Parts Used For The X-Axis
Below are the main components used in the x-axis assembly. These are the hotend carriage, stepper and idler z-axis supports, x-axis tension block, stepper motor and various nuts, bolts and bearings used to connect them all. You can skip to the end of this post to see the time lapse of most of this assembly, or click here to watch it on my YouTube channel.
X-Axis Idler And Tension Block
First up was to set up the x-axis idler by adding in two M4 nuts into their printed slots. The Idler bearing is built in a similar way to the y-axis idler bearing; with two MF126 (flange) bearings, a couple of washers, an M5 bolt and M5 nylock nut. I think eventually I will replace the bolt, washer and nut with black versions – just to keep it looking sweet! The idler mount has two LMU88 bearings inserted into it in the main large hole. They should slot in with a little force if you widen the expansion gap a little. Slide them all the way in. The part has a notch half way down the slot so you will have to insert one each way.
X-Axis Stepper Mount
Behold… the only video time lapse I could find of three versions of each part printed?!!
Next up is the construction of the stepper motor mount on the x-axis. This is secured onto the stepper with three M3 bolts. Doing the same with two LMU88 bearings in to the large slot and that part is done – simples!
You will then need to add a GT belt gear – I went with the 20 tooth version, same as the the y-axis version. Slip it onto the motor shaft and tighten it up using the grubs screw. Before tightening it all the way, make sure it is aligned with the gap in the plastic part so the belt will run freely through, as per the image below:
On both parts (motor and idler) the LMU88 bearings are held in with friction. There are holes to allow retaining fasteners to be used to keep the bearings in place. For this I used mounting M5 5mm screws which have a flange washer of 7mm built in. These allow just enough to connect to the edge of the bearing, but not block the hole where the 8mm smooth rod will go. You could use M3 bolts and a washer, but these were a neat and tidy solution. I drilled and tapped the holes with an M3 tap first to reduce the chance of splitting. The plastic is thin at these sections. Toolson was clever enough to add in a small notch in the design which allow the washer to fit perfectly, and the bolt screws in beautifully.
At this time the z-axis stopper bracket is added to the stepper motor section, as seen above and below. It is secured with an M3 bolt and nut. There is also an M3 nut inserted into this part to secure the long M3 bolt with will eventually trigger the z-axis endstop. I’ll cover that in another post.
Now comes the step of adding the 8mm smooth rods to join the two end up. These two will insert into the stepper end all the way till they cannot go further, it’s best to add them to this part first. Before adding I drilled out the holes of the part with an 8mm drill bit. It was surprising how much material was removed, and even after a little trial fit I still needed to sand and file the holes down. I suspect that was due to my printer setup – as I have recently been playing with “flow rate” and realised I am extruding way too much plastic which is causing all my tolerances to be too tight. Anyhow – once the holes are drilled, sanded and filed to perfect 8mm bores – insert the rods into the stepper end. and then move onto the idler end.
Here you can see how the idler end works, and how the Toolson Edition changes compared to a standard Prusa i3 model. The belt tension on an standard Prusa i3 pulls on the idler end and through the z-axis. Toolson’s version exposes the 8mm rods as per below image and then the idler tension block directs the belt tension force down these rods, rather than along the z-axis. Line up the rods so they are about flush with the end of the plastic part.
Below is a test setup of the belt and tension block, and how the M4 bolts line up with the ends of the 8mm smooth rods. To add more tension to the belt you would turn these bolts which would in turn pull out the tension block and tighten the belt.
BUT WAIT! Don’t think you’re done here – where’s the x-carriage?! If you’ve followed along blindly you printer is missing the x-carriage! If so – remove the idler part and move on to the next page as per below!!