I am sure we have all been there; there must be a servo connector loose somewhere, you firmly press each one with fingers too large to press just one connector, you wondering whether the wires in each connector are well-crimped, you stare in dismay at at the spaghetti emerging from the APM. While working on my computer last week I just may have come up with a solution. Why not use flat ribbon IDE cable instead and 3x8 headers (http://www.pololu.com/catalog/product/1038) instead of 3 conductor servo wire? Here is what I did:
1) Reduce the width of the IDE cable to 24 connectors (3 conductors x 8 channels)
2) Split the ends into groups of 3 conductors
3) Strip the plastic off
4) Split each group of 3 into individual wires
5) Tin each wire
6) Tin the 3x8 plug
7) If you want to use very thin heat shrink tubing, slide it over the wires now
8) Solder with a quick touch
9) Cover in liquid plastic / slide the heat shrink in place and heat it
10) Repeat for the other side of the wire
That's it! Now you have connector that is much less prone to move about or come loose, there is less risk of bent pins, you can be press it in or pull it off easily without pulling on the wires, and it has the benefit of soldered connections. It may not be lighter that a traditional setup, but the flat ribbon can fit above or under batteries without any issues, takes up less space and just looks much neater than the traditional spaghetti.
If I am not mistaken, you can also reduce weight a little more by only conn
ecting 8 wires to the signal pins and connecting a single power and ground wire. If you still want to make sure each channel still has signal, power and ground, just solder a small wire across the power and ground pin rows on the back of the 3x8 connector. Would love to know if my theory holds water!
Notes:
!) The 3x8 plugs fit my ImmersionRC receivers perfectly, but not my Hitecs receivers. I am not sure it is possible to get them in different widths, by you can always use the 3x8 plugs on one and and traditional servo connectors on the other, at least this cleans up the spaghetti!
!) Make sure the wires line up correctly
Happy soldering!
Robert
Comments
Hi everyone,
I'll put the photos up as soon as I am home (I actually thought I had saved this as a "draft" but I must have sent it in by accident. R_Lefebvre's point on retention is interesting, it could be dependent on the connector as retention is main advantage I have noticed between this solution and "normal" servo connectors. The friction of all 24 pins holds mine in place much more solidly than traditional housings.
The IDE cable is a good idea and Starwalt's products are cool, but I think we need more conectors for example for wings conection would be interesting have a small conector with four pins (aileron signal, flap signal, positive and gnd) or six (aileron signal, flap signal, servos positive, common gnd, ASsignal, AS possitive).
I made one of this six pin connector with two glued MXP connectors (the green), I don't have photos becaruse it's mounted.
I'd like have some connectors models to be safety, small and easy to plug.
Although not exactly what Robert is discussing, here is a paper on servo connectors that I could not have written better. Hansen Connector Article
If there were the ability to make something a sticky resource, this is an excellent candidate.
Robert is emplementing a solution we all deal with in one way or another - cable management. The redundancy of connectons on the APM2 is somewhat intimidating for a neophyte. Yesterday, after receiving my order from 3DR, I found that even with careful thought, I still had one connector that required some alteration - the power connector for my AR6210 receiver.
I will discuss my modifications more in a blog post after some testing this weekend.
Paper and magnetic medai were the growth markets when computers came out in the 80's. Now printer ink seems to be seeing a slow decline. Wiring? It will never go away but take different forms.
Hmmm... I'm not so sure about this. I'd seen people do similar with the LED wiring, and so I gave it a shot. I found these female headers to make HORRIBLE connectors. They have very little retention force, and will intermittently lose contact. It's tollerable for LED lighting, but I'd never use it for servos/ESCs.