QUALITY servo DIY extensions extendors wires

[Microbatman]

I just tried making a custom length servo extension.


Using these

http://www.bphobbies.com/view.asp?id=V895018&pid=V657932


Only to find out the connection was terrible.

It was too loose to trust and barley gripped when plugged into the reciever.

I am looking for a MALE plug (inside has female pins) solution that is reliable and will work

I have made three of these using these parts and non of them had any quality to trust.

What I am doing wrong?
Do I need a special crimping tool?
Do I need better quality pins?

If I give up,
Is there any source that makes custom length to order servo extendor wires?

[ghoti]

I buy extention cords that are too long and cut them down. You end up with 3 soldered lap splices, staggered so they don't overlap. They are insulated with three small lengths of shrink tube. Works fine for me but requires skillful soldering. Bill

[Nightz]

I never has any issues before I got a crimp tool. I used pliers and bent the little tabs by hand. When finished I put a tiny drop of solder. Using the crimp tool, I still put a very small amount of solder to help ensure the wire won't pull out.

-Rocko

[ZAGNUT]

I am looking for a MALE plug (inside has female pins) solution that is reliable and will work



no, you're looking for FEMALE plugs if you want FEMALE sockets inside. the pins on the receiver are MALE. for some stupid reason people in our hobby like to assign the sex of a connector based on the housing or shroud instead of the actual pins/sockets. learn to use the right terms and your search will be much easier when looking outside the standard hobby suppliers. :)


dave

[ZAGNUT]

and to be on topic: go browse the digikey catalog for 2.54mm connectors.

check the current ratings, cycle life and contact length to find something that suits you. for my servo leads i actually prefer connectors with solder tails and not crimps. after soldering i use a good flexible shrink tube on the connections. if the pin spacing on the reciever i'm using allows i also put a large shrink tube over all the connections and the plastic housing, and while srinking it fill the area around the wires with hot melt glue.



dave

[XJet]

I never has any issues before I got a crimp tool. I used pliers and bent the little tabs by hand. When finished I put a tiny drop of solder. Using the crimp tool, I still put a very small amount of solder to help ensure the wire won't pull out.
-Rocko

Nooooo!

Don't solder those connections, they will fail early if you do.

I never believed that a *properly* crimped connection was better than a well soldered one until I did the research myself.

But (and the FAA agrees), a properly crimped connection is superior to a soldered one in almost every way.

It's stronger, electrically more conductive, less susceptible to vibration (a *big* point in nitro/gas-powered models) and more reliable.

By adding solder to a crimped connection you are significantly reducing its reliability and performance.

It's worth noting that the housings used in our RC connectors are *not* designed for soldered connections either and don't provide the level of support necessary to promote vibration resistance -- this can only be done through the use of a proper crimping tool and technique.

It's really not worth risking a model for the sake of a few dollars.

[Matt Edwards]

Ditto what XJET says.
A poorly constructed crimp tool is a total waste of time, but shouldn't be used to disregard all crimp connections. A good crimping tool costs big $, but they work well giving reliable results. A crimp done properly will give years of reilable connection. One reason crimps are favoured is the fact that tehy are generall chemical free. No flux wicks up into the core
Good luck
Matt

[village_idiot]

electrically more conductive


I would need to see tests on that one, but the rest I would agree with. One reason the FAA might like crimped connections is that if the wire/connector over heats, then you won't get the wire pulling out of the connector when the solder melts. Also by not soldering, how much weight will be saved in a full size aircaft?

[XJet]

They are more conductive because solder (which is an alloy of tin and lead) has a lower conductivity than either the wire or the connector itself. When you solder a connector, you're introducing the resistance of the solder to the circuit. Crimp it properly and you have a direct gas-tight cold-weld between the wire and the connector = no solder to impede the flow of electricity.

[Nightz]

Conductivity, flux, temp, impedance, ect.....hardly an issue on my RC model.
It certainly is no worse than the other end of the wire thats SOLDERED to my ESC or servo PCB.

My opinion anyway.

-Rocko

[village_idiot]

I don't want to drag this out but again I would need to see proof. By that theory crimping tinned copper to gold connectors would be really bad, or even bare copper to gold.

[vintage1]

All I ever do is cut the servo leads and solder a bit of three core ribbon to each end.

Lighter than anything else.
More relaible than anything else provided each joint is braced with heatshrink.

[AndyOne]

Soldering flying leads is definitely not recommended in a IC engine installation because the fatigue performance (resistance to vibration) of solder is quite shockingly bad. Crimping is in every way superior to soldering in this application. The problem is that finding the correct crimp tool is very difficult and expensive. I tried a couple on the hobby market but they could only be described as dangerous. I only have to try the test where I remove the part of the connector that grips the insulation then crimp it as normal onto the exposed conductor. In some cases the connector just falls off in others it can be pulled off easily, neither of these is not acceptable. The connector should be clenched so tightly onto the wire that a cold weld is formed and the wire strands should break leaving a full set of strands in the connector when pull tested.
Crimping or clamping to solder tinned wire is the worst of all worlds because the solder doesn't form a cold weld no matter how tightly it's gripped and it's surface oxidizes forming an insulating layer in the joint over time.

Andy.

[Rodney]

I can confirm Xjets findings. As part of an aerospace lab test , we also found that properly done crimp connectors were far more reliable than soldered connection in all respects. I also agree with Vintage1 on soldering in extension (cut the original lead in half) wires is more reliable than any type of plug in extension.

[Microbatman]

Any one try these pins?

http://www.allerc.com/product_info.php?cPath=10&products_id=2030


All I want to know is how are you making custom length servo extenders that are not the standard lenght 8 inch 12 inch 24 inch ones you can buy.

I tried using the pins from my first post and they did not work.
I am quite sure it was the quality of the part rather than the assembly of the part as I tested the pins unassembeled and the connection was not acceptable.=

Lets not get into a solder vs crimp debate been there read that already.

All I want to know is how to make or BUY servo extendors that are custom length.

[vintage1]

I can confirm Xjets findings. As part of an aerospace lab test , we also found that properly done crimp connectors were far more reliable than soldered connection in all respects. I also agree with Vintage1 on soldering in extension (cut the original lead in half) wires is more reliable than any type of plug in extension.


IF you SUPPORT the wire with heatshrink so that the abrupt transition between solid (filled with solder) and stranded (and flexible) is not allowed to take any strain, you will get a far more relaible joint than any crimp done outside carefully controlled conditions.

The reason that crimping is done so extensively is that

1/. Its very cheap and easy to automate

2/. Its very predictable.. if the right tools, consistent stripping and suitable materials are used every time, the joint is 99.999% good every time.

3/. It does not lead to localized stiffening of stranded wire.

HOWEVER in an arbitrary situation outside production and quality control I maintain that soldering and heat shrink is a far easier joint to make well, and has BETTER failure for the same reason. If the joint takes a tug, it generally won't fail in flight. How many crimps have YOU seen come apart with a tug..or some years later when corrosion has wicked up the stands...

The key to joining wires is to twist them together by overlapping them, and to fill them with good solder and above all to put a fat piece of heatshrink over the lot to support it.

Our looms are not subject to heavy vibration..there is little need to go beyond that.

[ZAGNUT]

Any one try these pins?

http://www.allerc.com/product_info.php?cPath=10&products_id=2030




i prefer the type that wrap around all four sides of the pin, the one you linked to looks like it only does three sides and won't provide a very secure connection.

look for C-Grid connectors from molex. for the same price as that one connector you can probably get ten that are better quality.


dave

[dleroi]

All I want to know is how to make or BUY servo extendors that are custom length.


I get the parts here and make my own. High quality pins, no problems. Bought the crimping tool here, also.

http://www.hansenhobbies.com/products/connectors/connectors/

After crimping, I flow a bit of solder into the crimp joint. It doesn't weaken it, make it less conductive, or any of those things. (Sorry, just had to get that off of my chest.)

[Microbatman]

DLeroi

Just the answer I was looking for.

You da best.

Just read the PDF
Instructions on how to do it correct.

http://www.hansenhobbies.com/products/connectors/Connectors.pdf

Will place an order with these people soon.

Looks like my problem was not using gold pins as other materials have less than 10 cycles of use and become loose very soon in thier use.

And not having the right tool. The tool they have looks like a good deal I am going to buy one.

Good prices on all the other stuff too.


Thanks for all the help.

[Richard Ingram]

On the issue of crimp vs solder, for hobby use we are not looking for 20, 30, 40 year life. The crimp tools I have seen are junk, not much more than bending the lug with needle nose pliers. To not add solder is asking for a failure in the near term.
Richard :)

[XJet]

On the issue of crimp vs solder, for hobby use we are not looking for 20, 30, 40 year life. The crimp tools I have seen are junk, not much more than bending the lug with needle nose pliers. To not add solder is asking for a failure in the near term.
Richard :)

Wrong -- the levels of vibration encountered in any nitro/gas-powered model are so high that you won't get anything like 20 years -- or even 20 hours in some cases.

I make all of my own extensions using a relatively cheap crimping tool I got from RadicalRC.

It works very well *but* if I suspect any of the crimps I've made might be less than 100% (and sometimes they're not perfect) I re-do them.

So far, not a single failure and some of my planes (especially very light profiles with big 4-strokes) shake like hell.

In fact, I had a vibration-related failure on one of those planes -- it was where the power wires were *soldered* to the switch and that was despite a degree of physical support. The three home-made extensions on that plane have since done many more hours without a problem.

So, my practical experience tallies rather nicely with the theoretical predictions.

[dleroi]

Look, you probably don't have to solder the connection if you make a good crimp, but if you want a little insurance and you do it right, it won't turn a good crimp into a bad connection. It may turn a bad crimp into a good connection, though.

Yes, if you let the solder wick up under the insulation, the joint will be more prone to failure due to vibration. If you do it properly, though, the solder stays in the section of the terminal where the wire is crimped. So, there's the crimped section with the solder, a short section of bare wire (no solder), then the insulated part of the wire which is also crimped. This crimp, along with the short length of bare wire, isolates the soldered joint from vibration.

You accomplish this by using a low wattage iron, small diameter solder, and by applying the heat to the end of the wire. The solder is drawn toward the heat. If you do it right, no solder flows the other way to wick up under the insulation.

You should also be careful to not let solder wick under the insulation when soldering wires to circuit boards, switches, or terminal strips. Leave a little section of bare wire between the insulation and solder to absorb vibration, then cover it with heat shrink. Whenever possible, provide a strain relief.

[AndyOne]

I can't see how you can get the connector hot enough to solder properly without destroying the grip the crimp has on the insulation, it's bound to melt.

Andy.

[vintage1]

A hot iron and a deft hand. I make up power connectors (Tamiyas) that way.


In response to the nitro man..yes, nitro planes that have unsupported wiring looms will fail. Crimped OR soldered..first thing I was taught as an avionics 'prentice was 'make your joint, and TIE THE CABLE DOWN'

We tended to use solid cored wire as well, laced into looms and tied down at specifically designed points. There are no stress points from flowing solder in solid copper: Just where it transits from a tag to a wire. So that was sleeved, BUT as you have pointed out, that's still not enough.

Its not enough for crimps either. Seen plenty of broken crimped tag-to-wire joints that have fractured where the tag ends, on many older cars..especially on starter motors subject to heavy vibration.


The answer is not to have long looms of cable that can resonate with the engine..and fracture. Tie them down. Build a wiring loom if necessary and tie wrap it to things.

If the wire can't move relative to the joint, it won't fail under vibration. Relying on crimping the insulation to make a strong enough joint is very very foolish, and there are not a few crashed aircraft to bear witness to that.

[AndyOne]

A hot iron and a deft hand. I make up power connectors (Tamiyas) that way.


When I used to make up Tamiya connectors by soldering, I always left the insulation crimp till last so the insulation wasn't melted by it's contact with the connector.

Andy.

[Richard Ingram]

I tried to get a decent picture of two crimps. The one on the left is a crimp with solder. The one on the right is crimp only. There is some melting on the insulation when soldering but no bad. You need the correct wattage pencil iron to solder something this small. The crimp only connection does not get tight on the wire strands. I grabbed the crimp only lug with pliers and pulled on the wire. The lug pulled off with little effort. The crimp with solder lug took a very hard pull before the wire broke. It could be that my junk crimper is no good. I will buy a new one. If I could get a crimp like a store bought servo extension I would be confident without solder insurance.


Richard :)

[jeffs555]

If you want a quality crimped connection, you need a quality tool. I bought one like this from Ebay for around $15. I think the new price is several hundred. http://cgi.ebay.com/AMP-CRIMPING-TOOL_W0QQitemZ250074336254QQihZ015QQcategoryZ66987 QQrdZ1QQcmdZViewItem

The difference between crimps with this, and with the cheap universal crimp tools is like night and day.

[Richard Ingram]

Jeff, can you put a picture here for a crimp made with this tool ?

[jeffs555]

Here is one.

[AndyOne]

Jeff,

It looks really good but have you tried my test by removing the insulation crimp and doing a pull test.

Andy.

[jeffs555]

Never saw a need to test without the insulation crimp. If the wire is going to pull out, it doesn't matter if the insulation is crimped or not. The insulation has very little resistance to pulling. I have applied quite a bit of pull on the wires(sometimes unintentionally), with no pull out. I have been using it for years with no failures. I think the main difference between this and the cheaper tools, is that the ratcheting action of the tool applies tremendous force to the crimp. Also, once the crimp is started, the tool will not release until the crimp is complete, so you always get a good crimp. I used to use Berg crimping tools at work, and they worked the same way. I actually liked the old Berg tool better, but couldn't find one on Ebay.

[Richard Ingram]

Yes that looks really good. See how the crimper folds the lug over and down through the strands ? That's what does the trick. So that pic is one that you did with the tool on ebay, right ?

[jeffs555]

Yes

[Eagleburger]

This is my current method of extending servo wires.

Cut the servo wire and the servo extension to the required length and solder together Solder the two remnants together for another short extension

[ghoti]

Yes, that is the best way to get there! I have done it for a long time and never a failure. Careful soldering with a hot, tiny tip is necessary. I use 800 degree tips and wet surfaces first with solder then cool then align and reheat to fuse solder surfaces into one solid, itegrated form, one secure glob of shiny metal usually in a short lap joint. If not shiny, joint was too cold. A hot tip allows high temperature attainment at the solder site quickly so the joint is fused before much heat leaks to nearby plastic sleeve that could melt if too hot. Bill

[WingsWest328]

Sorry to bump an older thread. I bought a crimper similar to Jeff's, AMP 9030-2-J off ebay and it works great. I have had no problems with wires pulling or any of that and I am very satisfied with the quality. It looks just the same as OEM products. I recommend buy one of those crimpers if you are going to be doing a lot of homemade extensions and such.
Great tool,
Cameron :D