Advice on New Robocutters X4

[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-m...me-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.