Watercooling a CoreXY with a 120°C Heated Chamber

Frederik

@CaLviNx are the Nema17 or 23 available with longer motorshafts? Like the one with integrated spindles?

I dont have access to a cnc or even a drillpress. All I have are hand tools, 1 electric cordless drill and a small grinder.

My possibilities are very limited when it comes to fabricating metal.

The next thing I have to learn is how to use a CAD Programm like fusion 360, So that I can modify stl. or step files and design my own parts from ground up... But that's a complete other story

Frederik

@DaBit thanks for the tip. 5 weeks ago I didn't even know what ballscrews or linear rails are..

What would you choose for the Z Axis?
SFU1204 or 1605

I'm assuming the first two numbers are the diameter and the other? Is it the pitch?

How can I find the right spindle for my application?

Like max. load, repeatability, backlash and so on....

What differences can I expect between cheap and medium priced ones?

And where can ifind better spindles and nuts?

I got 3 complete sets from ebay including the nuts for 30 Euro each with nut!!!

DaBit

Ballscrews from a higher segment means possibly longer lasting, usually better accuracy, stiffer nuts, screws straight instead of bent from internal stresses and shipping from China.
Except maybe for the 'longer lasting' part (on which you can improve a lot by doing your homework) it is quite insignificant for a 3D printer.

1204: 12mm diameter, 4mm pitch. For a 3D printer that is already overkill unless you use a very long screw.

You already have them, why not use them? Replace when measurements provide proof that you need better ones.
If you are set on quality screws you might want to check out the dy-global store on Ebay. They sell pre-owned quality parts for reasonable prices.

Maybe get your printer up and running first and gain some experience with it, then decide to do the 120C build chamber.

A Former User

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

@CaLviNx are the Nema17 or 23 available with longer motorshafts? Like the one with integrated spindles?

I think if you actually talk to the motor manufacturers they will fit a custom length shaft.

I use Stepper online and LDO

Any shaft extensions I have required, I did it myself, the LDO motors I installed longer shafts on were quite easy to change, the original shafts were centre punched around one end and epoxied to the stator.

so I just pressed the original shafts out and used ground shaft of the same diameter cut to the new length I wanted then replicated the centre punch points and pressed them in with new epoxy.

They are running fine on a core-xy.

Frederik

@DaBit The Printer is running at the moment with the mosquito as Bowden Setup. The only thing at the moment that isn´t working as supposed is my Toolboard. everything else works fine in the meanwhile.

When the Polycarbonate Plates arrive this week, I will build the enclosure first.

Then I will print a few test parts with ASA and without an additional Chamber Heater... Only the Bedheater fat 110C. Then I will see how high the temps in the chamber will be.... and if everything is working, I will add the PTC chamber heaters and start slowly increasing the temperature.

I installed 2 additional Thermistors on 2 m cables so I can place them quickly where I want to check the temps.

What Sensor is the most accurate for this type of measurement?

PT100, PT1000 K-Type, Thermistors without the enclosure?

DaBit

Pt100 with the Duet add-on board would be the most accurate I think.
I use a regular thermistor; the Pt100's are more useful in the hotends. Not too interested in the last 0,5 degree C accuracy anyway

ASA with enclosed but otherwise not heated chamber works fine until the parts grow bigger. I tried whatever I could to print a ~350 gram model taking up most of the build volume (~220mm cubed in my printer). Rafts, draft shields, giving the printer plenty of time to get to temperature, etcetera. No luck; kept suffering from layer splitting. Had to switch to PETG for that one and subsequent prints of similar volume.

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.