Submitted 3 weeks ago by Rolive@discuss.tchncs.de to 3dprinting@lemmy.world
Right now all it has is a plotter adding but I’m also making a mount for a mill and lasercutter. It’s meant mostly for making circuit boards but should be able to handle other projects as well.
It’s designed in FreeCAD and some parts were sourced from discarded laboratory devices from my job as well as a broken 3D printer.
Let me know if you’re interested in the FreeCAD file, right now it’s a bit messy but I intend to post it to printables.com later when it’s fully done.
I’d like to see the FreeCAD file both in the “a bit messy” form as well as in the cleaned up form.
I’ve updated the OP with a Google drive link.
Cool! This was interesting to see.
On the design: It looks like it could be good for laser cutting but I doubt it will do more than CNC engraving wood. Would love to be proven wrong. I think the screws are too close and the leverages too large to be solid enough for cutting. We cpuld simulate it to verify the weak spots. No problem for plotting and laser cutting though. I was surprised by the deflection of the Indymill which has more metal parts.
On the CAD file: I could easily find my way in the file. I generally constrain more (also importing shapes from other Bodies) which makes it more automatic but also more error prone and harder to calculate. It will be interesting to see an assembly of these parts too.
Looking forward to updates from this build.
Same, I’m also a learning FreeCAD user.
Nice! Once you get the hang of it FreeCAD is quite pleasant to use in my experience. I’ve updated the OP with a gdrive link.
philpo@feddit.org 3 weeks ago
Interesting concept,seems to mitigate some issues of the MPCNC. The Z Axis assembly looks a bit on the weak side, especially for heavier spindles. I see the most problems in CNC builds here,tbh - the Z axis is far more of a problem than the other ones as it tends to destabilize itself due to the lever effect it does suffer from.
BTW: In terms of Google: Why not put the file on something like Github/Launchpad,etc. so others can contribute,comment or fork it?
MysteriousSophon21@lemmy.world 1 week ago
Spot on about the Z-axis being the critical point of failure in most DIY CNCs - harmonic resonance at higher speeds will absolutley kill accuracy before anything else.
Rolive@discuss.tchncs.de 3 weeks ago
Thanks! Indeed the Z axis rests on only one MGN12H block. For stability it can be changed to two sliders per rail at the cost of work area. For circuit boards and wood it should be strong enough to handle the load.
As for github/launchpad, I never used those before for sharing anything. I will look into those.
philpo@feddit.org 3 weeks ago
The issue with the Z axis is not only the slider but also the threaded rod. Just a few thoughts/experiences on it based on my experience with the MPCNC and various different changes to Z axis group people made:
rigidity of the axis is paramount. When the router moves it does move toward the material. If there is not enough rigidity the material will push the router bit away variably and an angle is created which then exercises pressure on the router bit, creating enormous loads and usually kills it - which is bloody dangerous.
The other issue is the weight of the spindle. A makita RT0702C is around 2kg, but has its drawbacks. A water cooled “China spindle” weights around 5. That is, from my experience, too much for one threaded rod.
Don’t get me wrong, your design is great and imho you are onto something - it removes a lot of other issues the MPCNC has and might be the perfect middle ground between “MPCNC” and “full aluminium build”. I like it a lot for this.