V8 - Altered the top 'extrusion' slot part to make it much shallower. this allows T-Nuts with a taller T part to better grip the bracket
i.e. the bracket bit now doesn't sit as deep into the extrusion as it previously did
V7 - Final version. Fits perfectly for me.
Feedback appreciated please if there's any issues.
Simply put.........this is an ESSENTIAL UPGRADE
if you don't use this bracket, your bed will be pulled down when it moves from front to back. this will affect your prints and ability to level the bed.
You'll also experience slight ringing as the standard plastic bracket flexes during sharper bed movements
Improved stepper motor mount for the Duplicator 9
Significantly stiffer than the on-printer plastic version (that came with most printers, earlier ones had a metal one)
This also fixes a potential issue with the factory bracket being about 6mm too low, making the belt slope down from front to rear.
This ‘slope’ will lead to variable tension in the belt as the bed is a fixed height, there will be less tension at the front where the bed belt holder is level with the front idler.
There will be more tension at the back where the stepper driver is 6mm lower than the bed holder , making the belt have to ‘stretch’ further.
I don’t know how this affects prints but it isn’t right.
This bracket corrects the slope, now the bottom of the belt off the stepper driver is level with the bottom of the belt on the front idler.
Just to stress,
Earliest versions on the printer were metal and quite sturdy
Later versions seem to be some form of plastic, which is a little flexible
Summary - The D9 Y axis belt isn't level, the top belt is NOT parallel with the bottom. It's close to parallel with the bed at the front of the printer. it's quite angled at the back of the printer.
See pictures that I've added to make this clearer. as the bed is driven to the back, the tension on the belt pulls it down, stretches the belt and flexes the bracket.
as it moves to the front, the tension becomes less
box.co.uk PLA (not recommended but works for me)
V7 Fits superbly. No idea how to get those horizontal T nuts in mind :-), doesn't really need them though!
V6 - The long slot that sits in the 4040 prints 1/2mm too wide. Easily fixed by heating it up with a hairdryer and gently hammering it down....BUT, i'm re-designing with an 8mm wide slot which 'in theory' will give some play but in practice seems nice and tight in testing...
Very high infill suggested to ensure it's as robust as possible
First run print at 10% fits like a glove with no tweaks needed
V6 - Total re-design. removed rear 'lip' as it was nigh on impossible to align the T-Slot nuts to lock the bracket in plate.
Added a 3mm deep location strip that'll assist in fitting the bracket
V4 - (V4) fits perfectly, I've enlarged the holes for the M5 extrusion bolts to M5 (not M4 as previously in V3)
Also now tweaked the 4 x M3x15 bolt holes so that they sit 2mm 'proud' of the surface, just like the original.(V3 holes were a little bit too deep so the standard screw bottomed out)
This version can now use the M3x15 that came with the printer
The standard mounting bracket has an 8mm thickness 'plate' holding the stepper motor, I've beefed this up to be 10mm thick.