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View Full Version : Dynamixel Cheap Chinese Knock Offs!



Fatfrank69
02-16-2013, 03:56 PM
Look what I found on ebay earlier:

http://www.ebay.com/itm/130417832266?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649


Plus these copying the Herkulex, but they've only copied the body? They're just analogue servos!

http://www.ebay.com/itm/140741256873?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648

Comments?

Gertlex
02-16-2013, 04:19 PM
With the high shipping costs, those are more expensive than AX-12's, and only a tad stronger. No mention of wires with them, either, and I'm sure they don't have their own brackets.

Analog servos = wires everywhere. No thanks :)

Fatfrank69
02-20-2013, 12:31 PM
I'm not sure how you worked out they're more expensive? Comparing an individual one of them to an individual AX12 you'd save around £10 (around $15) but the Chinese one is only 8 Kg-Cm of torque and I'm not sure its worth saving $15 when you can guarantee they won't be as good or last as long as the Dynamixels. I just posted out of curiosity mainly. :)

Gertlex
02-20-2013, 04:17 PM
Like I said: shipping cost. $8 at best per servo, versus ordering AX-12's in bulk, with no shipping, for ~$35 apiece.

robotmaster
02-21-2013, 03:40 PM
From where and in what quantity are you getting the AX-12s for $35 a piece? The best I could find was $44.

Tyberius
02-21-2013, 03:59 PM
$37.42 a piece: http://www.trossenrobotics.com/p/ax-12-dynamixel-actuator-6-pack.aspx

Just need hardware/cables.

As someone who has dealt with literally dozens of various chinese manufacturers of servos, I'll take known quality and reliability from Robotis any day of the week. Saving money often means you'll spend it in time.

Slugman
02-21-2013, 05:51 PM
I'd go even further, & say it often costs you not just time, but money as well.
If you order cheap shit that fails, then you still have to buy the decent stuff.
You have wasted the time spent ordering/waiting for two sets of gear, plus the cost of the cheap shit & two amounts of postage.

A mate of mine who buys computer components describes it as "The sweet spot". The cost of something rises exponentially as you increase the quality, so find the product that lies in the part of the cost curve just before it skyrockets in price. Assuming of course it will still do what you want/need. The sweet spot moves over time, as products get more & more features built in for the same price.

For me, the AX-12's are a little low on the curve as I want more torque, but I don't want to outlay big $$$$ for 64's. I am prepared to use reduction gearing & levers to get the AX-12's to do what I want in some parts of the robot, & reduce weight in other parts so they can cope.
Back to the original comparison of servos, 8Kg of torque isn't really enough for an AX-12 scale quad/hex/biped anyway, so there's not much point considering them. :sad: