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View Full Version : [Question(s)] Poor quality of PhantomX Reactor slewing ring?



Puffin
05-23-2018, 02:47 PM
We've just built a PhantomX Reactor and the slewing ring appears to be really poor quality. It does not spin freely, has visible gaps in the visible ball race, the centre moves around horizontally relative to the outer ring and the motion even "sticks" at certain points. It seems a terribly poor quality part compared to the rest of the kit. Is this expected, or have we received something particularly substandard here? It's certainly not at all impressive.

jwatte
05-23-2018, 04:06 PM
If it "doesn't work" then something's probably off.

However, the Reactor is a low-cost AX-12 based arm. I wouldn't expect it to use the same $200+ slew bearings that you'd find in industrial automation equipment.

Puffin
05-23-2018, 05:10 PM
What does "something's probably off" mean, really? I do have a bad bearing?

Certainly I don't expect a $600 arm to have a $200 bearing - that would be ridiculous. But this bearing is so poor that I can't imagine it actually cost even $2 and as such a $600 robot is hobbled by this one very low quality part.

What I'd like to know is how smooth-running are other people's slew rings on the PhantomX Reactor.

KurtEck
05-25-2018, 05:08 PM
Have you contacted Trossen, either by phone or email? Maybe there was a defective part...

Puffin
05-29-2018, 05:53 AM
@kurteck - I haven't contacted Trossen about this particular issue yet (other issues with PhantomX reactor, I have, and no responses yet). I was hoping for a bit of feedback as to the general quality of the part here first. After some "running in" it's working to a "sticky" but workable level, but actually I'd like to have a "really good" quality bearing here instead of this crappy thing, even if not supplied through Trossen. Would anyone know of sources for suchlike?

KurtEck
05-29-2018, 10:43 AM
Sorry, I am not much help there. I have one of their Arms, that I received when they first were coming out. I have not done much with it in a long time. I sometimes use it to test out some software controller stuff, but that is about it. Hopefully someone else will have some ideas on different options

jwatte
05-29-2018, 11:52 AM
I like vxb.com for bearings: http://www.vxb.com/SearchResults.asp?Search=slew+bearing
Another name for slew bearings is "slewing rings."
You may be able to get away with a thrust bearing rather than a full slew ring, though, which would be cheaper: http://www.vxb.com/Thrust-Needle-Roller-7-8-x1-7-16-x9-64-inch-p/kit12679.htm
(I think a 7/8" ID bearing will fit pretty well around the horn of an AX-12 servo, but make sure to measure yourself for best results.)
You may also be able to use a conical / tapered roller bearing, typically used for drive axles, if you can fit it appropriately.