Posts made by coredump

@chapelhill I am using this https://www.thingiverse.com/thing:2206664 + a thing I made https://www.thingiverse.com/thing:2868944

It is pretty accurate/repeatable.

@chapelhill I am using a nimble, yes, with their supplied 95 cm cable. My filament is feed from a shelf up the printer, so I don't think that can put any spin on it.

I've been playing/testing different belt tensions on the d-bot carriage to see if there's something that I can do there. Also a dude on the 3d printing discord chat suggested using a bullseye level to check the gantry and I will do that later today.

@deckingman indeed the straight edge on the front helped, the bed is indeed sagging in the middle. I also found almost half a millimeter drop measuring the left side front to bottom.

Somehow, I was able to bend this MIC6 plate.

@dc42 shouldn't that be compensated by the bed auto compensation thing with the independent z motors?

I read that as bed twist, not gantry twist. How one proceeds to try and identify/fix that?

So, I have this CoreXY with a bed made of MIC6 plate + steel plate + PEI, and I use the 3 independent Z screws to do bed compensation/leveling. Even so, I get horrible first layers some times. So I started using the mesh compensation and I get this every time I probe:

(I am using a lot of points on that one to give more detailed visuals). The thing is, I put a straight edge from the red area to the blue area, and tried to fit a 0.03 feeler gauge under it, and I can't find ANY gap, what kinda means to me that I am doing something wrong.

Everything is probed using a Precision Piezo probe, and I tested repeated probing and I get consistently:

G32 bed probe heights: -0.045 -0.049 -0.043 -0.046 -0.044 -0.049 -0.043 -0.045 -0.047 -0.046 -0.045 -0.047, mean -0.046, deviation from mean 0.002

So, now I am kinda lost on what to check? Maybe something mechanic on my build?

This is the bed, the lower right spot with filament squished is where I prime the struder at 15,15, so you can orient that with the probed mesh.

Also, this is my current gcode: https://gist.github.com/coredump/b0e76e62d348a3373ffaa67fd2f31052

Am I overlooking something?

@hurzhurz said in Berd-Air pump configuration notes for Duet users:

@msquared About the flayback diode, your link points to a 1N4007.
I have first tried this one, but it got pretty hot.
After some googling I think the reason is that the diode is just too slow for a high frequency of 25kHz (reverse recovery time of 30us).
I have replaced it by a schottky diode that doesn't get warm.

Are you using a 1N4148 or something different?

@bendiesel unfortunately they are all one piece injected plastic, so it's not trivial to open.

They definitely lower the noise tho.

Responding my own question: that mosfet module that I added definitely blocks the high frequency PWM trick. I took a chance and connected the 24v pump I got from markerhive and connected it directly to my duet wifi (1.02) and with the highfrequency PWM I can run it at 20-30% with minimal noise.

Lets see how many fan ports I burn on this tho

So, did anyone try the high frequency PWM with a module like this?

In my test here, using F500 and keeping the pump running at 30-40% gave me a lot of air, and not a lot of noise (I am using this on both intake and outtake), but the F25000 took away my ability to control the pump speed and sounds a little higher. I haven't tested temperatures yet with the two different F values.

I wonder if I should try to connect the pump directly to the DuetWifi. If there's not a lot to gain from that change in the noise department, I think keeping the module makes it safer.

@dc42 said in Probing speed changes with no reason:

The slow down is intentional for sensors that provide an analogue output that increases as it gets nearer the bed. It allows you to use a higher initial probing speed. But I'm not sure that the piezo sensor is intended to be used in analog mode.

Well it only happens on one of the points, that's what I think it's weird.
And I was following @DjDemonD post here.

EDIT: just noticed this was added after I configured it the first time:

Please note as of RRF version 1.20 you can use M558 P8 instead (other parameters are the same) which is a digital probe but without filtering or smoothing of the signal. This increases accuracy, as it takes less time to react to a trigger.

I will try that when I finish this 5h print...

So I am having a weird issue here. I have a precision piezo to act as a z-probe/endstop on my corexy. It works fairly well with the following exception: sometimes the z speed on probing will randomly slow down.

I have this:

; Endstops
M574 X1 Y2 Z0 S0 ; Define active low and unused microswitches

; Piezo
M558 P1 I0 R0.4 F420 X0 Y0 Z1
G31 X0 Y0 Z-0.360 P600

Firmware is latest (1.21) and it's a duet wifi+duex2.

And I have like 5 points defined on bed.g for 3 lead screw bed leveling. The thing is, sometimes one of the probe points will just be REALLY slow. Like less than half the speed of the other ones (that is set to 420 on G31 above).
I think there must be something to be related to jerk or changing speeds too fast, but I am unsure how to solve that. Maybe lower the travel time between the points so it has more time to 'recover'?

Thanks for any help.

Also I am pretty sure that I should change my M558 because apparently it changed on 1.20.

@dc42:

@coredump:

I am having slow upload speeds via the DWC. Via FTP it works as expected but over the web control it goes to like 20 K/s speeds.

Thanks for your feedback. Can you provide a Wireshark trace of a HTTP upload?

Sure: https://www.dropbox.com/s/4x20l1f4m59r12y/dbot.cap.pcapng?dl=0

But sems to be a lot of window errors and retransmissions. That doesn't happen with port 21/ftp.

I am having slow upload speeds via the DWC. Via FTP it works as expected but over the web control it goes to like 20 K/s speeds.

@deckingman:

@coredump:

…............................ but not the H0 and L0. What those do?

See here. https://duet3d.com/wiki/G-code#M305:_Set_temperature_sensor_parameters

BTW, the duet g-code wiki is a great resource if ever you have similar questions.

Sorry, I read the wiki and I understood what the parameters do, was just asking why those values exactly

I have the same values, but not the H0 and L0. What those do?

I got those values from the official E3D docs.

Got some good prints the last few days. I had to use the bed compensation AND mesh leveling. I guess somehow I got a 6mm aluminum plate bent

So I changed the belts, added a 300mm PEI cover to the bed, and that seems to have helped on some of the shift issues

The first layer problems still here tho. I am printing a big box for my duet now, and for the first layer to stick I had to print it with like 10 mm/s, on a Pei bed at 70 degrees. Still I get this:

In this the skirt is raising up on the border because when the nozzle goes throug there, it forces it up.

This is a photo of the first layer, as you can see the bottom part is very squished to the bed while the top part totally isn' t.

I tought that with a MIC6 plate, independent screw correction and mesh maps, I would not have to worry about it getting a correct first layer ever again, but it seems that I may be better manually changing bed screws since I can't reliably believe this printer.

@deckingman:

Edit, here is why those multi start screws are my pet hate https://somei3deas.wordpress.com/2017/01/31/z-axis-lead-screws/

Also I read this and now want to find a way to adapt a 1:2 gear on my current screws. Or change them to a 1 start or threaded rod.

Ok, I did the Z change, but it didn't stick again. The Y is really faster and the Z seems more controlled.

I am going to change belts and re-tighten and re-check the build to see if I messed up somewhere, and will report back with, probably, more questions on Friday

I think that I am indeed using the awful lead screws that you mention

I let the babystepping there to be able to test other stuff, and I am getting stuff like this

I tried to make my xy belts as tight as they can, and I don't think that kind of ringing is related to that but who knows.

Yeah it's tooling plate, so it is supposed to be super flat, but still have to level the actual gantry/bed

G1 X99.4 Y138.5 Z0.35 E0 F6000
G1 X99.4 Y138.5 Z0.3 E0 F1800

Those are the first Z changes for the prime pillar, the first layer starts with 0.35 too.