Hybrid View
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25-08-2013 #1
Yes - the Kress and high speed spindle options come with different mounting hardware. Specifically, within each of the two spindle choices, the collet to bed height as you pointed out has some flexibility in its set-up if required - be it from the tool side, or the work piece side. The high speed spindle position, for example could be adjusted to change this height depending on the work being carried out.
I think JAZZ would agree that we provided timely and comprehensive details when asked (if a bit waffley ey Jazz?)
There is a video of me perched on the machined bed. And subsequently on the Gantry. I''m tipping the scales at over 90kg... 90kG is about 880N. no rude comments please...... So that is 90kg going through the surface area of my scruffy shoes in the middle of the machine - and then around the machine a bit. I then stood on the gantry in the middle - somewhat precariously.
whats the going weight of a 8 foot by 4 foot sheet of 3/4 ply? over 30kg.. ish?
I also have this vide below if it is of any value here. The UC100 that we offer from CNCdrive motion controls is a nifty little gizmo. I'm sure most of you are aware of / have seen some issues with Mach3 running on windows. Windows put up the road block to the likes of Artsoft that is, they don't let you have control over what the processor does and the PC hardware has to generate the control logic for the drives... The result is potentially poor performance that is nothing to do with the machine but to do with the pulse streams to the machine. Now in fairness to Artsoft, to produce a software package able to be as cross platform compatible as well as they have done is , in my opinion, very very impressive. Mach 3 also is also invaluable in its ability to customize, tinker and add I/O etc. Something the bigger manufacturers just don't do.
The new generation of motion controllers like the UC100 as well as the Smooth stepper, PlanetCNC USB etc etc are allowing industrial CNC control to happen on a desktop PC. The DSP in the controllers generates the pulses to the steppers independent of windows. The communication between the PC and the controller DSP occurs via a USB with the UC100 as examples. In these examples, processor intensive tasks on the control PC can be carried out without compromising the quality of motion of the machine.
The max rapid feed you can get on Mach3 running with a Kernel Speed of 25kHz is a tad over 9,000mm/min? Please correct me? Granted you can increase the kernel speed to increase the feed but you put pressure on the PC hardware. The 15mm/min feed rate shown in the video is there not to demonstrate the the machine can whizzz quickly - its meant to convey the importance of clean pulse streams for reliable machine operation. It is equally necessary for slow movements and for 3D machining where 3,4 and 5 simultaneous pulse streams may be required.
It is also worth noting that you can spec a top of the range W7 64 bit PC packed to the gills with ommph and you'll possibly get better performance out of an old Pentium machine.
if its felt that this is not valuable to the current thread context let me know and I'll move it elsewhere - I did a quick search - if there is a thread where this content would be more suited - let me know.
more details to follow on other machine aspects.Last edited by StoneyCNC; 25-08-2013 at 03:42 AM.
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25-08-2013 #2
Yep I agree on both counts Esp the Waffley. .
Nice Video not sure of the point has it's mostly meaning less.? . . . It's a CNC machine not a sit on lawn mower.!!
If your going to bother with this stuff then Better IMO to apply some lateral tests simulating real world cutting forces. . . . . Push & pull on the bugger in all directions and lets see how it jiggles.!!
Regards the Motion control card then I'm a big fan of them and thou I haven't tried the one your using I have most others and they can make a huge difference to speed performance (which doesn't mean much to me.!) but more importantly how smooth the motors accelerate and perform.
That said I much prefer Ethernet over USB has it's much more reliable, USB can be touchy and shouldn't be relied upon for providing power has it's very flaky.
Edit 2: Not all motion control cards are equal thou so anyone seeing this and thinking to buy then please checkout before doing so has while they all tend to offer smoother pulse train etc they can lack or be flaky on over features they have to take over from PP, like spindle control, Homing/limits functions, Backlash comp etc.
EDIT: Ok years of tuning race engines has taught me that the ear is a highly tuned indicator showing when things are running nice and smooth.!! . . . When I ear growling noise's I get concerned to why.? (growling = vibration)
The growling I'm hearing I believe to be those linear rail bearing blocks on the Rails.?
So with that I'd request a Video of all Axis disconnected from the ball screws being manually worked both fast and slow.!!Last edited by JAZZCNC; 25-08-2013 at 01:05 PM.
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26-08-2013 #3
Not a lawn mower...?
It demonstrates the tower stiffness and that there is no slop/deflection when my 90kg..slim fame puts pressure on the gantry and the slides. It also shows that when you move the load point around the bed does not twist up and deflect. Will look to get other data too.
I've often heard that a wind turbine monitoring expert puts a piece of metal against a turbine structure and can tell what the bearing situation in the gearbox is. The human ear is quite the sensor
aye aye capitan!
to keep the threads cleaner and on topic I've put this here http://www.mycncuk.com/forums/manufa...n-control.htmlLast edited by StoneyCNC; 26-08-2013 at 02:42 AM.
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08-09-2013 #4
In relation to the comments and opinions that have been put up on this thread we have had a meeting with JBEC and the German machine builder and had a discussion. Firstly we would like to be clear on a few key points in this response so that the message is not taken out of context. We would also like to advise the general audience of this forum to be mindful of relativity and comments and opinions that can be taken out of context.
- Profiled rails (THK and HIWIN for example) are the best linear translation system for a CNC application.
- There is a mine of exceptional information on this forum and the active members go to significant effort to help others and in our opinion are enhancing the CNC community in the UK no end – we commend this – it’s a fantastic resource.
- We are of the opinion that there is a disconnect on the forum between a commercial CNC system and a full on informed home build. The two approaches in terms of the manufacturer and the end user fall into very different categories. The general jist of what we have read on our, and indeed other posts, is that “nothing is ever perfect”. We would ask the general audience to consider the difference between a home build DIY CNC machine vs a machine that is produced in volume, commissioned with training and supported actively by the supplier. The two scenarios are very different and the perceived “value” needs to be put in context.
- We approached this forum with the aim to help the CNC community be more productive and to offer our share of experience to those interested or looking for help – as well as to inform of the products we offer. We felt our experience and ability to supply CNC equipment and control products could benefit the community.
- We are not here to make a quick buck, we believe in our system and our reputation in IRL. We would not be offering and supporting the system in the UK if we did not stand by it.
- Anyone who feels they have the ability to do a DIY CNC home build should do so and spend the money and get the extra functionality. This extra performance comes at the expense of your own time to make it happen and the inevitable head scratching. If you ever give yourself the opportunity – do it! You’ll not regret it.
- Those who opt for an off the shelf solution should be given access to a fair and honest information source about the relative performance aspects the CNC systems on offer.
Linear rails
There is no question that the linear profiled rail and carriage system is the highest performing linear mechanism there is for CNC applications – hands down. Linear rails are the only system that can provide load ratings for even the most-high spec CNC applications only allowing motion STICTLY in their desired direction of movement. However, the tolerance levels demanded of a CNC system using profiled rails is in the order of microns in bed tram and global machine alignment. This is why when you look under the bonnet of any big commercial machine they will be there.
Typically therefore, linear rails suit machine builds where solid steel or equivalent machine beds are machined with precision to take such a rail system and to realise the accuracy they can provide. Either that or great lengths and effort have to be gone through to make them work on other frame designs. Applying a linear rail does not add the performance of the rail system if it is not backed up by the bed design, precision and stability. Only then can twist and tram be true and give the level of performance that the rails can realise. In order that the performance of such profiled rails can be fully realised depends on the bed design.
Hats off to Jonathan’s latest build http://www.mycncuk.com/forums/router...g-machine.html. What a great insight into CNC machine building - the level of detail and open source nature of the build is fantastic and there is no questioning the level of work that has gone in and the result is a good machine – the video speaks for itself. For someone looking to build a machine this and other such posts on this forum are an exceptional source of information – far above and beyond any consultancy invoice. Hard detail is given at every step - invaluable.
Contextually the build has highlighted the importance of the bed alignment in a CNC system. The welded frame predictably has twisted and bent from the thermal loading generated by the welded frame and this design decision has challenged the use of a profiled rail from the outset. This has been clearly illustrated by the work required to align the rails on the machine and to align the machine for accuracy – tram and twist etc. It may well have been the most cost effective frame build in a DIY context but it is not sustainable commercially. Also the estimated price tag of 4-5k not including the time and extensive know how gives the general audience a feel for the cost and effort that goes into a “sufficiently stiff” CNC router. There is also the question of relieving the stresses in the welds and the long term stability of the bed.
There is also the question of Mach3 lost position? Possibly due to missed steps perhaps due to some slight lock up – eliminated by the cleaner pulse trains from Linux giving more motor performance perhaps? Unless there is a software issue with Mach (not passing the driver test – or other quirk) then the software fix (move to linux) has potentially overcome what is actually a hardware issue? Perhaps there was a motion controller used with Mach3 and not a LPT - in which case the previously stated possible issues are invalid. These and other comments are based on images and description and are therefore limited in the amount of information available and cannot be taken as conclusive, but purely observational.
In the words of JAZZ “First let me say not going to pull it apart or condemn because the machine is very well thought out and professionally put together” The comments and message in the previous two paragraphs are aimed at putting some context behind what we feel have been very strong statements towards our design on the basis of a “digital viewing” – handed over in detail and in a timely fashion not attempting to “hide” anything – but in essence are only observational context.
If every second machine didn’t work with Mach we couldn’t offer it. It has to work every time, every machine. The machine has to be stable long term. The bed is put together with refined assembly processes in Germany. The system is very portable and retains its performance in transit and does not require any tuning on arrival. It arrives and it works. Here are a few videos of the machine being put through its paces. (no backlash/geometric compensation was used in any video posted to date)
The JBEC CNC router series linear slide system went through a full digital mock up (DMU) and was also been mechanically tested and refined in a physical kinematic system analysis. For intellectual property reasons further details will not be disclosed. On the bigger machines with a different application space profile rails are used. We are working on a bigger machine currently that will indeed adopt profiled rail due to its size and performance parameters and consequently will have a bigger price tag.
We feel that such severe comments should not be made on the basis of a digital viewing without access to materials, BOM with fits and tolerances. We, JBEC and our German colleagues welcome criticism based on the machine in action and subjected to tests.
In light of the above post content JBEC wished to explicitly convey the following message.
- JBEC has opted not to use welded frames in CNC builds as it is too difficult to machine/prepare the frame surfaces for profiled rails. It is viewed as not a viable option to mount a profiled rail on such a system commercially.
- JBEC has concerns over the use of welded frames long term, as table stability will be a major concern. Any stress relief or shift in the frame alignment will cause the rails to misalign and the machine will lock up/ torque out.
- JBEC strives to match the components to suit the design/market sector and end user and to provide an economical and fair cost basis.
- JBEC recommends the use of only HIWIN or THK Rails on the larger Bed type machines which will be made from machined steel to maximise the accuracy and precision
- The JBEC series machine is tried and tested, has long term stability and hits heavy in the functionality and performance on offer in the target market and is more than fit for purpose.
Our German machine builder is of the opinion
that a commended and tested design should not be likened to a skateboard for the reasons stated heretofore.
Our philosophy is that CNC technology empowers people, business and education, and that the product, correctly placed and supported with appropriate training, can help to provide new employment. The JBEC system and CNC support is helping to grow small and developing SME’s in Ireland and JBEC has seen a rise in the level of production here as a result of the machines sold into the Irish market to date.. Indigenous business growth is an important economic pillar in the fight against mass production from abroad. We don’t manufacture indigenously enough here...... This needs to change. It is for these reasons and due the demand for a professional CNC router platform within this price bracket that we have taken on supporting the machine both here in Ireland and in the UK.
We were curious as to why some of the competition was not present here and we now have a feel for possibly why.
It is important to recognise that there is a goldmine of detailed information on this forum and the active members do a great deal for members and go to significant effort to help out members and in our opinion are enhancing the CNC community in the UK no end – we commend this – it’s a fantastic resource. It is also VITAL for safety aspects of CNC when people try to build machines.
However we are considering whether or not to continue with a presence in this forum. We set out to provide and support a professional CNC router with the best available components and within a modest budget. We are confident that this has been achieved with the JBEC Professional Series, that the machines themselves will “do the talking”, and that we welcome any further enquiries at [email protected]
We are now an official supplier of Mach3, CNC Drive motion control electronics and of the Fogbuster coolant delivery system.
For what its worth here are a few examples of work done in house just to show that we are not just a CNC supermarket.
Aluminium bike parts
In house machining
In house machining
Built enclosure for small machine
Mould machining
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08-09-2013 #5
Accuracy is just one advantage of linear guides though - the other important parameter is their high stiffness. On a lot of 'diy' builds you'll find linear guides not mounted to the specified manufacturers tolerances, however so long as the surface is reasonably accurate they will still make the machine more rigid and last a long time.
Thank you for the comments about my friend's machine. We will post a video showing what it can really do in a few weeks, i.e. cutting aluminium over 10x faster than that.
I feel I should clarify a few of the points you have highlighted.
We did spend a long time getting a suitably accurate surface for the rails to mount on, however this was only due to trying so many different methods. In future I would just go straight to using epoxy, as it's quick and easy and as you can see from the reading I took it's plenty accurate enough.
Perhaps I wasn't clear, 4-5k was my estimate for a finished machine. The cost of all the parts (metals, rails, spindle, motors, control box etc) was just under £2500. The biggest purchase was about £950 in aluminium, which could perhaps be improved upon in a future build.
I agree that was an oversight on my part - I should have got the bed stress relieved before pouring the epoxy. On the plus side I can check it again in a year with my surface plate and pour the resin again if it's twisted substantially. The frame did have about 6 months left outside after powder coating, so the thermal cycling there will have stress relieved it a bit, in the old fashioned way!
If you're referring to my experience when making the 'sufficiently strong' machine, then I'm certain it was not a hardware issue - otherwise I wouldn't have posted it. The only change I made which affected the problem was changing the software from Mach3 to linuxCNC, which I've stuck with since as it seems to be more reliable. That said, I don't think this is the place to discuss the virtues of mach vs linuxcnc.
Similarly if you've got any more comment on my build log, then I'd be interested in hearing them so feel free to post in the thread.
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08-09-2013 #6
StoneyCNC, Good post, I have learned several things here;
1. Use linear rails
2. On a welded frame use the jazz method of bolting the top member where the rails attach so this can be shimmed as required.
3. Try out the Linux software before buying Mach 3
You are under commercial pressure whereas I am not, that makes a big difference and I agree with most of what you say in that respect, also I was surprised you went to such lengths on this forum as it is clearly aimed at DIY self builders. I started out with the intention of buying a machine but after reading the information on this site and seeing the difference between self builds and some of the flimsy commercial offerings I have decided to self build. Best of luck in the future with your product.
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08-09-2013 #7
Oh Dear oh Dear that's a bit pathetic mate.!! . . . After trying to serve waffle topped with Bull shit you then launch the teddy out the pram just because we didn't coo and Agh over your baby..! . . . Then you try to pick on other peoples baby's to make you look or feel better. . .Lol
If you care to look again at the post's none of us questioned the machines ability to do it's intend purpose. We only stated the obvious and that was at this price level it should come equipped with profiled linear rails. Plus a few other minor design features that are less than desirable at this price level.
Now being in business over 30yrs I fully understand the pressures and dynamics of business so lets cut to the chase and cut the bull shit.!!
Mostly the Market dictates the price level you can charge for a given size machine and when first starting up it's important to come in at the magic figure that's attractive and appealing to "hook" or pull in the sales.
Finding this hook to often means being on the lower end of the price scale and often this means a compromise some where.? . . . You either take less profit or you find cheaper ways to produce the machine or cut overheads.
Now here's what I believe is the truth of the matter.!! . . .You are a middle man . . so the profit has to be shared.
The only way this machine can be competitive so the Germans can sell to middle men is to cut overheads, and when building a high quality CNC machine one of the largest single expenditures is the cost of profiled linear rials. This means they needed another approach to maintain profit for all concerned but still try to maintain accuracy and maybe individuality which meant round rail was out the question.
Now IMO they probably succeeded in the goal of producing cheap and reasonably accurate rail system that allows them to maintain profit levels for all involved but still it doesn't take away the fact that at this price level the machine should come equipped with profiled linear rails. In this respect they failed miserable.!
Whether they are over the top or not is irrelevant and if that's the case then supply the machine at a lower price level which is more in line with the quality of rail system fitted.
At this price level there's no reason other than either Greed or Profit has to be shared, IMO it's the later which is better than the first but still unacceptable in terms of letting the product down.!
Now back to your Teddy flinging session.!! . . . . There's a genius man called Maris Freimanis which I'm sure you'll know is the CEO of Gecko. . . .Well . . . I suggest you take a leaf out of his book and instead of getting upset with negative Forum comments you embrace them, listen carefully and address the valid ones and let the silly ones pass thru.
None of what we have said are silly IMO and if taken on board can only help a company but to come out with childish statements like yours about leaving the forum and then while not directly attacking another forum members machine try to justify your machine based off there endeavours to produce what is a first class machine which yours IMHO couldn't hold a candle to is a pathetic insult.!!!. . . . .Bad form old chap.!!
Anyway stay or leave will make no matter here but I wish you every success and good luck.!Last edited by JAZZCNC; 08-09-2013 at 11:40 PM.
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09-09-2013 #8
Having followed this thread I would say Jazz is talking sense and if you come on to the forum offering a 'quality' machine then it is somewhat unprofessional to argue every constructive comment given to you and end with a 'well I am not playing any more' statement. People like Jazz on his forum are very knowledgeable (and helpful) and obviously have a great deal of experience to reap knowledge and benefit from. I certainly do not think JBEC have done much to promote themselves to potential customers. Annoying as I live in Ireland and would like to find a good machine here.
AlLast edited by alboy; 09-09-2013 at 07:46 PM. Reason: missed out part
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10-09-2013 #9
Hi guys!
Couldn't help and say my 2 cents about that machine. As i was 3 years ago newbie, so how to say it, a victim of a similar machine. Though have to say that for 3 years the market has changed a lot and your machine is quite much better, even in another category or two higher, from what i have bought at that moment.
I mean i now know much more, had a lot of experience maintaining and knocking my head, so lets cut the marketing crap and look at your machine with positive criticism.
1. First of all, lets be clear. Any machine which is not using square supported rails and carriages is pure woodworking machine + plastics and composite materials. Flimsy or superbly made like your machine, where there are V bearings, U bearings, skate bearings or so, this is a begging for trouble to route aluminum. Like Dean said, its a scratcher. For me even a machine with SBR rails/ round supported/ is a scratcher. So it should not be marketed as aluminium milling machine. Cause i know from my own experience it can do aluminum. A day, a week, even a month. But then starts the joy. What moves, which bearing, how the hell that happened, wow i bought a lemon...
2. Again the bearings. Self cleaning, the dirt will go in through the middle? Let me tell you. Route pine or plastic for a day, even with aspiration and the trouble starts. Hell, that stuff sticks to the steel and the bearings smash it further on themselves and the rail. Cleaning it scratches the rails and bearings, so it stick more and more.
Now the positive: You can incorporate simple cleaning seals so it could not be such a problem.
3. And the bearings again. Mistake. Lets assume your bearings cost you cheap. Say 150 euro per machine. German you say. I will tell you sth- if you dont incorporate something from China you can not make money. Lets look at another angle. Yesterday i ordered from China for a 1400x450x200mm travel machine
Hiwin bearings 20 size, long carriages,780$ . there were other options. Same quality TBI 130$ less, Chinese LG20, even 100$ more less.
In other words, you can do it, cut from some where else, push in other direction and incorporate square rails. Even 15 size, which are cheaper and quite more better than the ones you use. Leave the 20 size as an option for serious buyers or bigger machine.
Bottom line: that could make the machine more expensive with 300-500 euro. I will pay 300-500eur more in a blink just to have square rails even if Chinese and even if 15 size and even if not the long carriages. So it could be done. Even cheaper as you will buy regularly.
4. Yes you guessed. the bearings again, this time also the gantry.
I could not understand why sb who has so much experience and who is actively informing himself in this forum will make a PRO machine, at a PRO price with Flat gantry sides, even if reinforced. Let me tell you. The first bearings that will fail on your machine will be the upper gantry moving bearings that are nearer to you , looking at the front of the machine. Just changed 2 today on my machine, again, so take my word on this.
So the conclusion from these points is that the words Pro, Precision, Aluminum Milling don't go well together with U bearings and so and go well together with square rails. Same with gantry using side plates instead of forming a Profile.
Now to the electronics.
Ok, electronics. But i missed to see here or on the other thread you to mention what are the electronics exactly.
1. What drivers, driven at what voltage with what motors, using what transformer and what BOB?
Not knowledgeable buyers maybe will not care, but if you need our opinion its good to know if you did not hide another lemon there.
2.AC in and LPT connection and 4th axis connection.
On my machine is exactly the same. And you know what? Beautiful to look at but a big mistake. The connections stay permanently hot glued due to dust, mist and rust problems, which translate in connectivity problems, which translates in frustration.
Solution? A simple L shape cover would be enough . 5cm at least protruding .Or they should go inside a bit, so that could be protected.
Otherwise / but hey, the rails and the gantry are the back bone of any machine/ i like it. Basically what others said. The components for a beastie DIY machine are 2500eur worth. Top components i mean. So with the right decisions, investment, tooling and politics a lower price can be achieved. So a bigger profit but at the same time offering real quality.
I had a boss once and he told me: Without organisation, even if you own a gold mine you can fail.
I don't hear a purpose behind your machine. For whom exactly is made? Marketing rules say- Find what is wanted and make it, not make and find buyers. Who exactly is your target audience? So knowing the market, do you offer these people what they really search for, or you jumped high offering lower than expected from the price tag?
And make no mistake. You can sell. You will sell. But one day somebody like me will buy your machine, mislead by the mumbo jumbo. He will learn and cause he needed it for something else and you mislead him, he will open it, make a video, detailed review, spit off the anger but in a clever way and people will read it.
I know for sure this, as i want one day to make that for my machine and bury that misleading company. lets see how they will sell then.
I have a saying. One client gained brings 2 more. One lost, makes 36 more go away.
So use your brain, listen to the brains here/ not me/ and do what they tell you. cause they know from experience. Otherwise, why ask? Marketing tricks?
Wish you all the best!
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