Wiring a crossover with tam valley servos

[IDRick]

Appreciate your comments Mel, very true!  You've done an excellent job on your layout and share your wealth of information with others very well!

I will be retiring late next year and moving into a different home.  I'm just playing and dreaming of the next layout but there's too many unknowns to make any decisions for me...  I'll certainly visit with you again in the future, appreciate all your contributions to the forum!

[rrinker]

 I'll have to check out 7G servos. Have to make my own mounts since they are smaller than 9G and won't readily work with the common 9G mounts. Maybe better suited to other sorts of animation instead of as point motors, they I'm sure they have enough power for moving the points on HO and smaller.

                                     - -Randy

 

[RR_Mel]

Randy

 

I like using the 7g servos better than 9g.  They are easier to work with and although they really aren’t that much smaller I like the small size.  Their rotation is much less than the 9g on average, I bought 10 of the 7g and none have more than 130° swing.  I only have one servo in operation that requires the full 180° and that is my camera car.  It would probably work well enough at 120° but I really like the full 180° side to side movement.

 

The power of the 7g is more than enough for anything I could come up with.

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[rrinker]

 Only downside is the mounting. Everyone and their brother makes 9G mounts. Heck, if I had a 3D printer (one of these days), I could print the IASE ones for the material cost (they offer the files as open source, free to use, or you can buy them finished product from them). Space IS at a premium especially when I get to my second deck, but the 9G ones are already plenty small to not hang down into sight lines. Hmmm.

 For those special animation projects - there are even smaller ones, used in those flyweight RC planes.

                                        --Randy

 

[IDRick]

Mel,

Earlier in this thread, you indicated that you made your own servo extension cables.  Tell me more about this.  What type of wire: 24 guage stranded?  Do you recommend using a consistent set of colors for all the extension cables?  Do you use crimp pins like these:

https://www.pololu.com/product/1930 

Is there a special crimping tool for crimping the pins?

Do you use crimp connector housing like these?

https://www.litchfieldstation.com/product/0-1-2-54mm-crimp-connector-housing-1x3-pin/

I can see that it makes a much neater installation if one makes their own custom servo extensions!  Thanks for your help Mel!

[RR_Mel]

The standard servo female plug that comes on the servos are the square pin 2.54mm/0.1” standard connectors.  I buy male and female 40 pin header strips off eBay and cut them to size.  They are compatible with the Arduino connectors, very useful, durable and cheap that way.

 

Female:

https://www.ebay.com/sch/i.html?_from=R40&_nkw=40+Pin+2.54mm+Female+Pin+Header+Strip+&_sacat=0&_sop=15

 

Male:

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=40+Pin+2.54mm+male+Pin+Header+Strip&_sacat=0&LH_TitleDesc=0&_sop=15&_osacat=0&_odkw=40+Pin+2.54mm+Female+Pin+Header+Strip+

 

They are also available double row:

Female:

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=2x40+Pin+2.54mm+female+double+row+Pin+Header+Strip&_sacat=0&LH_TitleDesc=0&_sop=15&_osacat=0&_odkw=40+Pin+2.54mm+female+double+row+Pin+Header+Strip

 

Male:

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=2x40+Pin+2.54mm+male+double+row+Pin+Header+Strip&_sacat=0&LH_TitleDesc=0&_sop=15&_osacat=0&_odkw=2x40+Pin+2.54mm+female+double+row+Pin+Header+Strip

 

As for wire, any type wire #20 to #26 would work great.  You could go with the same colors to match the servo wiring, Orange (Signal), Red (5V Positive) and Black (5V Negative/Signal low or ground).

 

Because I have so much wiring under and around my layout about two years ago I found that buying multi conductor ribbon cable cheaper than single or paired wire.  I look for 10 to 26 conductor ribbon cable 100’ rolls.  The ribbon cable will split into any number of wires needed easily.

 

Most of the rolls are a light grey but I have bought some in a light blue.  For 10 wires and up I label the ribbon cable with a Black Sharpie.

 

For fewer conductors I use a toothpick dipped into crafters paint and pit a drop on each wire and or connector.  I use the standard resistor color code for ID.

 

The picture below is my MEGA Block Signal Controller and shows my method of color coding my connectors.

 

 

I have approximately 15 ribbon cables in my wiring loom under my layout along with about 300 single, double and triple individual conductors.  Ribbon cable is the only for me to go and cheaper too.

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=100%27+flat+ribbon+cable&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=ribbon+cable+flat 

 

 

Edit:

 

I watch for good pricing on the ribbon cable, my normal purchase is between $18 and $25 for a 100' roll.  My last putchase was 100' #28awg 16 conductor for $24 including shipping, that's 1600' of #28awg wire for $24.

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[rrinker]

 Yes, keep in mind there is nothing special about the servo extension cables. It's just s 3 wire cable. You want to extend one - do it the same way you extend the 3 wires from an Atlas turnout - cut the wire, splice in however much wire you need. No need to purchase expensive pre-made special extension cables. 

                                          --Randy

 

[IDRick]

Thanks, Mel!  Very helpful!

[IDRick]

Thanks, Randy! Good info and cleared up that question for me!

[RR_Mel]

The male “Arduino” connector type header strip cuts or breaks easily and you can use all 40 pins but the female header strip has to be cut and wastes a pin on each cut.  Even though it costs a pin for each cut it’s still a supper low cost connector.  Ten 40 pin male header strips for $1 = ¼¢ per pin each.  Female connectors at $2 for ten header strips = ½¢ per pin so no big deal at wasting a few pins.

 

I use Amazing Goop on the soldered end of the connector to form a stress relief to prevent the wires from breaking off.

 

 

Goop works great on test leads too.

 

 

I also use the round pin header strips.  They are compatible with the NMRA 8 pin connectors and again very low cost.  They also come in 40 pin single row and 80 pin (2X40) connectors.

 

https://melvineperry.blogspot.com/2017/12/december-15-2017-micro-connector-update.html

 

I use the round pin header strip connectors for all of my structures and passenger lighting.  Their standard 0.10” spacing makes the perfect female socket for two wire LEDs.

 

 

Four pin double row connector works great for my three color signals, they are small enough to fit through a Evergreen 234 tubing.  I mount a short piece of 234 tubing in the roadbed next to the track for each signal.  The four pin pig-tail easily drops through the tubing and plugs into the signal cable (flat ribbon cable) going to the Arduino Mega.

 

The signals are Mel made from brass and resin with a three color LED.

 

Being retired I make as many things as possible to keep the cost as low as possible.  I was brought up by my mother and father that went through the Great Depression so conservatism was drummed into me starting when I spoke my first words.

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.

 

[IDRick]

Thanks Mel, very helpful!  Wish you were closer!  Would love to spend a day with you to learn your many MR tricks!

[RR_Mel]

Check your Forum Mail

 

 

Mel

 

 

My Model Railroad   

http://melvineperry.blogspot.com/

 

Bakersfield, California

 

I'm beginning to realize that aging is not for wimps.