Build or buy a fairly large cnc router

[zwk]

hi all,
I've decided to take the plunge and either buy or build (or rather assemble) a 3-4 axis cnc router, capable of cutting pieces measuring at least 1250mm X 1250mm, but preferably 1250x2500.

The problem is that on the one hand I don't have any experience building CNCs, and on the other hand, I currently lack the time to dedicate more than say 18-24 work hours to building one, so I would need to get as many parts as possible off the shelf.

Either that, or buy a pre-made one, but from what I've seen, the prices for turnkey solutions are very high.

So my questions are:

1-Are there plans for 3 or 4 axis CNC routers capable of taking at least 1250x1250mm pieces which can be completed using only off the shelf parts?
If not, what would be the fastest route to building such a machine?

2-If using good quality parts, what price and degree of precision would I be looking at?

3-Is it much more expensive to buy a turn-key solution? Can you suggest reliable and cost effective UK/European manufacturers and models?

thanks
zwk

[zwk]

I would like to be a bit more specific about the diy option:

Since I want to use mostly off-the-shelf parts, are there available plans made for linear rails made by companies like Rexroth, ISel, Zihlmann, or similar companies?
Other than the linear rails, are there other structural ready made parts, like spindle holders for the Kress 800FME? Other parts I would need to buy from someone with a cnc machine capable of cutting metal, right?

Please accept my apologies for the basic questions, but as I said, I'm new to this, and considering that I currently don't have the time to go through the whole diy process, I need to use as many shortcuts (read pre-made parts) as possible, even if it means spending a bit more.

[GEOFFREY]

Hi, welcome to the forum. If you are making wide/tall cabinets, I do not think the Kress is a suitable spindle. G.

[zwk]

why not?
The wood panels are only 15mm-25mm thick.
Would a trimmer be better suited?

[mekanik]

Hi & Welcome to the forum.
The Kress spindle is not really upto the task of any serious work, when i first started looking through the forum i was thinking perhaps an 1800W router would be OK but the more reading you do you will find even these are not suitable(very noisy & bearings would be US in no time with constant use, most go for the chinese water cooled spindles that give very little trouble.
Hope that helps
Mike

[EddyCurrent]

How can you make tall cabinets with a 1250 x 1250 machine ? maybe you intend to feed a longer board through the machine ? it sounds like you mean the mdf / chipboard type of 'furniture'

[charlieuk]

what strikes me as the biggest problem is the 18-24 hours you say you only have to build something, if this is the case unless you can get some sort of kit that has everything there and ready to go it is going to take a huge amount more time to build something. If you are pricing your time into the costs and you can find something that will do what you want you may be better buying something ready to go.

[george uk]

Used ex industry machines are worth a look depending o. Your budget/know how. Building one isnt as simple as bolting things together, there are a few good recent build logs on here that will give you a good idea of whats involved in building and parts. All depends on your budget

[zwk]

After re-reading the thread and replies, I realized that I should have said a bit more about myself and my motivations for building a CNC router. Here it goes.

Having a background in Physics/Mathematics, I'm fairly obsessed with precision - even in diy projects. I decided to make cabinets (around 20) for myself and a couple of relatives - both because I like using things which I've built, but also to have complete control over the end product. I made a promise a long time ago, and now people are expecting results - only 3 cabinets were produced so far...

Although I own almost every conceivable power and hand tool, it's very hard and time consuming to achieve the necessary level of precision to make quality cabinets (eg a 1mm error in a 2000mm piece would yield a very poor result) - this is not trivial to achieve at home.
After struggling to make just 3 cabinets, I decided that it would be better to take a different route, by making a cnc router. This would save me time in cutting, measuring, cutting again, planing, routing, planing again, etc. But above all, a CNC would guarantee the necessary precision and repeatability. Even better, it would have future benefits, allowing me to embark on more elaborate projects.
I can only do this in my spare time, and the wife is going nuts about the lack of cabinets. So she has given me two options: either I make them quickly, or she will go out and buy the cabinets herself. Surely some of you will probably empathize with this!

So, given the above scenario, and since I can't justify spending upwards of £5k for a commercial CNC (divorce would surely ensue...), I have to make one myself asap. With this in mind, here are a few questions:

1- In order to save design time, are there services/companies who either sell complete plans, or are able to design a CNC router to meet custom requirements? Eg if I were to detail my exact requirements for a CNC router, would there be someone on these forums whom I could pay to produce a blueprint, detailing all necessary parts, etc? If not, are there companies who do that, or with a large portfolio of pre-existing CNC router plans where I could find a close match to what I'm looking for?


2-I agree that 1250x1250 isn't enough for cabinetmaking. 1250x2500 would be ideal, as it would allow me to work with 1/2 panels. But that would probably make it much harder to keep precision under control, no?

3- Regarding the amount of time I can afford to spend assembling such a machine, I will have to reconsider that, and make a compromise, allowing for more time. I've seen logs of complete DIY projects (including design and actual physical work) mentioning a total of around 100 work hours. If I outsource the design, do you think that 100 work hours is reasonable for a complete neophyte?

4-How much would you expect an all metal, 1250x2000mm, 4axis CNC router to cost in materials alone? I know that this is a very generic question, but from the build logs, I see wildly varying budgets for similar machines. So would like your opinions on that.
(btw, buying a 2nd hand machine isn't an option, as I'm in Portugal, and the market isn't as dynamic as in the UK.)

Many thanks for reading this long post, and for any help you can provide.

cheers,
Ze

[Ger21]

Not sure on what the conversion rate is, but I'd expect a good quality DIY cnc in the 1200x2400 range to cost about $5000 US.

CNC Router Parts in the US sells a complete kit that you could probably assemble in 100 hours, But I'd expect any DIY project to take much more time.

I'm a cabinet maker in my day job. When my wife wants cabinets in a hurry, we go to Ikea.

[EddyCurrent]

I'd say more like $6000 to $7000 but I'm talking about quality components, if using all Chinese stuff maybe $5000 is okay.
Personally I'm not 100% that it's a CNC machine you need to build cabinets, as Gerry says you can buy these off the shelf much cheaper and not too difficult to adapt to your own requirements.
You're tolerance of 1mm in 2000mm is fine but at the end of the day how many people have walls and floors to that specification ?

[zwk]

I agree that I could simply go to IKEA and get off the shelf cabinets, but it wouldn't be nearly as much fun as making my own, and getting to toy with a CNC, would it?
In a way, this is my chance to justify getting one to the powers that be...

If going the pre-built route, could you please recommend reliable UK/EU based companies (even if using a few chinese made parts)? I was offered a quote from a UK company, but these forums have a few users complaining about that particular company, so I'd like to find alternatives, and then compare them with the DIY route, pricing my time into it.

[Timo]

Hi,
I've built a 10'x5' with china steppers from Long motor corp.
3 1/2"x 2 steel tube, 3/4" plywood, 3/4 MDF top. Home drilled 3/4" round stock linear rails. The newer style plastic bearings. Nema 34 stepper motors Probotix USB-CNC and software .Worked so,so.
With all my errors in design, and rebuilds spent $3600.00
i now have 12 mm supported rails on order from china. It will be a lot faster.

Just started cutting new metal for a 28"x39" machine aluminum box tube,
16 mm linear rails, ball screws, and nema 23 stepper motors with Usb-cnc card and software, about $1100.00 cost.