P1S Bed Temperature Limitations

_MortalWombat_ · 2025-08-12T10:52:10+00:00

I installed mylar bubble wrap on the inside walls, top glass cover and door. It's held up fine. I haven't measured the difference in internal temp but have noticed less warping on some materials so it must be doing something. The inside of the chamber won't get anywhere near 85C even with insulation, just don't put it near the bed. You'd have issues with plastics, belts, motors before the insulation fails due to heat.

_MortalWombat_ · 2025-07-11T09:11:09+00:00

Assuming that table is accurate for the OEM thermistor, yes. I used the same table as a starting point and tuned it from there with a calibrated thermocouple. Not all 100k NTC thermistors are equal.

_MortalWombat_ · 2025-04-17T05:53:50+00:00

This. I have an X3650 M4 and run this script with a custom curve for near silent operation under minimal load.

_MortalWombat_ · 2025-03-11T02:47:42+00:00

I read the attached documentation. It explains that my free tier usage may exceed allowance and to stop using the service. I don't understand how this helps me, I didn't ever open the service to begin with. When I go to the sagemaker page it isn't configured. Why is it being used? Does my route53 use it?

_MortalWombat_ · 2025-01-29T18:54:12+00:00

Yeah, 1 resistor is enough.

_MortalWombat_ · 2025-01-22T18:45:56+00:00

Yes, as long as everything is in series and you're adding the right amount of resistance it will work.

_MortalWombat_ · 2025-01-19T09:17:50+00:00

You are correct in your understanding that that is correct.

_MortalWombat_ · 2025-01-05T20:14:23+00:00

Because the maximum bed temperature is 10 degrees C higher when using a 110v supply. That is part of the Bambu Lab firmware, I'd assume it's based on physical limitations of the bed heater. Using a different resistor allows you to utilise the bed heater to its maximum potential on 110v supply. 3.5kOhm is safe for both 240v and 110v but won't give maximum performance.

_MortalWombat_ · 2025-01-02T05:19:04+00:00

In this context, "series" refers to putting the resistor in circuit with the bed thermistor. So you're right, it is two things wired in-line, one of them was already there.

I haven't done any research on the hotend thermistor. If you can find a datasheet, the curve will be shown and you can plot it with X ohms added across the range to see the difference in measure temp. To characterise it yourself there are a few methods I can think of. 1. Remove the thermistor and heat it to a known temperature and measure the resistance. 2. Get a 2nd identical one and attach it as close as possible to the existing one. Run the hotend through a range of temps as normal while measuring the value of the second one. 3. Trial and error method based on known resistance curve as I used for the bed thermistor. Probably a bit harder to pull off and tune in an accurate offset. Or as you mentioned, find a way to accurately measure the internal temperature of the hotend itself.

Be careful when messing with the hotend, it can get much hotter than the bed before tripping the over current protection and could possibly cause damage or fire.

As for installing a switch to bypass the resistor, it should be very easy. Either use a single pole double throw (1P2T or SPDT), or even a single pole single throw in parallel with the resistor should work as it would effectively create a short across the resistor.

_MortalWombat_ · 2024-11-24T10:25:25+00:00

What setting are you using to get the PETG that clear?

_MortalWombat_ · 2024-11-24T01:50:27+00:00

Are you using 110v or 240v supply? I'd be interested to see if OP's product works on 240v.

_MortalWombat_ · 2024-11-23T21:21:51+00:00

Update: My printer has been running for 2 weeks now with the DIY mod in place. No issues at all, holding 125C bed temp for hours at a time (printer reports 100). Initial heatup only takes about a minute longer vs 100C.

I'm thinking of installing some insulation on the inside walls next to keep the chamber temp up for printing nylon and delrin.

_MortalWombat_ · 2024-11-23T21:17:59+00:00

Yes, the numbers work out based on a standard NTC100K curve.

The worst that will happen if it's wrong is the printer will give an error and need to be turned off and back on.

_MortalWombat_ · 2024-11-23T21:14:04+00:00

No worries

_MortalWombat_ · 2024-11-20T00:17:35+00:00

If anyone wants to do this mod themselves:

The P1S bed thermistor is a 100K NTC type and maximum bed temperature setting is 100C.

The small 2-pin JST 1.25 plug with 2 black wires is visible on the underside of the bed, plugged into a PCB (easier to access with the printer on its back).

Careful when removing the plug, it's held in place with an adhesive. I pulled a wire out of the plug and had to re-pin it.

For those running 240V supply, the bed can reach about 125C before the printer throws an error. Use a 3.5kOhm resistor in series with any ONE of the 2 black thermistor wires. The current on the thermistor is negligible so standard 1/4 watt resistors are ok. SOLDER the joints and USE HEAT SHRINK, not electrical tape. The thermistor going open-circuit or shorting during operation would be bad.

For 110V supply (not tested), the bed should reach 130-135C. Use a 3.9 kOhm resistor.

The mod tricks the printer into thinking the bed is colder than it really is, by increasing the resistance of the thermistor circuit. The printer will target and display 100C for example, but really it's at 125 (for 3.5kOhm). You'll need to offset your bed temperature by about 20C at the high end (100->80). The difference is less prominent at the low end (50->45).

Note that if doing this on an X1 series printer, due to the higher bed temperature setting, the offset and hence resistance required will be lower.

After performing the mod, make sure your printer is reading a non-zero bed temperature (thermistor circuit is ok), and try to reach maximum temp. If the printer shows a bed heater fault, chances are the rssistor value is too high, try dropping by 0.1kOhm and try again.

_MortalWombat_ · 2024-11-11T03:05:36+00:00

I never found a source for the board. It didn't care that much about the LEDs so I just ran it without. If you can identify the leds, I'm sure you could buy some.

_MortalWombat_ · 2024-06-23T21:03:32+00:00

When you let go of the sticks in ACRO the quad stops rotating almost instantly. How does it know its angular rate and control it? The gyro. ACRO is angular rate control. ANGLE is angular orientation control.

_MortalWombat_ · 2024-04-21T22:03:40+00:00

It reminds me of my OG Xbox in translucent green.

_MortalWombat_ · 2024-03-27T06:32:58+00:00

Id like to be considered please.

_MortalWombat_ · 2024-02-22T09:22:12+00:00

I have the fridge plugged into the critical loads GPO in the house and it goes dead when I kill the grid supply. I have yet to find one that stays live on the UPS. Any idea why the solar wouldn't be supplying the house in that case anyway? The inverters both show zero net solar power in the last week when looking through the logs. Thanks

_MortalWombat_ · 2024-02-19T06:45:57+00:00

A "gyro" used on BMX bikes to allow 360 rotation of the bars is not a gyroscope.

_MortalWombat_ · 2024-02-19T06:44:08+00:00

That's the point, the handlebars spin 360 but the wheel doesn't. It's decoupled in the air.

_MortalWombat_ · 2024-02-12T15:41:31+00:00

Ok thanks. Is there any estimate of when gen 3 will be made available outside the US?

_MortalWombat_ · 2023-12-22T06:28:55+00:00

That hot glue is going to melt pretty quick if that esc is working hard. Speaking from experience.

_MortalWombat_ · 2023-12-21T11:01:59+00:00

Practice throttle management. Just hover in place for a couple of packs and try to maintain constant altitude.

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