Author Topic: What kind of quality to expect for chinese "Precision" tools and stuff  (Read 6400 times)

Offline lesterhawksby

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Re: What kind of quality to expect for chinese "Precision" tools and stuff
« Reply #25 on: October 17, 2016, 07:15:07 AM »
I would recommend checking if the ARC nut, on its own, is enough to sort out your ER collet problem. I had something similar - disappointing ER collet accuracy, replaced nut with a better one (ARC, not a real posh'un), same socket, same collet, problems went away. I have formed the impression that ER is sensitive to a bad nut.

I have a slight suspicion some categories (not all) on Banggood are the "seconds" that didn't go to named importers... even if you get the same item there are higher odds it's iffy. Other things are absolutely fine. Definitely not consistent.

Hope that ARC haul is all good stuff :-)

Offline tom osselton

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Re: What kind of quality to expect for chinese "Precision" tools and stuff
« Reply #26 on: October 17, 2016, 02:51:54 PM »
They probably are seconds I have never used them but the name says it " banged good "  but not  everyone can afford top notch components for something they will not use  that often.

Offline DavidA

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Re: What kind of quality to expect for chinese "Precision" tools and stuff
« Reply #27 on: October 22, 2016, 07:23:29 PM »
Just to add a bit.

Today I used for the first time my Chinese boring read.

Not a top of the range item by any standard, but looked as if it would be ok for the kind of stuff I do.

But I was a bit disappointed by the lack of detail to a couple of simple things.

The head came with half a dozen brazed-on carbide tipped tools.

I fitted the appropriate tool and proceeded to bore out a socket for a hex bolt head in a piece of Dural.

No real dramas, but when I came to remove the tool from the head it wouldn't come out.

Eventually I managed to tease it free and found a couple of marks on the shaft that had been snagging and that was what had prevented it coming out.

Further investigation revealed that the small grub screws that hold the tool in the head had conical tips.  And it was this cone that had dug into the tool and raised a couple of burrs.

Also the Allen keys that come with the kit are soft.
I have only used them for this one job and they are already rounded over on the corners. Virtually useless.

Still, you pays your money and you takes your chances.

The head is usable. But the screw tips need attention and the damage has to be removed from the cutter shaft.
And, of course, decent Allen keys obtained.

Dave.

Offline sparky961

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Re: What kind of quality to expect for chinese "Precision" tools and stuff
« Reply #28 on: October 23, 2016, 12:30:33 AM »
... it was this cone that had dug into the tool and raised a couple of burrs.

Also the Allen keys that come with the kit are soft.
I have only used them for this one job and they are already rounded over on the corners. Virtually useless.

The head is usable. But the screw tips need attention and the damage has to be removed from the cutter shaft.
And, of course, decent Allen keys obtained.

Dave.
[/quote]

May I suggest milling or grinding a small flat on the shaft?

Also, don't stop at tossing out the allen keys. Replace the set screws with high quality ones before you're cursing one with a rounded out head.

Online PekkaNF

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Re: What kind of quality to expect for chinese "Precision" tools and stuff
« Reply #29 on: October 23, 2016, 02:51:59 AM »
I got friday two same items: ER25/MT3 shanks, cleaned them up and assembled with a good collet and mesured silder steel rod. Put them on surface plate and measured: Other was 0,06 mm and the other 0,8 mm TIR. Paid 12 per piece....so, other one is usefull for drilling and other uses I got it.

Other one is a plastic bucket of "trash tools" waiting insipration to check further or used for something that accuracy is on the list.

To the booring head: I would chance allso all screws and specially the set screw. Had one breaking in the hole and it was a proverbial to move.

Online PekkaNF

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Re: What kind of quality to expect for chinese "Precision" tools and stuff
« Reply #30 on: October 23, 2016, 06:41:06 AM »
Soo...turned better ER25/MT3 shoulder down (because my mill has a slot at the end of spindle for dog. OK. for normal spiral drills.

But sometimes you'll get a nice surprice. Years ago I bought one long single tip MT3 boring bar from ARC. It seems to unbelievably straight for such a tool. 0,02 mm TIR near tip! In a pinch I could use it as a MT test bar. I never used it first while waiting for it I rushed to work with a boring head and later didn't have faith in that bit, but it is standard 8*8mm bit. Should get one.

My setup for MT taper shanks, I found one MT/MT adapter that has female taper very concentric with outer shell.

Pekka