Best place to buy parts for a cheap first CNC.

[Boscoe]

So I am looking to build a CNC machine designed for cutting wood and aluminium. I haven't fully decided but I think I want a cutting area of about 750mm x 500mm. I don't have any access to any milling machines currently and so would like to buy a Z axis kit to make sure it's good. I'm only a real budget because I'm a student and so probably have around £750 to spend over around 6 months so this will be a gradual long term project. I plan to use supported rail and timing belts for cost, if it's worth it I will go with screws. I've been looking around and ebay seems to be the cheapest place to buy this sort of stuff (I need everything) however I think I will put an advert in the wanted section to see if anyone has anything second hand.

I'm an electronic engineer and very skillful with my hands and designing mechanical objects so a challenge is not scary!

Thanks
Boscoe.

[Jonathan]

You wont cut aluminium using timing belts and no screws, it's simply not stiff enough. £750 is probably just about enough to make the machine with ballscrews, but not if you have to pay people to make parts.

[Boscoe]

You wont cut aluminium using timing belts and no screws, it's simply not stiff enough. £750 is probably just about enough to make the machine with ballscrews, but not if you have to pay people to make parts.

Not even if I use wide belts?

[martin54]

Welcome to the forum, have a read through some of the build logs to get you started, you may well find you need to look at building it over a longer time period so you can save more money for the project.

[Boscoe]

Is ebay the best place to get cheap items? Is the quality of the items acceptable?

[Jonathan]

Not even if I use wide belts?

Maybe, but I expect you'd end up paying more for the belts then the ballscrews. In addition you'd need to gear the motor down substantially to get enough resolution.

Is ebay the best place to get cheap items? Is the quality of the items acceptable?

Often it is, but there's also AliExpress.com - Online Shopping for Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles from China.. Quality of the ballscrews I've had from eBay has been perfectly adequate.

[Boscoe]

Maybe, but I expect you'd end up paying more for the belts then the ballscrews. In addition you'd need to gear the motor down substantially to get enough resolution.



Often it is, but there's also AliExpress.com - Online Shopping for Electronics, Fashion, Home & Garden, Toys & Sports, Automobiles from China.. Quality of the ballscrews I've had from eBay has been perfectly adequate.

Wow it's a lot cheaper on there. Is there something I should look out for?

[birchy]

I've just bought ballscrews and ballnuts from Chai on eBay. Very cheap, very fast delivery (3 days from China) AND they'll machine the ballscrews for you to a high standard for next to nothing. You're looking at about £150 for 3 ballscrews, ballnuts, bearing blocks and machining, including shipping. Bargain!