THB6064AH MassMind.org Stepper Motor Driver

Luc's THB driver joins the other open source drivers supplied by the MassMind.org store, adding support for BiPolar (4, 6 or 8 wire) motors up to 4 amps/phase at 50 volts. It is based on the new THB6064AH ( Datasheet ) chip (also known as the Toshiba TB6564AHQ^) which is a design improvment over the TB6560, adding support for better microstepping, lower resonance, and protection for power on sequence^.

* These are electronics KITs, you need to solder them together.

The Honest Truth: It is a "chopper" type driver, so it doesn't require a terribly large heatsink, but you can expect to hear a little bit of motor "hiss" or "squeal" during operation (see the video below), and in high power systems, the motors may require more cooling than the driver. There are other drivers for different needs:

Providing a range of drivers is in keeping with our "more is NOT necessarily better" approach.  The same is true of motors: Unipolar motors cost less, provide less torque at low speeds, but maintain torque as speed increases. Bipolar motors, only when connected for parallel drive, provide better starting torque, but may not turn as fast and will generally be more costly. Pick the right motor for the job, based on your needs.

Here is a nice video from H500 with the THB6064AH driving a Keling 280 oz-in motor (kl23h276-30-8b) on the Y Axis (in and out from the camera) at 200ipm with a 40 volt power supply and the current set to 3Amps:

THB6064 MassMind.org Driver Assembly instructions

Version 1

Version 1.1

Parts list

Options

Standard rules:

1. Long lead in the square hole. Pin one or the positive lead is always marked on our PCBs with a square hole. On components where pin one isn't marked on the component package, the longer lead is always positive, and we make that pad square on the PCB.

2. Don't solder the component in right next to the PCB; leave a little bit (1/4 inch, 1 mm) of lead.

a. This helps prevent the component from overheating when you solder, and during operation. It also gives you some lead to cut if you need to repair the board or if you get the component in the wrong hole. Trying to desolder the leads without cutting them is much more likely to damage the PCB.

b. To keep the components off the PCB, insert the leads so that the component is about a quarter inch up, then bend the leads together at that point, crossing them over each other at about 45 degrees. You could also bend them out, but then they would be in the way of the soldering iron, which is almost always coming in from the outer edge of the board. When you turn the PCB over to solder on the back side, the component will fall down to the point where the lead is bent, providing the correct spacing on the component side.

c. Solder one lead, stop and check the positioning and that it is the right component in the right place the right way around... then solder the other lead.

3. Work from the inside toward the edge, low components to high components. It's best to solder down any SMT components first, since they are certainly the lowest, then work up and out. Solder a few through hole components in a line if you can, then clip leads and do the next line.

4. It's important to clip all leads as short as possible to prevent shorts to the heatsink.

Keep the leads... they become the jumper for the power source and can be used for the test points.

Passive Components

1. [ ] Surface mount Resistors. There are only two surface mount devices on this board, unless you count the driver chip as SMT because of the way it's being mounted. The components are large compared to most SMD and they really are easy to solder. The only trick is that there are no holes to hold the components in place by the leads, so you need some way to keep them in place while you solder. Almost anything that has 3 or 4 corners and won't melt can be used. A metal box, a heat sink, an aluminum extrusion, … anything. Probably the best is made from vice grips and a screw driver tip. If you don't have vice grips, wrap a rubber band around the far end of the handle of a pair of pliers. Or just tape one side of the part down with clear tape!

Once the part is held down in position, touch the pad, next to the end of the part, solder, flow, off. Solder one side of each part, check position, solder the other side.

2. [ ] Resistors: There are several different values of resistors and a lot of the values look alike. Take care and be sure you have it right before you proceed. For example, there are 47K, 4K7, and 470. And there is a mix of 4 and 5 band resistors (low and high precision). Getting them right is harder than you think, certainly harder that soldering surface mount components. An amazing percentage of people are, at least partially, color blind. Some don't know it until they start trying to sort out resistors. And even if you aren't, it takes a strong light and good luck to tell orange from gold or brown from purple on some of these packages.

We strongly recommend using a multimeter to check the values of the resistors rather than reading the color codes. When using a meter to read resistance, be sure not to let your fingers touch both leads. In other words, one test lead should be held to the resistor lead by a clip, or by pressing it against a surface and NOT by holding the two together with your fingers. Otherwise, the reading can be off due to the lower resistance path offered by your skin.

If you must read the bands, start by arranging them with the colorful bands to the left. In most cases, that will give you the correct order, with the tolerance band on the right and the actual value reading from left to right. There are exceptions. The 5 band 10K resistors currently supplied with the kit are brown, black, black, red, brown (1, 0, 0, two more zeros, and a 1% tolerance). Read it each way, figure out which one makes more sense given the resistors in the set... and then check it with your meter. Really... For less than $25 you can get a half way decent digital multimeter (watch out, it doesn't include the special battery) from your local Radio Shack right now or order one from eBay china and wait a month for it to show up. Believe it or not, WalMart (gag) sells a pretty good one in most of their stores: The "Equus 3320 Innova" for less than $20.

The PCB is marked with the values rather than the component name to eliminate another possible source of error in transcribing the part (R1) to the value (10K) to the actual physical component (brown, black, black, red, brown OR brown black orange gold). Now you just go from value to component. There wasn't room to put the colors on the PCB.

Errata:

On the first version of the PCB "Rev. 1.0" the resistor supplied for R21, to pin 1 of RN2, which is marked on the PCB as being 560, may actually be anything from 330 up to 1K. This is not a critical value component. Populate the other resistors first, and whatever is left over, should be a value in that range, and should be installed for the 560 or R1. On Rev 1.1 this same resistor is marked R1 next.

On the first version of the PCB "Rev. 1.0" the value for R36 (next to the Err LED) is incorrectly printed as 560 when that resistor must be a 4K7. Place the supplied 4K7 resistor in the position marked "560".

Note: On the Rev 1.1, PCB "ERROR LED" R36 is labeled R7 on the new board and should be 4K7 with the red LED installed on the side of R2 above J7 with the long lead in the square hole marked Q1 and the short lead in the hole nearest the "E" in ERR. R2 is not used. This provides a simple error indicator via the LED and no amplification of the error signal.

3. [ ] Variable Resistor: This is the drive current adjustment. It can be installed either way but being able to get in there to turn it is the trick. Make sure you will be able to get to it after installing the other components. On PCB Rev 1.1, it's probably best to install it facing the edge of the board. If you install it facing the capacitors, and you leave about ¼” of lead between each capacitor and the PCB, you can bend them over out of the way after they are soldered down and so clear a path to adjust the current. Take care not to melt the case by letting each lead cool a bit after soldering.

If you like, you can even bend the leads on the variable resistor and install it flat agasint the PCB, with the shaft up. It will just hang a bit over the edge that way

4. [ ] Network Resistors: It's all about the dot. Network resistors all have a (very tiny, dimly printed, very hard to see) dot at one end, usually down next to the pin. That pin is pin 1 and pin 1 goes in the square hole. Bend the outermost pins out so it won't fall down when you turn it over to solder it. Then push the pins back down so they are just through the hole so you leave a little lead on the component side. Solder one pin, check positioning, and solder the rest.

5. [ ] Capacitors: The little capacitors will be marked with a number: 101 or 104 which represents the first two digits and the number of zeros in pico Farads. 101 is 100pF. 104 is 100000pF or 100nF or 0.1uF. So the ones marked 100n on the PCB get the 104's and the 100p's get 101s. (on the Rev1.0 PCB only: Watch out for the block of caps between VR1 (the current adjust potentiometer) and the top of the board; the top cap is 100p, not 100n. The 100n is the second one down. The next two are 100p. Note: Be sure to install those caps next to the current adjust potentiometer in such a way that you can bend them down clear of the screwdriver so you can make that adjustment.) On the Rev 1.1 PCB, all the caps are clearly labeled and do not get in the way of the current adjust pot.

The bigger electrolytic caps go in with the long lead in the square hole, and the stripe side towards the round hole. It's probably best to set those aside and come back to them after you have done all the other components. And the really big one is an exception to the "leave some leads" rule. It can be installed all the way down on the PCB for physical stability.

6. [ ] LEDs: The long lead goes in the square hole, leave a little lead so the LEDs are up off the PCB and where you can see them. On the Rev 1.1 PCB, with a standard build, the Red LED should be installed between the ERR and Q1 labeled holes (long pin in the square hole as always) and NOT at the position labeled ERR near the 5V indicator LED. If you want to feed back the error signal to your controller see the "Rev 1.1 Option 2 "AMPLIFIED ERROR FEEDBACK" text above. This is not recommended.

7. [ ] Terminal Blocks: Slide the two sets of terminal blocks together so that the rail and groove interlock.

8. [ ] Jumpers: When you solder on the 2x5 header for the options jumpers and the shrouded 2x5 PMinMO header, it's a good idea to bounce around in the pin order rather than just going down the line. It keeps the plastic from getting soft and perhaps not holding the pins straight.

Note the notch in the shrouded header is towards the resistors. On the Rev 1.1 board, the order of the option jumpers has been re-arranged in numerical order.

9. [ ] Use one of the clipped resistor or other component leads to short J7 so you can get logic power via the PMinMO header. The PMinMO header can be connected to the 4Axis board, or directly to a PC parallel port cable. You can provide power on that PMinMO header, pin 9 from the 4 Axis board, a USB port, or your own 5+ regulated power source. If you keep that J7 jumper wire up off the board a little, it makes a great test point for logic power.

10. [ ] Test Points: Form loops from a couple clipped leads and push both ends into the hole for the VREF test point and the GND test point.

Preliminary Inspection and Test:

11. [ ] At this point, without the chip installed, do a visual inspection, preferably with a magnifying glass. Then apply 5V logic power at pin 9 of the PMinMO header. Now the 5V logic power system can be checked, the +5v led should be on and the Vref can be measured and adjusted to a low value: 0.4-0.5V. Power off and prepare for finally assembly.

Final Assembly:

12. [ ] The big THB6064AH chip: Since this product has a MOS structure, it is sensitive to electrostatic discharge. These ICs are highly sensitive to electrostatic discharge. When handling them, please be careful of electrostatic discharge, temperature and humidity conditions. Wear a grounding strap when touching the chip and work on an anti-static surface. 

The IC fin is electrically connected to the rear of the chip. If current flows to the fin, the IC will malfunction. If there is any possibility of a voltage being generated between the IC GND and the fin, either ground the fin or insulate it. We recommend that you directly connect the IC to the heatsink, and ground the heatsink.

If consistent mounting hole locations are important to you, use a drilled heatsink or template plate for this last step. A drill guide is available, if you print it, make sure you set your PDF viewer to print at the real size and not shrink to fit to the page. Drill and tap for M3 or #4-40

Mount the chip and PCB using 3 #4-40 or M3 screws. Temporarily mount the chip to the heatsink first. Mount the PCB with a spacer to raise it up a bit so it won't short out underneath. Spacer height can be about ? inch or 3mm. You can use an M3 or #4-40 nut which you drill through with a 3mm or 1/8th" drill + a couple of washers. A stack of washers should work also. Or cut off a bit of tubing. We used part of an old bic pen barrel. Slide the PCB between the chip's pins, align it carefully, and screw it down.

The wide point on the outer pins should be just at the edge of the PCB. Any farther in, and the pins will start to spread apart and not lie flat on the pads. Make sure all the pins are flat on the pads so the solder will flow nicely over the length of the pin and form a strong connection. Bend them carefully if needed. Solder one pin by placing the tip of the iron on the pad near the pin and let the solder flow around and under the pad. Check placement, alignment, and orientation and then solder down the rest of the pins. It's a good idea to bounce around and pause once in awhile to keep the heat from building up in the chip.

Now take the chip and the PCB off the heatsink, turn them over and solder the pins on the back side.

Finally, reassemble with a bit of heatsink paste under the chip. That paste makes a huge difference in high temperature operation.

Final Test / Power Up

13. [ ] Apply only the +5 volt power again, verify the power LED lights and nothing gets hot.

14. [ ] Power off, connected motor power and the motor. For help with sorting out the motor leads, see: Stepper Motor wiring

15. [ ] Verify the current control potentiometer is set all the way to the lowest setting. Apply logic power first, then motor power. The motor should lock, but not turn. Make sure the drive chip and motor are not heating. Carefully adjust the current setting to 30% of the motors rated capacity. Why only 30%? Because when the motor is not turning, the driver is in idle and as soon as it gets a step pulse, it's going to increase the drive power automatically. Please do NOT measure the current via the +VM or positive motor supply lead: Because this is a chopper driver, the current measured at the +VM line is much lower than the actual motor; as much as a quarter to a fifth the actual current. Please set the current by measuring the VRef voltage.

To calculate the correct VRef voltage: Io = Vref * 1/3 * 1/Rs
Since Rs = 0.20 Ohms then Io = Vref * 1.667
For example, when Vref = 2.4 volts, Io = 4 amps (max) and when Vref = 0.5 volts, Io = < 1 amp (minimum)

16. [ ] Now connect the step and direction signals and spin the motor. Let it work for at least 10 minutes to verify that nothing is overheating.

See also:

• http://users.skynet.be/ldt/CNC%20electronics/Pictures/6564_flat_drill_locations.pdf Printable Drill Guide.+

Questions:

• TakeThisOuTalessandro.torrebo at gmail.com asks:

  Hi james, forgive my ignorant question of electronic, but is it possible, with ramps 1.4 and marlin, move 3 axis, and then 3 stepper motors of my 3d printer, with the kit "3 AXIS FULL KIT"? ?If no, what else (or less) I need? Thank you in advance.
  Alessandro

  James Newton of MassMind replies: No worries! The RAMPS board would replace the 4Axis board in that kit, so you only need 3 of the THB6064 driver kits, and you will need to make a cable to connect the RAMPS board to the drivers. I'll be happy to help you make the cable, showing which wires need to connect where. In the future, we hope to provide a ready made cable, but that is not available yet.+

  +

• can I work this driver with nx 7.5 cam software
  James Newton of MassMind replies: Any system that puts out step and direction pulses should work just fine.+

  +

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