I’m thinking I’ll head down the path of upgrading my MPCNC to a Primo as well. I’m going to do this by building a whole new machine and moving over the electronics. This gives me the chance of upgrading from the 3/4" EMT to 1" DOM.
My current MPCNC has a 24"x24" cut size and about a 4" Z depth. The only reason for the 4" Z is because sometimes I need to mill the top of 3" stock. I use extra MDF plates to raise the cut platform when milling thinner stock.
What are some of the sizes others are building theirs at?
I’m thinking I’m going at 30"x24"x3.5" which is roughly the size of my MPCNC burly. I am also upgrading to SS/DOM.
BTW if you’re in the DFW area I saw that Coremark metal in FW has some pretty good prices on 16ga 1" SS and DOM tubing. I need to call them and verify actual measurements. They say their 16ga is .0598 wall most everywhere else 16ga is .0625.
Mine I’m working backward from a table that’s 24" x 30", and I ordered tubes that are 25" and 31" with 16" Z rails. I’m thinking I’ll build at the minimum height of 82 mm with a drop table down to about -5", and the extra Z rail hanging off the top is useful not just for drop table but also if I rework the tool changer.
So many Texas (re)builds! I’m upgrading/rebuilding but dropping an inch on each dimension, so about 46"x26". Taking this as an excuse to upgrade to 1" DOM too
The tubes here come in 2m lengths(Biltema). They are quite sturdy. Therefore I’ve been thinking about making x and y 1m, (40"), with a low Z as possible. That would give me about 700mm(28") workarea. I’m not sure if it’s too big or not. I would love to have some space and to maximize the potential in my small workshop. What do you think? Is it too much?
I had a 4’x4’ mpcnc for a while and it worked just fine for me. I shrunk it just to reclaim the space and because I only needed it that large for a one off project.
Awesome! Now I need to rethink my table design. Currently targeting a 24”x24”x3.5” cut volume and was already planning on having a drop table for future functionality and to increase Z but now I’m thinking I may want to increase my Y to accommodate a tool changer. I can add a second set of supports to improve X & Y rail stiffness but don’t think I can do much for the Core rails.
Have you made anymore progress on the tool changer? The last post was awhile back.
No, I haven’t worked on it lately. The issues I’m aware of are:
Not parametric for different build sizes. This is especially an issue now.
The cleats are under a pretty heavy load and they tend to break.
I would like electrical contact through the tool mount to enable touch probes, 3D printer extruders, or tool on/off in a scalable way. (Scaling to a large number of tools is not on the horizon for me practically but it ‘feels right’ to implement it that way.)
I have tried to figure out if there is some way to mount a turret to enable multiple tools without consuming too much XY workspace, but I haven’t figured out how to do it without tangling up the power cords. (And I’m not comfortable sending 110V through the electrical contact on the tool mount.) There’s plenty of room for innovation in this area if you have any good ideas.
I’m actually planning to rebuild my MPCNC Burly into a Primo and downsize it. It’s currently got a 3ft by 5ft footprint, and I’ve decided that is too large to manage. Plus, I have only ever used that full size once. New build is aiming for a 24x24 in work area.
Would recommend to get stainless from a boat supplier. Then you dont need extra support. I paid about 1500NOK for the parts, about same size as your build. And all boat firms got the 25mm in stock this time of year. But again the Biltema is almost no cost compared
Thanks for the great tip. I’ve called to all the local steel supliers(Tromsø), and none of them had 25mm pipes in stock. They could order from their central supliers, but that takes time, and is probably quite costly.
But I wonder - do you recommend SS because of the rigidity only, or also the rust protection? I keep the cnc in a heated shed, so I don’t need to worry about rust. But I want it to be rigid! From Ryans size recommendations, he suggests that anything OVER 1m should have mid-span support. I think that with keeping a short Z, an being just within 1m for the tubes, I might be on the safe side. My current MPCNC is about 60x70cm (tube length). That gives me 433*337 work area. I would very much like to increase that a bit. The biltema pipe seems very stiff as by now.
The steel is polished, smooth and stronger. I have a 800x800mm work surface and when I apply force in center at one side. There is not a single mm movement from the steel. It cost more, but I like the feel of the steel. I prob went a little overboard with my build, using high quality ball bearing that cost a total of 200$. and so on
