[tauntdesigns]

I haven't had time to fully look over the pdf's, but I did notice a little something.

On page 3 of the G251, under the current set resistor, where it talks about I-set(p25) and signal gnd(p30)

I can't wait to get a couple of these drives for my lathe!!!!

Hoping for the best,
Jack

[skmetal7]

Okay, we ran our first panel today and will be testing it tomorrow. I will post pictures of it and the G540 with its non-anodized can tomorrow morning some time. I have been writing the manuals for the G250 and G251, and have attached them for you all to look at. Please let me know if you find any typos or stupid mistakes in them, but they should be pretty much done. Thanks, and enjoy!

Marcus Freimanis

you have the G250 in the G251 manual, its mentioned in the current set resistor info. some ppl might me a little confused

[Mariss Freimanis]

Thanks for catching the G251 typo. We have a lot of stuff going on right now.

Mariss

[Mariss Freimanis]

skmetal7,

We decided to simplify a few things seeing as how the G250 / G251 are a 'clean sheet' new design.

The current set resistor on all of our other drives uses a semi-complicated formula for selecting a current set resistor. We decided to cut through this complication and make it very simple. 1K equals 1A.

You want 2.2A of current for a motor; uses a 2.2K resistor.
You want 3.3A of current for a motor; uses a 3.3K resistor.
You want 1.0A of current for a motor; uses a 1K resistor.

Simple as could be.

Mariss

[kiwibum]

Please let me know if you find any typos or stupid mistakes in them, but they should be pretty much done. Thanks, and enjoy!
Marcus Freimanis

I've spotted one for the G251 manual.
In the paragraph bellow:
"(TERM. 4) CURRENT SET"
replace G250 with G251 3 times.

Also the board measurements don't seem correct, looking at a ruler it's just way too small to be real:-).

One question about putting in fuses for the supply line to the drive.
"CAUTION! Never put a switch on the DC side of the power supply! This will damage, if not destroy, your drive!"
Wouldn't having a fuse cause the same problem if it blew from fatigue (age) rather than excess current draw?

Finally, am I correct in assuming that "(TERM. 11) DISABLE" is for Emergency Stop?

thanks, really looking forward to seeing these in the flesh.
Steve

[phomann]

Finally, am I correct in assuming that "(TERM. 11) DISABLE" is for Emergency Stop?

No, not just EStop. It is very convenient to use a manual switch as well so that the drive can be disabled and the axis adjusted manually, say for setting a home position. I do this all the time on my Taig mill.

Cheers,


Peter

[kiwibum]

No, not just EStop. It is very convenient to use a manual switch as well so that the drive can be disabled and the axis adjusted manually, say for setting a home position.

Very cool, hadn't thought of that. Just keep seeing more and more reasons to get a set.

Is anyone doing a 3 axis board with optical inputs/isolation for mounting 3 G250's? I'm going to be running mine from a Laptop and from what I've read will need that to get the correct 5vTTL voltages.

[dmauch]

I built a 3 axis system using the G251's which are the same as the G250 except that they don't have the heatsink and have a different connector.
The G251's are not optically isolated however, in 99% of the applications you woul;dn't need opto isolators.
The G251's with read any signal down to 3.2V so it should work with any pc.

[CoAMarcus]

Very cool, hadn't thought of that. Just keep seeing more and more reasons to get a set.

Is anyone doing a 3 axis board with optical inputs/isolation for mounting 3 G250's? I'm going to be running mine from a Laptop and from what I've read will need that to get the correct 5vTTL voltages.

The G540 will have everything optically isolated when it is released. The G540 will be able to augment the G250 into everything the price it is sold at and the size it is prohibits currently.

Also, the manual has been fixed from those two errors you guys found. I guess that is what happens when you think you are just so clever with copy and paste... ;-)

Marcus Freimanis

[lagfish]

Should I use a breakout board with the G250s? From my understanding, breakout boards just make connecting to the PC, limit switches, E-stop easier, and can also provide opto-isolation. But since it seems it's easy to do all those with the G250s, should I still get a breakout board for them?

[CoAMarcus]

We always recommend using a breakout board because of isolation. It is always a good idea to use one. I know there are several manufacturers that will be releasing breakout boards for the G250s and G251s or entire packages with them already in there, so it should be very easy for you to do.

Marcus Freimanis

[CoAMarcus]

Okay, after a long wait, I have a lot of good stuff for you guys. I have attached a bunch of pictures and an updated manual for the G251. We are currently testing all of the G250s that we ran, and should be able to go into full production some time this week. Enjoy!

Marcus Freimanis

[phomann]

Okay, after a long wait, I have a lot of good stuff for you guys. I have attached a bunch of pictures and an updated manual for the G251. We are currently testing all of the G250s that we ran, and should be able to go into full production some time this week. Enjoy!

Marcus Freimanis

Hi Marcus,

The manual for the G250 states;

This input programs the G250’s current output to the motor windings. The G250 will accommodate motor winding currents from 1
to 3.5A and 0.3 to 2A. The G250 uses a linear current set formula, meaning that if your motor is 1.5A you will use a 1.5K resistor;
if your motor is 3A, you will use a 3K resistor, etc.

On the larger drives, i.e. G201, the low current range is selected via a jumper. How is the low range selected on the G250, G251?

Cheers,

Peter.

[phomann]

Marcus, Mariss,

I've noticed that the pinnouts for the G250 in the Rev5 manual have changed, making it no longer compatible with the G540 mother board.

The differences as I see it are;
Pin Original Rev 5
------------------------------
26 Aux VDC Step
28 Step Do not Use
------------------------------

Apart from the step pin moving from pin 28 to pin 26, the Aux Vdc pin has been replaced with a Do not use pin. It was my understanding that the Aux Vdc pin was for powering opto-isolators for the step/dir pins as shown on the G540 schematic.

Can you you confirm that the change is correct, that pin 28 cannot be used, and if so, do the optos now need an external supply?

Cheers,

Peter.

[skmetal7]

yay! looks good. so are some boards green and some blue? i like the blue ones have any pics of the g251?

are all the components placed using the pick-and-place machine?

that g540 looks soo awesome! and so compact, just throw it in a controller box and you're done! ok maybe not throw, but you get what i mean

cant wait!!

[skmetal7]

(TERM. 5) PHASE A Connect one motor winding to this terminal
(TERM. 6) PHASE B Connect the other end of the winding to this terminal
(TERM. 7) PHASE C Connect the other motor winding to this terminal
(TERM. 8) PHASE D Connect the other end of the winding to this terminal

this might be a bit confusing. people might look at this and say "but I dont have a phase c and d!!" i'd go with the standard a, a\, b, and b\


oh yeah and what do we put in the step pulse for mach3 in motor tuning? 4us?

[jalessi]

I second the motion

this might be a bit confusing. people might look at this and say "but I dont have a phase c and d!!" i'd go with the standard a, a, b, and b

[phomann]

Marcus, Mariss,

Any chance of addressing my questions in post # 894?

Cheers,

Peter.

[Mariss Freimanis]

The attached thumbnail is the actual, final pinout designation, dimensions and specifications for the G250-REV6 that we will be putting into production.

Speaking of which. Notice it's REV6 now; that means there were bad problems with the REV5 boards. These problems were entirely my fault; a via that should have been marked GND was marked 3.3V and a via adjacent that should have been marked 3.3V was marked GND. This is an idiot's mistake.

The 3.3V and GND distribution planes are of course the inner two layers on this 4-layer board. It also means there is a hard short between the GND and 3.3V distribution layers and it means there is no way to cut and hack way to correct this error. 2,400 G250/G251 boards have to be trashed and $2,000 are down the tubes.

The $2K I don't care about. What hurts is the 2 weeks it will take to get replacement boards.

Oh yeah; the G250 works perfectly. I did some inner layer, under the microscope surgery to clear these two faults and jumper around them. Once done (45-minutes of work), the G250 performed as expected. It is a very sweet drive.

"Other than that Mrs. Lincoln, how was the play?" pretty much sums up how yesterday and today went.

Mariss

[phomann]

TEST

And the answer is...-)


Cheers,

Peter.