Help with CNC "router"

Someone donated a nice x-y gantry to the team with nice ways, ball screws and servo motors. We’d like to make it into a router.

I started a thread on cnc zone about it with more information.

A few of us can CAM, run CNC’s, etc… and We can all run manual machines, but we’re CLUELESS about what to do here in terms of getting it running. We know we’ll need a controller for the motors, and then a PC with software to run it. We’re unsure what the best way to test the motors is as well.

Anyone with any experience with homemade 2d routers if you could point us in the right direction that’d be great!

http://www.rockcliffcnc.com

I have had good, although limited, experience withGecko drives.

Looks like all of gecko’s products are under-powered for this application :frowning:

This is helpful for the software part assuming that you use AutoCAD, but if you use a 3d program (Inventor or Solidworks) then get Cut2D which is a stripped down version of V-Carve Pro which is what 461 uses. In Vectric’s software you have to make a drawing, and then save it as a pdf or dxf and then just assign feed rates and spindle speed (try 3/16 2-flute carbide bit at 2500 rpm and a feed rate of 6-8 inches/minute).

That’s a really heavy duty gantry you got there. Honestly, if you can restore the ballscrew, linear rails/bearings and various other parts you might be able to sell them or the gantry assembly as a whole for a pretty penny and start a CNC router build from scratch using NEMA23’s for your steppers. That might be a suitable alternative over working around that behemoth for your application. Ballscrews are real nice but you can get pretty similar performance out of a rack and pinion.

My team has had a real good experience with the Gecko 540 and the pre-fab’d parts from cncrouterparts.com. They’re all designed to interface with 8020 or T-slot extruded aluminum.

Holy huge stepper motors batman!

I like thermal’s idea.

Adam,

We currently use a CNC Router that uses a controller by A2MC.

http://www.a2mc-cnc.com/

Maybe they might have resources and accessories that can bring your project to life.

Adam you may want to take a look into the motors this company uses. I don’t know what type of work your planning to do but 1251 has a couple small divinci routers from them and they do the trick for routing work. http://www.techno-isel.com/

Yes, they are huge motors, and servomotors at that, not steppers.

The Mechanical system needs no restoration, and both motors are there. One appears to be broken, but we’ve found replacements for $100. We need a controller, spindle, and then software as far as we can tell.

We’re really not interested in selling it, this bad boy is rigid and the motors are real powerful. It also seems like a lot less work as this is mechanically good to go minus a table. Having a router in house to us isn’t terribly useful if the cut speed is slow and we’re limited to light materials. We want to do some serious work on it, or not spend hundreds of hours getting it made setup and running.

Thanks for the advice guys, I’ll be reading about what all these companies offer when I get some time. The biggest variable being what to do for a spindle, followed by what controllers to buy for our existing (200V 100-300W) AC servomotors.

Do you already have an x-axis for this build? All I see is a gantry in the pictures.

I ask this because designing an x-axis around this system is going to be quite expensive and labor intensive. This is quite a large build.

I currently have a CAD model for a future build I want to do with the team that is R&P, easy assembly, 500ipm rapids, rigid enough for light steel work, and capable of mowing through aluminum and delrin. Parts list and price list included. For the most part there’s little machine work, just cutting 8020 and getting some reinforcement plates made via waterjet. If you’re interested, shoot me a PM i’ll gladly send over pictures or even the assembly for your perusal. Though, i’m sure you’ve read through all the build logs on cnczone and know whats out there for DIY. What a great treasure-trove of information over there.

I must say though, if you go ahead and do a build around that gantry, please post up a build log because it’s going to be a real impressive machine and i’d love to see it :slight_smile:

In that picture, the long and exposed axis is the X. The axis parallel to the horizontal frame of the picture with the boxes on it is the Y. The Y has somewhat limited travel, but plenty for our purposes.

I imagine the machine it was taken off of has that as your Y and Z. I can’t see it functioning too well as your X+Y.

Interesting point, that is probably what is was intended for, but when we got it whatever was mounted where a spindle was was mounted facing the floor in that pic, making us think x-y.

In this configuration it would have very limited Y travel when compared to X, but that is not an issue for us. We really only need 8" or so of Y.

Spindle: You can initially go with a wood router (1 to 1.5 HP) with a variable speed controller, and stick with 1/4" shank mills, to save costs and get a feel for what it can do. Easily mills aluminum, steel not so much.

Later, you can engineer a real quill once you learn the kinds of rigidity and precision required. For now, a reasonably rigid Z axis with perhaps 6-12" of travel will be fine. (Trust me: approach this like a robot - build a low-investment prototype first, then redesign after learning the lessons)

Controllers: Obviously you use a computer to ‘control’ it, with software like MACH3. What you’re looking for a nice “driver” board, and possibly a power supply as well. eBay can be your friend here, several companies such as Omron, Mitsubishi, Panasonic, etc. make boards that will drive your motors. Plan on looking carefully for one that drives 200V AC at over 1.1 A (220W - buy one a little bigger). For three phases expect to spend $300-800, more if new.

There’s a lot of expertise here, keep asking questions.

So, if we were to mount a spindle on the “Y” which is really the Z in the current orientation, we’d get very limited travel.

But what if we turned the whole thing over, and hung the Z down below it? We’d still geometrically get the same travel, but do these need to be run in the orientation they were designed for?

A router is certainly the cheapest option, but I’d be worried it’s RPM would be a little fast, it’s bearings might not last for heavy milling in aluminum, it probably wouldn’t take larger endmills, and it would be really loud.

There’s this spindle but it’s not cheap and a little on the small side. Also, it could stand to be a little faster. Nice thing is, it’s a complete unit and it’s R8.

You could use a Tormach spindle assembly which is pretty nice (they have two different ones), but it would run you about $1100. It’s a bit large. I’m not sure how it would fit in with the scale of your machine.

I’m not aware of any other spindle assemblies for sale separately. You could contact some mill manufacturers though such as Industrial Hobbies or LatheMaster and see if they’d be willing to sell you just a spindle assembly.

Of course, with all of these options, you’d still need a Z-axis.

Wood routers are quite capable of sheet aluminum work but you have to get a little creative about it. http://www.vhipe.com/product-private/SuperPID.htm is a great tool for that.

You’re correct about the bearings though, heavy aluminum work will destroy wood router bearings in a few months. Handily though, replacement bearings are relatively cheap and not too difficult to replace.

Depends, some can, some cannot. Consider moving the material in X and Y beneath a fixed gantry for Z

Yes, so the wood router is a temporary solution ONLY, a $50 investment to get a feel for the machine on the cheap. Then a real spindle can be developed, after the hard lessons have been learned inexpensively.

Looks like we might have the controller with it, need to poke around more.

We came up with the basic simplest option. Use the x-y as is, sell the motors on it, make a basic z-axis w/ spindle, and then buy one of those high powered stepper motor, software and controller packages. This would get us about 16x48" of travel.

We still have more research to do, but we’re committed to using this guy during our 2012 season.