List of parts
- 3 M3x20 screw
- (Scalar XL) 1 M3x50 screw
- (Scalar M) 1 M3x30 screw
- 1 M3 nut
- 1 M3 washer
- 2 plastic washers
- 1 625ZZ bearing
- 1 plastic cage for 625ZZ bearing
- 1 plastic fork stretcher
- 1m40 GT2 2mm belt
- (Scalar XL) 1 XCA 10 plastic support
- (Scalar M) 1 XCA 8 plastic support
- 1 GT2 16 teeth pulleys
- 5 cable ties
- 1 stepper motor
- [provided] 1 allen key
- [not provided] 1 cruciform screw diver
- [not provided] 1 cutting pliers or pair of scissors
Insert a M3x20 screw + M3 washer and then close the whole system with a M3 nut.
On X Axis slightly space the linear bearings and move them on the center on the axis.
Also make sure the heads have at least 1 or 2cm of free length, this will makes things easier later on when you will tight them up.
The back view will give you more access to the cable ties and will make it easier to handle them.
Tight the cable ties so that the ties heads stay at the outside of the part.This will allows to have more free room for the belt later on.
Front view, the carriage looks like the picture.
Notice the cable ties that enroll the bearing.
Now take a stepper motor and 3 M3x20mm screws
The wires from the stepper motor needs to be oriented toward the machine .
Now , install the pulley on the motor axis. Place it as shown on the picture so that the thicker part of the pulley is facing the opposite of the motor. This will allow you to properly align the pulley’s teeth with the belt slot on the stepper motor support.
This side you should help you understand how to align the pulley with the belt slot.
Now take the belt stretcher that you assembled at the beginning of this chapter.
Scalar XL: Take also a M3x50 screw, a washer and a M3 nut.
Place the nut inside the belt stretcher, there is a dedicated slot on the side of it.
The washer will be mounted on the screw and will help to tighten the stretcher.
Use the tensioner support and place it at the end of the X axis smooth rods.It’s purpose is to make sure the tensioner will force on the X axis smooth rods ends and not on the Horizontal Z axis smooth rods.
She should be free and be fully inside.
Notice the triangular shape slot. The stretcher should be able to get inside properly.
The purpose here is to make sure the stretcher is in place and that we have the maximum amount of possible movement to stretch the belt later on.
Also take 2 cable ties
Insert the belt inside the slot of the stepper motor holder plastic part.
Insert it at the bottom of the bearings, the belt’s teeth facing the bearings.
On the other side, handle the belt so that it goes around the pulley.
With the belt’s teeth always facing the pulley.
Take care to push the belt on top of the bearings. The bearing will keep the belt straight to the X axis carriage so that when the motor pull or push the belt, it’s always rectilinear and parallel to the smooth rods.
Then pull the belt so that at least 10cm are available in the void.
Push it behind the X carriage.
Those 2 ends must be located at the top of the overall belt assembly.
If you have the proper length, the belt should slight cross with enough free belt.
Place it in the center of the X carriage
Take one end of your belt and push it inside the tight gap dedicated to keep the belt into position, between the 2 linear bearings.You might need to force a little bit so that the belt is slightly smashed between the plastic.
You can use your nails to push the belt up to the end of the slot.
At this moment try to pull the belt a maximum already so that it’s quite stretched .
Whatever you do, the belt will keep a small flexibility. It’s normal, the side stretcher will cope with that later on.
Now close the cable tie but make sure the belt stay aligned and parallel to the smooth rods. The belt must always be aligned at the top to keep the mechanical motion of the carriage linear.
You know that your belt is stretched when it seems very hard by pressing on it.
Considering the length of the belt, even when properly stretched, it might still seem a little bit flexible or might vibrate a little bit. It’s normal it shouldn’t bother that much the printing but might impact the maximum acceleration you can use on that axis.