Brig's 3DFused Hemera Mount by Brigandier

Last crawled date: 3 years, 3 months ago

UPDATE: 10/10/2020
I recently upgraded my Hemera to Volcano and decided to make the move to BLTouch. I've added a BLTouch volcano mount and updated the Fusion 360 source file. Enjoy.
What is this thing?
This is a (hopefully) well designed Hemera mount for 3Dfused kits or anyone else needing to mount a Hemera to an MGN12H block.
After having some issues printing PET (not PETG but real PET. It's awesome, check out https://fusionfilaments.com/collections/pet-standard-spools ) with my Microswiss all metal hotend, I decided to make the jump to Hemera. During my search for a mounting solution, I came to the following conclusion:
People suck at making things.
Why are the other solutions bad?
Here's a short list on what I didn't like about the existing options:
They quite frequently leave the 3Dfused X carriage plate on. Why? It's just extra weight. Are you scared of that homing switch destroying plastic?
With or without the carriage plate, they frequently mount the heaviest Hemera component (the stepper) far away from the screws that attach the flexy plastic mounting plate to the printer. This creates a condition where the plate may flex under fast movement, affecting hotend position.
They all look cheesy.
Okay, how is yours different?
Here's how mine differs from the above:
It's tiny, the whole thing is nearly hidden behind the Hemera's stepper,
It very rigidly mounts into the MGN12H block directly, which then mounts very rigidly (and centered) in relation to the Hemera stepper. No flexing or bouncing here, if you print the plate strong enough. Take the old aluminum carriage plate and use it as a coaster,
It supports both EZABL and BLTouch or any other type of bed leveling sensor you may want to use,
It has minimalistic cable management that still rigidly holds your cables stiff so no movement is happening at the hotend/bed sensor,
It's designed in such a way that you home further left, MUCH further left. Your hotend will have to travel 54mm before hitting the X "0" point. Why do this? Because it allows your bed leveling sensor to level your bed edge to edge,
It comes with an upgraded combo rail endcap / X limit switch for those of you not yet using sensorless homing.
How should I print this?
I would recommend printing this in Fusion Filaments PET: https://fusionfilaments.com/collections/pet-standard-spools - This is not PETG, you'll need a printer capable of doing around 270C to print it. If you can't do PET, I would recommend Fusion Filaments 3d870 (HTPLA+): https://fusionfilaments.com/pages/high-performance-pla to get this off the ground and reprint it in PET once you have Hemera working. PET has much higher heat deflection temp and better suited for a part hear the hotend, but HTPLA+ or PETG may work okay as well.
I have designed the mount plate holes with built in bridges. No need for supports. I would print the plate at 5 walls with 100% infill (if you can't do this without a mess, you're over extruding). This part needs to be very rigid. 0.2mm layer height is fine.
The X endstop piece and sensor mounts can be printed at more sane values to save weight, use your discretion.
Some Assembly Required
Here's how I went about installing this (all screws should use Loctite Blue!):
Print an MGN12H insert (I used https://www.thingiverse.com/thing:1972859 ),
Take the right hand X rail endcap off and thread the MGN12H block carefully onto the insert. Be careful, doing this wrong will cause the bearings to drop out of the block and you may lose them. Set the block aside,
Attach the bed leveling sensor of your choice to the mounting plate using two M3 screws. They will thread directly into the printed sensor mount, don't strip them out. This needs to be done before putting on the block, as the block covers a screw hole slightly,
Being careful that the keeper doesn't fall out, attach the MGN12H block to the mounting plate using 4 appropriately sized M3 socket head screws. Don't forget the Loctite!
On the Hemera, slide in two more flat nuts into the back end. By default it already has two captive towards the center of the unit, this will be the ones on the end. This needs to be done now, as the filament sensor will cover one of them,
Attach the plate to the Hemera using M3 socket head screws. Make sure these are short enough to not bottom out into the Hemera and cause damage. Also, don't forget the Loctite!
Very carefully align the assembly to the rail, and slide it off the keeper,
Replace the right hand X rail endcap,
Remove the crummy left hand X rail endcap, mail this back to 3Dfused and tell them to quit printing such horrible parts,
Replace the left hand X rail endcap with the new one, only putting in one screw (the one that is deeply inset),
Attach your limit switch using a long M3 screw in the top left that will thread all the way through to the 3dFused backing plate (don't overtighten, snug is fine). Use a smaller M3 in the bottom left, don't strip the plastic,
Attach limit switch cable, ensure that the hotend assembly clears the switch and that the switch isn't buckled out. These things are cheaply made and may vary, so be careful there,
Thread one end of your X belt through the attach point on the back, the teeth should be pointing up as you thread this through,
After threading through, fold over the end of the belt onto itself so that the teeth mesh together. The folded over section needs to be approximately 1/2 to 5/8 long,
Push the folded over section back into the hole it came out of, being careful to keep it pinched together hard. As you keep it pinched and apply downward pressure, begin to pull on the belt using your other hand. The hole the belt is going into is tapered so that the further in it goes the tighter it squeezes, and it works great once you get it to "bite" hard enough,
Repeat this for the other end of the belt,
Tension the X belt.
Part Cooling
Due to my design's full frontal Hemera exposure, I leave cooling completely up to you. There's many Hemera cooling designs, choose the one you like best.
Design Notes
I'm by far not a professional CAD designer, I do this as a hobby. This was designed in Fusion 360 with a lot of trial, error, and test parts. Expect some dirty work in the attached Fusion 360 file; but hey, I included the real source file and not some crummy STL or step!