Anyone tried these cheap eBay 5-axis trunnions with harmonic drives?

[Corvus]

https://www.ebay.ca/itm/223958526107...53.m1438.l2649

I'm tempted to take a chance on one. I'm making some very small parts which need to be cut on 4 sides plus an angled slot so indexed 5-axis cutting would save a ton of re-clamping on my 3-axis bench top mill.

If anyone has tried this one or anything similar I would love to hear about your experience.
Thanks,
Leo



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[cncmakers001]

Curious about the accuracy and quality, please kindly share experience after you got one.

[fc60]

Greetings,

I wrote to the seller asking for a PDF of the Owner's Manual.

Reply was...

"
Hi
Thanks for your message .
Sorry , the item do not come with user manual .
We do appreciate your understanding and time.
If you have any questions,feel free to contact us,we are always here to serve you.
Best regards"

While it seems a useful tool, I would look further and find a seller/vendor that will offer help should it be needed.

Cheers,

Dave

[CL_MotoTech]

It's listed for engraving, which to me would seem to imply thats it's probably not well suited to actual 5 axis machining. Even with 100:1 reduction, the steppers don't look particularly large.

[cncuser1]

If it on eBay then it is probably on Aliexpress. You might find other sellers there willing to give more information.

The thickness of the side wall where the connector is located tells me the maximum proportion of the bearing in that wall.
Also the construction material is aluminum, including the chuck.

So overall if I was machining steel, I wouldn't use a cutter bigger than about .048" diameter.
Also take careful note of the height of the unit, add your material holding to that height. That leaves little Z movement left to work with.
And the Z height of the head will be far up to column, increasing vibration.

Careful what you wish for.

[Corvus]

Well I've taken a chance and ordered one.

I'm only planning to make very small parts out of brass so if it's a genuine harmonic drive mechanism on each axis I think it will meet my needs.

I'll post again once I've got it set up.

[CL_MotoTech]

I look forward to the results.

[Halfnutz]

In the picture it does not look as though the table rotates.

[kawazuki]

In the picture it does not look as though the table rotates.

Have to look at all the pictures . . . . . https://i.ebayimg.com/images/g/BnEAA...xe/s-l1600.jpg

[cncuser1]

How will you do the post processing?

You will have to take great, very extreme care in setting it up. The alignment of ALL the axis of the trunnion to the rest of the machine will have to be accurate, otherwise errors in machining will be a multiple in the error in alignment of the trunnion.

[Halfnutz]

It is hard to tell from the pictures how rigid it is. If you bought one off of ebay from a well established seller with a 30 day no questions asked return policy, you could check it out anyway.. Like cncuser said, the post processing and set up would be critical. It could be a lot of fun using. Let us know how it turns out