I would suggest that you look at hobby machines and read their specs. As a start, I think that you will find that most machines of that size are using Nema 23 stepper motors. Many use 6600 drivers if they are using an arduino uno as the controlling computer. I suspect that more information from you will render more help here.

 

I have seen lots of examples with 6600 but they are more like hobby ones.We already have a Dewalt D26200 router and ı want to use it at my cnc.Since i want to engrave bigger parts than hobby ones(like speaker cabinets) ,im suspicious about using nema 6600 with bigger cnc structure.Do you know more powerful stepper motor/driver and easy to implement kit?

 

Not a CNC guy, but want to welcome you to the Forums. You might also want to search facebook for other CNC user groups. A few of our members are there as well as others.

 

Welcome to the forum @SoundOfThunder

 

Welcome to the forum.

 

I have built my own machine. I have not cut any aluminum on my machine yet, mainly because I hate dealing with cleaning up the shavings, lol. Rigidity is going to be the key for you here. I used SBR-20 rails, which are fully supported, for all 3 axis. When I started the build, due to budget constraints, I started out with a building torsion box for the main bed. The Y Axis rails attached to 80/20 that attached to the sides of the bed, and the gantry itself was made from 80/20 as well. Due to life circumstances the build was put on hold for several years. When I started again, the constraints weren't nearly as tight so I thought about remaking the bed from 80/20 as well. However, this was 2021 and 80/20 and orders were may months out, and I wasn't willing to wait. That said, the table design is very beefy, and it is effectively re-enforced with the 8020 rails attached to it, it is proven to be a rigid design. I used NEMA 23 381 oz/in 3.5 Hybrid Steppers, 2 on the Y Axis, 1 each for X and Z. All 30 Axis use ball screws, which run very smooth and have very limited back-lash.

 

I really like those SBR rails!!!! Have some in the shop now that I'm using to build a sliding panel saw.

You have a good source to get longer ones (IE: in the 10' range)??

We are looking at building our third CNC to be a combination machine such that it can do both Plasma cutting and woodworking. We have a big shop but not so big that we want multiple 4x8 machines.

 

I got my SBR rails as part of a 3 Axis kit from E-Bay. I ended up ordering a couple additional ones from Ali Express. Those are the places I would look for rails that long. You may need to reach out to the sellers directly for that length as that may be a special order.

 

Yeah, it's the shipping costs that kill it!!

 

I would suggest you buy a low end unit and make some stuff with it and then if you want to build one go for it. There is a lot to it other than just the machine as far as the learning curve.

 

Take a look here: https://www.youtube.com/@corvetteguy50
Vince is a great source for motion control and motors.

 

Hi, I'm a bit late to this party but building your own CNC Router can be a lot of fun.

An important thing to consider - you can either build from scratch, use some one else's design and plans, get a partial kit or a full kit. A lot of builders that started from scratch often take a long time, sometime years, to complete. A full kit can be reasonably quick to do but will cost more. Another thing to consider is how sure are you about this hobby? A lot of people get into it only to discover that they liked the idea of it more than actually using it to make things. In the later case, those machines wind up getting sold. In fact, I would look for a used CNC machine to start out on. You get it faster than building and save a little money too. When you decide to move up, you can sell it for probably close to what you paid.

Personally, for the DIY approach, I would look to a design that has a number of people building them. That way you don't need to spend a lot of time figuring out things like what kind of motors, screws, etc. That is already figured out. One to consider is PrintNC. It uses square steel tubes for the frame so it's strong. There is an active Discord group and a lots of "super" users that help each other. You can also buy parts for the design. Another group is CindyMill, they use aluminum extrusions.

Kits are good. My favorite is AvidCNC. Incredibly well thought out designs, great customer support and a very active owner/user group.(on Facebook). Pricey, though. You can buy parts from them, the whole mechanical frame or the whole thing with plug-and-play electronics, motors, spindle and so on. My main machine is a 48"x48" Avid Pro4848. I bought the mechanicals from them, bought the spindle/VFD from China and designed and built the electronics myself. I've had it almost 2 years now and am still super happy with it. Even if you don't buy from them, take a look at their machines. Use them as a yard stick for comparing other machines. BTW, my first CNC was a little CBeam machine from Open Builds. Low end extrusions, Vwheels, acme screws.12"x12" work envelope. It was a learning exercise and currently collects dust. I should probably sell it.

Finally, there are lots of resources for DIYers. Probably the biggest and most active is the Home Built CNC Machines and projects group on facebook. Lots of CNC builders there. It's a fairly friendly and supportive group.

 

Choose steppers based on the torque you need to move the weight of your moving pieces at the speeds you desire and the mechanical design of your drive system. look for sellers that provide data sheets with full torque vs. rpm charts, stall torque is meaningless (stall torque why there are “5hp” shop vacs that plug into 15A 110 circuits).
Based on the inductance of the steppers you will calculate the driver voltage V = 32 x sqrt(inductance). Hint, look for low inductance steppers (2-2.5mH) to operate on 48V. Based on the max current rating of the steppers, and the calculated voltage, choose compatible drivers (these are not the items to scrimp on, suggest Leadshine or Geckodrive). A power supply with at least 2/3 of the total amp draw is usually sufficient (they won’t all draw max current simultaneously). You do not choose electronics based on price, but based on requirements - the stepper “packages” on Amazon, eBay or Alibaba usually have high inductance steppers and too low of voltage power supplies (no Nema23 steppers will operate at peak performance on 24 or 36 volts).

The Facebook group listed above has some good info (I am a moderator and one of the group ”experts”), but a better source Is. DIY CNC Router Table Machines

if this is an assignment, suggest you do your homework and learn WHY to do things, not just how some else did it. Even if not an assignment, you will learn much more if you ENGINEER a machine, not just assemble one. The cheaper commercial machines are not usually well designed (which is why I built my own DIY machine and not a kit). They are built to be cheap, not to be good. For wood, you want to be able to cut fast (at least 200ipm) for best results. For either wood or aluminum, you want to be rigid, unlike 3D printing or laser, there are significant loads applied to the machine. Plastic, 3D printed parts, belts, or plastic wheels on extrusion are to be avoided if possible.
Lastly, you want to be reliable, I suggest a controller that is not USB (all GRBL controllers are USB).

And remember, no CNC router is a mill, you are not going to build a VMC at home. Any aluminum milling will be a bonus, you will not be holding .001” accuracy, no matter what anyone claims.
Good luck!

 

The Facebook group listed above has some good info (I am a moderator and one of the group ”experts”), but a better source Is. DIY CNC Router Table Machines

CNCZone is good technical resource but not nearly as active as the FB group. Also, the FB group is more interactive than CNCZone. One other thing about CNCZone that may bother people - some members can get argumentative about the "right" way to do things. For example, some there take great pleasure in dumping on GRBL and its users. It doesn't bother me as I have a fairly thick skin but others may find it annoying.