Im new, am a 3D designer. Need a New cnc machine and need advice and guidance

Hello, My name is Mike and im 20 years old. I have been using Solidworks for a few years and have become quite fluent with the software. I am keen to turn some of the parts I design(mainly Rc related) into life by the use of a CNC. I understand the concept and have sent Dxf and Stl files to companies to have parts cut and printed for me but would like my own CNC.

Could any of you folk out there point me in the right direction for a CNC.

Basic requirements

1) Be able to cut woods,plastic,carbon& glass fibers, Aluminium
2) be easy to assemble if required,easy to setup
3) cost less than £1200 for machine including electronics. ( CAM and Mach3 already acquired)

it would be a rel help :)

Hi Mike
Welcome to the forum.
If you let us know the size of components you intend to produce, our more knowledgeable members will point you in the right direction, a lot tend to build there own as you can end up with a good machine for a lot less cash than some of the commercial stuff that's available.
Regards
Mike

hello mike
there is nothing off the shelf that I know of within 1200 quid range other than these Chinese 6040 machines that are all over ebay

im thinking something along the lines of 600x600x100mm working area... Could you guys fill me in on what you reckon is best of these which I have found so far.

CNC1 - I have seen videos of this machine with good results gutting aluminium

CNC2 - I like the look of this machine but there is not much about it online...looks good but i hear allot of chattering while cutting aluminium

CNC3 - I like this one because of its low cost but am feeling quite skeptical of its linear movement mecanism, looks like it could be sloppy after allot of use


Thanks guys, so far this is what i have managed to find with my limited knowledge on these machines.

Hello FlyHighRC,

What sort of tolerances are you looking to achieve with the aluminium?

What thickness of alu are you wishing to cut?

Is cutting time a factor?

you be pissed off in no time shelling out for them then cutting aluminium

these are the 6040,s I mentioned 3-axis CNC 6040Z-S65J Router Engraver Milling Drilling Cutting Machine CNC 6040 | eBay
at least some of them come with a water cooled spindle but I still wouldn't buy that,with aluminium in mind ,although some get by with em and they have a following,with a 1400 quid budget consider making one

Hi

i dont think i would bother with any of those, like the others sya, you could build your own for that, a little more money, you could build one 10* better. There are already some good designs on here and some already done in sketchup for the size your looking for. I will try find the ones i was looking at in sketchup, they was compleate, I would imagine all them have rigidity and accuracy problems.... You may get away with cutting a wing profile in foam with them, but i think, ( am also into RC ), you might struggle with smaller componants on them. especialy hard small parts ( alu car frame, helli bits, cam holders ). Do You FPV ?

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Originally Posted by george uk

Hi

i dont think i would bother with any of those, like the others sya, you could build your own for that, a little more money, you could build one 10* better. There are already some good designs on here and some already done in sketchup for the size your looking for. I will try find the ones i was looking at in sketchup, they was compleate, I would imagine all them have rigidity and accuracy problems.... You may get away with cutting a wing profile in foam with them, but i think, ( am also into RC ), you might struggle with smaller componants on them. especialy hard small parts ( alu car frame, helli bits, cam holders ). Do You FPV ?

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Well CNC 1 has been on youtube and seems to go through aluminium fairly easily..6mm 6061 alloy and seems to do it in very little passes. If i wanted to build my own are there any build videos of a known machine where the parts are easy to findbuy and assemble? Id imagine getting the thing tuned would be a bi*ch.

Yeah I am into FPV. I Design Quadcopters mostly. I do love flying FPV and also do allot of survey work
Attachment 12512

I live on the coast, and its so relaxing FPVing the coast, and buzzing boats in the humber. I prefer planes, but love team blacksheep vids with quadcopters... I doubt they get permission.

The more rigid the frame, the easier to get repeatable accuracy, your best bet i think would be read through some of the build logs, you will see what problems people overcome, and will see why them three that you pointed at are a basic,

So what would I need? I wouldnt mind designing my own design and sticking up some renders on here for you guys to approve..If I build it I could then upload the files for anyone else to have a crack if the design works :) I suppose if its a homebuild then I could Increase its work area right?

The things I know Ill need

1)Steppers motors
2)Stepper wire
3)Link stuff
4)Controller
5)Stepper Drivers(Any all in one driver boards?)
6)Linear mechanisms? Any recommendations for for round bar or square rails?
7)Some sort of router..again any suggestions?
8)sacrifical bed, i see this this is most often MDF

Have I missed anything?

Where can I buy extrusion? And any dimensions online? Would really help with putting this all into Solidworks :)

Thanks again guys

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Originally Posted by FlyHighRC

Well CNC 1 has been on youtube and seems to go through aluminium fairly easily..6mm 6061 alloy and seems to do it in very little passes. If i wanted to build my own are there any build videos of a known machine where the parts are easy to findbuy and assemble? Id imagine getting the thing tuned would be a bi*ch.

Yeah I am into FPV. I Design Quadcopters mostly. I do love flying FPV and also do allot of survey work
Attachment 12512

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Smoke and Mirrors.!! . . Yes they show it cutting aluminium but what they don't show or tell you is how much it takes out the machine.!
Cutting aluminium correctly needs a much stronger spec machine than any of these. Most machines will scratch Aluminiun away but to cut it correctly and accurately requires rigidity and NONE of these have enough to cut aluminium to any decent standard and survive. They will even struggle on cutting hardwoods at deep depths and decent feed rates.

My advice as usual is to save up a little and build your own or save up a lot and by something much better. The reality is that there isn't anything available to buy off the shelf much under 2.5K that is worth bothering with. The 6040 and these cheap Kits etc are just hassle and false economy, they under perform, break down wear out very quickly if pushed hard, even when not pushed hard they can be fickle things.!

The other thing you need to be aware of is the feed and speeds, Soft materials require higher feed rates and these cheap machines with poor under spec'd components and electronics often can't reach the correct feed rates to give good finish and tool life. If they do manage to reach them then they are often performing at Max capabilitys which puts them under excess stress, at best this leads to inaccuracy and missed steps but worse than that it shortens there life span very quickly.

Following my previous comment is it possible to build a machine? for my budget range and achieve good quality?

just about, but if you up your budjet by a few 100 to say 1500, then yes , you can build a quality machine.

300-500 for motors, controllers BOBs and electricals excluding spindle and controller ( 200-300+)

about the same for linear components ( bearings,slides, screws )

there are about minimum, excluding the frame, if you look about BUT TAKE ADVISE BEFORE YOU BUY ELECTRONICS. BUILD THE FRAME FIRST.

If you know anyone that can weild, you can build a good frame cheaply enough out of steel, just use ally were required

IM loosly thinking about designing my own frame and posting the renders for approval by you guys, Is that a good idea or should i find a proven build? If so...know any? :D

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Originally Posted by FlyHighRC

Following my previous comment is it possible to build a machine? for my budget range and achieve good quality?

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Yes but don't be under any illusions that it's easy. To pull this off you will need to be well equiped and have the correct skills to use the tools.
With £1200-1500 budget you will have NO room for error or mistakes buying the wrong components.
Building with steel will cut the costs down but requires it's done correctly to achive accuracy, to be honest at this budget it's about your only option to achive accuracy/strength and still leave enough funds to buy the important stuff that makes for a good machine. These being Profiled linear rails, ballscrews and very important is decent quality electronics.

George runs thru the price of main components but what he doesn't mention is that there's a considerable amount of money that gets eaten up from things folks don't see or account for when planning.? Nut & bolts, Wire, Switches, connectors, cable chain and the list goes on. These can really eat money up fast if not careful.
One thing that often happens with people working on tight Budget is that they cut corners in the wrong places.? Often it's the electronics they turn on because they see this taking a big part of the budget.! This is the worse thing they can do and it's in this area where spending money on the correct components can pay dividends in how the machine performs. Get it wrong and take the cheap skate route and you WILL REGRET.
Next area to get the chop is Linear rails.? They often buy unsupported round rail because it's cheap, which it is, but it's also bendy and CRAP. Other option is to use supported round rail which is better but still not the best and comes with problems of it's own, Like constantly needing adjustment and poor accuracey.

Another area skimped on is the Z axis and material thickness.? The Z axis is THE single most important area of the machine and cutting corners here is BIG mistake as it holds the cutting tool and if this flexs or bends then doesn't matter how well rest of machine is built you'll get poor results.

Best advise is BUY NOTHING YET look around the forum at other builds to judge whats required and if you think you have the skills etc needed. If so then pick or design the kind of machine you require and start a build thread and ask advise. STILL DONT BUY ANYTHING until you have the green light and understand FULLY what and why your buying these componets. Again ASK advise on where to buy as often we will know where they can be bought cheaper.

With a Small Budget you have no room for error and in the blink of an eye with a few wrong clicks you could easily spend all your budget and still be some way off a fully working machine that will still under perform if you haven't done your home work.!!

Good luck and ASK questions before Buying.!!

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Originally Posted by FlyHighRC

So what would I need?
6)Linear mechanisms? Any recommendations for for round bar or square rails?


Where can I buy extrusion? And any dimensions online? Would really help with putting this all into Solidworks :)

Thanks again guys

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regarding screws and rail most of us use chia in the link he does the rail and ball screws,there are others but he was the only one ive come across that will machine the screws to length as well as end machineing to your specs to cater for pulleys should you use them.
6SE Linear Bearing Rails 3 ballscrews Balls Screws 1605 BK12 BF12 3 Couplings | eBay
profile rail would be nice but even used you might be pushing it on your budget.

extrusion.. just one place i and others have used a bit http://www.kjnltd.co.uk/

Is it possible to make a good SOLID machine using extrusion? I have read mixed points of view about this stuff...Some say its really ideal for upgrading a machine in the future and provides a good solid frame while other say that its rigidity could be called into question.

I am able to get easy access to a welding machine and welder(friend) but would rather not go down that route( Cutting steel,jiging, powdercoating etc) If i can make a CNC from extrusion..that would be ideal. Though I wouldnt mind making the gantry out of thick steel screwed into the linear blocks. That wouldnt be a problem.

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Originally Posted by FlyHighRC

Is it possible to make a good SOLID machine using extrusion? I have read mixed points of view about this stuff...Some say its really ideal for upgrading a machine in the future and provides a good solid frame while other say that its rigidity could be called into question.

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Yes it is possible but it needs to be done correctly and using heavy duty profile which is very expensive when you factor in the correct fixtures etc required to make it work. Flimsy 40x40 won't cut it and You certainly won't get much machine for £1500 using profile for the frame.
Steel in comparison is very cheap and stronger but requires more effort and skill on the builders part. If your on a budget then forget profile you just won't do it and have machine that's strong enough.

Hey guys, Spent most of the day researching CNC designs. I am now pretty sure I want to design my own. I Feel i am able to build this machine...I have a decent workshop filled with tool and my grandfather has a model engineering workshop with manual mills which could come in pretty handy.

The only issue im having is pairing up the hole sizes in the rails to be able to fit the extrusion. This is becoming pretty frsutrating as I cant seem to find extrusion,rails(supported round and linear) that want to fit eachother easily.

Could you guys point me in the right direction of parts that are almost plug 'n' play please.

I also found this CNC Kit it seems pretty good to me but im not the expert here haha. If you could help Id really appreciate it :tennis:

No extrusion then aye...bummer, look much simpler haha

a good material? Stainless Steel Box Section - 40mm x 40mm - The Metals Warehouse

once i get some info on a good material size and price i can start the design :)

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Originally Posted by FlyHighRC

No extrusion then aye...bummer, look much simpler haha

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Ye it can be simpler but not has much as your probably thinking and it will cost at least 3 times the price of steel. I build a machine that uses HD profile but it's used in a very specific way and using thick aluminium plate machined to match so it's not exactly DIY or cheap and you need CNC machine to help build another.! . . Chicken and Egg.!!

Steel will be much cheaper and far easier for first time DIY build.

is the above link good enough for the steel frame?

Im hoping to base the machine loosly off of this guys machine...though due to workshop size and the way this machine works it would be difficult to anything over 600x600mm cutting area...just because of the fact the table slides ather than a moving gantry...which to me looks like the better way to get the job done.

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Originally Posted by FlyHighRC

a good material? Stainless Steel Box Section - 40mm x 40mm - The Metals Warehouse

once i get some info on a good material size and price i can start the design :)

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No 40mm is too small section and you don't need stainless steel. 60 x 60 x 4mm Mild steel is what you need. If you have a local steel supplier it will be cheaper and if you buy in full lengths which will be aprox 7.5mtrs you'll get if for around £40-50 per length or less. The minimum size would be 50x50x3 and can be bought for around £35 per 7.5mtr length.

If you cut careful you should get away with 1 length.

Ok,cool :) Ill get on that then... So essentially once the frame is cut,welded and finished you then locate and bolt the rails onto predefined position on the frame, correct? after doing that you then add the stepper motors to the ballscrews, then add the wiring from the motors to the driver boards? then to the powesupply and computer? Make everything look pretty and add a router... is that the assembly in a big nutshell?

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Originally Posted by FlyHighRC

Ok,cool :) Ill get on that then... So essentially once the frame is cut,welded and finished you then locate and bolt the rails onto predefined position on the frame, correct? after doing that you then add the stepper motors to the ballscrews, then add the wiring from the motors to the driver boards? then to the powesupply and computer? Make everything look pretty and add a router... is that the assembly in a big nutshell?

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Wow slow down rover don't go jumping to far in front already. Your nutshell version is a very very very simplified concept and in reality theres a little more to it than that.
Like I said before go do some home work and look at other build threads and designs to get an idea of whats required. This may seem like wasted time but it's not and will payoff when you are ready to start. If you skip this step you will end up with a lesser machine and big potential for wasted money.

I Have been researching builds for little under a month so far...thats why i now registered with the forum so that i can start :) I never fully intended building one, but it would be a fun project and would make quadcopter building a fair bit easier..ecspecially cutting wing ribs haha. The builds i have looked at so far were to get an understanding and somevideos are quite enteraining...My CAD abilities will hopefully help me along and to make sure the design is solid before I make the first purchase and cut. Ill post the design on here aswell to see what you fine people think of it :)

A general question... What sort of accuracy can be achieved by an average well built,accurately assembled machine? Can they top some of the commerical machines?

The thing Im finding hardest in terms of research is the general jargon that goes with CNC, after thinking of the dimensions of the machine I would like 900mm rails and 600mm rails. Able to point me in the right direction?

Thanks again

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Originally Posted by FlyHighRC

I Have been researching builds for little under a month so far...thats why i now registered with the forum so that i can start :) I never fully intended building one, but it would be a fun project and would make quadcopter building a fair bit easier..ecspecially cutting wing ribs haha.

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Didn't know quads had wing ribs??!! ;)

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The builds i have looked at so far were to get an understanding and somevideos are quite enteraining...My CAD abilities will hopefully help me along and to make sure the design is solid before I make the first purchase and cut. Ill post the design on here aswell to see what you fine people think of it :)

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That's the best way to do it...

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A general question... What sort of accuracy can be achieved by an average well built,accurately assembled machine? Can they top some of the commerical machines?

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Only if you make them ridgid enough and use the correct equipment....but then would you expect to make your own car in your garage and expect it to be better that a production car?

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The thing Im finding hardest in terms of research is the general jargon that goes with CNC, after thinking of the dimensions of the machine I would like 900mm rails and 600mm rails. Able to point me in the right direction?

Thanks again

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If you have a look through build threads like http://www.mycncuk.com/forums/gantry...eady-eddy.html this one or http://www.mycncuk.com/forums/gantry...rst-build.html, http://www.mycncuk.com/forums/gantry...-building.html, http://www.mycncuk.com/forums/gantry...g-machine.html then you'll get the drift of what needs doing and roughly in what order. Look through all the build logs and then with your 3D design expertise put a couple of drawings up of the frame for people to critique and you'll be on the way. Once you've got your basic design then AND ONLY THEN can you think of ordering things like ballscrews and rails etc. Once you've got your frame, ballscrews and rails sorted then you can think about the electrics you will need.

Thanks, Wasnt expecing his forum to be so saturated with experts at this level on a UK site, Its very nice to see :)

In terms of my design, A plane is designed around engine and passangers, the same for a car in a nutshell. Well To make the design process easier I want to chosse all the size gear Ill need to get it off the ground. So I have found these rails...Are they good enough? If so I can take the dimensions and add them to solidworks so that the design is built around these giving me the size. Also motor mount dimension would be handy...Stepper motors to me seem to have the same mounting and bolt patterns and are just longer with power...Is this correct?

If so then again, the design process will be easier :)

Im also considering these rails also quite allot bigger but Im only 20 and am a student so funds are tight so I dont want to outgrow a machine right away... CNC 3D wings would be nice :D

What are your thoughts on going bigger?

Hi

few tips for you to think about.

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Well To make the design process easier I want to chosse all the size gear Ill need to get it off the ground.

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Design and build first. for 2 reasons 1. Getting the correct ones. 2 Saving on postage by ordering everything at once

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In terms of my design, A plane is designed around engine and passangers, the same for a car in a nutshell.

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CnC machine is the other way round. Biuld the frame as solid as you can... the rails, motors and sized around the frame, that why you should do it first

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What are your thoughts on going bigger?

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It goes up in complexity and costs, it a lot harder to get a big frame properly square, its easyer to get a medium size one accurate. Keep to a reasonable size.

I think I will still have to design around the rails, its the way I have been taught and may sound odd but without a reference it becomes difficult to scale the machine,for me anyways.

Are these chinese CNC parts decent quality or are they to stay away from?

A reasonable size sounds reasonable haha. I think I will just do that...I can expand once i get my head around everything and have sufficient finances in the future :)

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Originally Posted by JAZZCNC

No 40mm is too small section and you don't need stainless steel. 60 x 60 x 4mm Mild steel is what you need. If you have a local steel supplier it will be cheaper and if you buy in full lengths which will be aprox 7.5mtrs you'll get if for around £40-50 per length or less. The minimum size would be 50x50x3 and can be bought for around £35 per 7.5mtr length.

If you cut careful you should get away with 1 length.

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Would you say that 16mm supported bar is sufficient for my build? In terms of strength and abilities to machine aluminium?

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Originally Posted by FlyHighRC

I think I will still have to design around the rails, its the way I have been taught and may sound odd but without a reference it becomes difficult to scale the machine,for me anyways.

Are these chinese CNC parts decent quality or are they to stay away from?

A reasonable size sounds reasonable haha. I think I will just do that...I can expand once i get my head around everything and have sufficient finances in the future :)

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What is the max size you want to machine?

As a designer you'll know that first you need to identify the requirement before you can come up with a design/solution. Set out what you want the machine for, then you'll know what size you need to design. Then you can draw your rails and email Chai at linearmotionbearings2008 (ebay store, though don't go through eBay as you get better prices) to get a quote for the rails and balls crews all in one go, the more you order the cheaper prices he'll give you.

What you're saying is a bit like "I've got a 1000kv 24A out runner. ..I'll design my RC plane round that...which although can be done it's better to say I'll design a 1000mm span plane and then after estimating the Wright of it select the motor, ESC etc...

Sent from my Galaxy S5

true, Its just the way I have designed before, And the irony is a good designed plane is always designed around the propellor... Oh, I do have some big motors. 1600W to run on 22V, it is lying around and never came up with a use for it...And I have seen people use brushless motors as spindles... any success?

The machine I would Ideally have by the end of this is as:

roughly 800x600mm though that can give or take a bit...though preferably a little bigger than smaller.
Be able to machine carbon/glass fibers, plastics, woods and be able to do some aluminium work without feeling restricted
Be simple,cheap and easy to use.


They are my basic requirements :)

If you want 800 x 600 cutting area then your overall size will be approx 1200 x 900 which is just about desktop. My machine is going to have a cutting area of 1000 x 500 so I can cut whole sheets of balsa for ribs etc. Have a look through my build (so far) and you'll get an idea of the size of it, it's larger than you think in the flesh. My frame us from 50 x 50 x 4 mm steel and weighs 70 just for the bare frame...

Sent from my Galaxy S5

Putting a plan together for now :) Just to make sure i meet current and possible future targets...making it as future proof as possible...also simple assembly for maintenance and possible upgrades. With ball screws and rails being the parts that judge the machines length what do you think of these? though these are quite a bit larger,would expect the machine tp be in the region of 1600x1200 which is pretty big but i got the room :)

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Originally Posted by FlyHighRC

With ball screws and rails being the parts that judge the machines length what do you think of these? though these are quite a bit larger,would expect the machine tp be in the region of 1600x1200 which is pretty big but i got the room :)

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Your heading into trouble already and doing the classic mistake new builders make by thinking it can't much more difficult to go larger.? Well your wrong it's whole differant ballgame. First and foremost your Budget is blown to bits.!!
Long and wide machines need larger ballscrews and more of them.! Strength needs to increase to keep ridgidty this adds weight This means larger motors, drives, PSU and more of them.! Longer cable chains more wire runs and the list goes on and the cost goes up fast.
Then you have the build it's self with rail alignment and getting on same plane which over longer wider distance requires careful prep and some knowledge which for a first time builder to take on is a risk and not something to do if your on a budget.

My suggestion is take a step back.! Build to your imidate needs not the future as they will 99% change when you actualy start using the CNC machine. You won't upgrade this machine too much from original you will 99% want to build another machine with all your new found needs.
If you build this machine correctly and use decent quality components and electronics you will most likely recover all your initial outlay and possible more. Cut corners and you'll regret it later and will make selling on harder.

Regards the rails then Stay away from round type rails all together because even the supported ones are not so great. Chai as started selling profiled linear rails and they are cheap enough to warrent not using round rail and they make world of differance to the machine and it's sell abilty. They make the diffrance between just average DIY and Great DIY/Professional. They will will certainly add more than there value to the selling price and make sell abilty far higher.

Hi FlyHigh,

I've had a quick scan of this thread and haven't seen it mentioned yet - bear in mind that the profile of box-section isn't 100% flat and might cause you a bit of grief mounting the rails...

Here's an exaggerated view of what I mean:

Attachment 12520

Using the epoxy technique is one way to get around this - quite a few on here have employed that particular method - or getting your metal ground flat (a bit pricier...)

Good luck with the build - keep us posted with updates.

Wal.

Do you have a link to these linear rails?

I dont know much about CNC but i know how to incorprate strength into a design. If there is one thing Im good at its designing...dont get me wrong...i have seen builds on this forum which to me seem fine but people who have been there and done that have pointed out aspcts of designs that didnt show up to me...but all their critisims and expertise has been written down on my Pukkapad to bear in mind when designing my machine, which will be posted so others can tell me what needs improvong and whats ok etc etc.

Really appreciate the help :)

A very helpful tip! Thanks haha. I thought that they probably wont be perfect and could probably do with some work..the epoxy idea sounds good, any particular epoxy? Its just that i have some good westsystems stuff but its made for fiberglass which has a lower viscosity, so might not be hard enough for the job...