Why do 3 wire extension cables cost so much

Just had to buy some with a load of other stuff and noticed that a 4 pack of 12"cables cost more then a motor…


How about $0.50 a cable… They probably won’t have the key tab. If you can wait for the shipping which is free in some states then this is your place. The discount prices are amazing. I hate to not support Vex when I can…but this is too cheap.

Word of caution… I have not purchased these and they look a lot like the ones I purchase from ALLelectronics. These standard black cable sizes have slightly thicker plugs than the Vex green cables. If you fill up the cortex motor slots it can be a very tight squeeze. Also , I think 4 cables are too tight to get into the power expander. If you buy a bunch of Vex short cables…you could use them to interface with the cortex and power expander and use these as long extensions.

Anyway, …you would think Vex could get their prices more in line with these…but they have to stay in business.

It looks to me like both ends of those wires are females though, where as the Vex ones have one male side for connection into the Cortex and such.

No they aren’t, I’m pretty sure there is just the locks on the ends covering the male pins and you cant see them. It might not be the case, but we have some like this.

Thanks, Yes I agree looking at it, although the locks would need to be removed. Wish I’d asked this before I bought them, and searching for 3 wire servo leads brings up the identical pack on ebay, over here for £2.67… so basically 27p each compared to about £5.00 for the vex ones…

The locks are easily removed with the blade of a knife or razor blade. I have taken a lot off.

Thanks all, I know what to get next time, although for the moment I’ll keep quiet about it as I don’t want to get shouted at for spending 20 quid of our hard earned cash when I could have got away with less then a fiver :slight_smile:

Our wallbot last year required a bunch of extension cables, so we bought some from china that look exactly like the dealextreme ones posted.

Our advice: Don’t do that. The cables, as previously mentioned, were slightly thicker and needed to be sanded a little but that was no big deal. The smaller gauge wire and unreliability of the cables was, though. We had at least 3 crap out on us during worlds. This year we played it safe and bought vex ones. The Chinese ones are junk!

Good feedback. I never thought about sanding them. Perhaps that weakens the plugs.

We have used the Allelectronic ones that probably are made in China without much problem in FIRST.

I wonder where the Vex cables are made? Probably China too …but maybe from a higher quality supplier.

Be careful using non VEX cables on competition robots. The cables need to be identical to VEX cables otherwise an overzealous inspector may not pass you during inspection. Length and wire gauge should be the same, for example, AndyMark has some nice cables here but they are not ribbon cables and are covered in heat shrink as well as being of slightly thicker wire. These are (as I understand the rules) not legal.

I’ve used the same cables on other hobbyist projects as well without sanding them, and they have failed there before too. It’s just a general quality issue with them. It’s possible the allelectronics ones are better, but I would bet money that the DX ones linked are the same ones we had issues with. They are close enough to vex that we passed inspection without a glance at them.

i guess this thread can be more constrictive by linking to “identical” products?
and debate over said links :wink:

I don’t get it.

I just checked the price for cables from VEX.

2-Wire Extension Cable 12" (4 Pack) 276-1432
In stock

That is $9.99 for four cables. A 269 motor is listed at $12.99 and a 369 motor is listed at $19.99. I guess I don’t agree with your conclusion.

I checked Andymark and they cost $2.50 each (about the same as VEX). I then checked at ALL Electronics - the cost is $3.25 each (unless you buy 20 or more to drop the price to $2.80). I would also agree that they are NOT IDENTICAL.

I have checked the prices for fasteners and other parts and I find VEX to be fairly priced on all items. E.g. - I priced fasteners from VEX and from Grainger and McMaster Carr, VEX is still a good value. E.g. - I priced individual components of the Double Acting Pneumatic add on kit; quite simply VEX is a better deal than getting the individual parts from SMC suppliers.


The comparison was being made to 3-wire extensions. A four pack, 12" 3-wire is $19.99.

The problem with VEX servo cables is that the female end (technically the male end but in the RC world it gets called female as it’s normally shrouded) uses a male housing (again RC speak) rather than the shrouded female housing. This makes finding exact replacement parts hard. You could make your own, in small quantities they work out about $1.30 each.

One source of parts is here.
Male Pins http://stores.servosandstuff.com/-strse-355/30-pcs-Male-Gold/Detail.bok
Female Pins http://stores.servosandstuff.com/-strse-356/30-pcs-Female-Gold/Detail.bok
Housings http://stores.servosandstuff.com/-strse-352/10-pcs–Futaba/Detail.bok
Cable http://stores.servosandstuff.com/-strse-117/25-ft-High-Quality/Detail.bok

You could also buy this http://stores.servosandstuff.com/-strse-89/12in-%28300mm%29-22AWG-Futaba/Detail.bok and replace the shrouded end with the alternative housing without having to crimp anything. Cost $1.35 each and (although I have not tried) should look identical.

For more than you ever wanted to know here are instructions.


thanks for the Links James, I’ve been building my own cables for a while now and I always seem to get confused finding Pins and wires online.

I traded the cost of a crimper vs buying premade cables and found it would be more cost effective to build my own. They are legal in competition if they are identical i.e. length and gauge. but as I don’t compete I don’t worry about it that much, and make custom lengths as needed.

Cheers Kb