CNC machine

[gerrymoore]

Thought I would post some pics of the CNC machine I've been building for quite a while.

It's currently running an RTech plasma cutter.... but for the first few hours when testing it I had it fitted with a pencil drawing on paper - just to be safe!! - then I had a wood router on it and eventually converted to plasma....easier to say than do!

The Z axis is quite complicated as it now has an automated zero height control for the different pierce and cut heights- this took a lot of getting right.

I use Sheetcam to convert my DXF drawings into Gcode and Mach3 to run the code.

Electronics are currently contained in a biscuit tin - good for shielding!!

I'm still having the odd hiccup but once I'm happy I hope to sell the parts you can't buy to people who want to build their own machines.

 

[DrNik]

that looks great how easy is it to input data of item to be cut??

 

[gerrymoore]

Hi Nik...like everything it gets easier the more you practice! You start with a drawing but, to use Sheetcam - which is the easiest package I've found - it has to end up as a dxf, hpgl, excellon or dwg file. Import to Sheetcam, tell it what your using - plasma, mill, lathe, drill, whatever - then what size and thickness your material, feed speeds etc. then in the blink of a eye you have the magic GCode that Mach3 understands to run the CNC...simple!

A quick example...if you look at my post re the sack truck. I wanted to get my name 'carved' in the 3mm steel base. Had to do a quick search on the net for a 'stencil' font so it kept the letters intact. Found three different TTF's - all freeware. Picked the nicest one and loaded into Serif Drawplus ( a great program). Sized it to length and height then exported it as a .dxf to sheetcam - the rest is as above and only took about 20 minutes from start to GCode.

Three years ago I wasn't even sure what CNC meant!!

 

[excossack]

Looks an interesting bit of kit, kinda reminds me of the plotters we had at school controlled by BBC Micros. Do you need to change the tool if you want to drill/mill etc?

..and finally, another Wirral person (like myself) I think we increasing in numbers.

 

[gerrymoore]

Yes..it's basically a big heavy duty plotter!! I have it set up for plasma but depending on what you stick on 'the end' it will drill, mill, route, even plt if you stick a pen on it!!

The one good thing about plasma is it doesn't touch the material so there is very little strain on the machine....which can be accurate to .05mm !!

Anyway fellow Wirralian -call in for a cuppa one day and see it in action...I used to have a BBC micro!!!

 

[excossack]

A very handy bit of kit once finished..05mm accuracy i say is pretty darn good for homebrew gear

I might have to pop over one day for a looksee and a brew.
Oh and I still have the BBC Master in the loft!

 

[Wedg1e]

Like it! What sort of size rails are they, 30mm-ish?

 

[agrimog]

nice looking bit of kit, what are you using for THC, I know the R-Tech plasma doesnt have an ouput you can hook up, or are you using a touch and rise, then fire the plasma on a time delay, I am in the process of building something similar and the THC control is a stumbling block at the moment

 

[PhillipM]

Sooo, cheap profiles for forum members then?

 

[gerrymoore]

Some more info...main rails are 20mm and Z axis 16mm - never had any problems with 'flex' but the plasma torch doesn't strain the machine at all.

I use a floating head set up which touches the metal then goes up to pierce height (6mm) then down to cut height (3mm)....this can be set for every single cut or between preset distances. As i am only cutting new 2mm or 3mm steel at the moment I don't have need for THC.

I actually have an unused Proma THC for sale on EBAY at the moment - agrimog PM me if you're interested in it.

The machine has cost me a lot of money, so yes, I am looking for work for it and there would be rates for members!

 

[richi b]

cool bit of gear and iam another wirralite

 

[Shox Dr]

Any progress

 

[gerrymoore]

Hi Richi - fellow Wirralian!! The CNC is working well apart from it's tendancy to freeze an axis which is causing me a headache. I need to fit a UPS to the drive electronics to see if this will cure it. You may be interested in my segway build on the projects forum...I've used the CNC to cut out my chassis design - this would have been difficult to do 'by hand'

I have just started a new website selling my special CNC parts for people to build their own machines - made of course on the CNC.

 

[Premiershipman]

What was you overall budget gerry, i have ummed and erred about a CNC for a whileand looked at stepper and servo motors etc.

Realistically i dont have the space at the mo but we will see !!

 

[gerrymoore]

PM sent

 

[Coo]

Here's a link to more 'Stencil' fonts, should you want to find more alternatives:

http://www.dafont.com/search.php?q=stencil


Excellent work by the way

 

[gerrymoore]

Hi Coo...thanks for the fonts link...they look good! And thanks for your comment

 

[Badger1bear]

as a ball park figure what could you expect to pay for a working machine like yours Gerry ?

 

[gerrymoore]

As you can imagine, it's difficult to give an exact figure because the final price depends on the size of machine, and what you're going to use it for.

Using a CNC for plasma work is very easy on the 'mechanics'...the plasma torch does not touch the metal so the CNC just has to move it about, with exact precision of course, over the material.

Using the CNC for routing, milling, or drilling, is the exact opposite. The machine has to cope with the load of the tool plus the forces involved with moving that tool through the material as well.

Then there is the 'work size' of the machine. A small one can make do with lighter rails and bearings and lower power stepper drives and their associated electronics...as the worksize increases so does the cost...by a lot!

Lastly...if you build it yourself, you'll save a lot of money over buying one ready made....as long as you have all the skills necessary to do it.

It has taken me quite a while to learn about CNC and I built a couple of prototypes before I got it right!

Ball park figure...my CNC is relatively small with a 65cm x 40cm work area. I built the whole machine myself.....it has precision ballscrews, 1.7Nm steppers, quality individual stepper drivers, 20mm rails, etc......about £700. To buy something ready made this size would cost at least £1000, maybe double.

This doesn't include the plasma cutter, or the software you need.

As you go bigger the price rises fast...to get a decent 8' x 4' you need anywhere between £5 - 8 thousand.

I don't want to advertise but I do have a website that will give you some good information on building your own machine.