Raiscube A8R X upgrades

thingiverse

This is an upgrade of the X belt clamp / cooling system for Raiscube A8R 3D printer. This unit comes with a quite cumbersome extruder assembly, with a highly ineffective but very huge cooling system. It uses a couple of 40mm axial fans, each with an air duct and a very narrow exhaust nozzle, so air movement was barely zilch. I had to do something with it :) Same time, I wanted to make the usual, cable-tie type "belt clamp" somewhat better. Here I was hesitating for a while, what solution to choose for the variable clamp (tightening side). I was first thinking about something with a screw, then I saw a solution which was developed for Anet A8 printers, using a rotating ratchet wheel and I really liked it. Unfortunately here I had no space to implement this, so at the end I came up with a simple curved belt duct and a little wedge. One can pull the belt tight by hand, and then push the little wedge in to lock it. Belt tension tries to pull the wedge even more in, so it will self-lock it at the end. Regarding the fan: I wanted to have full view to the nozzle, so I thought to use a semi-circular air duct, and place the fan at the back. To fix the fan, I designed a little bracket which the same time holds the X home switch as well. Air duct is a remix of [thing#2322182](https://www.thingiverse.com/thing:2322182) , it has been modified to have a necessary recess to push it to the fan's output port, and was mirrored and lengthened to arrive to the correct spot. As a little extra: I planned to fix the fan to the bracket by using M3x20 screws, but found out that I didn't had them at home. So, as I have a hammer, everything looks like a nail, isn't it? I modeled and printed even the two pins which I used to fix the fan at it's place :) The last photo is a before/after: the black pin was printed with the original cooling system, the blue one with the modified. Same gcode file, nothing modified or tweaked yet! UPDATE 02/09/2019: During the past months of using the printer, I discovered a little design flaw. It looks like the weight of the air duct is pulling down the whole assembly and by the axis of the two pins, it manages to actually tilt downwards and the end of the duct starts to touch or even crash into the item under print (on one occasion this was so violent it actually kicked off the item from the build plate...) To solve the issue I designed a little clamp which connects the lower part of the fan to the mount plate. The item must be printed laying on its side as this way it is way stronger and can withstand the pulling forces. The other modification is a little mount for the cooling fan: originally it is mounted directly on the side of the extruder aluminium block. This actually blocking the air flow completely, so there is no cooling effect at all. By moving the fan a little more downwards and further away, there will be some air flow, which in turn can provide some cooling effect. I've replaced the original metal fan grill to [this reduced frame aperture design](https://www.thingiverse.com/thing:2802474) by mightynozzle as I really like it :)