beginning steps to building my cnc

Most of the electronics are modular so all you do in effect is wore between the PC and the breakout board and that breakout board and the drivers and the drivers to the steppers...a bit simplified but that's the gist. As Maryin said you can get an old PC tower case and put all the electronics inside.

Have you read any of the threads I linked to in my earlier post? You can see the components as they go together. Also shows you that mist builds evolve over the build thread from the initial design :)

Yes those are how the components basically go together although for the X axis you'll have one rail and one ball screw on each side of the table like you've sketched.

Thanx Neil, Much Appreciated! i will look over the design in the next few days and see if there is anything I need to think about. I will try (if i can) to sketch in google sketchup. I think Ive got the jist of it more or less, just need to get down to the nitty gritty such as the bearings (if any) nuts bolts and screws. should be ok to start once i understand this. Thats what im thinking. What do you guys think with regards to my understanding so far? am i on the right path? am I still far from the design stage and the knowledge needed to begin making? please let me know. Thank you

Keep reading the build logs and looking closely at the pictures, you will pick it up quickly.

You shouldn't underestimate the importance of rigidity This isn't just a case of using strong materials, but bracing too. There is no point making a strong gantry if the bed is plywood for example; if the work moves (bed resonates) it is as bad as the cutting head wobbling about. Making a machine to cut wood and plastics is one thing, making it cut aluminium is another so if you don't really need it to cut metal you can save money and design/build time.

Here you go....this is the sort of base frame you should be creating. It's only a quickly knocked up example but has a 50x50x3 box section outer frame, 50x25x3 bed supports and bracing.

Attachment 7431

Hi Neil Thanx for that! :-)

Hi Guys, just going to adjust my design again, I have been told to use belts earlier in this thread. Where would the belts go and what is the advantage of using them. Also what would it attached to?? does it attach directly to the stepper motors?

Is there anything else I need to know?? or have missed out from the diagram such as a vital component??

Also is it difficult to do the electronics and the wiring?

Thanx again :-)

You can do either of 2 things...one is to use a stepper on each X axis ballscrew the other is using pulleys and belts. running both ballscrews from one stepper. On the belt one you put a pulley on the end of each ballscrew and one on the stepper and connect them with a belt. Most people seem to use 5mm pitch HTC belts...

Belts and pulleys connect the stepper motor to the ballscrew. Some of the advantages are the ability to select the drive ratio, so you can make the motor operate in the optimal region of its speed/torque curve and they help damp vibrations.

Quote:

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Originally Posted by njhussey

Most people seem to use 5mm pitch HTC belts...

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It's HTD, not a mobile phone ;)

Belts and pulleys you can get from here:

5mm HTD® Timing Belts [4575] : Beltingonline.com, Supplier of power transmission and conveying products

Where about in Walsall are you, I'm starting my first build in the next couple of months and I'm in Bloxwich.

Edit to add: Jon's pricing seems optimistic and doesn't include all the little things that add up like a computer, software, router bits, cables, tubing for water cooling, bed material etc etc that you will actually need before you cut a single thing.

I think £1500-£1800 is a more realistic ball park figure to actually build a machine from scratch of the size you want that can do what you want.

Quote:

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Originally Posted by Jonathan

It's HTD, not a mobile phone ;)

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You are of course correct as always Jonathan....message was sent from a mobile phone and flipping auto correct must have kicked in ;)