MP3DP V4 Build

@probrwr, are you running V1E/similar 84oz XY Steppers at 1amp or something else? Several month old Snapshot of your Klipper config has 1amp configured.

Think I started with 0.8 but then dropped current after seeing the stepper’s steady state temp (using the V1E temp stickers). Mine are at a measily 0.6 ( my Klipper config ) which probably too low.

@SupraGuy curious what current’s working for you?

What is a safe temp for the drivers? some of them were around 53°C after just 2-3 min of printing. If I bump the current wont that make them even hotter?

I do have 2 40mm noctua fans here that I was going to put in the new LR3 that aren’t needed now that its switched over to jackpot. I could try to come up with some kind of mount for them to blow over the drivers…

I will look to see what my current settings are. probably still at 1 but maybe not as that may have been when I was using the smaller ones.

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Lol. Mine are juiced right up. 1250mA for XY and 900 for Z. I am running a Duet 3 6HC mainboard though, TMC5160 drivers, I think. Those drivers will dish out a LOT more current and not bat an eye. My motors stay reasonably cool, so I haven’t spent time tuning them.

A fan on the drivers will do wonders. I guess I dont worry too much about noise. I used to just have a 120mm fan pointed at the drivers before. I don’t have that now though, but the Duet doesn’t seem to need anything more than a vertical mount to let things cool by convection.


Well I have a print going now that SEEMS to be going good. No skipped steps so far at least. I did find one major deal (at least I think it is) in the slicer. Infill was set to 300% speed. And that’s where I watched it start skipping steps earlier tonight. I brought that down to 150% and its doing much better.

Another change I’m thinking about making is lowering the Acceleration down from 3000. This thing really jerks sometimes and I think that’s part of the cause of missed steps as well. This being a larger printer than Ryan builds I just don’t think it can quite handle as much. Or he may be running much different settings in his slicer… I’m not sure. I know as much as I thought I knew about 3d printing I still have a TON to learn LOL. Any tips or advice will always be welcomed!!

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It may be a worthwhile pursuit to share slicer profiles for the MP3DP. Of course some details will be off but if we can see results and cross reference speeds, we might be able to get some data that will let us optimize our own printers. This is lime the kind of leverege that Prusa gets within the slicer to get high quality printing when you use their printers.

It’s still a bit different, since we tend to be tinkerers. If we built our printers Ryan’s with the same control boards, firmware, settings and hardware, we could all find the ideal settings for different layer heights, filament types etc, but I think we could get closer based on that most of us would be using an SKR Pro with 2209 drivers, running the V1 Marlin firmware.

Outliers might be using Klipper, or like myself, RepRap Firmware, and of course changing the footprint or build envelope will have an effect… I don’t mess with the slicer settings much, most of my print speeds are maybe slight tweaks on settings that were there from some other model, or default settings that the slicer came with. I know I can often run with the speed factor up to 125% on the interface, and not have real problems, so I know I’m leaving something on the table… but sometimes, I don’t get away with it. (110% is pretty safe for thin to moderate layers though.)

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Well it finished the test. And the print looks good. But that’s where it stops. Its 8.5mm out of square… That’s measured with a tape measure as I made the model too large to fit my calipers over it. printing another now that I can measure that way, also printing it in the other orientation.

The one I’m printing now is in the opposite direction so we will see how far that one is out. Then to figure out how to fix this mess.

How do you know how much the motor hold torque rating is? Do you measure it or the stepper depth? I have some V1E steppers and some 6 pin steppers and some 4 pin ones… I was thinking the depth was of interest for this, but not sure. I’m seeing new z steppers in my future.

@orob please don’t take my build as anything negative toward MP3DP… This as all been my errors not anything on the design.

Ok both new parts have finished printing and for some reason are not near as far out of square as the first larger one. So that has me questioning some things. Also they both skipped steps at the same spot at the very top.

Just realized I’m an idiot yet again. If you take a close look the chamfers on the corners are not the same. That’s why it measured different. Couldn’t see the forest for the trees… Well that makes me feel a little better about it now. I know I set them all the same on the new smaller one. So now the question is how do I take that little bit of error out? or is that enough to even worry about?

this is all the risk we take when we DIY. I’m a tinkerer and a problem solver so, I appreciate the fact that you share the struggle so we all can learn in real time and not just post how smart you are after solving it. This is good info on what to watch for and then how to correct it. It is cool how people chime in and say, " I made an error here, try this." in an effort to spare you the time they spent figuring it out. It just speaks to the goodness in humanity. People helping people out because they can. I’m not done making all the mistakes yet, so when I mess this part up, you can help me out.

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Thanks @orob this thread is definitely full of that!!

It IS proportional to the length of the motor body. The 6 pin ones are generally Unipolar but can be wired for bipolar operation. 4 pins are bipolar only. The V1E motors are 84oz in. the ones with the plug on the motor body are typically less.

I am using the smaller motors on my z axis and have no issues with them. I was having the same shifting problems higher up in prints like @Jonathjon was with the smaller motors on xy.

As far as I remember I’m using the same 84oz motors on all of mine but i guess i need to double check that. What did you do to correct it?

One thing I find crazy is both of them skipped steps on the exact same layer

Here is the gcode for both prints if anyone things they can see anything that may have caused it…

XZ 100mm Squareness Test.gcode (527.9 KB)
YZ 100mm Squareness Test.gcode (522.2 KB) (4.0 KB)

It’s modern art! :smiley:

Expensive ugly “Art”

Anyone have any ideas on this skipped steps stuff? Seems so very odd to me that 2 prints did it in exactly the same spot. They were not printed in the same orientation. Why print the entire way up and then when you get to the last 2 layers it skips. If they had skipped steps in different t places I would for sure think mechanical/hardware. But for these both to do it in the exact same spot really is odd to me. Also there was no cool down time in between. As soon as the first one was done I started the second one

That is strange, is there a chance that your umbilical is sagging and snagging?

Just uploaded “aza-ptfe-guide-110mm.v4.stl” for the PTFE Guide, earlier version was 60mm radius, new one being 110mm radius helps suspend Umbilical higher off the rails.

Ideally, the aza-ptfe-guide-mount-v4.stl (that attaches to extrusion and Sensor) should also be updated to have a recess/well for the 90 degree bend to seat inside of.

Recent discussions, and previous ones (e.g. fans-on-stepper-motors and taller-lr3-build/…/81) about keeping steppers cool influenced me into trying out some cheap Alu 40mm x 40mm heatsinks. Hopefully the Temp stickers will reveal IF/What difference those make, am not wanting to put additional fans on the steppers if possible.

I haven’t printed as much on the MP3DP as you, so am looking to you for guidance/ideas from your posts. Appreciate you sharing your experience and observations. Cheers!

Thanks Aaron. I wound up having to ditch the mount/ptfe guide. I just have too many wires coming up though there. That’s what pushed me to look into the CAN bus. These damn wires are a mess. But I do need to come up with something. I don’t have a full enclosure like you do and don’t ever plan to go that route (as of now anyways LOL) so I’m going to try to come up with something similar to yours that mounts to the top of the 2020 extrusion. That should keep it up even more. Actually tomorrow I’m planning to laser cut some shelf brackets to mount a shelf above the row of printers and store my filament in the food safe “dry boxes” and feed filament from above so Ill have to see how that works out and what I need to do so all of that meets up smoothly.

I’m about to start a print and I have turned the speed WAY down. We will see how it looks in the morning. as you can see from the thermal images I posted my motors aren’t getting hot. Its the drivers that are getting hot. Makes no sense to me. The ones on the LR3s in garage at 90° do just fine. But these are in a semi enclosure right next to a 1/4" thick headed bed so that probably doesn’t help anything. I mounted a single 40mm fan on top blowing down. Probably should put that blowing up, or multiple blowing from the side. Actually I can rob the 2 from the old SKR case from the LR3 since those aren’t needed anymore going jackpot, until those get too hot and I have to figure out how to put fans on it LOL.

I will report back in the morning how the print goes. Will either be good or another waste of filament…we shall see. Hoping that slowing it down will help.