Robots in Architecture Forum

Robots in Architecture, Art, and Design => General Discussion => Topic started by: Xylotica on September 14, 2015, 09:49:47 PM

Title: Home made stand for a KR6
Post by: Xylotica on September 14, 2015, 09:49:47 PM
I am designing a stand for my KR6-arc, and I'd like some advice from anyone who has done that already.
Maybe a kind of twisted prism like on the attached image, if I can't get my hands on a large pipe segment.
I would like to run a FEM analysis on this part, but I don't know what kinds of forces and torques it will be subjected to.
Any ideas about that ?

Cheers,
Title: Re: Home made stand for a KR6
Post by: Johannes @ Robots in Architecture on September 14, 2015, 11:11:24 PM
Hello,

Here are the relevant values for the KR6-2, which should be very similar to your KR6 arc. That should make simulation and dimensioning easier!
Fv = Vertical force Fvmax = 4,600 N
Fh = Horizontal force Fhmax = 5,000 N
Mk = Tilting moment Mkmax = 5,200 Nm
Mr = Turning moment about axis 1 Mrmax = 4,200 Nm

Best,
Johannes
Title: Re: Home made stand for a KR6
Post by: Xylotica on September 15, 2015, 09:17:25 AM
Hello Johannes,

and thanks for your answer.
Any idea how I should combine those efforts to create load cases ?
In construction, for example, you would have to perform analysis with :
1.5*SNOW
1.5*WIND
1*SNOW+0.7*WIND
etc...

Factors above 1 are security coefficients which are not relevant if the given values are already "Extreme" values.
But it is important to know what combinations of forces and moments are likely to occur simultaneously because they can yield unfavorable cases.
For example, 0.5*Fh+0.5*Mk can be worse than 1*Fh.

Cheers,
Title: Re: Home made stand for a KR6
Post by: Johannes @ Robots in Architecture on September 15, 2015, 10:23:34 AM
Phew, not really my area of expertise, but I'm sure that the KUKA values already contain all kind of safety coefficients.
After all, they assume a maximum force of 4600N for a 200kg machine.

Best,
Johannes
Title: Re: Home made stand for a KR6
Post by: Xylotica on September 15, 2015, 11:47:38 AM
Hmmm... Load values, but no certified, normed, approved and stamped  load combinations ?
How un-German... :)

Anyways, thanks for the data, I'll try to mix it somehow.


Title: Re: Home made stand for a KR6
Post by: Johannes @ Robots in Architecture on September 15, 2015, 10:17:04 PM
For a final confirmation it may be a good idea to call the KUKA hotline. However, chances are good that they will also only quote the manual ;)
Title: Re: Home made stand for a KR6
Post by: Xylotica on September 16, 2015, 08:19:58 PM
I applied all the loads simultaneously on my FEM model.
Stress in not a concern, and max displacements are less than 0.2mm

That should be fine...

Height of the stand is 700mm ; weight : 67 kg.

Cheers,
Title: Re: Home made stand for a KR6
Post by: Xylotica on October 13, 2015, 10:58:09 PM
Oh well,

I found a piece of ø405x6 pipe rusting in the scrapyard, and I thought it would be even better than my fancy bent sheet metal, so I went back to the drawing board...
Laser parts are ordered ; can't wait to get this thing done and start the serious stuff.
Title: Re: Home made stand for a KR6
Post by: Xylotica on November 29, 2015, 08:58:27 PM
There 'ya go.