Using a Shapeoko3 to drill aluminum

[RobCee]

I can also confirm that although my Chinese spindle 'can' run at low speed, it will soon fry itself if it runs below 8-10,000 RPM. Just like a router, it has an internal fan attached to its spindle inside the case to keep it cool. The manufacturer recommends setting the minimum frequency to around 100Hz, if I remember correctly.

The problem with using a headstock like the Sherline one is that for it to work well, it really needs to be held more rigidly than can be achieved in a gantry mill like the ShapeOko. It would need (ideally) the rigidity of a more conventional knee mill design to support it properly, by which time it becomes more cost effective to be converting a manual mill than building one from scratch.

[samc99us]

Ugra CNC has some spindles that are rated for lower working speeds: http://ugracnc.com/CNC-SPINDLES/GMT-Air ... RPM-S.html

To big for the SO2/3 but an idea: http://ugracnc.com/CNC-SPINDLES/GMT-Air ... RPM-S.html

http://ugracnc.com/AIR-COOLED-SPINDLES/ ... 80V-S.html

Not exactly sure how to drive those, and the price isn't exactly cheap, but to me it seems more useful to have a spindle designed for say 2,000 RPM-10,000 RPM.

[samc99us]

Actually this looks pretty good on paper anyway: http://www.amazon.com/Konmison-Cooled-1 ... ed+spindle

3,000-12,000RPM. $200+VFD. Still not slow enough to turn large bits but getting darn close. Then again reading the details on this setup, which appears to be the same spindle, its like most Chinese spindles, good from ~8,000 rpm to 24,000 RPM: http://www.amazon.com/Konmison-Cooled-S ... VGP0EQTBQV

[Jimf]

Thanks for everyone's help. I think I'll try building our own machine using Open Build's V-slot instead. It looks like that would be better suited to customize to fit for our needs.

-Jim

Yes a custom build solution would be better. I would probably use a bench mill/drill like a g0704 from Grizzly as a base. Construct a custom longer X-axis using vslot extrusion and mount it to the mill bed with hold downs. There are plenty of howto CNC a g0704 build videos to get you started.

You will end up with a rigid and accurate drilling system.

[twforeman]

I was doing some Google image searching for DIY CNC spindle ideas and ran across this image:



While it made me laugh, I can see this as a germ of an idea that may lead to a possible drilling spindle for my Shapeoko 3...

It made me think about where to find a somewhat light weight, inexpensive motor that runs slow enough with enough torque to run a drill bit. Hand-held electric drills fit the bill pretty nicely - they even have speed controls.

You can't mill with this solution, but if you came up with a quick-change system you could mount up a drill for when you wanted drilling and you could mount up a router for when you wanted high speed milling.

Just thinking aloud at this point.

[cvoinescu]

That's not a drill, though; it's a rotary tool with a funny shape. I can't find that exact one, but here's another that looks a little like that.

[TomDChi]

Still, it's an interesting idea. I was just looking at photos of corded drills wondering what's inside the plastic case, and if there would be a good way to mount one with the bit aligned reasonably precisely. I don't drill enough holes in patterns to really consider it myself, but I could definitely see something like a drill mounted in a Shapeoko being very useful for some people.

[WillAdams]

Yeah, it seems strange to me that there aren't more options for this sort of thing.

[twforeman]

That's not a drill, though; it's a rotary tool with a funny shape. I can't find that exact one, but here's another that looks a little like that.

Ah, true, but my mind saw it as a drill and I started thinking about options.

[krtwood]

I haven't seen a corded drill on a cnc, but I've seen a lot of drill powered other tools. If you are a follower of Izzy Swan you know what I mean. A lot of larger corded drills have a hole for mounting a handle which gives you one solid attachment point. They generally just cut something to fit the shape of the drill and use a hose clamp and maybe some wedges for alignment beyond that. I've also seen a couple threaded rods with a bar between them on the trigger to make precise use of the variable speed, rather than just zip tying it at full speed.

The biggest annoyance trying to use drill bits is that the larger the bit the longer it is. I did the mod of attaching t-track to the z plate to stiffen it and that might be a viable way of mounting the drill with both a quick change (should be able to leave the stock spindle mount in place) while allowing you to move the drill up higher for longer bits. I don't think there's enough z travel on the Shapeoko to mount it in one fixed place.

You'd probably want to add some supplemental cooling since these things are designed for a low duty cycle.