Part of the reason I have been exploring options to make the z axis lighter, or relocate the router altogether, is because I’ve always had 5 axis machining in the back of my mind.
I was thinking it would be easy to build a 2’ rrotary table, the hard part would be rotating the spindle. A 90° bend will be too much for flex shaft, but a compact brushless system might still fit the bill here.
What do you guys think? Has anyone put any thought in this area?
The first obstacle is really the CAM software. I don’t have any idea how to control a 5 axis machine, really. Except for ROS…
It would be pretty cool though.
Fusion 360 works 3+2 axis control. It’s not true 5 axis. It may be worth it for some things. I’m sure others have suggestions.
I think one of the biggest mechanical issues you will have will be the clearance between your spindle and the X and Y tubes. Unless you’re dropping the whole Z axis way below its normal level the spindle will crash into those tubes passed a given angle. Or unless you have a very compact spindle.
But who knows, maybe it will work. I don’t know what to believe anymore since someone managed to mill steel with his MPCNC, which I thought was impossible. Maybe we live in some kind of matrix where everything is possible as long as you own a MPCNC, so I suggest you to try and push the limits!
Agreed, This keeps blowing my mind as well!
Clearance shouldn’t be a problem, as my brushless motor is mounted parallel with the spindle.
I haven’t started modeling the design for it yet. I’m having a hard time imagining how the center assembly actually works. If anyone has seen a plan for something similar, point me at it.
I’m thinking a belt will be the way to go. It makes sense since one might have some left over from the x and y axis’.
It sounds like you want to do 5-axis with the extra 2 axis being added to the tool mount?
Rather than hang all that extra weight on the tool mount, why not do something like
where the extra 2 axis are in the form of 2 rotary tables mounted on each other?
I’ve seen these trunion style systems, while nice, they really limit the size of the part.
No I only planned on adding one axis on the tool mount. I was planning on a flat rotary table. So one axis is the table itself. This maximizes usable workspace.
Secondly, you could add yet another axis this way for some really complicated stuff.
I really don’t plan on it being able to carve out wood, but rather cut machinable wax. I do mold making with polyurethane, so as long as it can cut a positive or negative, I can make a part with any number of mechanical properties.
I see how it looks like it can’t be done with a router as a spindle, but check out rc groups. Those guys build spindles from rc motors, and they can be very compact. The othermill is a perfect example of how compact a belt driven assembly can get. The height of it is like 4 inches. However the depth is bigger, but that’s of little concern.
This is definitely doable guys. Can you imagine a five axis machine under 500? It’s crazy. Take a look at the 5axismaker. It’s a very interesting machine. I really like the video where they are 3d printing in five axis’! The only thing I would change is not having both additional axis’ on the gantry.
Ah ok, if you are using a RC motor and plan on milling light stuff then there should be no big issue!
I suggest you to use the biggest diameter of bearing you can for this axis, to provide stability (but try to find a light one, you don’t want too much mass there). Then a big pulley and a belt going to a stepper motor for rotation, that should work pretty well. You can have a look at the moveo robot arm for the belt/pulley system, I think it would be easy to do something similar and, since I have one at home, I can tell you that this works well.
Good luck with your project, really wish you can do this. Mechanically speaking is doesn’t seem too difficult, it’s the software part that would scare me.
I suppose it would make sense to size the bearing based off of the next bolt size that will be the same in metric and imperial. That will keep it universal? Maybe Ryan already knows what size to use?
Great suggestion to look at the bcnmoveo. I wasn’t going to model teeth into the part, for simplicity, but it might not be a bad idea. It would certainly give it some more available torque.
i think just for test purposes or working with soft material like wood
4th axis with printable chuck can be used
like that https://www.thingiverse.com/thing:2673554
I saw that one. I was thinking it really doesn’t lend itself to relief carvings as well. Think traditional pocket milling, but being able to make a final pass from varied angles to get a mirror finish in an irregular pocket. Plus you would have to build a drop table to use it well
I’m thinking turning a 2 foot circle in the middle of the bed level with the rest of it, and if that axis is needed it can all ways be implemented in much the same way it is now.
Fusion 360 can do 5 axis CAM in the paid version. There is also http://www.cnc-toolkit.com. I have no idea how good it is.
To do 5 axis you need a robotic arm. There are lots of projects out there. I’ve been thinking of building an arm out of aluminum and conduit and use brushless motors as servos. Who knows if I’ll ever get to that project.
I know someone who has a warehouse full of kuka style(forget the actual model) arms for sale. They came out of a car manufacturing plant I believe. They’re the smaller ones, maybe 4 or 5oo pound capacity.
Ryan> To do 5 axis you need a robotic arm
To do 5 axis you do not need a robotic arm. There are plenty of people doing 5-axis machining using 3-axis milling machines with 2 rotary axis.
Barry> I know someone who has a warehouse full of kuka style(forget the actual model) arms for sale.
How big are these robot arms? There is a startup in California that is working on using a robot arm to 3D metal print entire rockets (except the electronics and fuel):
I agree with Fred. You do not need a robotic arm.
There are options as to how you want to achieve it, each with limitations and advantages.
You can put both a and b axis on the z axis. This adds a lot of weight.
You can put them both on the table. This is ok but limits you due to the size and shape of the trunion.
Or you can slipt them. One on the z axis and one on the table.
The reason I like this option is because you don’t need to unbolt and disconect anything to mill in 3 axis, if the table rotary axis is flush with the rest of it.
I’ve been out of town and haven’t been able to work on this for awhile but when I get back I’ll post a pick of what I do have.
So far a few mock up pieces as proof of concept.
Ok, you got me interested in 4 and 5 axis milling.
It seems like fusion 360 can do it even in the hobby version, which is great. I just generated a 4 axis toolpath in fusion to try it out.
Can we still use marlin firmware and a ramps or rambo board, or do we have to go to something more specifically designed for cnc?
How would marlin interpret the extras axis assuming it can at all? It should be able to do at least 4 axis, 3d printers are 4 axis if you count the extruder. looking at a the board it seems there is a space for a 5th stepper driver.
You could use a sliding tail stock like this to give a lot more support to the 4th axis. https://www.youtube.com/watch?v=Yzu6iqPmmNo
Just create two of the 4th axis printable chucks ( https://www.thingiverse.com/thing:2673554 and mount one of them on a sliding rail. The part would be turned on it’s side instead of the upright like the buda video you shared, but would be supported at each end. One motor at each end, just like the x and y axis are setup in the MPCNC.
For the 5th axis you could move the tool side to side on the bottom of the Z axis. I don’t think you really need a large range of motion. 45 degrees should be enough. I don’t know how to tell the CAM software how to limit the range of an axis though.
Depending on what you are doing, 4 axis is probably enough. This is just 4 axis and it’s doing a fine job mass producing Budas. (Budas seem to be what everyone wants to carve)
4 axis is awesome! Let’s build this thing.