Clough42 ELS lead screw project: New Banjo + Motor

 

Working from the pattern in the last blog I fleshed out the banjo a bit and started on the motor mount.  Need to extend the sliding part to include short slot and provide a location for the bolt to hold it down.  That has to go in a slot.   If there is room I will use carriage bolts in the slots with washers that fit over the square part of the bolt head.

The motor mount

The cutout for he belt may need to change and it needs screws to fasten it to the base plate.  Maybe some alignment features.

First view including encoder.  This was done to check clearances.

Need to calculate belt size range for the motor drive.
The line that translates the motor mount from the leadscrew position is

translate([55,60+slideForView,banjoThick/2])

using 24 and 72 tooth pulleys aks 1:3

The X offset is 55

The Y ranges from

60-25 = 35mm    ... hypot is 65.2  ...

60-0  =  60mm    ... hypot is 81.4  ...

This is not long enough if we extend the slots to the end cutting away some encoder adjustment

         60+35  =  95mm    ... hypot is 109.8  or 4.3 between centers

Requiring a belt of 368.40 mm pitch, what I can find is 

363-3M-06 / HDT Timing Belt 363 mm pitch length

While that is a good working lenght I need some additional adjustment.

 

Figured I might have to give up the slot to make enough room for the motor slide.

This is due to the size of the 3D printer bed 200x200mm aka 8x8 inches.

In the morning I need to take the template to the shop and test fit it with the fixed hole in mind.

The bolt can go between the slot nearest the encoder and the encoder. This will allow both slots to be quite long.

Figuring out what works is slowing this down.  Go figure.