I get quite a few question from users all over the world most asking very similar questions so I thought I’d post the most common questions and my answers here
Can I use NEMA 17 steppers motors for the machine ?
For my machine I think they would be too small but if you built a more lightweight version then they should be OK Having said that I have no experience of the Nema17 and if your build was light and very accurate so everything moved very easily they may be suitable.
Where can I download the plans from ?
When I built mine they were available but the website I had linked to my build doesn’t respond to users anymore. I’ve removed the link because original author required PayPal payment and recently he hasn’t been honouring user requests. My plans are here http://www.rckeith.co.uk/cnc-detailed-build-and-plans/ which can be downloaded by clicking the PDF icon.
Can I use the demo version of Mach3 ?
Yes you can but its limited to 500 lines of g-code. So for a very simple design you may get all the co-ordinates in 500 lines. What happens is when the machine reaches 500 lines, it just stops. Puzzled me a first but that’s what it was.
Can I use LinuxCNC (EMC)
Yes you can and I did try but I was anxious to get my machine working and found Mach3 to be very well documented with lots of how to’s on the web. I’m a Linux system administration for my day job so I was keen to use it but I needed to devote more time to it than I had available Check this link http://wiki.linuxcnc.org/
Update – Currently building a LinuxCNC machine and will be posting the results with some test cuts very soon,
The TB6560 controller board is it OK ?
The TB6560 gets some bad press on some of the CNC forums but I’ve had no issues with mine. I purchased it as a kit with the NEMA 23 stepper motors. As you probably are aware these come from China and quality control can be an issue when things are built to a price. I don’t use my CNC machine all the time in fact its built to be easily dismantled due to space restrictions. I have used it on several occasions for most of the day and its performed perfectly. One thing I would ensure is that your machine axis move very easily. The way I test this is without any power on try and turn each threaded rod by hand and it should not bind or feel tight. I spent some time making sure the alignment of the steppers and threaded rods were very straight and true which makes sure the steppers are not stressed.
How much will it cost
Hmm! Well it depends on how resourceful you are. The hardware for my machine used a lot of materials form an office clear out but I did have to purchase the drawer slides and the threaded rods. The main controller board came from eBay and if I remember correctly it was £169, including NEMA 23 steppers. I then built the powers supply form two old PC power supply units. The PC running Mach3 was and old one I already had. The biggest costs for me has been the software Mach3, Profili2 Pro and DevFus Foam. JediCut will do all this for free but isn’t quite as polished. I’ve spent more on this than the build.
Here is a free g-code generator that will generate the g-code for you http://swarfer.co.za/rc/wire/index.php I’ve not actually used it on my machine but should be enough to get you going for simple wings.
What type of foam do I use
I use mainly XPS foam which is a pink colour and similar to blue foam. I’ve also made wings with white polystyrene which is very easy to come by at most DIY stores. I get my foam from Wicks in the UK their XPS is a bit thicker than other places I’ve found.
What type of hot wire do I use
I’ve tried several different types including MIG welding wire and guitar string but the best results I get are with very thin Ni-Chrome wire about 0.5mm. It needs less power and the amount melted is very small which helps in calculating the kerf value. This is used in the software to allow for the amount of foam melted away. With the wire being very thin and you haven’t got the kerf value right it doesn’t make too much of an impact on your design
Can I use a laptop with Mach3
You can but its not supported by Mach3 and you probably not have a parallel port on yours, unless its an old one. I believe its to do with power saving and it can interfere with step pluses. My advice is to get and old desktop, I use a Dell’s compact GX620 which has a small footprint and a parallel port. You can buy a add-on card to go in a more modern desktop and that works. Check this link out on how to do it http://www.jcopro.net/2012/07/10/use-a-pci-parallel-port-with-a-tb6560-cnc-control-board/
What other controller boards can I use
Check this page and it covers several options including USB http://www.rckeith.co.uk/mach3-parallel-port/
What software can I use to generate g-code from my design
Profili2 Pro http://www.profili2.com/ is very good for generating the code for wings and has a massive database of airfoils. A new version is now available called DevWing Foam http://www.devcad.com/eng/devwingfoam.asp
DevFus Foam will generate the g-code to produce the fuselage sections. Both are available in Demo versions that are fully working apart from being able to save the g-code. www.devcad.com
Here is a free g-code generator that will generate the code for you http://swarfer.co.za/rc/wire/index.php I’ve not actually used it on my machine but should be enough to get you going for simple wings.
Another free one is JediCut which I haven’t tried yet seem to have good support https://www.jedicut.com/en/
This one cost a few dollars but I haven’t used it either NCGen http://www.foamcasualty.com/products/ncgen-2 Its a plugin for Sketchup http://www.sketchup.com/ . Skeckup is very good and the plans I’ve detailed on the build page were all produced with Sketchup