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jimchelt
21-02-2018, 09:57 PM
Hello
I'm a complete newbie and am about to embark on a build of a C-Beam Plate Maker. Still awaiting delivery of the mechanical bits and pieces so have been using the titmice reading and reading posts and build logs. I am wondering about the motion controller and the Centroid Acorn CNC12 system caught my eye. I've read through what threads I could find on the subject but haven't as yet found anyone in the UK who has tried it. As far as I can see, it's only available from Centroid in the U.S. or from Makersupplies in Denmark. The U.S. price (at 250) is 100 less than the Denmark price. Is the difference accounted for by import charges and VAT? By my reckoning the total from the U.S. should work out at around 310. Am I missing something?
Any advice will be very welcome. Thanks in anticipation.
Jim from Cheltenham, GLOS.

JAZZCNC
22-02-2018, 11:07 PM
Hi Jim,

I've got Centroid controller and it's nice piece of kit thou not quite router friendly just yet because of how it's mostly geared towards Mills/Lathe's regards tool changing and few other bits. However centroid are working on router specific items which will hopefully be in the next software update.

Can I ask what you plan to cut with C-beam plate maker.? . . . . It's not exactly the best of designs and lacks in lots of areas which will quickly show over time or if plan to do any proper cutting.

If you'd come on here and asked about the design you would have got numerous folks, me included, all telling you same thing.? DONT BUY IT.!
The design is weak and flawed in key areas.
Don't be fooled when you see videos etc cutting aluminium because while it may manage to survive a video or two scratching it's way thru aluminium it certainly won't last very long in real world. Those plastic rollers will be dead in short order of time from chips and will most certainly start jamming up causeing stalls etc if not constantly cleaning chips away from profile and rollers.

In all honesty the Centroid would be wasted on machine like this. Cheap BOB and Mach3 or Linux CNC are more than good enough for this machine.

My advise would be if can return the parts do so and look to build better machine. Might cost little more but you will have good machine that can do all you want and probably more.
With this design your just buying weak ticking time bomb that you will quickly find lacking.!

Sorry to be Doom & Gloom but we see this all too often.!

Neale
23-02-2018, 07:09 AM
Dean has been very restrained in his comments about this machine! My own first CNC router was built from MDF to a widely-available design, and I was attracted to that by plenty of video clips and so on showing how well it worked. And it did work, and turned out some useful work. But I spent more time tweaking and adjusting and repairing and strengthening it than I actually did using it! If you go ahead with the C-Beam machine, regard it as a taster and not a real machine, and one that you will grow out of very quickly.

On the subject of controllers, you are looking at something which is rather OTT for the machine. Cheaper and functionally better solutions for a machine like this (and that would be still be very usable on a Mk2 machine when you build it!) are available. Undoubtedly the cheapest but very workable solution is to use LinuxCNC with a simple break-out board. You could pick up a suitable second-hand PC from eBay for around 50, find a cheap monitor/keyboard, breakout board from eBay for a tenner, and you're ready to go. You are going to have to buy stepper drivers and so on anyway, so I'm not including those.

That needs a machine with a parallel printer port. If you want to avoid using one of these (and you are unlikely to buy a new PC these days that has one) then the next-best is something like a UC100 controller which connects to the PC using USB. That will run with Mach3, or can use UCCNC software which is cheaper and is becoming fairly well-regarded. Add in a breakout board again, and assuming that you have a spare PC available then you have a decent motion control solution for around half the cost of the Centroid and which will transfer to a Mk2 router very nicely.

Just some thoughts. There are plenty of build logs on this site which show the range of machines that members have built, almost any of which will beat the C-Beam hands down! And there's plenty of help and advice available once you get started.

JAZZCNC
23-02-2018, 08:29 AM
Dean has been very restrained in his comments about this machine!

I must be getting soft in my old age hey.!!. . . . . Must admit Neale It wasn't easy.:whistle:

jimchelt
23-02-2018, 10:11 PM
Well, that's blown me right out of the water. If I go for the UCCNC option what are your recommendations for the hardware? I mainly work in wood and had been thinking about inlays, relief carving, photo carving etc. with maybe some small engraving on thin brass and/or aluminium. I cannot see that I will ever want to do any serious milling. I have made a few of Clayton Boyer's wooden clocks using my Diamond fretsaw and I would like to have a crack at using a CNC router to cut the cogs etc. To repeat, most of my work will be with various types of wood. So, any thoughts or advice will be most welcome before I commit myself. Thanks to you guys who have replied so far.

Neale
24-02-2018, 07:21 AM
It's a difficult one to answer, as it's all about compromise and getting the balance between cost, complexity, time to build, materials to cut, etc. However, you are not being over-ambitious in your requirements - too many people start out with "Oh, I need to cut a little bit of aluminium as well!", not realising that it's not the amount of aluminium that matters, it's cutting it at all! However, you say engraving which is a very different matter.

The build-it-yourself answer in this size range is probably an aluminium extrusion-based machine. Very popular and seem to give very good results, depending on the effort and care you put into designing (with plenty of examples and advice from this site) and building. Lots of decisions about drive mechanisms - the high-end solution would use ballscrews and Hiwin-style profile rails. Alternatively, for a lighter machine, linear bearings running on steel rod. Possibly trapezoidal leadscrews with anti-backlash nuts. It's always possible to pay just a bit more and get a better machine - it's getting the cost/benefit balance right that's difficult. However, your requirements are not over-demanding, so that might work OK.

One alternative that might be worth considering is one of the cheap-ish Chinese machines. For example, I've just done a very quick search and come up with this (https://www.ebay.co.uk/itm/3-Axis-6040-DIY-Desktop-CNC-Router-Engraver-Milling-Machine-Engraving-Drilling/262884087487?epid=711214099&hash=item3d351cd6bf:g:ne0AAOSwi0xaNJXX). I have no experience of these machines, but mechanically this would probably fit the bill. This particular machine comes with a water-cooled spindle and variable-speed drive which is far superior to the Kress-type spindles from the point of view of noise/reliability - they will run for hours, which they might need to do with a lighter-weight machine taking lighter cuts. The big problem with these cheap imported machine is that the electronics is really poor, but you are looking at a price for a ready-built machine with spindle, including ballscrew drive, for around the same cost as a C-Beam kit (from a quick look at their web site). You might need to upgrade/replace the electronics but will have a larger capacity, more capable machine for not much higher cost.

I can't spend your money for you, but my personal preference would be to build, take my time, and look for good-quality components matched to my needs. But if you regard them as a part-finished kit of parts, the cheaper Chinese machines might be worth a look if you buy with your eyes open. At the very least, I hope that I have pointed out some alternatives worth researching.

By the way, it's a bit unkind to pick up a typo, perhaps, but this one is unfortunate to put it mildly. In the C-Beam machine write-up on the Ooznest web site, it says that " His video goes meretriciously through every step of the build". Pity this wasn't proof-read more carefully - "meretricious" according to the Oxford Dictionary of English means "Apparently attractive but having no real value". I'm sure that they meant "meticulously"...

Clive S
24-02-2018, 08:13 AM
By the way, it's a bit unkind to pick up a typo, perhaps, but this one is unfortunate to put it mildly. In the C-Beam machine write-up on the Ooznest web site, it says that " His video goes meretriciously through every step of the build". Pity this wasn't proof-read more carefully - "meretricious" according to the Oxford Dictionary of English means "Apparently attractive but having no real value". I'm sure that they meant "meticulously"...


That's the trouble with being educated Neale:hysterical:

Doddy
24-02-2018, 09:30 AM
Well, that's blown me right out of the water. If I go for the UCCNC option what are your recommendations for the hardware? I mainly work in wood and had been thinking about inlays, relief carving, photo carving etc. with maybe some small engraving on thin brass and/or aluminium. I cannot see that I will ever want to do any serious milling. I have made a few of Clayton Boyer's wooden clocks using my Diamond fretsaw and I would like to have a crack at using a CNC router to cut the cogs etc. To repeat, most of my work will be with various types of wood. So, any thoughts or advice will be most welcome before I commit myself. Thanks to you guys who have replied so far.

You mention engraving on thin brass and aluminium. This obviously isn't about hogging metal but my experience a long time ago with a Marchant Dice machine was that backlash, rigidity and frame strength will be your enemies here, particularly with the usual conical engraving bits - good engraving takes no prisoners and if the tool height above workpiece changes (in my old case - deflection on the unsupported X-rails) then the radius of the engraver cutter changes; backlash and rigidity will give you odd shapes when the tool path changes. Don't underestimate the challenges of engraving. My use-case was PCB routing - cutting through 35 microns of copper at a fixed depth is challenging (if the height varies, then so does the track widths, and artefacts around track corners can decimate the track).

JAZZCNC
24-02-2018, 10:16 AM
Pity this wasn't proof-read more carefully - "meretricious" according to the Oxford Dictionary of English means "Apparently attractive but having no real value". I'm sure that they meant "meticulously"...

Ah ah they may have meant "meticulously" but correct with "meretricious". . Lol


Well, that's blown me right out of the water. If I go for the UCCNC option what are your recommendations for the hardware? I mainly work in wood and had been thinking about inlays, relief carving, photo carving etc. with maybe some small engraving on thin brass and/or aluminium. I cannot see that I will ever want to do any serious milling.

Well don't be because better to know now than after you put lot of time energy money into it only to be dissapointed.

Now you say you don't have any serious milling needs but inlay work and fine detail engraving is very much serious milling. Maybe not in material removal terms but certainly is in regards to machine design strength/accuracy. The C-Beam doesn't come close for quality work.

However I don't agree with Neale suggestion to start with chinese machine as base starter. The Frame build quality on these things is rubbish. the mechanical components are rubbish and the electrics are rubbish. Lots of little things, which i could list but won't that amount to poor machine and not good place to start.
875 gets you good way down the road with good components and by that I mean Profiled linear rails, ballscrews with proper end bearings etc.
Let me break it down for you.

If you can work with Steel then the frame for small machine with cutting area size of C-beam won't cost fortune. Less than 50.
Aluminium for Z axis and Bed aprox 150
Frame total 200

If buy from China which we all do without any issues so don't be afraid. Then you'll get profiled Rails,ballscrews endbearings, couplers pretty much all the mechanical parts for 350.
Something like this.
https://www.aliexpress.com/store/product/EU-Delivery-Square-Linear-guide-sets-6pc-400-700-1000mm-3pc-Ballscrew-1605-400-700-1000mm/704350_32817942905.html?spm=2114.12010612.0.0.5f94 7123KaT2CY

1.5Kw Water cooled Spindle and VFD which will knock spots off Kress. 133.00
https://www.ebay.co.uk/itm/1-5KW-ER11-Water-cooled-CNC-Spindle-Motor-1-5KW-220V-VFD-Inverter-Drive-80mm-Dia/261971678847?hash=item3cfeba967f:g:N2YAAOSwPhdU3Ze u

Electrics gets little more tricky and expensive but lets give it go.
50V Digital drives x 3 81
https://www.ebay.co.uk/itm/Digital-Stepper-Driver-1-0-4-2A-20-50VDC-Nema-17-23-24-Stepper-DM542T-/122556551961?hash=item1c88f09319

Motors x 3 80.00
https://www.cnc4you.co.uk/Stepper-Motor/Nema23-3.1Nm/Stepper-Motor-3.1Nm-x-3-60BYGH301B-Nema23

PSU best building toroidal supply cost roughly 70.00

Motion controller UC100 80.00
Cheap Breakout board 10

So far we have 98% required for good machine. lets add it up.
Frame 200
Mechanics 350
Spindle 133
Drives 81
Motors 80
PSU 70
Motion C 80
BOB 10

Total 1004

The remaining 2% to finish will bring to roughly 1200. For this you'll have machien that knocks the living daylights out of the C-beam and any chinese machine. Which will do anything you want and to high standard provided you build the frame well.

So you see why I dont agree and just what can be done with not lot of money. If you decide to take this route then just ask questions or contact me directly I don't mind offering advise and quite pleased to give you my number if want to chat.

Neale
24-02-2018, 10:54 AM
I'm not going to disagree with Jazz (it ain't worth the effort, anyway :smile:) and I would build any day of the week. You might spend 50% more than one of the Chinese machines, but the end quality, accuracy, and general capability will beat the Chinese hands down. I just wanted to point out that there are alternatives to some of the "based on a clever idea" machines, even though you would still spend time fettling, setting up, and replacing bits to make them work adequately.

I would take Jazz up on his offer, and if you would like to see what can be done with relatively simple kit, take a look at JoeHarris's build log where he has done some excellent machining of aluminium components for his machine using a hand-held router, showing what can be done with limited facilities. You won't find this kind of thing in a book, but it shows what can be done with a bit of care. An inadequate machine is a continual frustration - I was talking to someone a couple of weeks ago who was really pleased with the machine he had just built. "I engraved a dial for a clock," he told me, "and when I engraved the circles around the dial, they very nearly joined up at the end!" A combination of lack of rigidity, guide bearing slack, and backlash, probably. None of which can be easily adjusted out, and which could have been avoided with better design and better components at the outset.

"Spend a little too much on a tool, and you'll have forgotten the fact the first time you use it. Spend too little, and you'll remember it every time you use it"

JAZZCNC
24-02-2018, 11:12 AM
I'm not going to disagree with Jazz (it ain't worth the effort, anyway :smile:) and I would build any day of the week. You might spend 50% more than one of the Chinese machines,

Good Man you know it makes sense. . .Lol

Ok lets look at this another way and look at the 50% more.? Lets say chinese machine costs 900 and Building costs 1500 which is very realistic figure for finished machine. 600 difference.
Now lets go 18mths down the road to the point when decide you'd like larger machine.! . . . Lets sell Both.!!

Ermmmm what to charge for used Chinese machine that can be bought for 900.? Ok lets be positive and go for 60% of new 540 = Loss of 360
So what do we sell Home built machine for that is good Strong bespoke design which uses decent components.?
Ok Lets offer it cheap for quick sale so 2000 = 500 profit

Which do you think will sell first.?

Doddy
24-02-2018, 11:16 AM
Which do you think will sell first.?

Bad example. 80% of the people will probably go for the cheaper, "professionally built" machine rather than the home-grown. Human nature.

The 20% who have an inkling of what they really want or need - I agree, would jump on the home-built, strong machine. God knows I've been looking long enough for a decent one to turn up on eBay. For now, back to F360 and steel suppliers.

JAZZCNC
24-02-2018, 11:35 AM
Bad example. 80% of the people will probably go for the cheaper, "professionally built" machine rather than the home-grown. Human nature.

Not my experience dealing with plenty people who have DIY built and sold.
Like your self, there are plenty of people who have done their research and know what to avoid but don't have the means to build but can see good machine when appears. They just don't have the funds to buy better professionally built machines which for obvious reasons cost much more money.

jimchelt
24-02-2018, 06:55 PM
A big thank you for those very helpful responses. My question was very timely because I was able to cancel the order for the C-Beam machine without penalty. Clearly i need to start thinking seriously about a scratch build. To be honest I was slightly intimidated by the idea, having no engineering background whatsoever, but that's also why I joined this forum.
I had at one time been looking at a Stepcraft v2 420. Most recently a 1000x1000 xcarve machine has become available locally. Am I right in thinking that these too won't come up to scratch in your opinions?
I found your costings very helpful Jazz as costs are always (for most of us old farts anyway) a limiting factor. I must admit I think 1200 for a finished, quality machine is pretty good. I will definitely take you up on your offer of advice and guidance. I ope I don't try your patience too much.
Thanks again to all.

Neale
24-02-2018, 07:55 PM
Good result! Hope you have a good sense of humour to survive here, but take it all in good part and there's going to be plenty of advice and help.

JAZZCNC
24-02-2018, 10:26 PM
Most recently a 1000x1000 xcarve machine has become available locally. Am I right in thinking that these too won't come up to scratch in your opinions?

Correct much the same basically would be frying pan into the fire. The building isn't difficult even with no engineering experience provided don't rush and have little patience.
I'll PM you my number then can give me ring when suits you.