[TroyO]

Starting out, so far I have really liked the kit. The PCB is pro made, well designed and with only a couple of exceptions well documented. There are a couple of minor details which will probably be fixed in the next version, but none of them are enough make anything not work.

So, to start out...

Here's the kit... packed in a regular baggie. Ehh, a static shielding bag would be better but I seriously doubt it will matter. The chip is in a static dissipative tube but while that will help keep it from generating static it doesn't really protect it from existing static. So, don't shake the bag or scoot your feet across the carpet, you could still give it a zap. (In theory).

The SMD resistors are taped to the inside of the bag. Great way to keep them from disappearing! Red marker or something circled around it could make it more noticeable... I almost threw my bag out before I noticed them, LOL.

Other than that..... good to go. Resistors, caps etc were bundled by value and easy to identify. There was a missing network resistor in each kit but James wrote me about it before I even got my kit... replacements are on the way.

Tip, tape your resistors to something you can write on... makes it easy to jot the values down as you measure them.

[TroyO]

First up, soldering in the SMD resistors.... pretty much a non-event. The instructions have some suggestions of weighing them down with some pliers contraption....I just use tape to hold one side while I solder the other.

[TroyO]

Two resistors .....47K and 2.2K. Tape is just under there to shim the resistor up off the board slightly. (I use electrical tape for a lot of stuff, can you tell?)

[TroyO]

2.7K and 470 ohm resistors, same story.

[TroyO]

R7 and R1 is where the documentation gets a little hard to follow. Best I can figure the top one (R7) is supposed to be 4.7K and the one beneath it is a (R1) 330, although anything between 330-1K is supposed to work.

There's discussion in the section about old revisions and a non-standard implementation which kind of muddies the directions there, but I think have it sorted out right.

I'll post more tomorrow.

[TroyO]

100p Caps go in next.... all in a row on this revision and they don't seem likely to interfere with the variable resisitor as mentioned in the directions. Easy peasy...

[TroyO]

100n caps go in next, same proceedure for all.

[TroyO]

Network resistors next.... I had to use a magnifier to see the little dots, LOL. (Old and blind... )

[TroyO]

Next up is little test loops for Vref and GND which will come in to play when adjusting the unit later.

I also attached the variable resistor, although I broke from tradition and mounted it face out. I plan to mount mine in such a way that this angle is better. I used a dab of epoxy on the back to make up for the lack of support in mounting it this way.

[TroyO]

Error and power LEDs are next. Power is pretty straight forward, long lead in the square hole.

The Error LED is a little different.. it *doesn't* go in the space marked ERR unless you installed some of the non-standard parts. It goes in the area marked as Q1, still long lead in square hole and short leg in the round hole. The silk screen does a good job of indicating the dual LED/Transistor option but it's still just a little confusing.

[TroyO]

The big caps are next, they are polorized so make sure the long lead goes in the square hole and the lead marked - goes in the round holes.

Mount these flush to the board.... as a matter of fact if you may have vibration in your machine some dots of hot glue at the base wouldn't hurt.

[TroyO]

If you will be getting your 5V power from the PinMo connector you will want to jumper J7.

Connectors come next. This is where I botched my first board.. LOL. I soldered the jumpers where the connector should go... the pin count matched and it fits there so I did it. The PCB is plainly marked with silkscreen indicating which goes where and I just wasn't paying attention.

Anyway... these pics show the correct locations and not my bonehead mistake, LOL.

Thats where this ends for the moment...I have not tested board with 5V yet, nor have I installed the chip yet. I'll hopefully get that done early next week.

For now, I want to point out that when I ordered another kit, James was kind enough to throw in a spare PCB even though the problem I had with kit #1 was entirely my fault. Way to go!

[James Newton]

I knew that err option was going to confuse people and I really did try hard to find a clear way to explain it, but didn't quite make it. Let me know if you have any thoughts on how it can be improved.

Love the tape to hold down the SMD resistors! I'll have to add that idea to the docs.

[TroyO]

I think breaking out the section about the optional stuff to it's own section separate from the main assembly directions would help... and maybe a closeup of one installed too.

The silk has a nice diagram of the LED overlaid on the transistor diagram so I think that part is about as good as it gets.

I've used tape on all kinds of SMD stuff down to TSSOPs and 0805 caps/resistors. It gets it done, LOL.

The "Optional" section of the board....
From what I get the drive current on that error output pin on the chip is weak and the transistor is used to pump up the current which both drives the LED brighter and allows it to use a pin that is not-quite PMinMO compliant to send the error signal back to the PC? That could be handy.

[James Newton]

Thanks TroyO! I've made those changes as you suggested; setup a new section at the top for the options, removed that from the assembly instructions. Then added a bit about using tape to hold down the SMT parts.

You understand the option exactly. I've expanded the description of the option to explain that.

Thanks so much for that feedback!

[TroyO]

I'm not dead yet.... errrr... mostly not! ;-) Believe it or not I have continued to work at this thing. I have the drivers built, and installed in an ATX PC Case along with all the parts of a PC, in hopes of ending up with an all in one CNC Controller box. So far so good, nothing smoked (yet, LOL)

I have a question about the decay and step settings on the 6064 though.... first, it looks like the selection pins on the chip are all pulled high and get pulled low when a jumper is in place? (Which means they are opposite of what is in the chart in the datasheet.)

If I got that right, I have attached a chart of the jumper settings and what they do. There may have been one on the website but I missed it. I also haven't double checked it yet so take it with a grain of salt, LOL.

Finally... what does Decay do... I read the datasheet and the only real impact I can noodle through is that a high decay rate is faster because it lets the signal rise and fall in less time. A lower decay rate is probably smoother?

What is a real world "this usually works just fine" decay rate?

[James Newton]

Yeah, your table is correct. It's the same as the one on the schematic at:
THB6064 MassMind Stepper Motor Driver Kit

Decay is complicated. It's effect with also depend on the motor. Luc can probably make a more coherent explination than I can, but I just try different settings and see which one works best.

[TroyO]

I somehow totally missed the chart in the schematic, LOL. But, in the important news...... WE HAVE MOVEMENT! LOL, I am using LinuxCNC as the controller software, but I also have an XP installation w Mach3 demo on it too. I haven't decided which to concentrate on yet but both will move the steppers at will. Whoooo hoooo! I need to finalize some brackets/wiring and clean up the interior of the machine some but the all-in-one CNC controller/driver box is almost a wrap.

[James Newton]

Excellent! Would love to see a pic of the machine as well.

[TroyO]

LOL, "The machine" doesn't exist yet.... I have a manual X2 now but am starting to work on a Sx2 table and base which will be hand scraped in and built up bit by bit. Right now, that is just a parts pile. The electronics I can work on sporadically during "off" times at work... hand scraping not so much. It will be a while before I get to making parts with anything. I just figured if I never started, I'd definitely never finish so I decided to dive in "somewhere". A turn key electronics/motor package is some definite progress! (And way better than just sitting back thinking "gee, I sure wish I could get a CNC machine too....) Hmmm..... maybe I can hack together the X2 and at least get something going using the stock leadscrews and use it to make parts for the SX2.