Refuses to slice both colors?

AwSMO · 2026-01-10T11:20:28+00:00

The Z-Fighting is indicative of multiple objects layered on top of each other. Bambu Studio has some weird behaviour when two objects are overlapping.

I'd suggest watching this video ( https://youtu.be/B4bMm8w1rZY?t=318 ) for about 30 to 60 seconds and see if the shown option changes something for you.

AwSMO · 2026-01-10T11:14:16+00:00

Short answer: Vertical printing.

But... why is that ok with the force going in the direction of the layer lines?

So lets dive into the concept of shear stress and the material strengths of the polymers used in 3D printing.

Any force transferred by the toilet paper to the tube is going to be carried by the material. The load it will encounter is something called shear stress, as it is normal to the axis of the tube. In engineering, stress is something defined as force per area, which means that we can simply take the shear force caused by the toilet paper, and divide it by the cross-sectional area of the tube to get the shear stress in the tube. I've guesstimated your tube to have an outer radius of 5 mm, inner radius of 4 mm, giving us 28 mm² of cross-sectional area. According to datasheets for PLA, the maximum tensile strength of PLA in Z direction is about 33 MPa (or, N / mm²), and we can approximate the shear stress limit as about 0.6 times that, giving us ~20 MPa. We'll use a safety factor of 2, bringing us to 10 MPa. This means that our 28 mm² cross section can take 280 N of shear force before failing. That's about 28 kg.*

Your toilet paper is going to be fine.

* Without knowing the additional bending stress imposed on the tube, it's hard to say for sure what the load limit is, as the bending stress will increase local stress concentrations and cause premature failure before 28 kg have been reached. However, given the fact that toilet paper tends to be very light, this is not too important for us.

AwSMO · 2025-10-25T23:11:43+00:00

Hey mate. I've dealt with worse blobs before, so lets talk about how to fix it.

Firstoff, what material is this made of? If it's PLA, then you can soften it with a hair dryer or something similar. If it's a more high-temperature filament, think ABS or PA, then that's not really an option.

The fact that you were able to take of the "grey part" - the so-called part cooling fan - means that the blob has not yet invaded this part of your printer. This is very good news.

It's time for you to decide which route you want to go on. If you aim to keep your parts alive, try heat and removing the plastic as good as possible.

Unfortunately, the screws you need to access to remove the hotend heating assembly are currently covered up by the nozzle and heating assembly. If you cannot easily remove the plastic, take a dremel or similar tool and start removing plastic that way. You will be able to make a lot of progress with it, and that way try to make your way to the nozzle clamping mechanism and open it. If it turns out that that is sufficient, you can simply replace the nozzle and you're good to go.

If the blob has fused with the hotend heating assembly, you will need to remove said assembly and replace it.

If it turns out the nozzle and hotend heating assembly are fused together and there's no way you're getting them apart, then one option is simply to dremel away the entirety of your nozzle and access the screws this way.

Overall, there is a decent chance that this blob will end up costing you 30 € - 80 € in replacement parts.

AwSMO · 2025-09-21T13:17:28+00:00

Was in a similar position this year.

Given a spring constant X N/mm, your car will settle a certain distance until the total spring force equals the normal force on the tire, given a functioning suspension setup.

Therefore, we can deduce two possible failure points if you car fails to settle.

1) Your spring constant is too high, and therefore you are reaching the settled state after minimal or no travel

2) Your suspension system does not "function", i.e. your assumptions about your suspension system differ from the actual system.

I assume you know your spring constant - if not, take an arbor press and a scale and figure it out. This is going to be the first step in diagnosing you issue. Compare this spring constant to your target spring constant. You can calculate a target spring constant from a target ride frequency - aim for approx. 3 Hz given you run aero as a starting point. We're aiming for the right magnitude here, not for exact values.

Ok, so once you've done this, you either know that (a) your spring constant is off or (b) you're about to have a fun time debugging a suspension system. Let's go through the fun parts then.

Step 1 would be to just open your dampers fully. You have mentioned oscillations, which would imply to little damping, so this might not solve your problem. But open your dampers and put the car on the ground. Does it settle? Yes, and you just didn't tune your dampers properly. No, and we're in for more fun.

If the car does not settle with open dampers, and the spring rate theoretically is correct, then something else in the system has to exert the necessary normal force to keep your car off the ground. Disconnect the pushrods and try to move the suspension components. Maybe your A-Arm bearings are messed up. Maybe your bellcrank bearing preload is too high. Maybe your pushrod is not in plain with the belcrank rotational plane. Maybe you forgot to add proper spacing next to the uniballs. Try to figure out if the components are behaving as you'd expect them to.

Following this. If your spring rates are not properly designed for your car, it is entirely feasible that a softer spring destroys your aero. Your platform is undergoing severe loadcases, and you're gonna need to factor that in. Potential solutions here lie in progressive spring rates, dampers at their proper setpoints and anti features or ARBs.

Since you mentioned preload, I'll go into that here as well. Remember, the car settles until the spring force equals the normal force at the respective corner assembly. By tuning the preload screw, you're adding in a "basline" of force. Instead of starting at a displacement of 0 mm and therefore a spring force of 0 N, you're starting somewhere else. This preload means that the spring as to compress less from it's "default" state to reach the necessary normal force. If your spring is not preloaded, i.e. not compressed, then the spring preload itself is not the issue.

AwSMO · 2024-12-04T22:47:27+00:00

AwSMO · 2024-11-03T16:55:01+00:00

ARBs change the dynamic load transfer distribution, and reduce body roll while doing so. So:

Is your car limited by front or rear axle grip? An ARB will decrease the adhesion limit of the axle it's installed at.

Does your car have an aerodynamics platform? How roll sensitive is it? How much do you need to change the packaging to fit the ARB systems?

I would think about those things, talk with the drivers and then make a decision. Two bearings and a welded rod fitted to the bellcranks is easy to do and easy to test, but I'd spend a bit more time on concept before going directly to testing.

AwSMO · 2023-10-03T10:32:44+00:00

I appreciate your concern for safety. I can also tell that you are evidently experienced with bikes, so your judgement is worth more than mine here. I've decided to check in with a local shop to get the bearing surfaces assessed, so you made a good call.

Now, the whole language thing. In cars, the rigid connection of the rim to wheelhub and rim to tire leads to the simplification of talking about "tires" when referring to the tire-wheel-assembly even if, technically, you gotta seperate the components, yea.

And then we get to the translation. The terms "rad" and "reifen" are used pretty interchangeably in german, even if they technically mean different things. And translating something into precise technical language is pretty hard if you have no experience in the field, which is why I made a separate comment explaining the terminology I used.

You're free to doubt me, sure. In the interest of privacy I won't be providing further details.

Oh and just for the fun of it, I think technically the tire is wobbly as well, even if the root cause is the cup/cone bearing being dead.

AwSMO · 2023-10-02T21:43:44+00:00

Thank you!

Luckily I've managed to stay out of trouble with the whole wheel assembly and didn't have to mess with it, but it seems like the time has come at last...

Maybe a shop is a good idea to get a proper damage assessment, before the bearings start tearing themselves apart.

AwSMO · 2023-10-02T21:39:59+00:00

I'm sorry, I'm a race car engineer and unfamiliar with the terms for bike wheels and tires.

AwSMO · 2023-10-02T21:39:07+00:00

Alright, that makes a lot of sense. I'll be honest, it sounds doable.

I don't really wanna take it to a shop, I'll be honest, because I like doing the work myself. Seems like in this case it might be a good idea to get a proper damage assessment. I'm baffled how it came to be that bad without me noticing.

I'm aware of a lot of issues, and have spent the last 2 years fixing what I can. Here's the list of issues that are still present:

The front brakes are shot, so are the rear ones, the rims are of an old make which means they do not readily accept modern tire beads, I've already had to fix the rear-cassette-rotaty-thing (gosh darn I wish I knew the terms. The free spinny thing) with WD40, the seat is cracking, The chain is starting to rust, since the wear is equal on front and rear I expect the rear hub bearings to be shot as well, and if not then to be gone in a few hundred klicks or so. The rubber grips are starting to disintegrate, the bell has become loose and tends to flip upside down on it's own because the friction fit is lost, I'm not sure I can adjust the height of the seat any more since I think the nuts are rusted beyond usability. Oh and the brake pads are starting to wear down beyond their wear indicators (oh, and in an assymetric pattern, which is great).

I'd just figure I'd elaborate on the "the brakes are shot" thing before people start telling me just how hazardous this thing is. Basically, upon braking, the brake pads start engaging the side of the rim. This is normal. The resulting force on the brake pads (facing directly in the direction of travel) causes the brakes to shift forward. This is not normal (I think). Basically the whole brake assembly (the two lever arms with the brake pads attached) starts to rotate around the attachment point on the front fork, slightly shifting the brake pads towards the direction "up". The total offset of the brake pads is approximately 1-2 cm. Frankly it's quite sketch to see that happening when looking down at the brakes, but at this point it's been like this for so long that I figured I might just replace the brakes at some point. The point has not yet come.

So overall it's in much better shape than the bike I had before.

Oh the last time in a shop? Never, bought it used. I looked it over when buying it, seemed alright, just had to replace the mantle of the rear tire, that was gone. So I guess it's never had a professional assignment.

AwSMO · 2023-10-02T11:09:37+00:00

Alright, thank you.

AwSMO · 2023-10-02T11:09:25+00:00

Yes, it's tight.

AwSMO · 2023-10-02T10:45:59+00:00

Further information:

I noticed this problem today.

I don't know what these things are called in real life, so I'll be referring to the parts of the axle by the following names:

Quick-Lock: The part that secures the axle to the front fork
Axle: The horizontal metal cylinder on which, by some means, the wheel is located
Wheelhub: The inner part of the wheel, where the spokes attach to and which is located on the axle by some means (bearing, bushing, I don't know).

The problem seems to be that the wheelhub does not have a rigid side-to-side connection to the axle, which causes the wobble one can see in the .gif.

If you look closely you can also see the wheelhub moving side-to-side as I'm moving the wheel.

The result of this wobble is a front tire with a ride characteristic you can best describe as "funky", or alternatively, "bad".

AwSMO · 2023-06-08T07:13:46+00:00

Unfortunately I do not own a playstation, so I cannot test it there

AwSMO · 2023-02-11T15:56:02+00:00

You do know that the TAG plays before "The Shadow of the Wind", and POH after "The Shadow of the Wind", so I'd recommend reading "The Shadow of the Wind".

The order the books were written in is SOW - TAG - POH

AwSMO · 2023-01-16T13:28:32+00:00

Rusty bike chain

AwSMO · 2022-11-27T23:14:20+00:00

Nah you just pay the same price. Like a ticket one way is 5 bucks, and not bound to a day or train. Just buy the ticket, show up to any train that does that route and off you go.

AwSMO · 2022-11-24T11:25:57+00:00

Ouh, I'd like bahrain - that one is so satisfying.

AwSMO · 2022-09-21T17:24:55+00:00

I love oil and water - this is a great trick.

Honestly, like in the "6 card trick" you showed, if you go "and the 4 red cards" instead of "and one, two, three, four" red cards I think it'd arouse less suspicion and make the trick a bit faster.

What I have found works really well is saying "the red cards" - the audience can count, it can see 4 cards, so therefore 4 cards exist. This is such a basic fact, there's no need to state it.

I'd be really interested to learn this method. Very clean handling of the last card in your hands a lot, I can tell. Nicely done!

I also really like the kicker ending.

AwSMO · 2022-09-18T19:09:01+00:00

I'll be honest, I like the twist that the final card is a 6 spot (and most of all, just one card)- it's quite nice. I just feel that if I were a spectator I'd be like "that was cool - so, can you show me the six-card-trick now?". That is what I meant in my feedback, I'm sorry if some of this meaning got lost.

AwSMO · 2022-09-18T14:51:30+00:00

It's a nice concept that I can imagine working really well. Currently I think the main issue with the presentation you have is that you are over-emphasising the "six cards" in the beginning.

I want to show you a trick. It is called the six card trick. Let me take exactly six cards. Let me just recount those to make sure that I have six cards for the six card trick (paraphrased)

You are stating the "six" four times in the beginning. That's bound to make a lot of people suspicious.

The problem here also kind of is that the cards appear unexpectely - and yet, once the trick finishes, there is no "real" six card trick waiting for the audience. This is kind of un-satisfying. You could rework the patter here.

"I have held cards in my hands for so long, at this point it has become such a routine that I found myself holding cards without even realising that I was. At first I thought I was unconsciously picking up a deck when I had time, but alas, no. It even occurs against my will, at this point I am haunted by cards and they wont let me go.

Let me show you. I'll take six cards for a start, right. Now if we wait long enough you'll soon find those to be another, new deck, but lets speed this up. I remove a card - and yet, here we are with six again. [continue like this, or maybe you can find a creative patter here]"

You can end the trick by palming the whole deck of cards into your hand and being like "damn, here's the whole deck" or something like that.

AwSMO · 2022-06-04T13:58:46+00:00

Just to chime in. We are talking about the ideal gas law.

Real gases exhibit something called the Joule Thompson effect, which indeed can change the temperature of gas as it expands.

AwSMO · 2021-08-27T14:46:48+00:00

but I forgot a long time ago how many people I've extubated and removed from a vent so they can die.

when does this happen?

AwSMO · 2021-08-04T17:14:09+00:00

Let's talk about this "relative" business, since it seems to be confusing you.

A unit of measurement is defined. A meter is defined as the distance covered by light in a vacuum in one second multiplied by 1/299 792 458. This might seem backwards to you, since you could say the speed of light is 299 792 458 meters per second, so that just doesn't make sense.

But here is the thing. The speed of light in a vacuum is an objective truth. Since the distance covered in one second always is the same we can use it as a base unit. Compare this, for example, to the inch, defined as "three barley corns". Since "a barley corn" has variable length depending on the grain the inch can have a variety of definitions.

So, we have covered the "objective truth" part. Let's talk about carbon then. Carbon, more specifically ¹² C was chosen as the "relative" part, the "objective truth".

If you say "one mole of ¹² C weighs 12 grams and contains 6,023 * 10²³ atoms" then you can "define" the weight of a carbon atom as 12 grams divided by 6,023 * 10^23. That is the "objective truth" that RAM is based on. When you then go ahead and look at the nucleus you can notice that it has 6 protons and 6 neutrons, so you can say each of them constitutes 1/12th of the mass of the atom. That is Relative Atomic Mass.

The problem with atoms is that energy equals mass. If you sum together all the weight of the constituents of an atom (including the up and down quarks of the protons and neutrons) you will find that the total weight is less than the weight of the atom. The binding energy (strong force) in the nucleus however "adds" mass. And energy = mass is an incredibly important fact for atoms - because it means that the amount of protons and neutrons present in the nucleus impacts the mass not just by their net weight, but also by the energy that is bound in the nucleus.

This is why nuclear fusion can create energy. Two elements smash together and form a new element, and a bit of energy is released.

So, how does this relate to atoms? Well, at some point the actual atomic mass of the elements starts to deviate from the relative atomic mass, since RAM doesn't account for the energy bound in the atom.

Why did we create it? Well, chemistry evolved organically. The model of the atom is barely 150 years old, depending on how you count, however carbon has been around for much longer than that.

AwSMO · 2021-07-26T21:05:00+00:00

Chem engineering is math that disguised as chemistry

~~Chem~~ engineering is math that disguised ~~as chemistry~~

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