High speed spindle for Sieg X1
Just pondering the easily available options and looking for opinions...
Sieg X1, for anyone who doesn't know: http://www.arceurotrade.co.uk/Catalo...Super-X1L-Mill
CNCing this little beast was a fun exercise resulting in quite a tough and willing little machine. But it does flex, the head droops, the gibs and screws are not designed for the relentless movements encouraged by CNC making adjustment a constant necessity and the spindle is limited to 2,000 rpm. As such I don't want to spend too much more money on it but since the next step up will cost something over £1,500, well, this is where your all important opinions come in :smile:
I want to mess with some higher spindle speeds up to 24k - 30k appears reasonable, partly for PCBs but with a view to machining aluminium in less time than it takes to watch the entire first season of Game of Thrones - slight exaggeration here. The options so far considered...
In an ideal world I'd find a ER20/ER16 (8mm shank is a nice size) spindle exactly 50mm in diameter which would be a drop in replacement for the entire existing motor + head + spindle. It would drop right into this hole:
http://littlemachineshop.com/product...ory=-166688942 . It leaves me the question of how much spindle power I'd need and at the end of the day I'd still be left with a slack and wobbly machine.
Dremel
Haha, just kidding. From what I read even if the bearings are good, fixing the tool is not a repeatable process. Also highly unsuitable for side milling?
Proxxon IB/E
http://www.proxxon.com/us/html/38481.html
Repeatable tool mounting, low runout, not so expensive, light weight so could be used as a second spindle. Low powered, limited shank diameter, but may be ok for light milling? Not something I can move on to a bigger machine, at least not with any real value.
Chinese 0.8KW water cooled
Worst value, at lease size wise, for money out of the three common Chinese spindle options, getting costly but a viable device for a future machine, ER11 so limited shank size. 65mm diameter is a nice size, if I remove the X1 head etc and side mount on remaining spindle housing or even chop the end off the housing and do a proper job. Also weighing about 2.5kg (?) it fits well within the approx 15lbs weight of the existing assembly.
Chinese 1.1KW water cooled
Priced about the same as the 0.8, larger and therefore not quite so comfortable a fit at 80mm diameter, still ER11. In the end all I gain is more weight at approx 4.5kg. Still, perhaps more viable for a future machine.
Chinese 2.2KW water cooled
Not much more expensive than 0.8. I have no idea how much electrical noise this would put into my domestic mains, though I doubt I'd ever be close to its full power. 80mm diameter may be worth the hassle for the sake of the ER20 collets, here I guess I'd need to buy a 7mm collet to take 1/4" tools. Weight, about 5.5kg so it fits into the 15lbs limit I'm imposing, still I don't know if the X1 would like that kind of weight side mounted onto the existing spindle housing. Also, 2.2kw on an X1, are there any safety concerns?
As for the future machine? It's in progress, but I admit, it always has been :whistling:. At the moment it's a 500x500 fixed gantry :)
All ideas welcome
Re: High speed spindle for Sieg X1
The problem with the water cooled 0.8-2.2kW spindle is they lack torque at low speeds, so much so that if you need to machine steel you'll be limited to very small (3mm or so) carbide cutters. You get roughly full power down to half speed, then it drops linearly to zero at zero rpm from there. That does mean for aluminium with cutters up to about 8mm they're excellent as that's within the roughly full power region.
It's difficult to find a spindle that will cover a good range of speeds, so the best way in my opinion is to make your own using a brushless motor or incorporate pulleys. www.hobbyking.com has plenty of good ones to choose from
I doubt putting a 2.2kW motor is a safety concern and due to the above you've not really got much choice. I've just stuck a 6kW motor on a C1 lathe...
Re: High speed spindle for Sieg X1
Thanks for the feedback Jonathan.
I read that the Chinese spindles lacked torque but not having seen any figures and in all honesty having no 'feel' for torque I was willing to take a chance on 2.2KW bettering the X1's 150W in most applications. All be it the X1's 150W is geared for torque I guess. I could always swap the original parts back in if necessary, so long as any changes I made were non-destructive, or buy a spare spindle housing from LMS - maybe 2nd time around I'll get my improvised oil ways right! The long and the short of steel on the X1 is no matter what, cutting will be compromised by the machine itself.
I did check out the brushless motors last time you mentioned them, got as far as watching a youtube video on replacing the shaft. Need a small arbor press, they're not so expensive and certainly cost less than a lathe. They are basically just supercharged stepper motors so loads of low end torque I guess dropping off with speed. At the time I was put off by the UK pricing of the motors, and fear of the unknown, but now I see hobbyking can ship from Germany I'll investigate some more.
What are you going to do with 6KW on a poor little C1?
Re: High speed spindle for Sieg X1
Quote:
Originally Posted by
ecat
I was willing to take a chance on 2.2KW bettering the X1's 150W in most applications.
I wouldn't be so sure. From basic physics Torque is proportional to Power/rpm. So the X1's 150W will give approximately 60% more torque at 1000 rpm on it's low gear than a 2.2 kW spindle running at 24000 rpm (assuming similar efficiency). Of course, how well it behaves at lower speed will depend on the motor and controller design.
Russell.
1 Attachment(s)
Re: High speed spindle for Sieg X1
Quote:
Originally Posted by
ecat
What are you going to do with 6KW on a poor little C1?
Nothing, it's a dick slapping contest because I drive my C0 with the 15Kw motor on the big TOS. :rofl:
Attachment 5577
Re: High speed spindle for Sieg X1
Quote:
Originally Posted by
russell
I wouldn't be so sure. From basic physics Torque is proportional to Power/rpm. So the X1's 150W will give approximately 60% more torque at 1000 rpm on it's low gear than a 2.2 kW spindle running at 24000 rpm (assuming similar efficiency). Of course, how well it behaves at lower speed will depend on the motor and controller design.
Russell.
Thing is, I can do little to increase the speed of the X1, there may however be a way to increase the low rpm torque of the 2.2. Sensorless vector drive is available on some quite reasonably priced vfds, I do not know if such vfds can drive a Chinese spindle. The few I've looked at state 'standard induction motor', eg, http://www.inverterdrive.com/group/A...F/default.aspx .
The trade offs are:
More expensive than Chinese vfd but possibly more reliable
High end is caped to around 300Hz in vector mode
I have no idea if it would work - I know nothing of motors and drives
Quote:
Originally Posted by
John S
Nothing, it's a dick slapping contest because I drive my C0 with the 15Kw motor on the big TOS. :rofl:
Attachment 5577
Like an elephant humping a Chihuahua!
Anyway, enough dick play! We all want to see your list of 6040 improvements, costs and test results:clap:
Re: High speed spindle for Sieg X1
Quote:
Originally Posted by
ecat
Anyway, enough dick play! We all want to see your list of 6040 improvements, costs and test results:clap:
Can't really answer that question as I have never seen one in the flesh, from all the Ebay pictures i have seen the build looks OK provided they have fastened everything up square and free.
What they don't show you is the control box internals but I reckon that if you cost out for a complete new box, transformer, cap, bridge rectifier, 3 drives and possibly a new breakout board you will have a bomb proof system.
I'm a big believer in having spare capacity and have found out that on the smaller motors that need 3 or 4 amps if you get the bigger 80 volt 7.8 amp drives and run them de-rated, they never get hot, never break down and fly.
Ok more expense but how much does a ruined job or having to mess with a machine when you are supposed to be earning really cost ?
If you know this figure needs to be costed in whether or not you go for it on day 1 is another point.
Re: High speed spindle for Sieg X1
Quote:
Originally Posted by
John S
I'm a big believer in having spare capacity and have found out that on the smaller motors that need 3 or 4 amps if you get the bigger 80 volt 7.8 amp drives and run them de-rated, they never get hot, never break down and fly.
Agreed 100%, this applies to most things and not just steppers.
The problem is convincing the customer that the additional money is well spent, especially in a consumer product which is essentially what these Chinese routers are. Eg. Build a router with good electronics, it costs an extra 10% and some will gladly pay for the additional robustness, reliability and utility. My router design costs less and word gets around the internet that the controller is a bit dodgy but if it causes a problem then the cost of replacement is not so high and phrases like 'learning experience' are used to justify the gamble. I sell a shit load. Next thing you know, the manufacturer of the 'good' router has a cost reduced 'light' version for sale - they need it to stay in business. The sad part is that now the world + dog believe that this is the way routers should be. The up side is that many more people at least have the chance of getting their feet wet in the world of routers.
I'm lucky enough to have a full controller set-up, it will be fascinating to hear how the mechanics of these routers hold up.
Re: High speed spindle for Sieg X1
You shouldn't have to convince a customer, once you have explained why you have gone the route you have that should be enough.
You don't need the customer who buys on price only, they will be nothing but a pain in the arse. I give a price and that's it, you know straight away whether or not they are interested.
As to regards holding up, only time can tell. I have a small Techno Isel router, no idea what it cost new and it's only 300 x 300 working area but it's been a very good machine for me.
Is it well made ? So so, never gave trouble other than having to strip down to lubricate but it could have been made a lot better, supported rails etc but it is robust.
Looking at it you can see ways of improving it. Then looking at the 6040 other than possibly better stepper mountings / bearings and supported rails on the Y axis [ although some say they have them ? ] it looks a good design.
Then look at a Heitz <sp> machine and for what you get for the price I think these are total junk but a lot of users swear by them.
