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Seeking advice for cnc machine purchase
Hi All,
My brother and I are looking for a cnc machine on a limited budget for some prototype work - mostly cutting wood & plastic, but possibly some light aluminum. I've been researching the Chinese built 6040 and 6090 machines and would really appreciate some guidance! We were hoping to get a 1.5KW spindle (or better) based mill for around 1 to 1.5K USD.
We would prefer a unit ready to run, but many warn that the motion controllers are pretty terrible (black box, blue box, etc). Do any companies offer good controllers with these yet, or is the best route still to buy one and retrofit it with a G540 or Leadshine controller? Would it be too ambitious to try to buy a frame and source all the components ourselves? We would like to get up and running as soon as possible, but not at the cost of having to replace inadequate or dead components later.
Also - I found this machine from "Jinan Blue Elephant CNC Machinery Co.,Ltd" on Allibaba.com. Is anyone familiar with this company? It looks like a decent deal but It's a little over our intended budget, and like anything on Ali - it's only good if the seller is reputable.
Here is a list of my notes from various posts here. Any comments welcome:
- 6040 "z" denotes ball screws, which are superior, correct?
- Quote from JohnDeere630: "I don't use USB to control steppers because USB is not a real-time protocol. I use the parallel port because it is a real-time system"
- Is this true? Has anyone experience this issue with USB?
- What is a list of components needed to complete a 6040 frame?
- Spindle: Prefer 1.5 or 2.2KW water cooled
- Variable Frequency Drive (NES1?)
- Power supply - should be 48w or higher
- Stepper Drive (like G540, but preferably USB like a Leadshine MX3660 or MX4660)
- Motion Controller (UC100)
- Shielded cables
- Mach 3 or LinuxCNC? (Are these compatible with USB?)
- Add limit switches
- Cables should be grounded at the controller end and on both ends for the spindle<->VFD to earth the mill frame.
This site has been an unbelievably great resource of information for me, and any help/advice/input from all the knowledgeable folks here would be greatly appreciated!
Danny
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Re: Seeking advice for cnc machine purchase
690*Gantry*moving*cutting*aluminum*
https://youtu.be/EDCTP5OqNvE
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Re: Seeking advice for cnc machine purchase
Hi Danny,
I posted some responses to you in the other thread you posted, but in further answer to these, if your looking at a 6040 then 1.5kw is really going to be the very upper limit, and it would likely need to be one of the rarer slimmer and less weighty versions of the spindle as the z axis on the 6040 is not that powerful. Generally they come with a reasonably good 800w VFD/spindle which really isn't at all bad considering, or they come with the crap DC brushed spindle/motors up to 400w or thereabouts, but these are pretty crap and don't last long generally, I would avoid them at all costs.
I think first and foremost you'll need to sit down and really work out what your buying limits are, and how committed you are to what your trying to achieve by buying a cnc machine!
The reason is that no matter what you buy, it will be a very large and expensive purchase that you will likely need to live with for some years. The forums are full of posts all the time from people who in my opinion make the same basic mistake repeatedly, they have an idea for a business that involves buying a cnc machine, they buy the cheaper (and less capable!) model with the view that they will sell it and upgrade to a more useful machine the second things improve, but what generally happens is that they realise cnc is a real benefit and quite empowering, but they are stuck with a machine of very finite capabilities (thus reducing production capability and income generation), but they aren't generating enough income to make it worthwhile selling the small machine at a loss, to then start the process of upgrading to a bigger and more expensive machine all over again.
It's horses for courses, and budgets are there for a reason, but if you have a good business plan and idea, and feel committed enough to make it work, no matter how long it might take, the trick I really believe is to buy once and buy well.
Having said that, if the 6090 with the better spindle and rails is an option, it will be one you won't regret, and will hold it's value far better than any 6040 variant.
All the 6040's available via Ebay and Ali are the bluebox controller variety, usually with round unsupported rails, lower quality spindle, and utterly useless TB6560 based controllers and power supply, that ultimately mean you will NEED to spend additional on a G540, and a decent 48V power supply to suit. For serious hobbyist use this will be more than adequate, to base a business plan on however, in my opinion not a good idea if there are any better options.
To answer specifically some of the questions you raised,
USB is perfectly fine along with ethernet for some of the better controllers/interfaces out there
I far prefer water cooled to air cooled, having been in IT most of my life "I don't trust no stinking fans", especially in an incredibly dusty environment such as a home workshop!
1.5kw is very adequate for all wood and plastic machining, and even aluminium, I do heaps of alu on my machine, but on a bigger machine 2.2kw is definitely better!
VFD's are base on budget, a Hitachi or similar would be good, but the cheap Chinese ones do work well, the SunFar 300E on my machine has been perfect all these years.
A G540 would be required for a 6040 or similar in my opinion to get any level of decent performance and reliably out of it, on a bigger machine it will come with Leadshine quite likely, and these should perform just fine. Mine are M542's.
The UC100 is quite popular and by all reports very reliable, but if you buy a bigger machine that has NCStudio as the control software, you wouldn't need any additional software or I'F cards of any sort. On a 6040 though, they would be sorta overkill I would think. A lot of money that could have been put to better use buying a better machine I reckon.
Shielded cables are good for the spindle/VFD, but not always necessary unless your really having interference issues, which if your using a 6040 you'll definitely be having plenty of those!
Mach3 is pretty much the industry standard for hobbyists, but if your somewhat comfortable with Linux then that's a nice free option. I must admit though that I'm really used to the NCstudio that came with my machine and find it just perfect for my needs, simplicity is always the best!
Any half decent machine will come with limit switches, if not you will need to fit them, as the machine ca do itself quite serious damage without them.
Earthing is a whole different kettle of fish, there's a really good long thread with input from from more knowledgeable people in these forums. Just do a search and you find it easy enough.
cheers, Ian
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Re: Seeking advice for cnc machine purchase
Thanks Ian! I am in awe of the amount of information that you so generously shared - and mere hours after I posted! You make so many good points that I feel confident a 6090 will be best for our needs. Hopefully our budget and timing will allow us to step up to one of these units from the smaller ones we began looking at. I'll keep you posted with my progress and hopefully you won't mind if a few more questions arise along the way - cheers!
Danny
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Re: Seeking advice for cnc machine purchase
Your welcome Danny!
I should point out that I'm not bagging the 6040's at all even though it might seem that way, they are a product with a level of build quality that no other manufacturer can even come close to for anywhere near the cost, so they are amazing value for what they are. Even factoring in a G540 and a new PSU they still represent great value, but, for any reasonable commercial endeavour it would be throwing moeny away in my opinion as you'd realise pretty quick it may not be suitable for your needs in many cases.
Of course if your planning on little trinkets or small carvings, wooden jewelry, etc, then the 6040 would likely be more than adequate. But it would still be somewhat limiting in many cases.
CNC definitely isn't cheap, and this is a case where spending a little more can save a lot in the long run.
cheers, Ian
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Re: Seeking advice for cnc machine purchase
Hey Ian,
I'm going to contact Jcut to get some quotes on a 6090B. The first job we're hoping to do with a mill is cutting wooden sunglass frames in batches of 5 (see mocked up pic). Some things I'm wondering are:
- If we end up needing to do low-volume production with this thing, are we crazy not to have a tool changer?
- Could one be added later (I realize probably not)
- Is a 6090B already outside of a (roughly) 2k budget?
- Do you have any recommendations that we look at for that range?
As always - thanks a bunch!
Attachment 345970
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Re: Seeking advice for cnc machine purchase
I just got one of these, incredible build quality, almost no flex in the gantry and the company will do a deal like chuck in mach 3 etc
I'm very happy with mine, they even chucked in a free 2nd user pc... all cheaper than a chinese machine
2500 euros all in thats about £2200 !!
Kompas H - 1000 HF | Cau Cau
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Re: Seeking advice for cnc machine purchase
... Oh I just thought of one more question too - I know that each company is probably a different scenario - but when you ordered from Jcut - did the 6090B come in only one configuration, or did you spec it out yourself? Spindle size, tool changer, etc? Is this stuff configurable to some extent?
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Re: Seeking advice for cnc machine purchase
You're asking about a tool changer on a $2000 budget.
An ATC spindle and toolholders alone will cost at least $3000-$3500, with no machine to put it on.
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Re: Seeking advice for cnc machine purchase
Quote:
Stepper Drive (like G540, but preferably USB like a Leadshine MX3660 or MX4660)
The Leadshine drives you mentioned are not USB, and are no different than a G540. Both will plug into a UC100.
Quote:
Mach 3 or LinuxCNC? (Are these compatible with USB?)
The UC100 will only work with Mach3 or UCCNC. (Mach4 at some point as well)
I'd recommend UCCNC.
LinuxCNC only works with Mesa boards.
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
ger21
LinuxCNC only works with Mesa boards.
Since when?
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Re: Seeking advice for cnc machine purchase
I was assuming that he didn't want to use a parallel port. What other options are there besides Mesa boards and the parallel port?
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Re: Seeking advice for cnc machine purchase
@ger21, thanks for the ballpark info on an ATC spindle. You'll have to pardon my ignorance on the relative pricing of components as I'm new to the cnc milling domain. Input from you folks is helping me to cover a lot of ground in short time as I try to understand what machining capability our current budget will afford us, and whether it will cover our needs going forward. If our current needs exceed our budget we will consider outsourcing until we can afford a more appropriate mill. But at least we'll know going in. :)
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
... Oh I just thought of one more question too - I know that each company is probably a different scenario - but when you ordered from Jcut - did the 6090B come in only one configuration, or did you spec it out yourself? Spindle size, tool changer, etc? Is this stuff configurable to some extent?
Hi Danny,
With budget, $2000 will be close to getting a working 6040, not really anything better than that, and as Gerry pointed out an ATC alone will be thousands. But I really couldn't see the advantage of an ATC on a machine that size in a semi-hobbyist/commercial environment. The few seconds it takes to change and set the z height of cutters is really insignificant. You'd be far better putting any ATC money onto a better machine to start with IMHO.
I started looking at the table model 6090 but didn't like the mass or rigidity of it, so went to the big frame model. From there I went from the round supported rails of the A version to the better linear rails on the B model. A really, really important thing to note is that not all 6090's are the same, Keling CNC had or have, a 6090 with much thinner gantry sides than my machine, which caused many people to complain about the amount of flex when machining as a result.
The frame, build quality, and things like the dimensions of the gantry, Z axis, etc, were all compared with the other models around at the time.
cheers, Ian
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Re: Seeking advice for cnc machine purchase
Hi People,
Great thread Danny, I'm in the same boat as you.. Is thisn any good for you?
I'm looking for a machine to work on carbon fibre with and came across this with the 500watt computer controlled spindle- https://www.stepcraft-systems.com/en...tepcraft-2-840
I saw it being used by easycomposite and looked as though it done the job well. It's also very versatile as it has a 3d printer and hot wire cutter adaptors available for it. As well as a load of other bits and pieces.
What I'd like to know is, does anybody have any experience with these machines and are they any good/accurate? And straightforward to use?
I'm completely new to all this and hoping to find a machine that will not have to be upgraded for a while,, for a budget of about 3,500 oz dollars.
Also, what user interface does anyone recommend? What is usb beginner, usb full version, uccnc, parralell port all about????
Thanks in advance
Rob
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
fragged
I just got one of these, incredible build quality, almost no flex in the gantry and the company will do a deal like chuck in mach 3 etc
I'm very happy with mine, they even chucked in a free 2nd user pc... all cheaper than a chinese machine
2500 euros all in thats about £2200 !!
Kompas H - 1000 HF | Cau Cau
There is a reason why the machines are so cheap... they look good but are very slow. That is a problem if you are using a high speed spindle because most of the time the feed rate must be kept high, twice or even more than twice, compared to the maximum speeds they have. The only other option is to reduce spindle RPM, but in that case you lose torque.
Also, if they include a Mach3 license AND a second PC for that price than I wonder where they come from... even an old PC costs about 200-400 EUR and a Mach3 license costs about 2-300 EUR as well, the UC100 is about 100 EUR, and what's left is really not enough for good quality parts, so something is fishy here.
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Re: Seeking advice for cnc machine purchase
Ian,
Thanks again for the great info and guidance. I completely agree that without good rigidity, a machine will be useless to us at some point. I'm glad that you feel an ATC is not absolutely necessary (at least while we're starting up). Right now, if we found a good mill similar to the 6089B in the 3K range we would consider stretching our budget to own rather than outsource.
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Re: Seeking advice for cnc machine purchase
I saw your picture look at the gcode you need to produce that frames I am sure you need more than one miller in one setup to be efficient I have a Heiz 400 t which was around 2k € without pc if you use existing pc and linuxcnc you will be in you budget and I used a kress where I later put an atc on it pcb milling sucks without atc ;)-
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Re: Seeking advice for cnc machine purchase
Hi again all, so here's an update, and another humble question:
Update: We requested initial quotes for three comparable mills so far: ELE6090 (Blue Elephant), RDG-6090A (Rodeo Machinery), and 6090B (Jinan JCut). As expected, prices are comparable and I think we will be able to get one this quarter, but there are minor differences between the mills and I'd like to be sure we know what's important. I'd like to compile a short list of important specs that I need to ask each vendor for. Here's what I have so far:
-- Structure: Cast iron > Steel > Aluminum > Cardboard (little joke there!) Most of these use a combo of the first three I think.
-- Rails: Linear are better than Round Supported Rails - thanks to Ian for this info. So far I'm seeing Taiwan Hiwin Square rail. Jinan JCut denotes square rails with "B" suffix vs "A" for round in the model number (Thanks Ian) do they all follow this convention?
-- Spindle: 1.5KW or better water cooled & brushless preferred. How do I research these? One company offers a 2.2KW Changsheng. Anyone have one of these?
-- Stepper motors: So far I see one quote with 86BYG steppers, and one quote with 450A Steppers. Anyone have experience with these?
-- Ball Screws: They all have them. (I believe they're better than ACME) Are some better than others?
-- Cables: Are they Shielded?
-- ??? Am I missing anything else important?
I will continue to try to research this myself on here and elsewhere on the web as well, but all of your input here has been extremely valuable!
Many thanks ahead of time!
Danny
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Re: Seeking advice for cnc machine purchase
Hello this looks like a good place to ask ....I just ordered a Chinese 6012 (2x4') router and I've requested that they video a performance test to show accuracy and integrity before I send the balance. Can anyone out there suggest a good run test for these machines? I figure right off the bat it would be good to see if the cutter is in the same plane as the table - anything else? Ian?
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Re: Seeking advice for cnc machine purchase
Breaking my responses in two as they were too long sorry Danny.
-- Stepper motors: So far I see one quote with 86BYG steppers, and one quote with 450A Steppers. Anyone have experience with these?
Generally for the big 6090's they'll have roughly 380 oz/in NEMA23's on X and Z, and a 380-420oz/in NEMA34 on the Y, for the big machines I found they seem to spec the steppers pretty well with the PSU and drivers. The 6040's are a little more loose. I've seen some that came with 420 oz/in steppers which given the crap controllers and PSU for them is just ludicrously bad. This is where the optimal PSU value determined by 32 x the square root of the inductance is critical. If your machine has 8mH steppers, it requires 90VDC to run optimally, but if it came with a 24VDC PSU and TB6560 based drivers, your in trouble!
-- Ball Screws: They all have them. (I believe they're better than ACME) Are some better than others?
This can vary greatly between sellers, not so much on 6090's but mainlyon 6040's. I've seen 6040's with unsupported round rails and ACME drives screws, utterly crap on a machine that size and build design. Drivescrews come in different grades, all the Chinese ones come with a generic grade pretty much across the board, and in practice will perform perfectly fine. The expense to go to a better grade would be really hard to justify in most cases. If a better grade drivescrew is required, then your really looking at the wrong machines I think.
-- Cables: Are they Shielded?
I don't think any of the Chinese sellers even get the idea of shielded cables other than a selling point, as they barely get the idea of proper earthing, so unless you get a really switched on seller (yeah right), you can expect non shielded cables, even if they were shielded, you could pretty much guarantee it would be purely cosmetic!
-- ??? Am I missing anything else important?
Not really, just hassle them heaps during the process to keep the pressure on you being happy as a customer!
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Re: Seeking advice for cnc machine purchase
The follow on from the previous split responses Danny:
-- Structure: Cast iron > Steel > Aluminum > Cardboard (little joke there!) Most of these use a combo of the first three I think.
My 6090 is a real behemoth made from very a substantially welded frame, and cast iron top assembly/frame.
-- Rails: Linear are better than Round Supported Rails - thanks to Ian for this info. So far I'm seeing Taiwan Hiwin Square rail. Jinan JCut denotes square rails with "B" suffix vs "A" for round in the model number (Thanks Ian) do they all follow this convention?
Manufacturing in China for a lot of this sort of machinery is done more or less like a (government subsidised?) collective or umbrella company, with minor cosmetic differences between the products different sellers have, so they are all somewhat similar in options and specs, so yes, 6090B would generally infer linear rails. Very similar to the current situation on Ebay where there might be 10000 different 6040 sellers, but there's maybe only 10 or 20 (or more) real distinct umbrella corps that trade under the different accounts. So buying from seller doesn't mean a great deal over buying from another except for the end specs and individual seller performance.
-- Spindle: 1.5KW or better water cooled & brushless preferred. How do I research these? One company offers a 2.2KW Changsheng. Anyone have one of these?
They'll all be offering slightly different variations, mine came with a Sunfar, my 6040 came with the generic Huang-something, just query the specific one they will supply for YOUR machine and google to see if it has issues. Chinese spindles and VFD's are very, very, cheap, so I take it with a grain of salt and don't really see much of an issue with whatever they supply. My spindle has lasted way longer than I expected, so I consider it a bonus.
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
Teddyo
Hello this looks like a good place to ask ....I just ordered a Chinese 6012 (2x4') router and I've requested that they video a performance test to show accuracy and integrity before I send the balance. Can anyone out there suggest a good run test for these machines? I figure right off the bat it would be good to see if the cutter is in the same plane as the table - anything else? Ian?
I just asked for videos of MY machine in action and luckily they did some hard hogging and also finer engraving work which was good.
cheers, Ian
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
Hi All,
We would prefer a unit ready to run, but many warn that the motion controllers are pretty terrible (black box, blue box, etc). Do any companies offer good controllers with these yet, or is the best route still to buy one and retrofit it with a G540 or Leadshine controller?
Danny
Since I have taken a step off the reservation (not using Mach 3 or LinuxCNC) and opted instead to purchase Planet CNC's USB based controllers with a variety of different motor drivers, I believe that these represent a good value. Mind you I have not pushed these controllers to the limits of what can be done but I have not had any problems that I could identify with them either.
Quote:
Would it be too ambitious to try to buy a frame and source all the components ourselves?
We would like to get up and running as soon as possible, but not at the cost of having to replace inadequate or dead components later.
You said it, time vs money. I would opt to get a complete machine (minus the electronics) and install the controller/drivers/motors that I wanted. I am actually building a modular setup that I can use to run multiple kinds of machines (at different times) e.g. Lathe, router, mill. The electronics are fairly easy to sort out to be honest. I purchased a 3040 router, converted to CNC a 44991 HF mini-mill with a CNC fusion kit, and I am in the process of rebuilding my 7x16 mini-lathe (which was originally a 7x10 HF machine) into a CNC lathe. These projects take time and money to do right, so if production is something that is more important, buy a complete solution that is tested by the community at large and has support (e.g. like a Tormach or similar setup).
Quote:
[*]Quote from JohnDeere630:
"I don't use USB to control steppers because USB is not a real-time protocol. I use the parallel port because it is a real-time system"
- Is this true? Has anyone experience this issue with USB?
This is someone who has no idea of what they are talking about. True that USB does not allow you "real-time" access to the hardware, but that's not a big deal. You don't need real-time hardware access at the G-code level if the USB controller is properly designed and implemented.
[quote][*]What is a list of components needed to complete a 6040 frame?
- Spindle: Prefer 1.5 or 2.2KW water cooled
- Variable Frequency Drive (NES1?)
- Power supply - should be 48w or higher
- Stepper Drive (like G540, but preferably USB like a Leadshine MX3660 or MX4660)
- Motion Controller (UC100)
- Shielded cables
- Mach 3 or LinuxCNC? (Are these compatible with USB?)
- Add limit switches
- Cables should be grounded at the controller end and on both ends for the spindle<->VFD to earth the mill frame.
You probably can't go wrong with the Gecko as a motor driver... I have used a bunch of the "knock-off" Chinese motor drivers to include drivers from Longs, WanTai, etc. Only one has ever failed/gave me a problem out of the 10 or so I own. The stepper drives should be directly wired to the motion controller (vs a USB connection - I don't believe I have seen a USB motor driver) and the motor controller needs to speak to the motor driver in "real-time".
The power supply should be lower voltage than the maximum that your drivers can handle. So if your motor drivers are 60v max, your power supply needs to also be below 60v. I would recommend a 500 watt power supply, motor drivers capable of handling that voltage (preferably DSP based motor drivers), and motors appropriately sized for your application. (I am using 400 oz/in motors which are overkill and perhaps even slowing down the machine due to the fact that rotor inertia is higher on a bigger motor - I still had no problem getting 60 ipm rapids with 36v).
Hope that helps!
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
aarggh
I just asked for videos of MY machine in action and luckily they did some hard hogging and also finer engraving work which was good.
cheers, Ian
Thank you Ian, After having your machine for so long is there any tests you perform to see if it's calibrated right? I was thinking of having them route a large rectangle to see how well the spindle stays in the xy plane and a large circle to see out well it's closed. I wonder if there is any way to see how well the spindle is perpendicular to the xy plane? Any other ideas?
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
Quote from JohnDeere630: "I don't use USB to control steppers because USB is not a real-time protocol. I use the parallel port because it is a real-time system"
Is this true? Has anyone experience this issue with USB?
He doen't seem to have a clue about USB vs. parallel port. USB is not used for controlling steppers, USB is connected between the PC and the steppers via a motion controller. USB is just a communication interface. That motion controller buffers the G-code, converts to pin signals (input and output signals) and outputs to the necessary pulses to drivers (normally through a BOB) in a more even and stable flow than ANY parallel port can ever do because the parallel port is dependent on the PC, which is normally an old Windows PC, and on hardware which is old and outdated.
In terms of real time... well, USB is not a real time protocol, it is a serial protocol, just like Ethernet, RS232, RS485 and many others. It is NOT possible to have a real time protocol unless it is parallel interface, so that is true. On the other hand, it is NOT necessary to use real time protocol at all, since the motion controller handles that part MUCH better than a PC can handle a parallel port, even if you run Linux. If you have a good and reliable USB motion controller than it is not a problem, it handles the flow of G-code better than parallel port does.
Ethernet is even better, but the biggest advantage of Ethernet (apart from higher flexibility) is that it is completely isolated and it has a built in error handling for handling communication errors, it is much less sensitive to noise than USB is. USB can lose contact with the PC in a noisy environment. This is basically non-existent with Ethernet, so you are better off with Ethernet controller than a USB controller. It is slightly more expensive, but worth every penny.
I had UC300USB before but now using UC300ETH. Both are excellent products, well made and very good support. Beware of the fake UC100 controllers sold on eBay. If you want to buy the products of CNC Drive then you better buy them directly from the manufacturer.
Quote:
Originally Posted by
dalcini
Spindle: Prefer 1.5 or 2.2KW water cooled
Variable Frequency Drive (NES1?)
Water cooled - air cooled... never ending story. I prefer air cooled. Have a 1.5kW and never regret the decision of buying it. If it stops working I'll buy another air cooled one. The argument that in a dusty environment the fan is a problem is just nonsense. If you use your CNC is dusty environment you must have a dust extractor regardless if you have water cooled or air cooled spindle. The argument that water cooled is quieter is also nonsense. Yes, it is quieter if you only milling air and not running the pump, but once you start cutting real material, even plastic and wood, than the cutting noise and the noise of the vacuum cleaner or whatever dust extractor you have is far above the spindle noise. Both water and air cooled have a minimum usable spindle speed of about 6000rpm, so even in this respect there is no difference. Buy whatever you prefer, water cooled is the buzz word on this forum, but there are quite a few people who have issues with water cooled because of the cooling fluid (which is NOT supposed to be pure water) and because of failing pumps and leaking tubes, but if you are not worried about any of that then of course, why not buy it and see it for yourself.
I chose a quality VFD, I think that is worth every penny extra. Never had any problems with it, setting up was really easy and is well documented.
Good luck.
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Re: Seeking advice for cnc machine purchase
Ian, Markphd,
Thanks for all the excellent information! I really had not anticipated this much help when I began posting questions.
Researching specifications of the parts of the machines quoted to me has been a challenge but I'm making progress. I'm putting all the information into one spreadsheet which contains the specs of all three quoted machines, along with a list of information that one should request from additional vendors. When finished, I will share it here as a sort of RFQ template so that others may also benefit from all the knowledge you guys have shared. I need to get answers to some additional questions from all three vendors to fill in some information gaps, but we should have a pretty good comparison matrix for our purchase after that. My brother and I hope to have enough information for a purchase some time this week or next.
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Re: Seeking advice for cnc machine purchase
Hi Danny - I bought a 6090b from jcut a couple of years back, other than initial difficulty setting up the spindle in Mach properly (& some minor rewiring ) it's ran with zero issues ever since..!
I router 18mm mdf 3mm passes 10m/min, just making a vacuum table so I may be able to push performance a little more after that, but I'm happy at those production rates.
Would I buy another, well I was only messaging Mandy from jcut last week about the next size up, so yes I'd buy off them, just maybe go for a slightly larger table next time round for my application. Like you I'd also love a toolchanger but probably couldn't justify it...
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Re: Seeking advice for cnc machine purchase
JQ_Quint,
Thanks for sharing your experience! We've narrowed the field to 3 suppliers and Jcut is one of them. I have to say that hearing from owners who have bought these units is the best confidence boost I've found. It sounds like Jcut does a pretty good job putting these things together. I'm just getting ready to share a matrix that I put together for myself to aid in shopping for a 6090 router. This will be my way of giving back some of the great help that everyone here has shared with us.
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Re: Seeking advice for cnc machine purchase
Hi everyone,
Here's a link to a spreadsheet where I compiled (what I believe to be) a bunch of relevant information for the purchase of a 6090 router. I wanted a way to compare apples-to-apples on the specs of these units, and am using this currently to get quotes from the three companies listed. From the link below, you should be able to view, edit, and even download a copy of this as an excel document. Hopefully everyone will find this useful.
My disclaimer: I don't claim to be an expert on this stuff - in fact quite the opposite at this point. If you see a mistake, irrelevant line item, omission of something important or useful, or any other opportunity for improvement, I welcome your edits and feedback!
Please edit responsibly!
https://docs.google.com/spreadsheets...it?usp=sharing
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3 Attachment(s)
Quote:
Originally Posted by
dalcini
Hi everyone,
Here's a link to a spreadsheet where I compiled (what I believe to be) a bunch of relevant information for the purchase of a 6090 router. I wanted a way to compare apples-to-apples on the specs of these units, and am using this currently to get quotes from the three companies listed. From the link below, you should be able to view, edit, and even download a copy of this as an excel document. Hopefully everyone will find this useful.
My disclaimer: I don't claim to be an expert on this stuff - in fact quite the opposite at this point. If you see a mistake, irrelevant line item, omission of something important or useful, or any other opportunity for improvement, I welcome your edits and feedback!
Please edit responsibly!
https://docs.google.com/spreadsheets...it?usp=sharing
I orderd a 6090 cnc router from Donglian on Alibaba. It is built with heavy box tubing and heavy side plates for the z axis. Rack and pinion on the X and Y axis. 3 kw spindle, and a large control cabinet. It will be here in 2 weeks. Michael at Donglian has been very responsive to any and all questions
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Re: Seeking advice for cnc machine purchase
@Jddewilde - wow, that looks like a pretty stout gantry. Linear rails in both Y and Z - which (unless I'm mistaken) I have not seen previously. It's certainly a nice looking machine, and the increased Z height will surely be nice too. I'll be interested to get your impressions when you receive it.
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
jddewilde
I orderd a 6090 cnc router from Donglian on Alibaba. It is built with heavy box tubing and heavy side plates for the z axis. Rack and pinion on the X and Y axis. 3 kw spindle, and a large control cabinet. It will be here in 2 weeks. Michael at Donglian has been very responsive to any and all questions
Very substantial frame and gantry build! You'll definitely be happy with them. You won't however be happy with the table, as the aluminium profile they use is fairly thin and tends to flex quite a bit, especially when clamping materials down. It also is usually extruded and fitted a little less than desirable. For my machine I bought a large sheet of 20mm thick solid aluminium sheet to replace mine with, but after putting a temporary 40mm thick sheet of HMR (Highly Moisture Resistant chipboard) on it some years back, never got around to it as the sheet has well and lasted many years beyond what I thought it would. Which is good as I have too many things on the go all the time anyway.
When you get the machine best bet would be to immediately pull the top off, clean all the sand and swarf that will be encrusted underneath it on the frame (free sand direct from China! Yay!), and then re-enforce it from underneath when you re-attache it to reduce flexing and movement.
cheers, Ian
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Re: Seeking advice for cnc machine purchase
Ian, I assume you're drawing on your experience with your Jcut and inferring that Jddewilde's table will be made the same way, correct? Tonight I'm reading through another thread from someone who bought a Jcut 6090B here:
http://www.cnczone.com/forums/chines...6-finland.html
Great information on what to expect - and it looks like he experienced similar issues with the table.
P.S. - I'd be interested in everyone's feedback on the quoting guide. I've already asked vendors for all this info - hopefully I'm not making an a** of myself! :)
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
Ian, I assume you're drawing on your experience with your Jcut and inferring that Jddewilde's table will be made the same way, correct? Tonight I'm reading through another thread from someone who bought a Jcut 6090B here:
http://www.cnczone.com/forums/chines...6-finland.html
Great information on what to expect - and it looks like he experienced similar issues with the table.
P.S. - I'd be interested in everyone's feedback on the quoting guide. I've already asked vendors for all this info - hopefully I'm not making an a** of myself! :)
Hi Danny,
Yes, looking at the pic the aluminium extrusion looks identical to mine (it's pretty much the same on all these variants), and not really up to the same build level of the machine in general. It will usually be supported at the ends, with a middle cross support. So this actually leaves an awful lot of ability for flex to occur depending on what your machining and how aggressively you're machining. The other thing to consider is any flex means vibration and also the accompanying noise. A little flex means the machine will likely sound like a screaming banshee when your machining something like aluminium. The trick is to strengthen all the parts which in turn dramatically helps to dampen noise and vibration.
Obviously the gantry can only weigh so much given the components used to push it around, but the frame and table simply can't be too heavy or too solid!
cheers, Ian
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Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
@Jddewilde - Linear rails in both Y and Z - which (unless I'm mistaken) I have not seen previously.
The 6090b I had from jcut has linear rails on all three axis....
Sent from my iPhone using Tapatalk
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
Hi everyone,
Here's a link to a spreadsheet where I compiled (what I believe to be) a bunch of relevant information for the purchase of a 6090 router. I wanted a way to compare apples-to-apples on the specs of these units, and am using this currently to get quotes from the three companies listed. From the link below, you should be able to view, edit, and even download a copy of this as an excel document. Hopefully everyone will find this useful.
My disclaimer: I don't claim to be an expert on this stuff - in fact quite the opposite at this point. If you see a mistake, irrelevant line item, omission of something important or useful, or any other opportunity for improvement, I welcome your edits and feedback!
Please edit responsibly!
https://docs.google.com/spreadsheets...it?usp=sharing
Good work !
Wondering whether it's worth adding motion controller (make & connection)... I settled for an ESS , but if I'm honest I'm out of sorts as to what's available today...but at the time I was encouraged to go Ethernet over USB and parallel port.., & the smooth stepper seemed to be flavour of the month.
Sent from my iPhone using Tapatalk
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
JQ_Quint
The 6090b I had from jcut has linear rails on all three axis....
Sent from my iPhone using Tapatalk
Mine too!
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2 Attachment(s)
Re: Seeking advice for cnc machine purchase
Another thing I'd highly recommend for these 6090's that use the same extrusions for the table, is some brush strips along the side of the table, which greatly helps keep the dust off the rails. I bought mine from a crowd that sells the industrial roller doors with spiral brush strips, truck bodies, etc. They coke in various sizes but the 75mm long one in the 8mm square molded rubber insert fits just beautifully in the groove along the edge of the extrusion.
The crappy left shows the brush sticking out above the rail, the even crappier pic on the right shows the rubber inserted into the groove of the extrusion.
cheers, Ian
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Re: Seeking advice for cnc machine purchase
Quote:
Originally Posted by
dalcini
Hi All,
My brother and I are looking for a cnc machine on a limited budget for some prototype work - mostly cutting wood & plastic, but possibly some light aluminum. I've been researching the Chinese built 6040 and 6090 machines and would really appreciate some guidance! We were hoping to get a 1.5KW spindle (or better) based mill for around 1 to 1.5K USD.
We would prefer a unit ready to run, but many warn that the motion controllers are pretty terrible (black box, blue box, etc). Do any companies offer good controllers with these yet, or is the best route still to buy one and retrofit it with a G540 or Leadshine controller? Would it be too ambitious to try to buy a frame and source all the components ourselves? We would like to get up and running as soon as possible, but not at the cost of having to replace inadequate or dead components later.
Also - I found
this machine from "Jinan Blue Elephant CNC Machinery Co.,Ltd" on Allibaba.com. Is anyone familiar with this company? It looks like a decent deal but It's a little over our intended budget, and like anything on Ali - it's only good if the seller is reputable.
Here is a list of my notes from various posts here. Any comments welcome:
- 6040 "z" denotes ball screws, which are superior, correct?
- Quote from JohnDeere630: "I don't use USB to control steppers because USB is not a real-time protocol. I use the parallel port because it is a real-time system"
- Is this true? Has anyone experience this issue with USB?
- What is a list of components needed to complete a 6040 frame?
- Spindle: Prefer 1.5 or 2.2KW water cooled
- Variable Frequency Drive (NES1?)
- Power supply - should be 48w or higher
- Stepper Drive (like G540, but preferably USB like a Leadshine MX3660 or MX4660)
- Motion Controller (UC100)
- Shielded cables
- Mach 3 or LinuxCNC? (Are these compatible with USB?)
- Add limit switches
- Cables should be grounded at the controller end and on both ends for the spindle<->VFD to earth the mill frame.
This site has been an unbelievably great resource of information for me, and any help/advice/input from all the knowledgeable folks here would be greatly appreciated!
Danny
Dear sir,
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Thanks for your inquiry.
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Web: Jinan Blue Elephant CNC Machinery Co.,Ltd.
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https://www.youtube.com/watch?v=kdiHUgtlngs
https://www.youtube.com/watch?v=VUxK9LUfkZc
We will provide best price and service.:cheers: