Toolhead change R-3

I decided to make a change to the toolhead for a number of reasons. Maintenance was tough with the extruder and hotend mounted to one plate, the toolhead was inducing some hotend movement as it was connected to the extruder. This design mitigates those issues and the hotend is moved lower to move the center of gravity lower. I saved about 2 grams weight with this(LOL) at 289G without the carriages.
I have printed, so far, 3 rear upper ducts and 1-11 minute annex cube. Results seem to be the same so far so I will need to print a 4 minute benchy to see if it can take the pain!
The original Goliath heat synk was not used! I had some left over E3DV6 smooth bore heat synks and cut one down for this build. This is truly a Frankenstein build!
VZHextrudort, Goliath hotend, .4CHT nozzle, 2504AH LDO gantry motors, 5160 drivers @ 48V running Octopus Pro V 1.1 MCU @ 550MHZ.

[@nirodper]

Loved the explanations, I see how the belt stretch contributes more to deflections than any flexibility the 12mm rails have in the xy plane, hence the no need for beams

[@MrRocksalt]

I am not saying you don't need backers. Tests/engineering FEA show you do need them. But... what level are you trying to achieve? I like to get some experience on a platform and then change to see if there is visible outcome. This new toolhead can take backers with a slight change, so maybe I will try them later to see the effect.

[@Apophis-en9pi]

I love your project man. Best parts of the Annex, Voron, VZbot, and Hevort projects. Well done and keep going!!

[@46449771]

Awesome machine, thanks for sharing your progress.

[@dansxmods]

Looking sweet

[@RebelPhoton]

I had issues aligning the two 150mm z rails on a V0 😂. I shudder to think what this takes. I'd pay money to know more about how to go about tramming those rails.

[@hd-be7di]

I'm curious to know why one of the rails gets significantly more acceleration / less resonance and vice versa... the off-center mass of the toolhead maybe ?

[@MrRocksalt]

mine are almost exactly the same

[@MrRocksalt]

What is probably happening, in your case, is there is some mechanical error in the mounting of the Y cross to the outer carriages.

[@cdl1701]

I see you are using a triple Z belt drive system, how is it working out? Do you get any drop when the motors are unpowered? What is the weight of your bed? I have been thinking of doing this belted Z on mine but afraid of the bed dropping when power to the motors is removed.

[@MrRocksalt]

Check out one of my other videos for the new Z system. The rear is counter-weighted with constant rate spring and all belt drives are 4:1 gear reduction. Zero bed drop at 'motors off'. The bed plate is MIC-6 cast aluminum, 9.5mm thick + magnet + PEI spring steel.

[@Leviathan3DPrinting]

Do you even need the heatsink with that massive aluminium plate? I'm sure it helps but given what I've seen from slice removing the heatsink entirely on their new hotends I think you could get away with it.

[@MrRocksalt]

This has to be mounted with some care. The heat break has a ceramic, or some sort, heat break area. Any lateral force on the top section will cause it to break. I have some clearance, from the O.D. of the heat break, to the plate and use paste to conduct to the plate and to the heat synk. Also, heat synks are designed to have a lot of surface area to wick off heat. Without it, I think, it would overheat the filament. It's 8 grams for the heat synk, so no big deal.

[@Leviathan3DPrinting]

@@MrRocksalt Vez3D also has a mount that uses water to cool the motor and heartbreak together. (But I think a large enough piece of aluminium would work just fine) you're using a bird air which I like significantly better because it can't leak lol. I believe it's zirconium which is technically a metal I think(acts like a ceramic). Trust me though I completely understand the fragility of ceramics. I was originally using custom made YTZ(yttria-stabalized zirconia) for my heated bed spacers. 6mm OD 10mm length and M4 threaded. Backing out some cheap fasteners one day I cracked one of the spacers. All in all it's a $250 fuck up because I can't use 3 spacers. They're titanium now but yeah ceramic = very fragile. Originally I intend to go with ZTA (zirconia toughened alumina) but due to the low quality and made to order ceramic it was a no go on cost. I don't know Vez3D uses black zirconium(he wouldn't tell me or "he'd have to kill me " 😂) but only so many types of ceramic are black and readily available. I didn't realize it was only 8grams though. At some point you'd be chasing milliseconds of time saved so I don't blame you for keeping it. As some might say cheap insurance. Keep up the good work! I love the attitude of seeing how far one can go with what they have on hand!

[@Leviathan3DPrinting]

@@MrRocksalt one last question just so I'm understanding the mount. You have the heater bolted directly to the carriage plate and the heatsink sits on top sandwiched between the upper and lower plates?

[@MrRocksalt]

@@Leviathan3DPrinting yes, if you click on the video, without watching, you can see a pic of the bottom. The 3-2mm standoffs are bolted directly to the bottom of the bottom plate. The heat break protrudes 7.35mm above the bottom plate. It's running 40-50C on the heat break fins as it prints at 275C. I want to install a thermistor on that heat synk so I can see how much air it needs from the berd. Currently using 70% output for Berd. Maybe can lower to 20-30%, but I need to see what it is before I start playing with it.

[@Leviathan3DPrinting]

@@MrRocksalt sounds like a plan. It's a very clever way to cool the hotend for sure.