Watercooling a CoreXY with a 120°C Heated Chamber

Frederik

@DaBit I ordered only one Ballscrew to check for bending, quality, and machining.
I was really surprised by how good they looked and even feel. I would have bought immediately 3 Pieces with 550mm in length, but on every shop, the sizes between 450 - 600 are sold out and will be restocked perhaps in 2 - 3 Months. But when I look at the price difference, I think I will wait for the next 2 months.
On eBay, 3x SFU 1204 500mm would cost me including the Nuts ~115 Euro.

Frederik

@DaBit Did you test the daughterboards ? is there a big difference from the measured temperatures?

At the moment I use also only Thermistors

2x E3d Standart Thermistor for my Buildchamber (Top and Bottom)
1x Slice High Temp in the Hotend

1x NTC 100k for the Heated Bed. I'm quite happy at the moment, but I don't have an infrared or other Tool to check if my Values in the DWC are correct

DaBit

I am running a Duet 2, so no daughterboards. For my upcoming printer I am not sure which Duet to get; I would need at least 7 stepper channels and the Duet3+expansion seems to add a lot of cost for little benefit.

However, regarding thermistor temperature sensores; I do not expect a significant difference in accuracy between Duet3 mainboard and daughterboard.

Regarding the ballscrew: I learned the hard way that 'look and feel' does not tell much. A dial indicator does. But as said before: for a 3D printer it is not a big deal. No micron-level accuracies needed, practically zero load on them.

Frederik

@DaBit What would you suggest how i should mount the SFU1204?
With Bearing blocks on top and bottom, or would it be better to only use an Block on the motor side, so the imperfections don't get transferred to the build plate.

I already have 2x Mgn15 Linear Rails on both sides to get a smooth Z movement with the spindles only attached via the motor couplings and the Anti Backlash Block on Top.

DaBit

Normally a fixed bearing block (e.g. FK8) is used on one side of the ballscrew, and an end support bearing block that allows axial movement (e.g. FF8) on the other side. Don't use two fixed blocks unless you know what you are doing and why that would be beneficial.

However, you must be able to align those bearing blocks and ballnut so they are accurately inline. I think you lack the tools for that, in which case I would leave one end of the ballscrew floating. That limits your ultimate speed (at a certain speed the screw starts to whip around when one end is unsupported), but that happens above sane Z-axis speeds for a 3D printer anyway.

Frederik

@DaBit Thanks for your tips, What difference does a faster Z-Axis speed would give me? For example:

Z Speed A: 50mm/s
Z Speed B: 250mm/s

Z-hop activated in slicer with a 1mm hop

do you think it makes a difference in overall Print Time?

Are there any other benefits other than the homing and mesh probing will be a lot faster

M566 X6000.00 Y6000.00 Z3000.00 E5400.00                 ; set maximum instantaneous speed changes (mm/min)
M203 X12000.00 Y12000.00 Z6000.00 E5400.00               ; set maximum speeds (mm/min)
M201 X500.00 Y500.00 Z100.00 E250.00                     ; set accelerations (mm/s^2)

These are my actual movement parameters

Later I have to retune it anyway because I finished yesterday a new Toolhead with a Mosquito Magnum as Bowden Version and now I´m really curious how much I can now increase the speed without ringing and other artifacts :)d

Weight Difference between the Heads:

DMG + LDO 0.9° Pancake Motor ~ 280g measured with an ~30-Year-old kitchen scale

Tew Head Design is printed out of Extrudr Durapro ASA - Neon Green

finally...while I´m writing this here, the Postman brought me the Material for the Enclosure.

Because of Corona and the high demand for transparent plates, I had to wait over 3 Weeks for this 4mm Polycarbonate Plates Order to arrive...

Now I can start building

Photos of my new PrintHead and the progress will come later this evening

DaBit

@Frederik: I don't think it makes much of a difference whether your Z-axis runs at 20mm/s, 200mm/s of 2000mm/s. It's not doing much, unless you have to compensate for a far-from-flat bed. And especially not with very slow accelerations.

Frederik

@DaBit I am more interested in precision than in maximum speed.

but back to the spindles:

my initial thoughts about z speed and design were similar but I had no experience.

after another long Thingiverse Evening and looking at different concepts, but couldn't find a better design in terms of size, used components add construction... but I'm open to other ideas

Here is the fusion model from MirageC and the new V2 triple Z id!)ea:

HevORT Triple Z V2 - MGN12 + SFU 1204

the integrated mounts for the 1204 Spindles are nice, so I don't need to buy additional bearing blocks (...is that a good idea?!?)
...instead can print them.

the only modification I would need is changing the design from mgn12 to mgn15 linear rails. would that be a lot of Work ?

i have no idea how to do that

A Former User

@Frederik said in Watercooling a CoreXY with a 120°C Heated Chamber:

I am more interested in precision than in maximum speed.

the only modification I would need is changing the design from mgn12 to mgn15 linear rails. would that be a lot of Work ?

What empirical and verifiable research data are you following that can show that for FDM ballscrews provide a higher level of precision over quality lead-screws, can you provide links ?
And what is the reasoning behind the desire to switch to 15mm linear rails ? again is there verifiable empirical research data to support the need to go up from 12mm rails ?

DaBit

the integrated mounts for the 1204 Spindles are nice, so I don't need to buy additional bearing blocks (...is that a good idea?!?)
...instead can print them.

My printer uses 608 bearings to support the TR12x3 Z-axis spindles. Sufficient for the couple of Newtons axial load; that was just above what the motor itself could handle.

the only modification I would need is changing the design from mgn12 to mgn15 linear rails. would that be a lot of Work ?

Why? What benefits would that provide? Did you ever check the load ratings on MGN12 rails? Those will surprise you; you can put a car on a single bearing block and then you are still far from the maximum allowed dynamic load rating.

My CNC mill uses (Rexroth) 15mm rail, that machine is rocking an 130kg gantry back and forth and putting up to 6kW of power into an endmill. And those rails are still only lightly loaded.

I think you need to adapt a slightly more scientific approach to all this. You need to obtain a feeling for the forces involved and the forces that can be handled by the components so you know when and why you need component X and not Y.

Printing all those mechanical brackets is fine, but probably not if you still insist on 120C chamber temperature. Maybe set the goal to 60-80C or so; far, far easier.