[Ohlsson]

Hi,
After a number of years I have finally decided (I think) to buy a machine. Most commercial hobby machines do not seem to have fully supported lead rails (such as the high-z from www.cnc-step.com, though quite sturdy rails). The videos on youtube all seem nice though. What are the experiences comparing supported vs non supported rails? I'm not into heavy steel milling but I want to be able to machine aluminium and possibly smaller steel parts whilst having no preference on speed.

For my needs and budget the smaller of the machines from either www.cnc-step.com, www.bzt-cnc.de or www.hobbycnc.com seem ideal. hobby-cnc are actually supported but claim less precision... The manufacturers specify very nice precisions and repeatabilities but thats probably unloaded?

Any thoughts or experiences with these or similar machines?

Thanks,
Daniel

[jalessi]

Daniel,

What size machine are you looking for and what is your budget?

Welcome to the Zone,

Jeff...

[Ohlsson]

Hi Jeff and thanks.
I am basically looking at something to mill moulds for composite model wings/etc. but also to be handy if I need to machine a smaller alu/steel part. Around 500*300 mm would do since I can always join the pieces afterwards but the larger the better of course For moulds I would probably machine plastic or equivalent and for alu/steel it's the precision I am after. I was thinking about building the router myself but since proper lead screws, rails and the rest in parts seem to break even with a complete machine I might just as well save myself the work for now. I am aiming for around 2k Euro with controllers/motors but with some flexibility. It seems for the precision/power and size this is most realistic? cnc-step and bzt-cnc are available on ebay as rather complete sets.

[jalessi]

Daniel,

Unsupported rails are going to give you problems when you attempt to cut steel or even aluminum.

They may deflect and cause inaccurate cut dimensions.

If you keep the depth of cut very low and do slow feed rates and many multiple passes it may work ok for your application.

Your budget may be a little low for a 300mm x 500mm machine with supported rails.

Jeff...

[Ohlsson]

With consideration to supported rails the Pro Basic series at http://www.cnc-modellbau.net/shop-eng/ seems quite competitive. It seems well supported and at a good price for the working area. Not for heavy steel milling but that's not my intention either. I haven't seen any reviews for these yet but they look as good as the others?

Anyone with experience?

Thanks,
Daniel

[shadowvoice]

I use High-z 720 and would have to admit - I simply love it. For wood/plastic application - simply perfect. Rigid, reliable and precise.

To be honest - never tried to mill alu so far ;-)