eBay router

How about all the missing bolts in the rails on all the machines in the range :cower:

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Originally Posted by m_c

I just had to go and have a look.
The VFD mount is my favourite part, followed by the control box cooling fan location

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Lovely long gantry on this 4 x 8 machine, and such a sturdy bed. Let's hope they are designed to wobble in sync.

There's an impressive cost escalator on size... and I honestly can't see how its justified. Each sized machine is essentially just a bit more box-section/rail/screw and not much else.

Anyway, what is curious to me is the choice to orientate the gantry to straddle the widest axis... Is that a good thing? (it feels like you're creating a problem with an unsupportable beam... if deflection was a concern)

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Originally Posted by Doddy

There's an impressive cost escalator on size... and I honestly can't see how its justified. Each sized machine is essentially just a bit more box-section/rail/screw and not much else.

Anyway, what is curious to me is the choice to orientate the gantry to straddle the widest axis... Is that a good thing? (it feels like you're creating a problem with an unsupportable beam... if deflection was a concern)

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Na the beams are full of helium to stop them from sagging :witless:

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Originally Posted by Clive S

Na the beams are full of helium to stop them from sagging :witless:

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I thought that by missing out alternate bolts on the rails, it would create triangular compression forces along the beam and hence the mechanical stiffness would be greatly enhanced.

Such a pity we are well past April 1:teapot:

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Originally Posted by Clive S

Na the beams are full of helium to stop them from sagging :witless:

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The helium is dual purpose.!! . . . It's so you can still laugh when you really want to cry because realize what a bog of shite you bought....:hysterical:

Hi JAZZCNC
I have been lookig at the same CNC router on Ebay and wondering about the quality of it, so your response to this question was very useful for me
I note you say that you build machines for people..
I am interested to get an idea from you as to what you would charge for a similar sized machine, (say 1000 x 1000 or 1220 x 1220 ie half sheet) that would be sturdy enough and suitable for milling aluminium.
Many thanks

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Originally Posted by JAZZCNC

Ok well I'm going to answer this but I want to make it clear because as most of you know I build machines for people that in no way what I'm about to say is said to pull this machine down for my own purposes because I really don't need to. Neither is it intended to say anything about the guy or company building them as I don't know him at all.

What you need to do is look carefully at the machine and ask some questions about it.!

#1 The frame is a welded construction which at first might seem good, but as any on here who have welded a frame will tell you they always twist and move. Also, it's critical to accuracy that the surfaces the rails fasten onto are exactly on the same horizontal plane and vertical planes. This is why we go to great lengths machining or using methods like epoxy leveling.
This machine as NONE of this done to it. Add to this that the 75mm with 3mm wall thickness isn't that strong and being thin-walled it resonates quite a lot which again affects quality of the cut.

#2 Gantry is a very weak affair that's better suited to a plasma machine, just.!!... and again no signs of any attempt to make sure it's flat and not twisted. Plates and connections to ballscrews and key areas like Z-axis are flimsy thin things.

#3 The motion control side is done from the PC with a £5 breakout board. From what I can see he's using commonly used refurbished Dell PC's, which are actually the same ones I use with Ethernet controllers.
If so then I can tell for sure that the parallel port on these is very flaky and I use exactly the same setup for testing and setting up machines with the same KKo1 board and they crash and lockup for fun. So bad that they won't even pass the Linux CNC latency test for using with a parallel port.

#4 Nema 34 motors are just wrong choice for a machine this size and I'd put a wager on it they are run on low voltage to boot. NEMA 34 motors need lots of voltage to get speed. Thou he does use 16mm pitch screws which will offset this to some degree, but still not a good choice for several reasons.

#5 The rails are the round type and the cheap variety, in fact looking closely at the components like ballscrews and BK/BF bearings I believe they are the lower quality units that come out of China, Not all ballscrews and bearings coming out of China are the same quality. Again many on here who have built and bought from China will confirm this.
I've spent a lot of years using various suppliers in China and I'm pretty sure these are the lowest spec available and is how they can sell these machines at this price. Which is ok but they wear out quickly and get sloppy fast and when fitted to a machine that isn't built very accurate to start with these all compounds to give a not so accurate machine.!

#6 The Z-axis is a weak affair fastened to flimsy plates that extend too far at 170mm with a heavy spindle on the end. The end result will be vibrations at the tool which is exactly where you don't want it.!

Other than these things then it's fine for light hobby use provided you are aware of its shortcoming and low-quality components. Oh and the shitty parallel port which I wouldn't trust to run my kettle.!

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Originally Posted by cncmystic

Hi JAZZCNC
I have been lookig at the same CNC router on Ebay and wondering about the quality of it, so your response to this question was very useful for me
I note you say that you build machines for people..
I am interested to get an idea from you as to what you would charge for a similar sized machine, (say 1000 x 1000 or 1220 x 1220 ie half sheet) that would be sturdy enough and suitable for milling aluminium.
Many thanks

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The machine on ebay cuts aluminium fine, all day long, despite being designed for cutting MDF. Nice clean cuts even in thin 1050 sheet.

In comparison to others in similar price bracket, i.e. 60/90 chinese routers, Xcarve and so on, it's far better.

Could the machines be better, yes, could the finish be better, yes but for around £2500k after some basic mods they work well.

Hi Chip Owner
Thanks for the feedback
What are the basic mods you are referring to ?
Is that the machine you are using ?
You are referring to thin 1050 sheet. Would it be OK to mill say 25mm aluminium parts ? (understandly with the appropriate depth of cut, plunge depth per pass and feed speeds)?
When you say ... the machine could be better, what parts are you referring to.
Many thanks
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Originally Posted by Chip Owner

The machine on ebay cuts aluminium fine, all day long, despite being designed for cutting MDF. Nice clean cuts even in thin 1050 sheet.

In comparison to others in similar price bracket, i.e. 60/90 chinese routers, Xcarve and so on, it's far better.

Could the machines be better, yes, could the finish be better, yes but for around £2500k after some basic mods they work well.

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Originally Posted by cncmystic

Hi Chip Owner
Thanks for the feedback
What are the basic mods you are referring to ?
Is that the machine you are using ?
You are referring to thin 1050 sheet. Would it be OK to mill say 25mm aluminium parts ? (understandly with the appropriate depth of cut, plunge depth per pass and feed speeds)?
When you say ... the machine could be better, what parts are you referring to.
Many thanks
_________________________________________

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Yes I have one of those machines, ordered just before lock down, I would have liked to visit during the build process but this wasn't an option. Things like all the screw in the rails as mentioned elsewhere, I had to finish drill & tap some of these. Also the cables weren't through the frame tube.

Position of VFD is personal choice.

I've added a galvanized plate across both sides of the bed side to reduce side spill of chips, I've added a similar plate to the rear of the gantry, I'll be adding a 4th to the very rear soon too. I've also added some triangle braces on the Z axis top plate, long term I'll do these properly.

Part way through a vac bed installation as I cut thin sheet and will eventually replace the supplied MDF wasteboard/baseboard with steel.

25mm aluminium parts would be fine, it's all down to bit you use and hold down method.

It doesn't do slow at speeds 300-1100mm per minute it's very noisy. Over 1150mm per minute it's fine. Our current bits allow cutting of 1050 sheet at 1150mm-1300mm - with a nice clean cut requiring minimal cleanup. We're changing to a slightly higher grade on next tool order to increase cutting speeds further.