Hi all
i recently bought a small mill on eBay and to say I am extremely unhappy with it. The guy that sold it converts them from manual to Mach 3.
should I post a link to the item ?
i don't want anybody caught out like I was.
cheers for reading.
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Hi all
i recently bought a small mill on eBay and to say I am extremely unhappy with it. The guy that sold it converts them from manual to Mach 3.
should I post a link to the item ?
i don't want anybody caught out like I was.
cheers for reading.
It would be interesting to see what it is, what has been done to it and why you are unhappy with it.
You could post a photo of yours, then we'd at least have something to look at ;-)
It was described as having servos with encoders on the drives and very accurate 0.01 mm on repeatability.
good for production runs. Everything setup and working.
got it and went to reference it and noticed the switch was in the wrong place for the x axis.
No ball screws on it, just the standard lead screws.
the z axis servo is atached to bevel gears and there is slap in the movement. He tells me there is zero backlash.
I will take some responsibility for not asking if there was ball screws and assuming there would be.
How much backlash is there on each axis?
http://www.mycncuk.com/attachment.ph...id=14791&stc=1
On the z axis just over 0.03 mm
What's the backlash on X and Y, and was backlash mentioned in the listing and have you measured the positional repeatability?
I only hope when you get it all sorted that you are happy with it. Perhaps the guy that sold it to you would do something about it.
The x and y axis aren't as bad, but with no ball screws it's going to need constant attention.
the guy won't help at all, I offered to pay for the ball screws etc and fit them myself if he machined them to suit the mill. No go.
he had it setup so the x axis referenced to the right. (Table move right ) never see that before on any mill.
what the hell is the point in fitting servos with encoders to a standard lead screw lol.
so the guy won't answer my emails or answer the phone, he has them on eBay as a classified listing. So no come back .
I currently have the same machine from the same guy I guess.ive had similar problems accuracy was out and still is. the mach3 licence was a copy.steps were out by alot.does yours reference to zero
Mine dosent reference, he has the switches setup as home and limit. So when it hits the switch the machine goes into fault condition .Quote:
Originally Posted by lukecnc2012
did you raise your concerns with him.
I sent a couple emails about accuracy as I was getting .1
And a couple over issues not being able to calibrate backlash etc.
The machines definitely need gas struts on the z had problems returning to z height on a job in the same place.if I can help with settings in anyway let me know .
Was he any help to you?
the settings I can do, the machine cost me £4500 with the fourth axis and delivery. As it is it needs a refit, and I don't have time to do it. So I am at a loss.
he won't answer emails or answer the phone.
Yup same machine
Wow I I only paid 3200 if I'm correct with the 4th axis.the 4th is only 150 new.he did reply to one email after I complained about accuracy and loosing steps he suggested getting the encoders setup but unfortunately didn't seem worth it at the time . £4500 does seem more as he sold an identical one for 3800 a couple months ago.
Yup was £4500 with 4th axis, delivery was £250
would the encoders not need to be calibrated only once though, sounds more like backlash to me and wear on the lead screw nut. Any way the machine isn't capabile of 0.01 accuracy as stated in his ad
It might be worth mentioning here the vendor's ebay username, his town might help in case he opens another account in order to lose his history with the current one, he might assist his previous customers if prospective ones start asking all sorts of awkward questions about his wares ;-)Quote:
Originally Posted by Hellfire
If you paid via paypal and they aren't interested but the transaction was funded with a credit card you can still talk to your bank about fraudulent mis-selling and get them to reverse the credit card payment which will such the money back out of the vendor's paypal account, leaving it negative if he doesn't have a balance.
You should report him on the Mach3 support forum for selling bogus licenses, they take a fairly dim view of this and given the very reasonable licensing cost it does make him look rather unscrupulous.
On the subject of setup Mach3 you can use one switch as limit and home without errors when homing. Mach3 also has backlash and leadscrew mapping compensation settings which would probably at least get you going, adding an automated oiler would keep wear to a minimum.
If you want to take some of the vertical load off the Z screw it's worth considering a cheap and easily set up pulley and weight arrangement, leave a few pounds of load on the screw though.
- Nick
Thanks for the help bud, I am going to give him one more chance to reply before I put details up. Not looking good though.
i paid by bank transfer, so nothing I can do there.
Ok still no reply from him.
before I post the link to the mill, can I ask a question.
am I being unresonable in expecting this mill to have ball screws. Can a mill be 0.01 accurate on all axis with ordinary lead screws. Is it suitable for production work.
ok three questions
No No and No Clive
From a long time i feel there is a need in this forum to have a WALL OF SHAME. Cause i am tired of reading overexcited stories from newbies. Lets hear the truth about the bad stuff they sell using fancy words out there. In my early learning stage, before a couple of years i also got scammed with my first machine. All were praising it on the Zone and i was like a stupid fish that bit the bait.
Hopefully there is a solution to your problems. I believe as ball screws are quite cheap, best would be to think it well and spend a bit more importing it from China and fixing it yourself. cause obviously the vendor will do nothing.
This is the link
http://www.ebay.co.uk/itm/251841731008
For that kind of money you can get a Seig KX1 from Arc Euro and have a lot of change left over. You get ball screws on all three axes and good backup from Arc. I've had one for four years and it has given good service.
Jim.
I have seen this same mill and asked the seller a good few questions about it, he even posted vids of it on YouTube kinda proving with out load it does do what he said.
It's not good for you and feel sorry has you paid a higher price and seem to need to spend more to get what you should have had from the off.
Looking at the original ad, my first impression is that it is cleverly worded.
.
There is no mention that ballscrews are fitted. But then again no mention that the machine uses the original leadscrews. Repeatable positional accuracy is quite possible when the machine is not cutting, so there is a bit of a mislead there, but is it intentional? I would tend to say yes.
.
The ad also states that it is 'laptop PC all set up. runs on mach3', but does not state specifically that a Mach3 licence is included. He ought to have deleted the licence file and stated that a licence for Mach3 will need to be purchased, but he could claim that this was oversight.
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If you were to seek Barristers Advice on the matter, you would probably be advised that the compensation you would gain would be outweighed by the costs you would incur. As for value for money, I would reckon that the price was reasonable for a hobby machine (have a look at ArcEuros conditions of sale) but the claim that it is suitable for production work would have to be checked by a qualified and respected engineer.
.
It seems this guy is buying Chinese mills and converting them to CNC as cheaply as possible. He is then using eBay 'Classified Ad' to shirk responsibility. Ebay might (but probably won't) check out his history to see if he is legit.
.
I agree with the wall of shame, and I have my own immediate candidate, but we must be careful about the legalities and also be aware that it could be indiscriminately used by members with commercial interests. Already we have seen the forum used to promote products by 'customers' claims (but I am just skimming the surface).
.
I have taken legal action in the past and won, only to be frustrated to find that the defendant was operating under a shell company with no assets to seize, so I ended up a further £1,000 out of pocket and in 1976 that was no joke. I would advise anybody to think twice before acting, then think again.
Bite the bullet Hellfire and fettle the machine to do the job, or if you can't - put it back on eBay.
Best of luck !!!
Rob