Help with CNC "router"

[AdamHeard]

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?

[sanddrag]

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.

[Thermal]

Originally Posted by sanddrag

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.

[DonRotolo]

Originally Posted by AdamHeard

do these need to be run in the orientation they were designed for?

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

Originally Posted by Thermal

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.

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.

[Mr. Lim]

Originally Posted by Thermal

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.

Team 188 has been cutting aluminum on a CNC router equipped with a wood router as a spindle for a number of years with a lot of success. Patience, conservative cut depths/feed speeds, a good cutter, and someone to stand over it with a vacuum to clear chips, and coolant are key. Don't expect to be able to hold tolerances to press-fit bearings though!

Here are the cutters that we swear by, and 188 also has adopted:
http://www.onsrud.com/xdoc/SuperO

We run them at 18,000 RPM. I think 188's wood router is a fixed speed at 24,000 RPM which is a bit fast I think, but it is possible. The single flute in the cutter makes a big difference in being able to run at these speeds.

[Mr. Lim]

A spindle option for you:
http://www.a2mc-cnc.com/Spindles.html

We use the Elte 3HP @ 18,000 RPM and have been quite happy with it. We also have an auto-mister, which is a very nice feature for cutting aluminum. We cut up to 1/4" thick plate on our setup - multiple passes of course.

AXYZ Router (http://www.axyz.com/) might even quote you an entire Z assembly + spindle. They build complete CNCs based on the A2MC controller, and do some custom work as well. Maybe they can give you a pre-fabbed Z assembly + spindle, and just let you figure out how to mod it to mount it on your X/Y gantry. If you go this route, again I'd highly recommend the mister.

As an aside, here are some options for stepper controllers if you don't get yours working, or if the old ones don't support ModBus:
http://www.a2mc-cnc.com/motors_drives.html