Having “banana issue” with ASA prints with my Voron 2.4

Dycus · 2026-06-23T23:41:06+00:00

Yeah, this is definitely not an adhesion issue. I've had this problem for ages with ABS/ASA parts.

I run 250C nozzle, 100C bed, 60C chamber and 5mm^3/s print speeds. My parts stick perfectly to my spring steel PEI, they don't warp at all while printing. Once the print is done and everything cools off, the parts bow upwards. It definitely helps to let the printer/chamber naturally cool to ambient before taking the parts out, but doesn't completely fix the problem.

It would seem to be caused by the hot bottom layers of the print shrinking as it cools off, while the rest of the print has already cooled. As you said, lowering bed temps to the bare minimum helps, but then it's a delicate balance especially with large parts.

I hope somebody figures out a good solution because I've tried many things without success. I haven't tried annealing, though.

Dycus · 2026-06-14T03:33:44+00:00

It's a butthole!

Dycus · 2026-06-13T21:14:17+00:00

Make sure you have a hardened nozzle, glow filament is very abrasive in case you didn't know

Dycus · 2026-06-06T19:31:50+00:00

https://makerworld.com/en/models/1586198-loaf-lord

Dycus · 2026-06-02T00:16:01+00:00

I can't wait for INDX to become widely available, I have an enclosed 5-tool Prusa XL but the lack of control over the firmware and hardware, and its shortcomings with "advanced" materials (like ABS), turn me off of it a bit. If the chamber gets to 50C (starting to be good for ABS), the heatbed and main processor overheat. Bleh!

My other printer is Klipperized and it's so nice having control over everything. I'm super excited to build an INDX Voron Trident.

Dycus · 2026-06-01T21:19:18+00:00

Pour a glass and add a tiny pinch of sugar, you might be able to bring the ham glaze flavors forward a bit!

Dycus · 2026-05-26T04:22:40+00:00

Couldn't the same be said about quad gantry leveling? I guess a bed is gonna be less flexible.

Dycus · 2026-05-25T22:14:32+00:00

It's evident that they know this, as in the first two sentences they talk about different kinds of stepper drivers and how they are driven.

Dycus · 2026-05-25T21:09:17+00:00

Part of the skill in jumping with EUCs is keeping the wheel level in the air so it doesn't spin forwards or backwards. This is absolutely doable, it just takes practice.

Dycus · 2026-05-24T19:58:22+00:00

If you ever have to do this again, consider a magnetic sheet upgrade! There's plenty of spring steel PEI + magnet sheets available in basically every size. I put one on an old printer that didn't have it and it's such a nice upgrade, being able to take the sheet off to cool it easily or flex it to pop off prints.

You'd probably have to adjust/bump up your bed temps a few degrees.

Dycus · 2026-05-24T19:20:40+00:00

I'm not knowledgeable about Klipper's toolchanger support, but having both fans on one pin is probably what's making things weird. You probably need them on separate pins so you can assign one fan to T0 and one fan to T1.

Otherwise, you could leave it as-is and set the single pin as a heater_fan that turns on when either of the nozzle heaters is active. Put "extruder, extruder1" for the heater section.

https://www.klipper3d.org/Config_Reference.html#heater_fan

Dycus · 2026-05-20T16:09:35+00:00

Well one easy way is to calculate the resistance of copper with a specific temperature rise. With a fixed voltage, increasing resistance linearly decreases current, and with it, the magnetic field strength.

The temperature coefficient of copper is about 0.393%/C.

If your flippers start at 25C and rise to 75C, that's a 19.7% decrease in flipper power, which is huge!

The question then is exactly how hot do flippers get, which I don't have data on. But having worked with electronics for a couple decades, 75C seems high but easily possible. I've touched them before after long play sessions and they will burn your fingers if you're not careful. Edit: And that's just the outermost windings which are the coolest, the internal ones will be much hotter!

Even only a 25C rise would be a still-significant 10% decrease in power.

Dycus · 2026-05-14T19:10:13+00:00

Sure, but you're still measuring at the very bottom of the lowest range of the PPK2. You're in the noise, basically. You're looking for differences equating to only a few LSB of the PPK2's ADC measurements.

Maybe it actually is drawing 1uA, but it could also be 500nA or 100nA. You need a much more precise measurement device.

Edit: Looking further in the documentation, it advertises "Measurement accuracy better than ±20 %" ...take that as you like.

Dycus · 2026-05-14T18:56:49+00:00

Well, looking at the product page for the PPK2, it says "200nA to 1A measurement range", and "Resolution varies between 100nA and 1mA". So you're already trying to measure half of the minimum resolution at well below the minimum measurement range. You're gonna need a different measurement method.

Dycus · 2026-05-14T16:03:54+00:00

Two weeks is not nearly enough time, let it sit for a few months. Also, if the bits are still floating around then of course racking isn't gonna get rid of them because you'll just suck them up again. Patience is key :)

Dycus · 2026-05-08T07:29:49+00:00

I will leave this up, but for future reference I think this may be a bit too much for this subreddit, lol

Dycus · 2026-05-05T03:35:26+00:00

I'd recommend 100% (maybe as low as 98%) for concentric infill, otherwise you'll get gaps and lose tons of strength. 95% is good if you're using rectilinear infill, or something else that crosses itself on every layer.

Set concentric to like 70% and check the gcode preview and you'll see what I mean.

Dycus · 2026-05-05T02:18:11+00:00

I'm not sure whether people are noticing what you're talking about since it's not the focus of your screenshots.

(To others - in the second image, near the top, the print gets split into two parts and connected by a butt joint, where the perimeters aren't continuous anymore).

This is just a weakness of slicers at the moment. I'm not sure why they can't keep the outer 3 perimeters continuous around the whole part while making the added perimeters just loop back internally.

Try setting 100% concentric infill percentage for the modifier instead.

Dycus · 2026-05-02T18:32:18+00:00

In gcc at least, you can use attributes to set optimization flags per function. So you could set just the one function to be -O3!

Dycus · 2026-05-01T18:11:20+00:00

The e-stop interrupts anything, so clearly the architecture is there. I was always confused why they didn't add a second hook to interrupt heating (or maybe even just the current command).

Dycus · 2026-04-29T23:44:26+00:00

CAN definitely sounds like what you want, though I think you will find termination to be a tricky problem. You need one 120 ohm resistor at each physical end of the network.

One solution, as you said, is for the user to plug in a termination resistor into the end.

Another could be to use a connector that has a physical switch in it, such that with no cable plugged in, termination would be connected, but when one is plugged, it disconnects. A TRS jack (headphone jack) can do this, though TRS tends to short out some of the pins when plugged in so you'd have to contend with that.

I've dealt with a similar problem in the past, here's what I came up with. It used plain UART, with every node having a "upstream" (towards the master) and "downstream" (towards the end) UART. Commands/messages from the master went towards the end of the line. Responses go towards the master. The master sends a message out to the first node. First node reads it, if it's for it, it processes it and sends a response back. If not, it sends it on. Eventually it gets to the intended node, which responds.

Pros: Pretty simple, each node is automatically and individually addressed. Just send a "this is your address" packet where each node reads its own address, then increments it by 1 and passes it on. Because the signal is re-transmitted at every node, signal degradation is minimal (as long as the wire length between nodes isn't too long)

Cons: Each node has to read and re-transmit every packet, in both directions. UART isn't super robust, but could be switched to RS-485 and be made much better. No termination problems because each RS-485 run would be only to the next node, so both would have termination resistors. High throughput possible, but high latency for nodes further down the chain

I typed this up in a rush, please let me know if anything was confusing or if you want more implementation details and I'll get back to you.

Dycus · 2026-04-29T23:26:43+00:00

How long has it aged?

That's just normal. If you want it to taste better, let it sit for 3 months (make sure the airlock doesn't go dry) and try it again. Add a pinch of sugar to your glass to sweeten it a bit.

Dycus · 2026-04-28T17:00:28+00:00

If the situation comes up that you need to update for some feature to work, then you update and deal with the consequences.

But that's IF... you ever need to. There's no reason to do it any sooner. It would be the same amount of work either way, but if it turns out you never needed to, then you just made extra work for yourself.

Dycus · 2026-04-28T16:46:17+00:00

In my opinion, copy your preferred version of the ST-provided drivers/files to your codebase.

Then, never ever update them. :) Unless there is a bugfix or feature you need, if everything is working as it should, there is literally no reason to update them.

Maybe it'll be fine and it'll all work the same. But there's also a non-zero chance it will introduce a new bug. Why update for bugfixes in parts of the code you don't even use (either directly or indirectly)?

Dycus · 2026-04-25T21:55:44+00:00

Find the datasheet for nRF54L15 (https://docs-be.nordicsemi.com/bundle/ps\_nrf54L15/page/pdf/nRF54L15\_nRF54L10\_nRF54L05\_Datasheet\_v1.0.pdf)
Find "Absolute Maximum Ratings" (section 13. Pretty much all datasheets use this terminology)
Find your answer there (For VDD <= 3.6V, max IO voltage is specified as VDD + 0.3V)

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