Anybody see anything terminally wrong with this ebay item no 140087278572 before I sell a couple of the kids and jump in? I realise that now I have drawn everybodys attention to it the price is going to be silly - DOH!
Towards the end of March you will see the appearance of the Sieg X2 and Sieg Super X3 cnc converted machines on the market. The price is to be announced, but expected to be in the region of £1800, and £2,800 respectively. There will also be conversion kits available.According to my sources they are currently in production and the UK web-site is currently under construction. That's about all I know at the moment, but I hope that helps. FWIW, I wouldn't chase the price up too much on the eBay one, you could be inheriting someone elses problems, on the other hand the seller has got good feedback and is well-establisehd. If I get any further information on the above, I'll post it. Hugh
I would hope that the reserve is lower than the buy it now price, but I'm cheap enough that I'd waste £5000 of my own time and pay more for the materials by buying the wrong thing too cheap several times :-(
Can't see anything obviously wrong, but Why hasn't he finished it?
It's not an X3 but an X2 and one of the early Simply conversions. If it starts to get anywhere near the buy it now price it's possible to convert an X1 long bed machine which actually has greater travels than the X2 for about the same price but better spec.
Those conversions used the 3 axis Xylotex driver card running flat out and to be honest it's not a good way to go as if one drive pops the whole board is toast and they have no protection or isolation circuits built in.
If it goes cheap ? and I suppose that's relative then it's a good start and can always be modified later.
No problem with belt drives, even the 45,000 pound machines use them. You can direct drive a stepper system but servo drives always have to be geared down to get the torque out of the high revving servo's.
No ball screw on the Z but a worn driven drive to the standard rack and pinion. Link to the X and Y ballscrew suppliers in the advert.
This is Simply new web page as they are now tied up with Warco Nice to see them with some new pages as at the recent shows their Warco machine has been sporting an X3 in red on the startup screen
As John S has pointed out, you can do better with the long bed X1 as a starting point, rather than this X2, and going the Xylotex board route for the driver wouldn't be my choice either. Much safer from the maintainability point of view to use three single axis drives rather than a single thre-axis drive.
Mechanically, it doesn't exactly look like a professional job to me either - maybe thats why the current owner was re-working it.
There have been one or two threads on X3 and other small machine conversions in this newsgroup over the past few weeks - worth taking a scan through those before you shell out for this one - unless it goes for a *really* low price.
Yep - its the old RoHS gotcha. You could always get some shipped to a buddy in the states & get them to forward on.
There is a company in the UK that sells similar boards based on the Allegro chip that Xylotex uses. However, from my own experience using boards based on these Allegro devices, they are very fragile, and can be prone to noise problems (I attempted to construct a workable 4 axis setup using them and failed - the axes would "creep" when they weren't being stepped...never bottomed the reason so I sold off my remaining Allegro-based drives having blown two three-axis boards in the process).
The better option from a number of points of view would be to replace them with decent drives such as the 3A ones sold by Arc. These will handle higher supply voltages and are (in my experience, at least) far more robust than the Allegro-based drives; they also have opto isolated inputs, which is a bonus.
Hi Tony, thanks for the info. I've set myself a target of finishing the X2 CNC here by the end of 2007 (it's been going on for more years than I care to admit to), and will likely visit the controller side again.
I'll use the Xylotex to get it up and running as all the noise & decoupling problems have been sorted out, and it's boxed up ready to go anyway.
I've had a look at the Arc 7.5A driver, not that I need anywhere near that current but it does 80V instead of 40V which confers other advantages (and only 20 notes extra).
You're right - the 80V supply capability does confer advantages in terms of the speeds that you can obtain with the same motors (broadly speaking, double the supply voltage and you double the speed for a given dynamic torque) - however, the real advantage that you would gain by that would be more apparent if you were building a large router or a laser cutter, where the improved rapids would be of real benefit in reducing machining time. On a small machine like the X2, you certainly don't need more speed for cutting, and the table is small enough that increasing the speed of your rapids won't deliver much real benefit in reduced machining times anyway. On my X3, I can manage in excess of 2 metrres/min rapids, but I have actually set it for slower max speeds (1 meter/min) as the X3 table moving at that speed scares the cr@p out of me.
No I didn't ! I decided my budget was what it would take me to get to the same stage with my X1 and since that looks like about 600 so far I ducked it. Oh and the X2 X3 mess-up was me - just wishful thinking I suppose, besides I've got a significant investment in M2 tooling now!