DIY 5 axis CNC with a double slide on the X axis.

DIY 5 axis CNC with a double slide on the X axis.
H=69"(Z~82") x W=38.25" x L=52.75" (X~66.75") Table H = 24"
Work area (movement) is 10.25" Z axis, 21.5" Y axis and 48" X axis.
Any help, criticisms or hate free comments are most welcomed…

The Z-axis doesn’t look very rigid. Are you going to be cutting only foam or taking very light cuts in soft wood?

For heavy milling some sort of 3-axis setup + a trunnion table for the two rotary axes seems to be popular, see e.g. Haas UMC or Hermle 5-axis machines.

@Anders_Wallin I agree. Tried to do a sliding pipe in a pipe thing, which could be longer at the top to add rigidity I think. Plus it’s only extending 10 inches so. But still just guessing on my part. btw, everything short of the pulleys, gears n threaded rods is aluminum. Trying to use parts I have on hand, and can fabricate/weld.

Like everything, it started out as a simple 3 axis, and will probably be built as one. But ideas hit, so I can’t help but try to incorporate them…

Thanks for the reply…

Added a photo (13) with a bit better look at the Z axis bracing… Although I still also think it will need a re-design…

Same thinking about your Z axis. Not very rigid.
Also you may want to use as spindle instead of a multi tool after placing so much effort into the carthesian setup.
What about an more traditional portal but tilting the portal back and forward and turning their spindle around the long axis.
That would be much more sturdy but still 5 axis with a stationary part.
A rotary axis for the part limits Z travel enormously.

@Marcus_Wolschon Actually playing with the Z axis as we speak, but getting a bit too elaborate I think. The muti tool (dremile) was just the first thing I grabbed out of the 3D warehouse,

Do you have a link to a pic of what your saying. I think I understand, but wouldn’t (or would) that cut you working area on the X axis?

My thinking was that if I needed more Z travel, I could just raise the gantry.

As stated by others, just say no to dremal type tools, a compact router will do so much better.

I would keep the focus on a rock solid X/Y baseframe first. Building the Z axis is the most critical part - if you plan Z too large for your frame, your construction will shake up and vibrate. You can’t just raise it. Greetings!

I agree, I think I’m way underestimating the forces on the Z axis. But more as an exercise than a real plan, I just added 2 more photos (14 n 15) with added bracing on the Z axis. But at this point I think the motor for the it would have to be bigger than that for the X axis…

Thanks for the comments and advice so far…

I use square telescoping tubing for my Z axis. I considered round, but there just is not enough going for round for me to use it. Square keys itself into alignment naturally. It is quite rigid too. Better than the half ass Z axises I often see hanging off the sides of Y axises.

@Paul_Frederick You’re right about that. I used round because I know I have it. I may have some square here I think. Pretty sure I’ve looked at some of your pics n videos here. Will have to check them out again…


Just looked, must of been thinking of someone else. Can you post or link to a few pics or vids?

Thanks again…

I made my square tubes out of melamine shelves which I bought at a thrift store for 50 cents a piece. Total cost $2.00 I achieved a level of accuracy with them that if someone had told me about it I wouldn’t have believed myself. I’m not sure if it was dumb luck, or I’m just that good. Although I think if I had it to do all over again I could do an even better job another time around. I wouldn’t clamp the outer tube to the inner one quite as tightly as I did while assembling it. I had to sand for a better fit, as mine was initially too tight. 320 wet or dry leaves a pretty slick finish on melamine. There’s a couple of thousandths of wiggle room to work with on the laminate.

My only complaint is the assembly is a bit heavy. Sometimes with machinery heavy is good though.

@Paul_Frederick A man after my own heart. Considered tearing into my hardly ever used plotter to build one here…

Seems like an amazing project !

Will the double slide on the X axis table work similar to the double drawer slides that allow drawers to be pulled out to the full depth of a drawer but maintain horizontal strength? It looks like the gantry can possibly move along the x axis as well or is the position manually set?

Any reason you prefer belt driven from motors versus direct drive? Belts offer another opportunity for failure with slipping, stretching and for chips to mess them up unless they are protected from dirt.

It would be great to see an animation of your design before you build it out too.

@Jean_Lotz The gantry (X1) and the table (X2) are designed to slide in opposite directions, but together (Pics 9-11) in order to double the X axis travel (work area).

The belt drives intended use are mostly as a force and step multiplier My thinking (which could very well be wrong) is that I could get away with cheaper/smaller motors by using multipliers. But the more DIY stuff I see, the more I keep hearing “skip”, which I assume means belt slippage. I know I’ll end up scaling it way down, but that’s the great thing about sketchup, I try ideas out before I build.

I was playing with a couple animation plugins yesterday. They don’t seem to like complex objects, and even if they did, they don’t seem to want to move them simultaneously, as would be needed for the inverse X1-X2 action. But it could be that I need more time with them. “Key Frame” n “Proper Animation”.

Skip in the context of stepper motors means skipping steps. In an open loop system a skipped step is often a ruined job. So it is something to be avoided. You can always run timing belts to eliminate belt slippage.

Your pulley system puts a stepper motor at a disadvantage as far as generating any linear speed goes. Because stepper motors do not produce much torque at high speeds. Stepper motors are just weird that way. Study stepper motor torque curves and note how the plot drops off as rotating speed increases.

Click on the images link for more examples.