[Smitty911]

Looking at the Gecko 203V as they seem to be made for people like me. Electricially challenged.

My understanding:
1.You take the wires from the motor and connect them in order to the 203V per axis.

2. Your plug somekind of power supply to the 203V.
a. How large if I plan on going someday to 4 axis and using 300-400oz stepppers?
B. Will one large unit take care of the power for all of them?
C. Are there some off the shelf ones that would work?

3. Than there is some magic happening
a. The 203V should plug into somekind of board to interface with the computer controller.
b. Who makes a good board that would work with the MACH 3 software?

Who give the best deals for the above?

Thanks

Smitty

[Richards]

Motor connections: Four wires from the motor connects to the Phase A, Phase /A, Phase B and Phase /B connections on the G203. On the Oriental Motor steppers that I use, the Black wire goes to Phase A, the Yellow Wire goes to Phase /A, the Red Wire goes to Phase B and the White wire goes to Phase /B.

Power supplies: Log on to PartsExpress.com and look at the Avel brand toroid transformers. I use the 25V 500VA model that costs about $75. It produces 33 VDC if wired in parallel or 70VDC if wired in series. (Add the current requirements for all of the G203/steppers and pick a transformer that gives at least 75% of that current. I always pick a transformer that gives 100% of the current, but many others have said that picking a transformer that gives 66% of the current is satisfactory. In my opinion, spending $25 more for a larger transformer is cheap.)

Power supply accessories: Visit the PMDX.com website and look at the PMDX-8020 power supply (about $100). You simply connect the toroid transformer to the PMDX and the PMDX takes care of everything else.

Breakout board: While at the PMDX site, order one of the PMDX-122 boards. It works.

The parts that I've listed are a bargain, both in price and in the fact that they work. I have all of them and have used them heavily for well over a year without problems of any kind.

[Smitty911]

Richards,

Thanks for the lead I have ordered the parts listed from PMDX site and well when they get here I'll attack that problem.

Snip

Power supplies: Log on to PartsExpress.com and look at the Avel brand toroid transformers. I use the 25V 500VA model that costs about $75. It produces 33 VDC if wired in parallel or 70VDC if wired in series. (Add the current requirements for all of the G203/steppers and pick a transformer that gives at least 75% of that current. I always pick a transformer that gives 100% of the current, but many others have said that picking a transformer that gives 66% of the current is satisfactory. In my opinion, spending $25 more for a larger transformer is cheap.)

Well the above is where things start getting really bad. You would think in 40+ years of being around I would pick up some electrical knowledge. Hasn't happen yet though.

1. I use the 25V 500VA model that costs about $75. It produces 33 VDC if wired in parallel or 70VDC if wired in series. How is this done? the difference between series and parallel? These wires from the transformer connect directly to the PMDX part?

The parts that I've listed are a bargain, both in price and in the fact that they work. I have all of them and have used them heavily for well over a year without problems of any kind.

Thanks again for the assist all the parts have been ordered and should be here within the week.

Smitty

[Richards]

Avel Y236801 Toroid transformer connection:
On the transformer's input side there are four wires, Black, Gray, Violet, and Brown.

If your incoming power is 120V, connect the transformer's Black and Violet wires through a fuse or circuit breaker to the power Hot/Line wire (usually Black). Connect the Gray and Brown wires to the power Neutral wire (usually White).

If your incoming power is single phase 240V in North America, connect the transformer's Black wire through a circuit breaker to one of the incoming power's Hot/Line wires (usually Black and Red), connect the transformer's Gray wire to the transformer's Violet wire, connect the transformer's Brown wire through a circuit breaker to the other incoming power Hot/Line wire. You'll have to use a 2-pole circuit breaker with 1-phase 240V power so that if either Hot/Line wire trips, the circuit breaker will disconnect both Hot/Line conductors.

On the transformer's output side there are four wires, Yellow, Orange, Red, Black.

If you want 25VAC out of the transformer (rectified to 35VDC (1.41 X 25V) at the PMDX power supply board), connect the Yellow wire and the Red wire to either J1 input on the PMDX power supply board. Connect the Orange and Black wires to the other J1 input on the PMDX power supply board.

If you want 50VAC out of the transformer (rectified to 70VDC (1.41 X 50V) at the PMDX power supply board), connect the Yellow wire to either J1 input on the PMDX power supply board. Connect the transformer's Orange and Red wires together with a wire nut. Connect the transformer's Black wire to the other J1 input on the PMDX power supply board.

(I make it easier to connect things by using DIN terminal blocks and 35mm DIN rail. The blocks cost about $0.50 each and the rail costs about $6.00 for a three-foot section.)

From the PMDX power supply, connect the POS output through a fuse to the Gecko G20x stepper driver. If you have four G20x drivers, you will need to have four wires and four fuses connected to the PMDX. Since the output connectors are only large enough to hold a 10 or 12 guage conductor, use DIN terminal blocks or some other method of branching the wires. DO NOT use a DAISY CHAIN or SERIAL configuration for the wires. Use a STAR or PARALLEL configuration.

On my system, I connect the PMDX's positive conductor to four DIN terminal blocks that have a jumper so that the four terminals act as one terminal with one input and seven outputs. From each of four outputs, I run a wire to a DIN fuse block. From the opposite side of each of the four fuse blocks, I run a wire to a G203's Positive Input. I connect the PMDX's negative conductor to four DIN terminal blocks that have a jumper so that the four terminals act as one terminal with one input and seven outputs. From each of four outputs, I run a wire to a G203's Negative Input.

[Smitty911]

Avel Y236801 Toroid transformer connection:
On the transformer's input side there are four wires, Black, Gray, Violet, and Brown.

If your incoming power is 120V, connect the transformer's Black and Violet wires through a fuse or circuit breaker to the power Hot/Line wire (usually Black). Connect the Gray and Brown wires to the power Neutral wire (usually White).

I'm in Southern California so I believe we have standard 120v line. I will assume we will need to use a three plug grounded outlet.

What size Circuit Breaker? 10, 15, 20 amp like you would get at Lowe's or Home Depot? Or like this?http://www.minute-man.com/acatalog/P..._Breakers.html

If your incoming power is single phase 240V in North America, connect the transformer's Black wire through a circuit breaker to one of the incoming power's Hot/Line wires (usually Black and Red), connect the transformer's Gray wire to the transformer's Violet wire, connect the transformer's Brown wire through a circuit breaker to the other incoming power Hot/Line wire. You'll have to use a 2-pole circuit breaker with 1-phase 240V power so that if either Hot/Line wire trips, the circuit breaker will disconnect both Hot/Line conductors.

I don't think this applies.

On the transformer's output side there are four wires, Yellow, Orange, Red, Black.

If you want 25VAC out of the transformer (rectified to 35VDC (1.41 X 25V) at the PMDX power supply board), connect the Yellow wire and the Red wire to either J1 input on the PMDX power supply board. Connect the Orange and Black wires to the other J1 input on the PMDX power supply board.

If you want 50VAC out of the transformer (rectified to 70VDC (1.41 X 50V) at the PMDX power supply board), connect the Yellow wire to either J1 input on the PMDX power supply board. Connect the transformer's Orange and Red wires together with a wire nut. Connect the transformer's Black wire to the other J1 input on the PMDX power supply board.

I'm not sure what I actually need here. I have three (3) 425oz steppers and three (3) G203V Geckos. To don't have the transformer yet so the wiring can wait for a moment.

This brings me also to an area on the Gecko that is printed "Current Set and Current Set". Does that mean that if the motors take X current than a resistor of the value needs to be connected across those two pins?

(I make it easier to connect things by using DIN terminal blocks and 35mm DIN rail. The blocks cost about $0.50 each and the rail costs about $6.00 for a three-foot section.)

This sounds like an easy and clean way of doing this wire stuff. Thanks

From the PMDX power supply, connect the POS output through a fuse to the Gecko G20x stepper driver. If you have four G20x drivers, you will need to have four wires and four fuses connected to the PMDX. Since the output connectors are only large enough to hold a 10 or 12 guage conductor, use DIN terminal blocks or some other method of branching the wires. DO NOT use a DAISY CHAIN or SERIAL configuration for the wires. Use a STAR or PARALLEL configuration.

I will be printing this page out and taking it to work with me so the EE can do the wiring stuff.

On my system, I connect the PMDX's positive conductor to four DIN terminal blocks that have a jumper so that the four terminals act as one terminal with one input and seven outputs. From each of four outputs, I run a wire to a DIN fuse block. From the opposite side of each of the four fuse blocks, I run a wire to a G203's Positive Input. I connect the PMDX's negative conductor to four DIN terminal blocks that have a jumper so that the four terminals act as one terminal with one input and seven outputs. From each of four outputs, I run a wire to a G203's Negative Input.

What are the chances of getting a picture of what you are talking about?

The motors came with eight (8) wires as follows:
Red
Red/White
Blue
Blue/White
Black
Black/White
Green
Green/White

There were no instructions so I assume the the same colors get connected to the same place. I could be wrong though. And that these pairs of wire will be connected though and extension cable directly into the gecko Phase A, -A, B, and -B.

Start EDIT:
I found on the Keling Inc. web site the specifications for the 425oz steppers. http://www.kelinginc.net/KL23H286-20-8B.pdf

It would appear that there are several ways in which to wire this. Looks like I need to read up on stepper motor operation to figure out which method. Good thing I read fast. Comprehension of the electrical will have to come.
Stop EDIT


There is also what looks like a trim pot on the top left hand corner, purpose?

I know that I am asking a lot of questions, thanks for your patience. The fire insurance premium is paid up, I just don't want to use the insurance for this. LOL

Thanks so much for you assistance.

Smitty

[Smitty911]

These are Bi-Polar motors: http://www.kelinginc.net/KL23H286-20-8B.pdf

That leaves us with either series or parallel wiring of the motors. Which is better, I've read the information about stepper motors on Geckos site, but it really didn't cover (or I missed it) about one over the other.

Parallel will need a 36k resistor to keep the current less than 2.8 amps?

Wires will be connected to the Gecko:
PHASE A = A, -C
PHASE -A = -A, C
PHASE B = B, -D
PHASE -B = -B, D

PHASE A = BLUE/WHITE, RED/WHITE wired together
PHASE -A = BLUE, RED wired together
PHASE B = GREEN/WHITE, BLACK/WHITE wired together
PHASE -B = GREEN, BLACK wired together

Thanks

Smitty

[Richards]

Fuses and circuit breakers are meant to keep the wiring from getting too hot. (The difference between your kitchen toaster and an extension cord is basically the guage and type of wire used. Believe me, you can make an extension cord heat up just like a toaster's elements by pulling too much current through the wiring.) So, based on that, I usually install conservative fuses in my circuits. On the input side of the toroid, I use a 7A Slo-Blow fuse. Between the power supply and the G203 modules, I use a 5A regular blow fuse. (Again, I'm protecting the wiring - not the devices. My intent is to prevent a fire not necessarily to pervent a device failure.)

From the KL23H286-20-8B data sheet, you can use a 70VDC power supply. The G203 can handle up to 20X the motor's rated voltage or 80VDC, whichever is lower. If you wire the motors as parallel, 20X 4.17V = 83.4V, so you would be limited by the G203 maximum voltage of 80V. (In actual practice, unless I need top speed, I've found that using 10X or 15X the motor's rated voltage usually works just fine.)

Adding the current of all motors together gives 8.4A. Multiplying that by 0.66 gives 5A and multiplying 5A by 70V = 350VA. So a 500VA toroid will work fine without getting too hot. (The 0.66 multiplier is generally used for CNC equipment as being reasonable.)

The current set resistor limits the amount of current that the drive will allow. It's important to use a resistor that limits the current to the motor to the motor's rated current or less. The forumula is: 47 X Amps / ( 7 - Amps), so, in your case 47 X 2.8 / (7 - 2.8) = 31.3K. You could use either a 30K or 33K 1/4-watt resistor.

You can get an idea of what terminal blocks are by visiting AutomationDirect.com. I use a local supplier, but the blocks at AutomationDirect look very similar to the ones that I use. Part no. DN-T10 is the terminal block. Part No. DN-EB35 is the end bracket, Part No. DN-EC1210 is the end plate. Part No. DN-4J10 is the 4-pole jumper. Part No. DN-R35S1 is the rail. Part No. DN-F6 is the fuse holder. Part No. WMS1B-6 is a 6A circuit breaker that can be used in place of the fuse holder.

(As far as uploading a photo of the wiring goes, I'll have to learn how that is done.)

The trim pot on the G203 is to smooth out the stepper. If you download the 'Stepper Motor Basics' White Paper from GeckoDrive.com, you see how that can help with some motors in some circumstances. With the Oriental Motor steppers that I use, I've not had to adjust the pot. I've tried, but the motor runs best at the factory setting. Your motors may run smoother after adjusting the pot.

I always use either parallel or half-coil wiring with my steppers. Serial wiring gives great low end torque (the same as the motor wired parallel) but much lower high end speed. If you read Mariss's white paper, you'll see the term "Corner Speed". That is the highest speed at which the motor can run before excessive heat starts to be generated. Mariss recently posted some formulas that help in 'guessing' the corner speed of a motor. Here are the forumulas:

1) W = (Vs * Th) / (10^3 * L * Ir)

Where:
W = motor power output in Watts mechanical
Vs = supply voltage
Th = rated holding torque in in-oz
L = winding inductance in Henries
Ir = rated phase current in Amperes

2) RPM = (0.191 * Vs) / (L * Is)

Where:
RPM = the motor's corner speed
Vs = supply voltage
L = winding inductance in Henries
Is = drive's set phase current in Amperes

So taking your motor wired parallel, you would get (0.191 * 70V) / (0.0068H * 2.8A) = 702 RPM as the motor's corner speed. If you wired the motor as series, you would get (0.191 * 70V) / (0.0272H * 1.4A) = 351 RPM as the corner speed. If you wired the motor as half-coil, you would get (0.191 * 70V) / (0.0068H * 2A) = 983 RPM as the corner speed, but only 70% of the torque of a parallel or series wired motor.

Wiring the motor as half-coil, you would use EITHER the A, /A OR the C, /C coil for Phase A and EITHER the B, /B OR D, /D coil for Phase B.

Remember that the Corner Speed and the motor's top speed are not the same. I have run stepper motors that have a corner speed of 1,500 RPM at 6,500 RPM. They get hot in a hurry when run at those high speeds, but it can be done. (I was testing the G100/G203 to see just how fast I could make a motor run.)

[Smitty911]

Well you haven't said to put it all in a box and send it back, so I'll plug along.

I will be reading and trying to understand your reply. I read the White Sheet on Geckos so the corner speed and a couple of other things make sense now.

I will be printing and reading the Gecko and Keling specification so that I understand (to a point) about what the correct method is.


Thanks for your replies.

Smitty

[Richards]

In the eighteen months that I've been pleasantly involved with testing and proving that Gecko products really work, I've had the chance to work with a lot of different stepper motors. Currently, I have more than sixteen motors on my test bench. They're almost all manufactured by Oriental Motor, but that's mainly because I've used Oriental Motor steppers in process control computer projects long before I learned about Gecko stepper/servo drivers. Frankly, I don't know that I'll ever buy another brand. That absolutely does not mean that there is anything wrong with any other brand of motor. It only means that I have confidence, based on years of experience, with one brand of motor.

I feel the same way about Gecko stepper/servo controllers. For the purpose for which they were designed, and within the sphere encompassing those design criteria, the Gecko products are also my first choice.

Mainly, I require that any process control product be absolutely reliable. I also insist that it handle anything within the design parameters of the process control computer for which the part was selected. It's always a big plus that the parts are affordable and that they come from companies that have a good reputation. Gecko products totally meet those requirements. There are limitations, such as a maximum of 80VDC, but those limitations are clearly stated in the pre-purchase literature.

Somewhere in the past, I heard someone say, "A poor carpenter always blames his tools." I've taken that to mean that it's up to me to know my equipment to the point that I know what each piece is capable of doing. Then, when I come across a limitation, I only have to select a different piece of equipment. It makes life easy.

One of the things that has made testing and evaluating equipment possible and even pleasurable is this forum. A lot of users freely give advice and relate their experiences with different brands of equipment. Most of the advice is trustworthy. Most of the experiences are based on a real desire to make something work. And, most important of all, there is a sense of family here where we sometimes play the role of the little brother who needs a guiding hand and sometimes we play the role of the big brother who has already had that experience. That free and friendly exchange of ideas and willingness to help whenever possible makes this community a great place to visit.

[Smitty911]

The only reason I am attempting this is that people on this board are helpful. Spending over $1,000 bucks on an anchor would land me in the dog house very quickly.

Thanks for you support.

Smitty

[Smitty911]

Well I have the eight wire 425oz steppers from Keling Inc. and the 203V's.

I have the leads from the Steppers twisted together to form four (4) pairs of wires. On the Gecko there are Phase A, -A, B and -B. Does it matter which pairs are connected to which phase?

The motor list:
A,-C Wired
C,-A Wired
B,-D Wired
-B,D Wired

How do the above relate to the Phase of the Gecko's?

Thnaks

Smitty

[Richards]

Smitty,

Connect the Blue/White and Red/White wires to the G203 Phase A (Terminal 3).
Connect the Blue and Red wires to Phase /A (Terminal 4).
Connect the Green/White and Black/White wires to Phase B (Terminal 5).
Connect the Green and Black wires to Phase /B (Terminal 6).

If the stepper's shaft turns in the wrong direction, simply exchange the wires on Terminal 3 and Terminal 4.

[Smitty911]

The Transformer arrived with all the PMDX stuff. I have taken some pictures to hopefully explain my questions.

1. On the Transformer side input Post #4 for 120V input you said to Connect the Black and Violet wires for the HOT though a fuse/circuit breaker.

a. Recommends for the size of the fuse/circuit breaker?

2. On the Transformer side output for 25VAC:

a. How much power will these things take? 25 VAC or 50 VAC I will do some of the math that you listed below as well. Hopefully my answers will match yours.
b. You listed the Black wire again, there is a blue one - so is it black or blue on the input or the output?

3. Than connect the wired directly to the PMDX-135-8020 as shown in the photo for the 25VAC connections?

4. Connect the 135 to the 122, I have attached a photo to ensure that I have done this correct.

5. Conneting the 122 to the Geckos though a circuit breaker, what size or style I found some push button ones, I was thinking the 3amp ones to match the output of the Geckos to the steppers, correct?

6. Geckos connected to the 122.

7. Steppers connected to Geckos.

Thanks for your help, with this out of the way I can work on an enclose and the mechanical portion.

Smitty

[Richards]

Smitty,

STOP!

Your toroid has different wire colors than mine. Look at the photo showing the toroid's wire colors. The BLUE and VIOLET wires are connected together and then to your incoming HOT/LINE conductor through a fuse or circuit breaker. The GRAY and BROWN wires are connected together and then connected to your incoming NEUTRAL conductor. (I'm assuming that you're still using 120VAC as your incoming voltage.)

Try a slow-blow 7A fuse to start with. What I do is use a clamp-on current meter to read the current flowing through the HOT/LINE conductor once the circuit is ready for use. Then, I select a fuse or circuit breaker about 25% higher than that current reading - depending on safety factors. For 14 gauge wire, I NEVER use a fuse/circuit breaker larger than 15A and for 12 gauge wire, I NEVER use a fuse/circuit breaker larger than 20A. Right now, I have a 7A slow-blow fuse in my test circuit that runs four G203 stepper drivers and four 3A steppers.

On the output side, you can run the motors that you specified at 70VDC (50V * 1.41 = 70.5V The bridge rectifier in the PMDX 8020 power supply produces 120 cycles per second whose peak voltage is aprox. 70V peak. The bank of capacitors holds that voltage very near 70V.

For 35V operation, looking at the photo of the toroid, the BLACK wire and the ORANGE wire are connected to one of the PMDX-8020's J1 inputs. The RED wire and the YELLOW wire are connected to the other PMDX-8020 J1 input.

For 70V operation, looking at the photo of the toroid, the BLACK wire is connected to one of the PMDX-8020 J1 inputs. The RED wire and the ORANGE wire are connected together with a wire-nut. The YELLOW wire is connected to the other PMDX-8020 J1 input.

The PMDX-8020's output J2 does NOT connect to the PMDX-122 breakout board. The J2 POS connection is wired to the G203's Terminal 2 (18 to 80 Volt) through a 5A fuse (3A might work; however, depending on the sensitivity of the circuit breaker, if may 'break' during normal operation). The J2 NEG connection is wired to the G203's Terminal 1 (Power Ground).

You can connect a 9 to 12V AC or DC power supply to the PMDX-122 J11. I use a $10 wall transformer with the correct plug to connect directly into the PMDX-122's J11 receptacle. (TRIAD WDU12-600)

Be sure to use a current limiting resistor (30K or 33K, 1/4W or 1/2W, will work fine for 2.8A) on terminals 11 and 12 of the G203. One end of the resistor attaches to terminal 11 and the other end attaches to terminal 12.

[Smitty911]

Richards,

Thanks for saving me a couple of hundred dollars and possible great personal damage. Now were did I put those receipts and a box to send them back in?

I have read mention of "Line Voltage" that kills people and Even though my relationship with Jesus Christ is secure, I'd hate to meet him and have him ask why I didn't have my work double checked.

I thought something might be wrong. My EE will checking over my work before any power goes though this thing. I am so paranoid about electricity. I work in fiber optics and can't wait for optical circuits. NO POWER will be applied until the whole thing is checked over a couple times by a couple of people.

Input:
Blue and Violet Hot 120 (From socket for cord as shown in photo) though slow fuse. Check with amp meter. Start with 7A.
Gray and Brown Neutral 120 straight into socket

Output:
For 70V operation, looking at the photo of the toroid, the BLACK wire is connected to one of the PMDX-8020 J1 inputs. The RED wire and the ORANGE wire are connected together with a wire-nut. The YELLOW wire is connected to the other PMDX-8020 J1 input.

To mount all of this down to something and secure it, I assume metal contact is bad. I have some phenolic sheets that it can be attached to. Use stand-offs for the boards, the Transformer has a foam sheet and large metal disk w/ bolt. Geckos should be placed on aluminum sheet for heat sink. I have seen other with all of the components in a aluminum enclosure.

PMDX-122 the power from were I had the transformer should only be a 5v than. That would have been very bad. I have a 9v wall power supply that will be used. I will check the polarity of the plug before connecting and powering up.

The Gecko receive their power straight from the PMDX-122 though a star/branch configuration using those connectors from those DN part numbers listed in a previous post. Using a 5 amp circuit breaker. Those wires will be connected to some 4 wire panel connectors I found. The female side will be attached to the case and the motor wires to the male side. They are twist lock.

I can't thank you enough for the assistance (and possibly my life). I probably should have purchased a complete turn key solution. I think I have most of it now, but as it comes together I will take photos.

Smitty

[dropride]

Great info. in this thread. Any updates on your progress, i'm looking at possibly going with the same stuff.

[Smitty911]

I have sourced the remaining parts, fuses, circuit breakers, 17 gauge wires, crimp on connectors. Work has been hectic to say the least. I'm ready to mock it up again and get it checked out though. Times a wasting.

I was looking for some 4 wire cable to use for running the motors to the control box. They have some 4 wire at Home Depot for sprinkler systems 17 gauge I believe. Nice heavy outer jacket. I'm doing some testing on some wires that will be going into the New Boeing 787?? so wear though is something I want to ensure is a non-issue.

What gauge wire should be used for the motor to plug and plug to Gecko interfaces? That should wrap up the needed items and on to the mechanical.

Hopefully I posses some ability to work that out with a little less assistance.

Smitty

[Richards]

I use four conductor 16 gauge stranded cable with a shield. The shield is connected to chassis ground at the controller. I leave the drain conductor at the stepper motor unconnected to reduce the possibility of ground loops. On my Shopbot CNC router, cable runs are over forty-feet long, so I am careful about keeping the stepper cables separate from the spindle wires. With jog speeds of 1800 inches per minute, I also try to keep the minimum bend radius at least twelve inches. And - this is important - I make sure that the wires are protected from being walked on or driven over.

The Amp chart (www.powerstream.com/Wire_Size.htm) shows that 16 gauge wire can carry 3.7A, 18 gauge wire can carry 2.3A, 20 gauge can carry 1.5A and 22 gauge wire can carry 0.92A.

Remember that all wire has resistance. The longer the wire, the higher the resistance. In my case, 16 gauge wire that is forty feet long has a resistance of about 0.16 ohms. Twenty gauge wire with that same forty foot length would have a resistance of about 0.4 ohms. The coil resistance on the motor that I commonly use is 1.5 ohms, so I try to keep the wire resistance to 10% or less of the coil resistance.

[joakim]

realy good descriptions and tips here.
Think i will go the same way.

[FPV_GTp]

hi


smitty , how is you project progressing ???

nice to see helpful people in this forum

yes a very interesting read .

cheers