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Gearbox

Important

Wires for the gearbox

During assembly of the gearbox there will be a point where you must be mindful about the endstop wires and gear motor wires. You want to make sure they are routed between the "Gear Box Front" and "Gear Box Back" parts when those parts are being mounted onto the 2020 extrusion. If you don't do this correctly you will likely find that you cannot install the bottom plate and will have to disaasemble and redo this area. I learned the hard way, hopefully you can avoid this.

I need to put some pictures up about this here!!! In the meantime you can refer to my gearbox assembly video at at time 22:50.

Extra heatset inserts

I made a mistake when I assembled my gearbox because I didn't install two additional heatset inserts. Those inserts retain two screws that act as pins for a "Latch" part. I describe this in more detail below.

Heatset Inserts

You should consult the original ERCF Build Manual. It helps you figure out where heatset inserts should be used. Even though we are using SturdyBunny the ERCF manual is still pretty close.

One big difference that I came across (or got bitten by) is that the gear box parts use inserts differently between SturdyBunny versus ERCF. With ERCF the "Gear Box Back" part uses 4 inserts. With SturdyBunny the "Gear Box Back" part requires 6, or so I now believe. I missed this because I reviewed the SturdyBunny CAD file to check for inserts and only counted 4, but after assembling the gearbox I believe it should be using two additional inserts to prevent the two screws that act as pins for a latch from backing out.

ERCF "Gear Box BacK" instructions that show heatset inserts

For ERCF the build manual (page 22) shows only four heatset inserts are used for the "Gear Box Back" part. image

SturdyBunny "Gear Box Back" CAD drawings that show heatset inserts

The Gear_Box_Back_v2 part viewed from the back. Notice you can see three inserts are needed from this view image

The Gear_Box_Back_v2 part viewed from the back and tilted back so you can see the bottom. Notice bottom has one insert. image

The Gear_Box_Back_v2 part viewed from the front. The insert at the top was already mentioned, but the two holes being called out do not have inserts....but I think they should. This would solve the issue of those screws backing out accidentally. image

IMPORTANT: When building the gearbox, please see if you can add those two additional inserts into the holes shown above

Another Video

I was able to make some time to cut the raw footage I took while assembling the gearbox and push out another video to YouTube Video

Note: The mistake I made with the two screws that act as pins for one of the latches is described at 14:09 in the video. I have not updated the video to describe where the missed heatset inserts should have been placed. Hopefully the notes and pictures I have placed in this guide will help explain what should have been done