Newbie- Thinking about making my first CNC

[keepcool]

Good night,

After thinking about making a CNC router/mill about 1/2 years I decided to read a lot about the subject but I still have a lot of doubts!
I would like to make a machine with at least 20"x20"x6"(50cmx50xmx15cm), capable of milling wood, pcb's, fiberglass and carbon fiber plates/sheets to be used in model planes, and also some aluminium work(dont need to be very fast doing aluminium) so I think that this rules out a dremel as the spindle, so I think that a router should be able to do it, but what model?

The best is if someone could show me some build logs that have every tiny bit explained so I can understand this subject a bit better.

I'm an electronics student, so I don't have problems in understand the electronics or the motors, and I'm also an ubuntu user, so I think I will use EMC/Linux cnc.
After reading some build logs I saw that some member use 8020 T slot aluminium and that looks a very good sturdy and pretty cheap material to make a nice and sturdy machine, the problem is that I cant find an European distributor of 8020 hardware and all the ebay sellers that I find only ship to USA :/
After reading I also think that ACME screws are way better than belt drive and coupled with anti-backlash nuts they don't have well any backlash.

For the linear rails I'm a bit unsure in what to use, but linear bearings and those chrome round shafts seem like a good way to go.
I have also read that as I want a fairly long table that I should use supported linear rails but I don't really understand how to do that.

Also, actually I only have one laptop so I dont have any LPT port, but I will try to find an old computer with and LPT port as it seems to be the most commonly accepted/used interface to drive the steppers and also the most supported one, and I dont want to use software that is crafted to only one proprietary driver board.

I know that this is a lot of questions, but if you can help me
Thanks in advance.

[eehobbytoronto]

Linux Users

Just finished my first driver board using IRF1405P,
no need heat sinks, no need fans, no need "inductive kick protection" diode.
Youtube link: [url="http://www.youtube.com/user/eeetoronto1"]

[deonsmt]

There are always more questions than answers when it comes to building your own. I have put in some effort trying to document a build in a way that gives you tangible choices for selecting motion components and router here

DLS Projects

I used 8020 but there are other vendors who make very similar extrusions. Must be at least one outside of the usa

For the spindle I used the hitachi m12vc. Variable speed is a great benefit. 2 1/4 hp and 8000 to 24000 rpm. This is a great router.

[keepcool]

I have already discovered that Bosch also makes similar profiles but I cant find any distributor for it.
There must be some one in the forum that is from Europe that knows where to get some of this aluminium profiles..

Another thing that I dont know how to size is the diameter of the ACME screw and the linear rails..

[deonsmt]

For the lead screw go with 1/2-10

Since you are trying for 30", you will have issues with flex if you use linear shafting even with 1" shafts. Might be worth doing a cost comparison between the linear shafting and a slide based system. You can bolt the slides to the extrusion creating a rigid setup. See latest on

Dlsprojects.blogspot.com

If you must use linear shafting without support, just get the thickest you can afford. For example 25mm X, 20mm Y, 16mm Z

X has to support the entire gantry which includes router so it is the most prone to flex.

[keepcool]

I have already saw the linear slides, and the price is not much different from linear shafts, but there are also supported linear shafts, so I think that using linear slides or the supported linear shafts have the same end result, maybe the supported linear shafts are a bit heavier because they are made from solid iron/steel shafts and then they also have the support that is in aluminium, using the linear slides, its old the slides and nothing else.

After more reading I read in some blog that Amazon is a good place to buy 8020 extrusions, as they ship outside USA, but maybe the shipping cost adds way to much, I will also try to find extrusions like the 8020 ones in Europe, but I cant find any shop that sells to particular persons, only to commercial/enterprises :/

[andypugh]

Originally Posted by keepcool After reading some build logs I saw that some member use 8020 T slot aluminium and that looks a very good sturdy and pretty cheap material to make a nice and sturdy machine, the problem is that I cant find an European distributor of 8020 hardware and all the ebay sellers that I find only ship to USA :/

How about: Equipo para Almacenaje, Logística y Taller | Perfilería de Aluminio Modular y Tubos de Acero | Elementos Mecánicos Básicos Bosch

After reading I also think that ACME screws are way better than belt drive and coupled with anti-backlash nuts they don't have well any backlash.

I would say that is debatable. Acme without backlash tends to get stiff, and even anti-backlash nuts don't stay that way for ever. Don't discount ballscrews either, there are some reasonably cheap ones available, and once you have bought the nut the extra length of screw is not that expensive. (about €30 to €50 / 1000mm)

I have also read that as I want a fairly long table that I should use supported linear rails but I don't really understand how to do that.

See Zapp Automation

Also, actually I only have one laptop so I dont have any LPT port, but I will try to find an old computer with and LPT port as it seems to be the most commonly accepted/used interface to drive the steppers and also the most supported one, and I dont want to use software that is crafted to only one proprietary driver board..

A PCI port is another possibility, there are a number supported by EMC2, though none are as cheap as the Parallel port.

There is loads of EMC2-specific help available on the EMC2 forums and the mailing list, and generally you can get live help on the IRC chat too. Have a look at the "community" link at LinuxCNC.org - Home

[eaglezsoar]

You should look at the kits on Home : Fine Line Automation and see if he can ship international.

[keepcool]

Thanks for the responses, I never though that RS could carry this type of hardware, always learning, I will search more in their site, but it appears that they dont have some types of the extrusion, like the ones that look like 2 extrusions in one, as those look handy to construct the base and the gantry.

I have sort of avoided the ball screws because I almost always read that those where pretty expensive, but they are more or less the same price, at least in ebay..

I will keep searching and posting here, thanks again for the help provided.

[keepcool]

I also have reduced my target size to 20"x20"x6"(50cmx50xmx15cm) as the original size is a bit oversized and I dont think that I would ever need such a huge cnc, also smaller means a bit cheaper, I also updated the original post so if someone reads it now it already as the new target size.

[tracyranson]

Originally Posted by keepcool Good night, After thinking about making a CNC router/mill about 1/2 years I decided to read a lot about the subject but I still have a lot of doubts! I would like to make a machine with at least 20"x20"x6"(50cmx50xmx15cm), capable of milling wood, pcb's, fiberglass and carbon fiber plates/sheets to be used in model planes, and also some aluminium work(dont need to be very fast doing aluminium) so I think that this rules out a dremel as the spindle, so I think that a router should be able to do it, but what model? The best is if someone could show me some build logs that have every tiny bit explained so I can understand this subject a bit better. I'm an electronics student, so I don't have problems in understand the electronics or the motors, and I'm also an ubuntu user, so I think I will use EMC/Linux cnc. After reading some build logs I saw that some member use 8020 T slot aluminium and that looks a very good sturdy and pretty cheap material to make a nice and sturdy machine, the problem is that I cant find an European distributor of 8020 hardware and all the ebay sellers that I find only ship to USA :/ After reading I also think that ACME screws are way better than belt drive and coupled with anti-backlash nuts they don't have well any backlash. For the linear rails I'm a bit unsure in what to use, but linear bearings and those chrome round shafts seem like a good way to go. I have also read that as I want a fairly long table that I should use supported linear rails but I don't really understand how to do that. Also, actually I only have one laptop so I dont have any LPT port, but I will try to find an old computer with and LPT port as it seems to be the most commonly accepted/used interface to drive the steppers and also the most supported one, and I dont want to use software that is crafted to only one proprietary driver board. I know that this is a lot of questions, but if you can help me Thanks in advance.

I have built a machine using 1030 t-slot which worked best for my application. I designed the z-axis around a 3 in table glide. The spindle is a 12mm shaft ER11 email me at TracyRanson@hotmail.com should your want more details of my build. I think that the reason few sellers on eBay ship over seas is due to the shipping cost.

[keepcool]

I'am willing to pay the shipping, and I dont know if it gets really expensive, aluminium is relatively light, but the packages would be pretty big :/
Thanks for your offer, I must study this subject a bit more and then I will try to start designing it in SketchUp, because that is the only program that is almost related to a bad CAD that I know how to use, but I will learn how to model in SolidWorks if I ever get a grasp on it!

I have a new doubt, what kind of routers could I use in Europe, the typical Hitachi M12VC used isnt even sold in Europe, only some rather big models that dont have any round part of the body to clamp it to the Z axis.

Setting up a cnc in Europe is really tricky, no good routers, and no 8020 extrusions :/

Thanks again for all the information provided.