Welcome to the forum and have a look through some of the build logs.
Don't start with anything.? By this I mean dont buy a single thing NOTHING AT ALL. The most common mistake made is buying parts before final design is choosen and components decided upon.
Even then still don't buy anything until you are actually ready to build then build in phases. It's good idea to get all the mechanical parts before starting on the frame so can offer them up and see any potential hidden problems you missed in the CAD design stage.
Electrics are one of the last things you'll need so don't buy those until mechanical is nearly finished. While it's tempting and exciting when it's first machine to buy motors etc and have spinning on bench it's also numb thing to do because your wasting warranty.
Don't rush and have clear plan and design in mind. Ask questions and do plenty of research until your sure you know exactly what's needed and understand why it's needed then ask again just to check you really know what you think you know.!!
I have bought most of the build kit, with only a roughed out design. I had good reason to do it that way, I had to spend the money before my wife decided something else was more important. I know that warranties will be wasted and some bits may not turn out to be appropriate, but I didn't see my build EVER happening otherwise.
At least now it won't be new carpets, furniture, decoration, etc instead. I have enough in the garage to start a construction and except for a pulley or belt or something, probably finish it too.
As my granddad used to say before they took him away - 'There's method in my madness'.
I have bought most of the build kit, with only a roughed out design. I had good reason to do it that way, I had to spend the money before my wife decided something else was more important.
Can you give us some idea what you want to cut ? It makes an awful lot of difference if we know whether you just want to gently slice spongecake or hew titanium at warp speed.
daveoHave you done any research on the forum and looked at some of the very capable machines if you are not careful you will waste a lot of money.
It shows you have not done much as you are looking at 25mm ball screws with linear supported rails.
for a decent machine for the size you are looking at you will need 1610 on X and Y and 1605 on Z also the square rails have come down a lot in price are are far better.
First start a build log with a new post to keep all the questions in one place and then design something in cad there is no problem copying other people designs and then you will have a much better idea.
The golden rule is don't buy anything until you have a design sorted then the wise ones on here will put you right.
so the 25mm ball screws i was looking at are to big?
Believe it or not (and you probably won't until you do the sums) an oversized ballscrew will be a bigger limitation on performance than, say, the weight of the gantry. Especially a 5mm pitch as it has to spin faster than, say, a 10mm pitch, for a given speed. When the gantry accelerates from rest, you have to spin up the ballscrew and the rotational inertia of the ballscrew will be a major factor slowing it down. Ditto fitting a too-big motor - a combination of inertia and other electrical factors will reduce performance. This is why it's important to take guidance from the community here - use their experience rather than paying for your own!
Dave whilst we'll all gladly point you in right direction with what's required for componets etc you are still the one who's got to build this machine so if don't do the research and come up with design and fully understand it then 90% chance your going to fail or at very least waste lot of money.
For instance You say 1400mm but haven't got clue what's required to have machine that length and not run into problems which can and would come with it if not done correctly.
There is no short cut to doing this correctly so if you Fail to prepare by doing the research then prepare to Fail.
Don't get me wrong I'm not trying to put you off, far from it. But I am personally deliberatley with holding information from you because I know it wouldn't help you from lots of experience helping builders who have Failed because they didn't learn the knowledge and did rush into buying without clue whats required and why.!
Strongly urge you to do the research and learn what's required and involved in building machine the size your asking. When you have done this it will become clear why the questions you are asking now are premature and potentialy dangerous to your wallet.
Do what Clive says start build thread and ask questions about anything you don't understand. By this I don't mean ask about suppliers this comes later and by which time you'll know exactly what you need.
First You need to know how to make the machine tick and why what you choose makes it ticks this way.!
Do this and I'll gladly part with my knowledge but won't help anyone waste money( It would Kill yorkshire Man to see wasted cash.!!) which you surely will if carry on without doing the leg work.!
Select machines tab and choose the option from there.
Just adding my words to what Jazz and Clive S have advised PLEASE take their advice. These guys saved me from making expensive mistakes and even then I still made some! You ask about completed projects - there are many under the build logs - here's mine here (http://www.mycncuk.com/threads/8206-Ar-last%21%21%21-Started-my-Gantry-3-Axis-CNC-Build) well nearly completed! Take time to study the builds, evaluate their strengths and weaknesses. Do your design and get it peer reviewed on this forum. Another pair of eyes from these experienced builders makes all the difference.
My router has a 1100mm, 700mm and 300mm ballscrews and may well be suitable for the types of projects you are suggesting. I made the mistake of buying 1605 ballscrews instead of 1610 - I did what you want to do - spending money too quickly without thoroughly working out what I wanted to do. For the materials you want to cut 1610 ballscrews on the x an.d y axes with a 1605 on the Z will do just fine.