Hitchhicker's guide to the Hardware
Here is an update and perhaps a little guide to our finalised hardware: practically from the day we finished our campaign the only things we kept were extruded frame and rails, most of the parts were improved for a better performance. The key idea for this machine when it came to improving the hardware was to keep everything very simple and design in modules for simpler maintenance.
Here is one of the modules, it's a x-axis module. The beauty of this motor module lies in its connection with a bolt and a spring. Essentially untying the black bolt above the motor and the spring will let you take the x-module off the machine, great for maintenance, it can be replaced with another x-module in a mater of a few minutes.
The spring is what keep the motor offset of the rail and prevents machine from missing a step, also because of this there is no backlash, if the machine happen to run into itself it disengages because of this very spring. This and built in sensors will prevent your machine from destroying itself, say even if it happens so you accidentally run the machine into itself it will disengage and stop without going of the rails, and you can start where you left of. This is probably one of the nicest things we always wanted in our cnc machine. the video below shows how it works.
Another cool thing the material quality has improved, as we wanted this machines to last we installed the stainless steel racks instead of carbon steel that we had on our working prototype.
On a y-module you see the same spring system.
Okay, the long vertical screw that drives the z-axis was replaced to a better part, to improve precision and avoid any backlash. You might ask but why does it really matter to go über-precise - the answer is when you have your project in which you invested a bit of time, made a nice digital model, say you use a nice piece of material, the CAM file is all set up nicely and then you go through the job, start milling, seems to be working AND! something starts to go really strange, the next thing you see you machine rams into your stock, its painfully dreadful to see that it completely destroyed your model, perhaps it was a large model which you were milling for the last half a day..we've had this as our personal experience, and it's the most upsetting thing to see your perfect setup go into a bust because of unreliable machinery. So to make this easier we just had to think of a safer system.
So going back to z-axis: we are still ironing out a few last kinks, and we aren't completely satisfied with performance of z-axis, thus we have to make couple of adjustments. In the video its not yet ideal z-axis performance. It is absolutely crucial for 5axis machine to have a perfectly smooth and fast z-axis, it's not a 2.5axis or any desktop 3axis machine which almost never relies on z-axis! By the way that musical noise your hear in the background is the music from the rehearsal space blow us, it's not the machine.
In light green are the sensors for B/C head.
Keeping the cable management clean and simple. In our next update this week we'll show more useful info on how to keep the cables managed.
not so managed cables, will update later on this week on progress of managing these. the clean and simple machine hardware requires a lot of things going on in the electronics area, hope to show it all managed in the next update!
Also still waiting for those motors!
Aluminium milling: here is just a few thoughts/ comments on what we think about milling aluminium on this machine: we get a LOT of emails asking if one can mill aluminium on this very machine. When we say no we get to asked something like: But why do other desktop machines mill aluminium, brass, etc. Well, professional aluminium milling isn't slow, and that why we tend to answer you shouldn't mill aluminium on any of the desktop machines. Coming from doing cnc service professionally one would suggest a much heavier machinery for a faster and more effective outcome. Generally if something too slow it isn't working, that is also the reason why we've build a large working volume, we want you to make real projects on this machine, to be able to use it not for toys but for real stuff like furniture, design prototypes, moulds, what have you.
Generally hardware turned out to be pretty good, we'll push more effort towards software once we release the batch. Won't say more, will be updating on this in time.