdf

they are basicaly the same apart from the lastest REV8 having the driver tuning pots move from the driver boards
and are now the main board that acts as the breakout board

the down side is earlier boards are not compatable with the latest versions - something to watchout for when buying spares


John

PS

I see Marcus was quicker with his reply

[Rimbaldo]

Rimbaldo,

The main difference is the trimpot being located on the motherboard so you don't have to adjust the drives with the small trimpot that was on the G250X. Aside from that, we massaged the short circuit protection to prevent false positives and changed out the fuse from 7A to 10A in the process. Nothing too major and it will work just as well as a REV8 once it is adjusted for smoothness with the G250X mounted trimpots.

Thanks Marcus!

Is it advisable/possible for me to change the fuse myself from 7A to 10A? Or it´s not possible in this version of the board?

Also, John above said something about spares... If something gets faulty along the way, is it possible to have it fixed? As it´s an earlier version board?

Thanks a lot!!

[CoAMarcus]

You can leave the fuse alone. I believe the short circuit protection circuit is meant for the small differences in resistance between the two types of fuses so it may now work correctly if a different one is used. We can always try to fix older drives but if there is extreme damage to the G540 it would not be fixable. We no longer have the older motherboards in stock and the G250XR2 that are inside that revision are not compatible with the REV8 motherboard.

[Rimbaldo]

You can leave the fuse alone. I believe the short circuit protection circuit is meant for the small differences in resistance between the two types of fuses so it may now work correctly if a different one is used. We can always try to fix older drives but if there is extreme damage to the G540 it would not be fixable. We no longer have the older motherboards in stock and the G250XR2 that are inside that revision are not compatible with the REV8 motherboard.

Thanks Marcus!! One more doubt, if you could answer it would be nice.
I plan in the future add a 5th axis. I saw in some posts that is possible to add an extra g251 externally to the g540, and another parallel port, to make the g540 support the 5th axis possible. In this older revision, would It still be possible, doable, as of today?

Thank you one more time

[CoAMarcus]

Yeah you can do that. There's a few ways of adding a fifth axis: The first one is to use a second parallel port or USB and a motion controller like the SmoothStepper to output STEP and DIRECTION.

The other way is a bit less "professional" looking and only applies if you have a slaved axis - you can cut into the DB25 cable and splice into the STEP and DIRECTION lines for your slaved axis and run those and GND to the G251X STEP, DIR, and COMMON pins. That drive would then perfectly synchronize with the drive it is receiving the same signals for. If you need to mirror the movement of an axis in this way you would just need to swap PHASE A and PHASE /A.

[aystarik]

Marcus,
Is it possible to get the schematics of REV4 board (at least the part near the LTV846 optocouplers)? I've got two units which move the mill (so the part around drives work), but fail with either charge-pump input or switch inputs. I see the "KT7" in SOT-23 blown on both boards near the "inputs" optocoupler. I identified it as BAV23A, am I right? It's pity that you've run out of replacement boards, it probably should have been easier to just swap in new boards...
Thanks in advance,
Alex.

[CoAMarcus]

Alex,

Yes, that is correct. Those are BAV23A diode arrays in SOT23 size. I will see if I can dig up an older schematic.

[aystarik]

Marcus, any luck with schematics?

[CoAMarcus]

Hey, sorry for the delay. The schematic that I have is an older revision that did not have those BAV23s on it so I have to generate a new one from our design file. I will put it up as soon as I have it.

[aystarik]

may be handwritten piece would be faster?

[aystarik]

Marcus,
Happy New Year!
Any progress with schematics?

[aystarik]

Hi Marcus,
ping?

[aystarik]

Hi Marcus,
It's been more than a year... You say geckodrive is any better than chinese at helping customers?
Regards,
Alex.