Wooden CNC

[routercnc]

Hi Andy,

Hang in there. My first machine was built just over 5 years ago from plywood and unsupported rails. It used a normal router for cutting. It would cut balsa wood, and liteply, and if you were not in a hurry plywood:



If you pushed it then it would tend to cut ellipses not circles, so it had it's limitations. Basically it was not very stiff. So here it is cutting bits for it's successor (the gantry sides):



And here is machine 2 which used alot more aluminum, plus linear profile rails on the Y and Z, and a water cooled spindle:



But it still had limitations especially when cutting parts off centre (single ballscrew tends to rack the gantry). The gantry sides were still plywood, and the roller bearings on the X axis needed continuous adjustment and cleaning. So here it is cutting parts for it's successor:



And here is that machine:


And here it is munching through some 20mm aluminium plate for the Z axis upgrade:

to make:


And here it is at the moment:


So it depends on what you want to achieve, and not being too disappointed if you build a basic machine. Good news is you can always build a better one, it just takes longer and costs you more. Good luck with the machine and your life circumstances in general . . .

[routercnc]

Hi Andy

Just so you know the sidewinder machine looks like the leadscrews connect directly to the stepper motors. This means all the cutting forces are taken by the stepper motor bearings which is not great and would cause them to wear out. Most machines on here use a separate bearing block which takes care of these forces (see BK or BF bearings as Neil mentions).

[Andyshomecrafts]

Don't think I'm bothering now mate.
thanks for the advise.

[Neale]

Lots of comments made with the best of intentions. It won't be popular, but I'm going to put a different point of view. I built my MDF router to the JGRO design around three years ago. It's a pretty poor machine by many standards. However, I originally built it to make an engraved plaque for a presentation, about 20"x16", with some nice lettering and a relief picture in the middle. It turned out OK. Since then, I've helped my son with an architectural project profiled from 18mm ply. All the bits cut and fitted together as drawn. I've engraved nameplates, and lots of other odds and ends (like profiling 25mm sapele about 600mm long) in between. So, why am I building something bigger, faster, stronger? Because it is slow, it bends and vibrates if you push it a bit, I used M10 studding with home-made anti-backlash Delrin nuts as leadscrews and the X leadscrew flaps in the breeze above about 900mm/min when cutting wood would be better at ten times that. The MDF moves with changes of humidity and it's near impossible to keep the bearings adjusted. And so on.

But, as I said, it does work. This is a hobby machine, so don't judge it by commercial standards. If you are doing fine engraving, top speed doesn't matter a jot as you'll never reach it - acceleration for all those changes of direction is much more important. Studding is cheap, even compared to multi-start trapezoidal screws. It's pointless thinking about ballscrews as the machine structure won't take the cutting forces involved at the speeds they would allow. I often hold work on small blocks machined in situ to give accurate alignment, even though the bed isn't all that flat. Jobs can take a while, so I get on with something else while the machine is running. In other words, I can work around or live with many of its limitations. I'm building a new machine in steel to overcome these problems, but that's at least in part because I love building tools and machines.

I wouldn't recommend, generally speaking, that someone builds a wooden machine, but everyone's situation and needs differ, so there's a place for them. Don't be put off by people whose needs and resources are not the same as yours. You might find more uses once you have a machine in the workshop; that might help you identify a replacement in due course. Pity that you are at the other end of the country or you could have had a warts and all look at a wooden machine and things made on it.

[Clive S]

Neale Well said as I have said on another post horses for courses and all that. ..Clive

[Andyshomecrafts]

I would just like to Apologise for my rant yesterday, things went from bad to worse as the day went on,
I get very frustrated, but I know I should not take it out on people who are only trying to help,
genuine sincere apologies.
I know what you are saying, but the one reason I wanted to use wood, Ive limited funds of £980 but trying to add too it,
I know it's not the way to go about things, Immature I suppose but I want it now or as soon as possible, and I'd deal with the consequences when they arise,
so massive thanks to everybody who took time to comment and advise me.
todays dry and sunny, and I'm thinking straight.
i know I'm not going to build anything decent for £980 so I'm going to put things on hold until I can save some more.

[njhussey]

Andy, a wooden CNC will let you learn all about CNC, teach you about how to and how not to build a CNC machine and most of all give you pleasure and enjoyment in making your own things. I'd say do one of two things.

1) Build a wooden machine with cheap components and make items and possibly make money from cutting things for other people or to sell and if you enjoy the CNC hobby then either save the money and build a bigger better machine or upgrade as you go along using your machine to cut parts for the new machine.

2) Keep saving and build a machine (or get your son to) from Aluminium profile which you can cut/drill with wood working tools (all you'll need is a chop saw or table saw or circular saw or jigsaw with ali cutting blades, a cordless drill and things like a centre punch set and tap set) which you can use to make an aluminium frame (like routercnc's machine) If you manage to buy good deals on ebay, second hand things off forums etc. then a budget of £1500 will see you have a decent machine capable of cutting most of the things you want to which is not alot more than you currently have.