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Resistor pack and 6p6c connection

chummee@...
 

Please don't laugh...When assembling the smart hand controller (which I bought as a kit), I soldered the 9-pin resistor pack in the wrong orientation. And I accidentally broke it in half when I tried to remove it. It's now removed, but I need to buy a replacement part. I found Dave's OnStep SHC ESP32 project but the resistor used there is 8-pin instead of 9. Would you please provide me with a link to the right resistor from a reliable vendor? It'd be great if the vendor also sells 6p6c connectors so I can save on shipping. 
...which brings me to my next question: I need to buy 6p6c connectors for the motors that I finally received after several weeks of waiting. I found YouTube videos about how to crimp 6p6c connectors, but haven't found one that explains which wire goes to which hole. And I couldn't find a tutorial in the OnStep Wiki. Can someone please teach me how to do it or point me to the right YouTube video? And since there are only four wires coming from the motor, what do I do with the two empty holes? 
Thanks!

 

The resistor pack I ordered is an 8 pin device. tt can be found here [Mouser] reisistor pack.
The 6p6c connector is also available from the same supplier  [Mouser] 6P6C connector
Note both parts are as listed in the BOM at EasyEDA.

chummee@...
 

The PCB and the part picture on this page, as well as the resistor that I broke, indicate that the resistor has 9 pins. I think I found the right piece using Mouser's filter: 4609X-AP1-222LF. Would someone confirm it for me please? I believe the part number on the BOM is a typo. 
Geoff, the 6p6c connector that you linked is the jack. I'm talking about the terminal that goes into the jack. So, I'm looking for instructions for connecting the wires to the terminal, both for the stepper motors and for the hand control. 
Thanks guys. 

Dave Schwartz
 

You can use either an 8-pin (7-resistor) or 9-pin (8-resistor) part. While Howard's original SHC which I was basing off of used an 8-pin part (for the 7 buttons) I could not find the 8-pin part on eBay. However, a 9-pin part was readily available (the 8-resistor, or 'byte-wide', parts seem to be much more popular) so I ordered those in big numbers and designed the PCB so that there's a hole for the 9th pin but it isn't connected.

In the second section, if you're talking about the motor connectors, those are 8p8c. Only the SHC cable is 6p6c.

It doesn't matter the order of the colors as long as they are in the same order on both ends. Well, technically it doesn't matter on the motor cables because you're in charge of wiring which pin you use for what on the motor end but its just nice to be consistent because I'm used to building ethernet cables so I still do it that way.

If you're using a flat cable, the choices are simple because the wires are held in a consistent order through the length of the cable - just make sure the sequence is the same on each end (holding the plug with the contact end up and the contacts facing you so you can see the colors). If you're using a round 4-twisted-pair cable the same applies although you need to untwist and hold the wires in a consistent order to insert them. I use the ethernet cable standard of orange/white, orange, green/white, blue, blue/white, green, brown/white, brown (this way my cables still work as ethernet cables if I pick up the wrong ones).

Of course you don't need to pay attention to the order if you don't use a connector on the motor end. Just remember that whatever order you do end up with, each adjacent pair in the PCB-connector end is the same. They are actually connected together by the traces on the PCB for robustness and added current carrying capacity (all the PCB designs do this). Just take each adjacent pair and tie them to a motor lead. Initially, do this temporarily until you are sure you have each pair going to the correct winding and the motor is going the direction you need (on the STM32 PCB you can change the order of the motor phases by swapping around the pins in one end of the Molex-to-Molex cable between the driver and socket... that's why they were put there).

Of course, I use a cable with a connector on the motor end and my solution for making the connection (yours may be different... there are lots of ways to solve this) was to solder an 8p8c socket to one of those breakout boards you can get cheap on ebay, put in an 8-pin Molex and make a y-shaped harness for each motor wire with 2 Molex pins and then insert these pairwise in the header shell in the order I wanted.

Pictures attached.

On 2019-11-05 7:48 a.m., chummee@... wrote:
The PCB and the part picture on this page <https://baheyeldin.com/astronomy/onstep-esp32-smart-hand-controller-shc.html>, as well as the resistor that I broke, indicate that the resistor has 9 pins. I think I found the right piece using Mouser's filter: 4609X-AP1-222LF <https://www.mouser.com/ProductDetail/Bourns/4609X-AP1-222LF?qs=sGAEpiMZZMvrmc6UYKmaNe%2F06YuXkIPstUi505WrMRo%3D>. Would someone confirm it for me please? I believe the part number on the BOM is a typo.
Geoff, the 6p6c connector that you linked is the jack. I'm talking about the terminal that goes into the jack. So, I'm looking for instructions for connecting the wires to the terminal, both for the stepper motors and for the hand control.
Thanks guys.

Dave Schwartz
 

My answer to the 6p6c cable crimping order is in https://onstep.groups.io/g/main/message/13737

On 2019-11-05 7:48 a.m., chummee@... wrote:
The PCB and the part picture on this page <https://baheyeldin.com/astronomy/onstep-esp32-smart-hand-controller-shc.html>, as well as the resistor that I broke, indicate that the resistor has 9 pins. I think I found the right piece using Mouser's filter: 4609X-AP1-222LF <https://www.mouser.com/ProductDetail/Bourns/4609X-AP1-222LF?qs=sGAEpiMZZMvrmc6UYKmaNe%2F06YuXkIPstUi505WrMRo%3D>. Would someone confirm it for me please? I believe the part number on the BOM is a typo.
Geoff, the 6p6c connector that you linked is the jack. I'm talking about the terminal that goes into the jack. So, I'm looking for instructions for connecting the wires to the terminal, both for the stepper motors and for the hand control.
Thanks guys.

Mike Ahner
 

Hi chummee, no need to worry about us laughing. We've all had similar problems, although we might not like to admit it. I find that as parts get smaller, it becomes harder to tell which direction is correct, AND, the longer I do this (meaning as I get older) I also find it gets harder to tell which direction is correct. It certainly becomes harder to see the smallest parts.

The only real concern you need to watch for when uninstalling parts from a circuit board is to be sure the copper traces are still good. It's easy to lift a trace off the board when desoldering, especially smaller traces. Sometimes, I've pulled out the feedthrough hole or via when I removed a part and couldn't get unsoldered easily. I find that's usually my impatience when that happens, but even the best have occasional issues. Vias/feedthroughs can often be fixed by using a piece of wirewrap wire (kynar) pushed into the hole, then the new part inserted, lastly soldering both sides of the board to make a good connection. Wirewrap wire will also fixed a lot of lifted traces. Hopefully, you'll never have to face these kinds of problems.

Having said that, with some circuitboards it's better to clip the part off and unsolder just the thru holes, rather than risk damaging the board traces. IC/s are an example, you can just use small wire cutters and clip each pin flush at the board, then easily unsolder the remaining piece. Of course, you usually have to get a new replacement part.

Anyway, good luck! I'm looking forward to seeing your finished project, I'm sure others are as well.

-Mike

Howard Dutton
 
Edited

On Tue, Nov 5, 2019 at 12:30 PM, Mike Ahner wrote:
We've all had similar problems, although we might not like to admit it.
Yea I hear ya, during my MaxESP3 build I soldered down one of the SMT diodes backwards.  These pull the Vmot rail up to 3.3V when the motor supply is off to protect the TMC stepper drivers.  The diode's polarity marking became obscured by flux and the darn thing did a back-flip whilst hiding on the other side of my solder iron tip...

On power up several devices on the PCB self destructed as the 3.3v rail was pulled up to 24V via the backward diode, not all were entirely cheap to replace.  Guess I should pull the socketed parts, power up and check the 3.3V rail before plugging everything in.  Setting my fancy power supply to cut out at 200mA (as opposed to 3A) for that first power up might be a good idea too.  Lesson learned.

 

Sorry for the misunderstanding.
For the 6P6C connection I just bought a suitable length telephone cable from  a local electronics outlet. For  the stepper connections, I used a CAT5 Ethernet cables  I had and just cut it in half and attached a G12 aviation style, 4 pin plug. Corresponding sockets are attached to the stepper mounts.
For one of the resistor packs in the SHC (the 4 resistor one), I used 4  x 1/8W resistors soldered together. Not that neat but a lot quicker and cheaper than ordering the correct part. The 3d printed case will cover up the mistakes :-)

Khalid Baheyeldin
 

On Tue, Nov 5, 2019 at 03:30 PM, Mike Ahner wrote:
The only real concern you need to watch for when uninstalling parts from a circuit board is to be sure the copper traces are still good. It's easy to lift a trace off the board when desoldering, especially smaller traces. Sometimes, I've pulled out the feedthrough hole or via when I removed a part and couldn't get unsoldered easily.
Been there, done that. Ruined a module that way.
So, not uncommon, specially for novices like me ...

Khalid Baheyeldin
 

On Tue, Nov 5, 2019 at 03:58 PM, Howard Dutton wrote:
SMT diodes
Replacing SMT with through hole components helps make them less unwieldy,
and reduce errors.

But maybe they are there for board real estate restrictions.

Howard Dutton
 

On Tue, Nov 5, 2019 at 02:16 PM, Khalid Baheyeldin wrote:
Replacing SMT with through hole components helps make them less unwieldy,
and reduce errors.
I considered that before, just never got around to it.

Howard Dutton
 

The reason for SMT is that those are the same diodes used on Watterot SSS protectors so I know they are appropriate.

 

On Wed, Nov 6, 2019 at 02:17 AM, Dave Schwartz wrote:
My answer to the 6p6c cable crimping order is in https://onstep.groups.io/g/main/message/13737
Glad you posted this. Ijust realised that the telephone cable I picked up is a crossover cable! Time to find a crimper and some plugs ...