[Senna]

Would the CNC4PC's C10 - Bidirectional Breakout Board... http://www.cnc4pc.com/Store/osc/prod...products_id=45 be a good match to the 251's? I haven't seen much on BOB's mentioned for the new 250's and 251's and thought I'd open some dialog.

If the above BOB isn't well matched... how about some recommendations...

Senna

[CROSSHATCH]

Can't wait to get my driver! I also cannot wait to finally run coolant on m8 am m9. It's annoying to constantly pull the plug after every use and not having the peace of mind that when I do the leave the shop for a little longer, nothing is leaking over

Plus, it's way cooler to have m8 and m9 !


-Jason

[Mr.Chips]

The G251's arrived this afternoon!

Now to read and read and make some wiring diagrams all aimed at making a one time, first time perfect wireup.

Thanks :rainfro:
Hager

Have a question about the G251 Users Manual Rev-7 July 27, 2008-09-12
There seems to be a mix up on the two sheets, or am I just not understanding?

The first page lists:
Phase A (TERM 4)
Phase /A (TERM 5)
Phase B (TERM 6)
Phase /B (TERM 7)

On the second page with the drawing and Main Connector, it lists:
5 Phase A
6 Phase /A
7 Phase B
8 Phase /B

[eightball]

The 2nd page is correct. They issued a correction like a week ago i think.

[klmjr]

I got my 6 G251's and am planning on using 3 of them on some steppers I picked up cheap at the swapmeet. They are Sanyo Denki's 2A 103H7126-0415. I cant find a exact match but believe they are about 200 in oz. My question is they came with some very nice brass vibration dampers. I am thinking they would be superfluous with the G251's but thought I would ask if should install them anyway. I am going to be running 48volts 1/2 winding. It is amazing how warm that 4 lb motor can get while that mini g stays cool as a cucumber. Great job on them Mariss
klmjr

[Mr.Chips]

[SIZE="5"]
Now to read and read and make some wiring diagrams all aimed at making a one time, first time perfect wireup.
Hager

Please Check My Wiring, I don't want to be the first to lose the Magic Blue Smoke in these little babies

OK this is my first attempt of wiring the precious Little G251's, take a look and let me know if I am interpreting the motor wiring requirements and the instructions on the G251 correctly.

Thanks :rainfro:

[ger21]

Don't connect terminal 11 (disable), you don't need to. Unless you want to use it to disable the drive.

[klmjr]

Please Check My Wiring, I don't want to be the first to lose the Magic Blue Smoke in these little babies

OK this is my first attempt of wiring the precious Little G251's, take a look and let me know if I am interpreting the motor wiring requirements and the instructions on the G251 correctly.

Thanks :rainfro:

I would hook them to the center tap and one end. Unless they are very low inductance you should get better performance. I also believe that if you hook across both coils. you need to cut the current rating in half. A "normal" hookup for 6 wire motors is unipolar where only 1 coil is energized at a time. So if both are energized at the same time, you can only run half the current. And as the inductance is higher, performance will suffer.
klmjr

[Mariss Freimanis]

Mr. Chips,

Your motor is a 6-wire 1A, 5V stepper. Run the motor half-winding (green and white, red and black). Leave the unused wires unconnected and insulated. Use a 1K resistor for the current set value.

Mariss

[Mr.Chips]

Mr. Chips,

Your motor is a 6-wire 1A, 5V stepper. Run the motor half-winding (green and white, red and black). Leave the unused wires unconnected and insulated. Use a 1K resistor for the current set value.

Mariss

Thanks!
OK I think I got it. :rainfro:

Revised the drawing to reflect changes.
Wired to use half-winding, 1 K resistor, and eleminated connection #11.

By the way what does the comment made by Ger21 mean? "Don't connect terminal 11 (disable), you don't need to. Unless you want to use it to disable the drive. "

[CROSSHATCH]

I am so excited!!!!!!!


-Jason

[acondit]

Jason,

My G251s arrived today. A big round of thanks to Mariss, Marcus, and the entire crew of Geckodrive.

Alan

[eightball]

Thanks!
OK I think I got it. :rainfro:

Revised the drawing to reflect changes.
Wired to use half-winding, 1 K resistor, and eleminated connection #11.

By the way what does the comment made by Ger21 mean? "Don't connect terminal 11 (disable), you don't need to. Unless you want to use it to disable the drive. "

It can be used as a estop i believe. I guess you send current through it to stop the driver, so leaving it disconnected should make it enabled always.

[PEU]

is the sale price over? web page shows regular prices. Thanks

[yngndrw]

Yes, we missed it a bit ago. :c

[Jay C]

ended 9/6/08

[greywolf]

Hello,

I'm a new forum member though I have been following this thread for quite some time.

I am also a new owner of some g251s which arrived last week. The drives were carefully packed (hermetically sealed I might add) and someone at Geckodrive also added a small bag of macadamia nuts to boot! What a company!

Well now that I have these little beauties, I'm going to need to power them up and so I have some questions...


First case:
If I were to use a variable power supply (such as a mastech HY3020E) which has a range of 0-30V and 0-20A, then will I still need to use a large capacitor as stated in Gecko’s STEP MOTOR BASICS pdf? I’m unclear on this point because this document is tuned to the larger drives. I am also wondering if I would need a zener diode as well, yet have no idea what that diode would be or how it would be connected. For this particular setup I would be looking at 2.4mh 3A bipolar parallel or 2.1A unipolar nema 23 motors. This would imply an optimum 47V power supply even though my supply maxes out at 30V. I don't need high speed for this scenario and have thought to run maybe at 24V as a start.

Second case:
I have a setup where I would like to run a nema 17 motor up to 1500 rpm from a battery supply. I plan to gang some 12V sealed lead acid batteries to achieve 24, 36, or even 48Vs if necessary. In this arrangement would I also need that large capacitor and diode??? I'm looking at a 2.65mh 2A bipolar nema 17.

I had thought I might just email Geckodrive directly with these questions, but then thought that some of you out there might as well be looking at employing these new drives in setups that are not specifically cnc related.

greywolf

[LeeWay]

I think you are talking about a lab supply. I have a Mastech with 30 volts each side and run it setup where I get 60 volts and 6 amps. My motors are running set at 3 amps. This seems to work very well.
I don't think you will need anything extra. The lab supplies are nice and clean outputs. Mine is petty steady as well, but different times of the day, the line voltage varies, which makes the supply output vary. With the knobs on there though, it is easy to achieve exactly the desired voltage regardless of line supply.

I think the caps are if you are building your own supply. Torridal type.
I bought one of those and it had the bridge rectifyer and caps installed already.

I also have a linear PS and those are onboard there as well. Then I have a switcher that acts kinda like a lab supply, but without the LED outputs.

I didn't have to add anything to any of these. They were basically ready to go.

[greywolf]

I think you are talking about a lab supply. I have a Mastech with 30 volts each side and run it setup where I get 60 volts and 6 amps. My motors are running set at 3 amps. This seems to work very well.
I don't think you will need anything extra.

Hi Lee,

Yes, many refer to this type of power supply as a lab supply. I am interested in the mastech because I would be able to use it for so many other things besides just running my 251s.

Gecko's "step motor basics" pdf says:

"If a linear regulated or a switching supply is to be used, then a large capacitor should be placed across the output terminals. A 2,000 to 10,000 uF capacitor should do."

Then with reference to unregulated power supplies it goes on to say that:

"There is a special consideration if the power supply voltage will be at or near the maximum voltage rating of the drive. If the motor will be rapidly decelerating a large inertial load from a high speed, care has to be taken to absorb the returned energy. The energy stored in the momentum of the load must be removed during deceleration and be safely dissipated. Because of its efficiency, the drive has no means of dissipating this energy so it returns it to the power supply. In effect, instead of drawing current from the power supply, the drive becomes a source of current itself. This current then may charge the power supply capacitor to destructive voltage levels."

I am just kinda wondering if I could damage the mastech without the big front end cap, but from what you say it doesn't seem to be a problem. Have you been running your mastech in this configuration for very long?

greywolf

[edferg]

Gecko's "step motor basics" pdf says:

"If a linear regulated or a switching supply is to be used, then a large capacitor should be placed across the output terminals. A 2,000 to 10,000 uF capacitor should do."

A related question - I purchased KL23H276-28-4B steppers and KL-350-48 48Volt /7.3Amp switching supply from Keling for my G540. I'm very close to hooking it all up, and wonder if an external capacitor is needed. If so, I need to make sure I provide the space.

Many people on the CNC Zone forums seem use a switching supply as-is. I'm curious if this is a recommendation, or a "must have". My application is a Taig Mill and my rapids are under 3 inches of travel, so I never really get up to full speed.

Ed