Advice on New Robocutters X4

[alphabeta77]

New to CNCs, but I 'think' I'm heading towards purchasing an X4 from Robocutters, see bottom of page here:
https://robocutters.co.uk/products.asp?cat=51

But struggling a little with the dizzying range of options!


Am 99% of the time looking to work in wood - likely softwoods also, but certainly want the flexibility to work in hardwoods. Don't plan to carve an aluminium etc Plan to mount this to my 8ft x 4 ft work table, so hopefully this'd give a pretty decent cutting area.


Spec from the site I've selected:
- 1500mm x 3000mm

- 5 axis controller
- Makita RT0700


Questions:
- 5 Axis controller - can I check I understand this. As I follow, this means the mill will be able to tilt to make angle cuts? Is this correct?
- if I follow, as I've selected the 5 axis controller I don't need stepper motors?
- Stepper cable - xlr or aviation - is there any big difference or recommendation here? Again do I need this if I'm using the 5 axis controller with motors included?
- Pulley/Coupling - again I assume I don't need these as motor selected?
- Ballscrew vs TR16 - no idea which is better here - any recommendations?


Feel free to just give me a better configuration if you think there's a smarter setup - really looking for it to be as simple and robust as possible!


Many thanks in advance for any advice!

[Clive S]

Hi and welcome to the forum.
Not wanting to hiss on your chips. But you need to some serious research before you go wasting one's hard earned dosh. First you say that you have an 8x4 table that you are going to put a 10 x 5 machine on it !! This machine is driven by belts and just running on wheels and is very very flimsy to say the least.

Please have a look at the build logs on here and get some idea of what is good and bad.

Also please do not be put off but ask as many questions as you like no matter how much you think they might be dumb. It will save to loads of money in the end.

[JAZZCNC]

Hi and Welcome.

Q1 Yes and No.? It means you can have 5 axis of movement but it will use 4 axis just to move the machine. The 5 Axis will be spare or could be used for adding an extra axis like Rotary 4th axis.

Q2 5 Axis Kit includes Steppers but doesn't mention much about the spec. I would want to know the complete spec of what makes up the kit. The electronics make huge difference to how it machine performs and often kits are consist of cheap components or badly matched components.
I'm pretty sure you won't be getting £480 +vat worth of kit.!! Or better put the same kit will cost more like £250 inc.

Q3 They are very similar connectors but I would go with Aviation ones has they lock better IMO. That said I woundn't pay £80 for something that can be bought for £1 each on Ebay.!!

Q4 Yes you will need some way to connect the motors to the screws. Belts or direct coupling I presume they mean.? In which case belts are best.

Q5 Ballscrews are far superior to Leadscrews go with ballscrews.

Now here's my opinion of this machine. . . It's over priced and weak.!!

The gantry connections are weak and flimsy. The Z axis which is THE most important part of any machine is very weak flimsy unit. Poor Z axis affects finish quality and cutting speeds you can achieve.
They don't show enough of the base frame and I haven't looked else where so it's hard to say how strong that is but looking at the rest i'd say it will be on same par.!
It does come with decent quality rails but that means nothing if the rest of the machine doesn't match and in this case with the above points it woe fully doesn't match.
This machine is long way from being Robust which will show in performance and finished work.!

Price wise while it's not overly expensive for machines this size. It is still however over priced for what you get and the simple weak design.
By this I mean you could buy the profiles ready cut to size and bolt together, which is all they are selling you, for lot less money. The same rails and ballscrews are easily bought ready machined direct from china for fraction of the price. (Which is all they are doing)
Same goes for the electronics, you'll buy much better electronics for same or less money than the cheap ones they will be selling. Or buy the same ones for half price.!

Sorry to be negative about this machine but I see BIG potential for dissapointment and would hate to think I hadn't said anything.!

[alphabeta77]

Hi both,

Wow - thanks both for your detailed replies - and please don't think I'll take offense, delighted to have some clear expertise on this (indeed this has been my biggest frustration thus far as it's very hard to get any statements of accuracy - ie if you imagine buying a printer, graphics card, electronics component etc, it's usually a lot much more transparent - eg they'll state dpis, range of colours, benchmark performance etc).

I have no attachment to this CNC at all, but it seemed to be the best I could find, however maybe I should angle this question another way....

If you had £1000-3000 to spend on a CNC, what would you get???

Few bits of background:
- Have a large double garage turned into a workshop, so decent amount of space - have an 8 x 4 table in there I'd be happy to convert (Clive - sorry wasn't clear, am happy to extend this table if need be, hence 3m x 1.5m!)
- Work in computing, wife studied electrical engineering and have renovated our house completely (electrics, plumbing, woodwork etc) - ie no issues at all building, programming components, soldering etc
- Also fluent in 3d software (3d Studio max, autocad, Maya etc) - so hopefully a fairly shallow learning curve to build models to then send to CNC
- Looking to build lots of woodwork elements - carved signs, tables with patterns etc so larger the better, but don't want to overly compromise quality/reliability

Stupid questions(!):
- When people talk about 'rigidity'/accuracy of CNC, how big a deal is this? Ie what's the scales? I can't tell if this is people who are carving Swiss watch components out of steel (ie they're getting worked up over 0.000001mm variance) or if it's pretty drastic - ie 1cm off. What is the effect I would see from this?
- How reliable is your average CNC? Assuming all configured etc, are they relatively reliable or should I be expecting every job to take several attempts? Are you able to set it running and come back and see the result in an hour or two or are you constantly nursing it through the process?

Many, many thanks for your responses - been really useful thus far!

[JAZZCNC]

Ok well on looking again it's actually much worse because I missed you said X4 when I was actually talking about the Rhino CNC version.
The X4 is Total rubbish and I've just been reminded that when asked same question some time back I replyed " It's only fit for Icing cakes" and nothings changed since then. . .Lol

Regards your questions about rigidity/accurecy then both are subjective to use. ie For Icing cakes you don't need much of either.!

But for most other work then it's a sliding scale and balance of both along with another unmnetioned but very important area.? Repeatabilty.

Wood's and plastics don't need the accurecy of watch making but they do need certain amount of ridgidty. Machine strength and ridgidity have big affect on the finish of work and the feeds you can cut that work at. It also affects other less thought about areas like tool wear and machine wear.
Repeatabilty is also important in some cases, wood working however doesn't need micron level repeatabilty, but it still needs to be factored in and moderately repeatable.

So for woods then in general accurecy of 0.01mm is more than enough. Ridgidity is hard to quantify but in general you need relatively strong machine to handle the higher cutting feeds wood requires. If the machine is weak then you'll get resonance which affects several key areas. Quality of finish is poor, tool life is shortened, machine component life is shorten and in some cases machine performance is affected badly.

CNC reliabilty mostly depends on the quality of the components used. Esp the electronic components. This is the Single most troubles some area of a CNC machine that is fitted with cheap poor quality electronics. Unfortunately for poor unsuspecting buyers it's also the area where profit greedy builders cut corners and fit rubbish.

In general if the machine is fitted with decent quality Components and built strong enough. Is fitted with quality electronics and correctly wired then you won't have any reliabilty issues.

Where to buy for between £1-3K for machine 1500 x 3000 from a company then it's not possible. Not for one that's any good anyway.
To do correctly then It would only just be about do-able if you built it your self. And I'm only talking about machine suitable for wood,plastics etc use.!

Edit: Also picking up on the software side. You fail to mention CAM. Cad skills is only one half the process and it's not a case of creating a 3D model and sending to machine.!
It's often made mistake to think that a 3D model is required when infact for many things you only need 2d Vector lines/arcs. Even when a 3D model is used the CAM software just uses the 2d edge geometery for anything but cutting true 3D surfaces.
So factor into the equation/learning curve CAM software.

[alphabeta77]

Yeah, think this is what I've been struggling with - lots of anecdotes (eg some folk saying it's good vs some saying total rubbish) and metaphors (eg 'tough as nails' vs 'good for icing a cake') , but very little science (apols for my analytical approach!).

Ok, so how would one go about building a plan/parts list for a 'good' CNC - are there open source plans or 'quality' components lists on this forum or folk who might share standard builds? Not wildly fussed about size either BTW, just most forums appear to be saying go as big as you can without sacrificing quality as it gives more scope.

RE CAM software - yeah, just being lazy with full list - solidworks has various cam addons (eg HSM works, CAMworks etc), used Fusion 360 and several others. Software should be the easy bit.... ;)

[Clive S]

Ok, so how would one go about building a plan/parts list for a 'good' CNC - are there open source plans or 'quality' components lists on this forum or folk who might share standard builds? Not wildly fussed about size either BTW, just most forums appear to be saying go as big as you can without sacrificing quality as it gives more scope. There are plenty of build logs on this forum some with cad models and it is OK to copy anybody's plans or modify them as you wish. Remember the bigger you go the more expensive and generally harder to get accurate.

At the end of the day the choice is yours but you will find loads of info and help here even if it might not be what you want to hear. Start by looking through the build logs and then put some plans up for others to chime in. Good luck with your build.
edit here is a link to some logs http://www.mycncuk.com/forums/253-DIY-Router-Build-Logs

[JAZZCNC]

Yeah, think this is what I've been struggling with - lots of anecdotes (eg some folk saying it's good vs some saying total rubbish) and metaphors (eg 'tough as nails' vs 'good for icing a cake') , but very little science (apols for my analytical approach!).

Yes I know what you mean and I come across this all the time. I often clash heads with others that have built a machines or used components on there build who will jump up and down because I call or don't rate the component they have used.
They believe it to be the Bee's knees just because they have used it, they don't consider for one minute that there's better out there for less money. This is there lack of experience showing and It's the same for those that call weak machines like these Tough.!! . . . They know no better.!!

I have lot of experience with using many different components and will only call, comment or recommend on any I have extensively used or experience with.

Similair thing applies to spotting flaws in machine design. My experience lets me see things less experienced don't or should say past the bull shit of smoke and mirrors like covers and fancy graphics or marketing.
I've proved this several times on Forum's when manufactures have tried to claim there machines are high quality. When infact they are quite the opposite when looked at in more depth. These types tend to get defensive and upset very quickly, I've even been threatened with legal action in the past. To which my reply was bring it on.!!

How to go about it is easy. Research, research, research and little more research. Then bit more for good measure.
The build process is like eating an elephant.? One small piece at a time.!

This forum has everything you need, all you need to know is here you just have to read the build threads and ask questions. Asking is very very important.
Don't be afraid to ask question, no matter how stupid it may feel, it will have been asked.

There are no plans to speak of, not any that are any good. But there's plenty of good builds that can be copied in some form or another. Look around take bit from this, bit from that and soon you'll have design that suits all your needs.

By this time your knowledge and understanding will have increased and some of the fog will be lifting. The correct components and why will soon become apparent or present them selfs.

Then you'll move onto the Electrical side of the build process. It's here where cutting corners is fatal so don't be tempted.
Again research and asking questions will give you the answer.

None of this should be rushed and you need to be very honest with your self regards your abilty and skills needed to build a machine if you under take building.
It's not difficult but you need a certain amount of tools and need the skills to use them. Patience is big help.

If you can't wait or feel it's beyond you or simply don't have time then I suggest you tread very carefully before buying and do some research. Again ask on here like you did this time before buying.

[alphabeta77]

Ok, as there doesn't appear to be any plans/direction around here, I figure I might as well do it myself as I go along, so will look to build a bit of a wiki of my research as I go to avoid anyone having to stumble around looking for stuff.

I'll compile a list below in what I'm perceiving is the order of quality (ie top is the most basic, bottom is best). I can flesh out with prices, and more variables as I find them.

Feel free to correct/add on etc as I update - only thing I want to avoid is sounding like a 1960s UK Car manufacturer (ie oh these Japanese cars are terrible with their low quality parts, cars are much more reliable with solid steel chassis etc etc) - cost and convenience need to be real-world balancers to cost. Of course we could get cheaper houses, cars etc if we built them ourselves, but convenience is important also.



Shapeoko 1:
Basic and entry level CNC for simple work. Open source plans means there have been many other designs that have used this as a starting point and forked other designs off this.
Difficult to source now.
Plans available - yes
Kits available - yes
Prebuilt - no


Shapeoko 2:
Upgrade to the original. Aiming to improve reliability and accuracy.
Plans available - yes
Kits available - yes
Prebuilt - no

eShapeoko:
A fork of the Shapeoko design - designed to strengthen and improve the original design. Broadly equivalent to the Shapeoko 2. Still relatively entry level, but some reasonable wood carving achieved with it.
Plans available - yes
Kits available - yes
Prebuilt - no

Shapeoko 3:
Much more sturdy design, but price point increased also.
Plans available - yes
Kits available - yes
Prebuilt - no

Robocutters-X4:
Another entry level one - whilst can be bought up to several metres in size, likely to have rigidity issues at this size, so probably best kept to around 1m by 1m.
Plans available - yes
Kits available - yes
Prebuilt - some

X-Carve:
This appears to be a reasonable entry level CNC setup - Keith Fenner appears to have had a reasonable time with it:
http://www.mycncuk.com/threads/9217-Keith-Fenner-Receives-an-X-Carve-from-Inventables-com-Part-1-2-Video/page2
Plans available - yes
Kits available - yes
Prebuilt - some

MyCNC Custom Build!
I guess the quality and reliability of your output here depends on your skill, design and probably some luck.
No recommended designs available, so you need to design yourself or reverse-engineer/side build from other people's designs.
Likewise no build plans or kits, so you'll need to pick through carefully. Every chance end quality could be much better, but likewise no benefit of mass production (ie testing, iterative improvement etc)
Plans available - No (except from picking through/hybridising multiple plans from forums)
Kits available - No
Prebuilt - No (unless JazzCNC is feeling bored....!)


OxCNC:
Appears an upgrade to the X-Carve/Shapeoko. Much more rigid build in comparison. Many folk seem to upgrade their Shapeoko 1/2 or X-carve to this.
http://www.mycncuk.com/threads/9278-What-machine-is-required-please/page2
Some decent work done with these too, see their community:
https://plus.google.com/communities/110852928951643236736

Plans available - yes
Kits available - yes
Prebuilt - no

[Clive S]

Ok, as there doesn't appear to be any plans/direction around here, I figure I might as well do it myself as I go along
I think so far you have had plenty of direction but it appears you want to be spoon fed all the way.


MyCNC Custom Build!
I guess the quality and reliability of your output here depends on your skill, design and probably some luck.
No recommended designs available, so you need to design yourself or reverse-engineer/side build from other people's designs.
Likewise no build plans or kits, so you'll need to pick through carefully. Every chance end quality could be much better, but likewise no benefit of mass production (ie testing, iterative improvement etc)
Plans available - No (except from picking through/hybridising multiple plans from forums)
Kits available - No
Prebuilt - No (unless JazzCNC is feeling bored....!)
If you read the build logs you will see there are a great number of recommended design changes from other members whether they are taken it or not is up to the builder.
.
I feel insulted that you come up with this attitude. But I wish you all the best in your plight.

[JAZZCNC]

Kits available - No
Prebuilt - No (unless JazzCNC is feeling bored....!)

Ok well here's my position.!!

I'm in awkward position because how do I negatively comment and keep credabilty/integrity if I then in next breath turn round and publicly say you should let me build you one.?

I never do and in the few instances I offer privately it's usually because I know for sure the person isn't capable of building but yet very likely to go out and buy these rubbish kits.

I've watched Keith Fenner for years and I've got massive respect for the man but I was shocked to see him using the X-Carve. Personaly I think he's sold is sole to the freebie devil.
Now dispite is huge experience within engineering he still fits into the "Know's no better" class when it comes to CNC routers.! . . Just watch what he ends up doing to that machine over time to bring it upto the standard he'll want.
So What's the point in buying ready made machine if you have to upgrade it your self, may have well just built it in first place and done it right cheaper.!

I'm not going to get into debate or fight with anyone over this because I'm sure there's lots of users of these machines that are very happy with them and produce great work which is great. But I've seen people produce great work with a converted drill press or machines made with MDF and Threaded rod but that doesn't make them good machines or reliable.

When I dismiss these machines it's based on mechanical and electrical design not what they can or can't produce.
Sure they can produce some nice stuff but for how long at what speed and with what reliabilty or Cost.? These are mostly dictated by design, mechanical and electrical components which these kits/designs fail badly on.

Just look at these machines closely and the obvious design flaws will appear.! (All of those built on same principle)
# Plastic or Steel rollers using skate board bearings for linear movement running directly on aluminium surface in an enviroment of abrasive dust.!!
# 6mm aluminium Plates for Z axis the most important area of the machine.!!
# Gantry connections held together with flimsy 2 bolt corner plates.
# Flimsy sized 20mm alumnium profile for major structual componets Ie Gantry, base frame.! (Nothing wrong with profile but 20mm is what I'd use for minor unstructual areas like enclosure's etc not frames)
# Driven by Flimsy narrow exposed timng belts

These machines designs are something I'd expect to see school children building in DT (probably showing my age here) with limited resources and budget.
Which is fine because these machines are aimed at low budget users but they are so basic those same people could build the same for much less money or better still much better for same money.! . . . . Convenience does play it's part but at what cost.? . . . It's not very convenient if your constantly chasing machine faults thru low spec components or results of poor design.!
It's not very convenient if the parts come out looking like the Dog chowed them up because the machine is so sloppy and weak thru wear after 12mths use.
It's not very convenient when your chasing elctrical issues because the cheap nasty but expensive rubbish they supplied either blows up or can't handle the resonance crippling the already dismal performance.!

If your going to spend £2K plus then I'd expect a minimum of Real linear rails idealy profiled or at least round rail type not skate board bearings on plastic rollers. Proper linear movement system suited to size and application idealy ballscrews or R&P on larger machines not 9mm wide timing belts.!
All attached to decent frame work and using properly sized mounts and plates etc.

So like I say I'm in akward postion when it comes to publicly offering to build machines or frame kits.!! . . . . . I'd rather not than be restricted to not able to comment freely. This is also why I will never Moderate on a Forum.

[alphabeta77]

Cheers both for responses!

Clive S:
I think so far you have had plenty of direction but it appears you want to be spoon fed all the way.
Sorry, am confused - on one hand saying ask as many questions as I need and other hand saying I'm wanting to be spoon fed. This you misunderstood what I meant - my point is, instead of just asking questions and taking knowledge for my own benefit, I tend to collate, organise and share it back - ie so not just selfishly supporting my own agenda.

If you read the build logs you will see there are a great number of recommended design changes from other members whether they are taken it or not is up to the builder.
I feel insulted that you come up with this attitude. But I wish you all the best in your plight.
Again, not sure I follow. With all these others lists, there is a kit you can buy with clear instructions, designs, videos of builds, part lists etc etc. I can't see the same on this forum - of course I can read through the build logs (and I am). What I'm classing as - prebuilt (ie pick up from Currys/PC World), Kit Instructions (All the parts for the PC with a guide), No instructions - ie loads of build tutorials, reviews of parts etc on the internet for you to find and order yourself. As far as I can see, you're recommending the latter - which is why it's classed as such. Not saying that's a bad thing, so don't take offense, I'm just saying that relies on a lot more time, effort and quality of your own experience.

PS I'm basing the fact there are no proposed/recommended designs on this:
http://www.mycncuk.com/threads/5520-How-about-a-mycncuk-cnc-router-project?highlight=mycnc
Appears to have been a discussion running for about 3 years with little progress - hence my point



JAZZCNC:
Heh, no, was only meaning that tongue in cheek (other than the CNCs you have built in this forum appear to have been well received, so good example of what you can achieve)

Really useful suggestions in your post, so I'll look to start distilling these.

these machines are aimed at low budget users but they are so basic those same people could build the same for much less money or better still much better for same money.

I'd like to test the difference here (ie in price or in quality) - what I'd like to sketch out is what would be the best application of resource if you had to build for certain budgets - this usually works pretty well in other hardware builds (eg if you ask an architect/engineer/pc forum to spec you best X, y, z for different amounts). I can then look to source online costs for each component so we get a more accurate budget. Naturally there'll be some areas of debate, but prefer to have some options rather than nothing.

Does the forum (or anywhere else) have example builds with budgets? eg best build for £1000, £2000, £3000 etc?

Let's start with £1000 and see where we get to - for a 1.5m x 1m build:

Linear Rails:
20x80mm Vslot:
http://openbuildspartstore.com/v-slot-linear-rail/
£13.77 per metre

There's also CBeam design. This any better?
http://openbuildspartstore.com/c-beam-linear-rail/
£19.28 per metre

Lead Screws
http://openbuildspartstore.com/8mm-metric-acme-lead-screw/
£21.69 per metre

Any better sources or improved parts for above (without going nuts on budget)? I particular Z-axis mount, is this an area I should invest more £££?

I'll keep plodding through various sites/forums to hone it up and start sketching out in Max/Autocad

[JAZZCNC]

Research, research, research then bit more research.!! . . . Then ask questions. . . . . Your missing the first bit and this shows by the questions your asking and the links your providing.

Read the build logs and you'll see that those components are not ideal and expensive. You'll also see where to buy better suited and where from.

We (the Forum) could easily spoon feed you but we tend not try to doing this because it won't help you in the long run. Unless you have clear understanding of why your using what's suggested or why it's designed this way then you'll never build a good machine and understand it.

I will always help guide folks in correct direction but end of the day it's down to you to put the effort in and do some research. If you want it handed on plate to be spoon fed then you'll get very little response. It's not in your best interest to do this.!!

[ckleanth]

Gents, what about the Rhino machine? I want to cut 12 and 18mm birch ply but I want a machine that can take 4x8 sheets...
Would like also to cut 2 or 3mm carbon fibre or epoxy resin
Can anyone recommend a suitable machine??

[Boyan Silyavski]

With 1000GBP you will go to nowhere, so better just don't start it. V rails is the worst thing you could do. I have one, so i know.

And yes, there are plans. I have the plan of the machine N1 i made/ look signature project 1/. Its for free and is uploaded in the build thread. Its absolutely and perfectly scalable to whatever size. And to the size you would like there are no changes at all . The plan is also in the Open Projects area of the forum. A couple of people have followed the design and have made great machines. If you read the thread you will know what motors and electronics, and over all you will find all you need to know to build a quality machine.

So as Dean said - just read the build logs.