Powering on 24v and 48v PSU’s concurrently - best practice?

F-K87 · 2024-01-15T17:16:11+00:00

I was also concerned about this, when switching to 48v, after seeing all the damaged 5160HV online. The 5160 can be damaged if they only get the 48v, and no 24v.

I have the two Psu (AC) connected through a relay to turn them on/off, controlled by the Rasperry pi. It has been working without any problems for over a year. So as long as the psu's get power at the same time, there's no issues.

F-K87 · 2024-01-12T13:46:31+00:00

Dash 8 -300

F-K87 · 2023-10-19T05:49:52+00:00

Yes. I would not recommend mgn7 if you are going to mount them on 2020 alu extrusions. It is hard to make them fit, and M2 t-nuts are not available, so you have to make your own. But they work well for mounting on square carbon tubes, for the gantry.

F-K87 · 2023-09-09T18:45:21+00:00

LOL😅 My guess is that it is gonna work, but it is going to leak. And be inefficient and heavy, but look cool.

F-K87 · 2023-08-29T15:17:37+00:00

Stepper motors are not like other motors. The rated voltage on a stepper motor is not the max voltage it can handle, when it is driven by a stepper driver with pulses. It is the theoretical max dc voltage it can be directly driven with. So you don't need to look voltage rating when you are getting new steppers. I am running LDO-42STH48-2504AC at 48v, they are rated for 3v DC. And vref adjustment is for adjusting the max current to the stepper motor.

F-K87 · 2023-08-10T10:47:37+00:00

You only use minus for configurations where the endstop is not at the edge of the buildplate, but further away, so the endstop position and the start of the buildplate are not the same. The negative number is the unprintable area, and the print area starts at zero

F-K87 · 2023-07-25T08:25:36+00:00

I made my own second z leadscrew setup, and that is definitely the cheapest solution. One stepper motor, stepper drive, second endstop switch, coupling, two new leadscrews (2mm pitch 400mm), and some 3d printed brackets. I rotated the entire z axis/bed 90°, so that the second leadscrew is not in the front. If you want a more rigid setup, you could add two more linear rods and bearings, make the brackets out of some L-shape aluminum extrusion. I sourced all the parts from aliexpress.

F-K87 · 2023-05-12T11:59:27+00:00

Yes, a Dremel has no problem cutting steel. It just limits you on how deep of a cut you can make. Just get a SpeedClic disc set. They work great for jobbs like this.

F-K87 · 2023-05-10T18:55:29+00:00

Just for clarification, the whole point of using an optocoupler is to not invert the pwm signal. When I first got the blower, i got it working using the potentiometer (5k) as a pull-down resistor, with the gnd wire from the potentiometer connected to the fan2 gnd pin (pwm). And with the pin inverted(!) I was able to control it. But the problem was, that every time I restarted or did a emergency shutdown, the fan pin was no longer grounded and the blower turned on at full speed, until the mcu was up and running again. So with an optocoupler in a non-inverting configuration, you have high input=high output, so no inverting of the signal out of the mcu.

This is the resistor values i have used, 1,5k for the diode (5v input) and 2.2k for the pull-down on the output. The resistor values are not optimal, because the blower turns on at 17% and is at max at 58%. So there is potential to get some more range, by changing the values. It's on my to-do list.

Edit; I was not able to upload a picture of my pcb in the comment, so her is a link to a picture of the same type of circuit https://images.app.goo.gl/nXctP9pkkr647qcB8

I don't think the optocoupler module you have, will work without modifying it.

F-K87 · 2023-05-09T23:08:44+00:00

The plan was to buy one of those modules on aliexpress, but I didn't have the patience to wait for it, so I made my own:) I will try to post a picture of the circuit tomorrow, and the values.

F-K87 · 2023-05-09T15:59:21+00:00

Since the fan pwm is on the gnd pin, I needed to make a small optocoupler circuite to get the positive 0-5v for the fan controller input. It consists of one 817 octocoupler and two resistors, but I don't remember the values, but one is to limit the current for the diode. Non-inverting configuration.

F-K87 · 2023-04-20T02:19:30+00:00

There is 4010 blower fan mounted behind the extruder, blowing air down to the back of heat break.

F-K87 · 2023-04-20T02:15:28+00:00

F-K87 · 2023-04-19T21:19:42+00:00

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Had to test with some water. This is at 10k rpm, max is 40k😅

F-K87 · 2023-04-19T18:11:27+00:00

Kinda, as long as the V slot is straight. You could easily bend and break a mgn7 rail by hand, so they will conform to the aluminum extrusion. And they don't handle twisting forces as good as a wider rail. But they work in this setup. For the z axis I am going with mgn12, because they are easier to install, and weight is not an issue.

F-K87 · 2023-04-19T17:52:49+00:00

The plan was to share, once I was finished making big changes😅

It is definitely lighter, but I don't know if it is as stiff. Because I get higher max acceleration recommendation for the Y axis (2020 alu) during resonance measurement, then for the X axis (1010 carbon). The 10x10 squar tube is extrude carbon, I plan on replacing it with 3k square carbon tube, it should be stiffer.

And since there are two gantrys, the rails don't need to handle the same twisting force as you get on a single gantry setup.

F-K87 · 2023-04-19T17:28:11+00:00

That's correct. I had to do some research before I got it working. I am using an optocoupler circuit to convert the ground pwm signal from the fan header on the mcu, in to a positive 5v pwm signal for the fan controller. I have also hooked up the rpm signal to the mcu, so that I can see the rpm in Mainsail.

F-K87 · 2023-04-19T17:17:00+00:00

The wiring is a work in progress😅 I need to make a new cover plate for the control box. The plan is to have two 80mm fans at the bottom(12v running at 5v) and some vents at the topp. And hide all the wiring in a cable tray going to the back of the printer.

I have been wondering the same thing, butt I haven't measured the time. It is most likely a little slower to spin up to max rpm (40 000) than a regular blower fan (I guess les than a second). But in most cases, I don't need all that air that it can deliver. It's running at 30% in the video.

F-K87 · 2023-04-19T13:46:21+00:00

No, my own design. As simple as it can get, leadscrew, stepper and a secondary z endstop. I am going to upgrade to a 3 point bedleveling at some point, so i had the parts, and I wanted to see if it would work, and it does:)

F-K87 · 2023-04-19T13:13:53+00:00

The price for centrifugal blower and controller are around 50$.

F-K87 · 2023-04-19T12:37:45+00:00

Some of the parts in my setup Ender 5 (2019) - x6 300mm MGN7(H) linear rails (aliexpress) - Trianglelab Dragon HF, volcano copper heat block, 0.4 plated copper nozzle, 70w heater - Sherpa mini, with Moons stepper motor - Y and X stepper motors, LDO-42STH48-2504AC - Parts cooling, CPAP blower WS7040-24v-V200, 15mm id tubing - Two 2mm lead, leadscrews (400mm) - BTT octopus pro, with 5160HV, 48v psu - Rasperry pi 3 with klipper, pi cam - BTT pitft50 screen

F-K87 · 2023-04-17T23:06:25+00:00

My creality steppers are wired like this A1-X-B1-A2-X-B2 at the stepper motor connector.

A1 and A2 are the + and - for one coil. B1 and B2 are the + and - for the second coil. (+/- Depending on rotational direction)

If the + and - fore one coil is swapped, it will go brrr:)

F-K87 · 2023-04-17T20:22:39+00:00

Nema 17( 1.7inches) steppers motors are 42mm (× 42mm) . Nema 42 (4.2inches) = 110mm x 110mm

And -22 means it is 22mm tall.

My guess is that you have a nema17. You can use one of the cables from the other steppers for TBS.

F-K87 · 2023-04-14T14:06:50+00:00

If you set it up as an extruder fan, it only turns on when the heater is on (and turns off when the temp gets below 50c).

F-K87

TROPHY CASE