Torque

Lynxmotion Robot Arms
1

I’d like to build a set of arms using Lynxmotion components if possible. Each arm needs to lift around 6.5lbs. Most of the weight will be on the ends of the arms. Possible? If so, which servos will work? I’ve not done any work with servos before so I don’t know the limitations. Thanks,
Darrell

2

Bueller?..Bueller?

3

You don’t say how large you expect each of these arms to be, but 6.5 pounds is going to be a bit more than many servos are going to be able to push around, let alone at the end of a compound lever such as an arm. The ability to do this would depend greatly on a number of factors, including but not limited to, the types and sizes of servos you use, the design and construction of the arms, how they’ll be anchored, the speed and accuracy you wish to achieve, etc. I am by no means an expert on robotic design, but these considerations are common to just about all arm systems, and it would be a good idea to start paring down your options from there.

Perhaps the reason why nobody has spoken up sooner is that “set of arms” and “6.5 lbs” is a bit vague. Maybe if you were a bit more specific as to what you need or are trying to achieve, people would be able to provide you with some assistance.

4

Not possible. Servos are not at the performance level yet to manipulate a 6lb object at any arm length. Sorry…

5

I second that.

While a 599HB with a 6:1 gear reduction box (www.servocity.com/) can lift 30 pounds, that’s only a single servo joint.
So, you might be able to build a very small 2DOF arm with that, but that’s just plain silly.

Look into pneumatics or hydraulics for your application.

6

The gear assembly is a fun idea, but it is S L O W. And there isn’t any easy way to interconnect them to build an arm assembly…

7

Thanks for the replys. I suppose I was a bit vague. My robot is a full scale replica of the Lost in Space robot. I’m currently using actuators to extract and retract the arms and remote auto door locks for the opening and closing of the claws. The claws/wrist assembly is connected to a flexible, rigid rod for each “arm”. I’d like to replace this with the servos. Each servo, elbow joint and wrist would be approx. 11" apart. A third smaller servo to open and close the claws. I can do all this with DC motors, just thought servos would be easier to control.

8

I may just keep what I have and use servos for the claws only. What is the most powerful servo available? Thanks,
Darrell

9

The HS-5995TG is currently leading the market.
They go for about $120.

Alternatively, the 599MG is quite a bit cheaper at around $40.
There’s a few catches with it, though.
It’s larger than standard size (which probably won’t matter for your custom application), draws a bit more current, is slightly slower, and is about 3/4 as powerful (still, by no means, shabby).

Both can be found on the main site:
lynxmotion.com/

10

Thanks Nick,
I think the best thing to do, is buy a couple and test them to see if they can indeed support what I’m trying to do. I’m not convinced they can’t given proper support via springs etc.