Motor step angle and screw pitch for MK3: 1.8* and .8mm?
 
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alan.e2
(@alan-e2)
Eminent Member
Motor step angle and screw pitch for MK3: 1.8* and .8mm?

Anyone know what the Z step angle is and pitch of the screw? Looking to set my layer height. Are they 1.8* and .8mm?

Veröffentlicht : 14/04/2018 8:29 pm
RH_Dreambox
(@rh_dreambox)
Prominent Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

Can you explain what to do? Are you going to make a script to set the layer height?
Why not adjust according to the recommended method?

Bear MK3 with Bondtech extruder

Veröffentlicht : 16/04/2018 5:04 pm
NG
 NG
(@ng)
New Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

it s 3 days long i m loocking for the default steps per unit in to the firmware but i could n t find anything .

do you know any value i could use on the prusa calculator Mostly for X and Y axis ??

Veröffentlicht : 17/04/2018 9:59 pm
alan.e2
(@alan-e2)
Eminent Member
Themenstarter answered:
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


Can you explain what to do? Are you going to make a script to set the layer height?
Why not adjust according to the recommended method?

Basically set the best layer height (ie .1978 or whatever it is instead of .2). A good explaination is the Layer Height section here: https://io3dprint.com/tips-for-3d-printing-miniatures/

Veröffentlicht : 22/04/2018 12:13 am
alan.e2
(@alan-e2)
Eminent Member
Themenstarter answered:
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


it s 3 days long i m loocking for the default steps per unit in to the firmware but i could n t find anything .

do you know any value i could use on the prusa calculator Mostly for X and Y axis ??

Send code M503. It's the E code.

https://mattshub.com/2017/04/19/extruder-calibration/ <-- section under tuning

Veröffentlicht : 22/04/2018 12:15 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


Basically set the best layer height (ie .1978 or whatever it is instead of .2). A good explaination is the Layer Height section here: https://io3dprint.com/tips-for-3d-printing-miniatures/

3200/8 = 400 steps per mm.
16 microsteps per step.

1 full step = 1.8 degree

1.8/16 = 0.1125 degrees of rotation per microstep.

0.1125 * 400 = 45 degrees of rotation per mm
1/400 = 0.0025mm

Keep your layer heights divisible by 0.0025mm.

EDIT: You are totally thinking of "the magic numbers" from say, the monoprice mini.

0.04375 (results may vary)*
0.0875
0.13125
0.175
0.21875
0.2625
0.30625

Yeah. That's what happens when you cut every corner possible. The mk2 and mk3 don't have that issue. (not sure about the original i3)

EDIT2: Just incase my math, which I derrived from reading the firmware wasn't enough. Here's the specs on the rods.
8mm diameter, 8mm pitch, 4 threads.

Which confirms my math above.
Keep it divisible by 0.0025mm
eg:
0.1975 <-- good
0.1978 <-- BAD.
0.0725 <-- good
0.2 <-- good
0.205 <-- good

Basically
0.xx <-- any numbers in these digits are GOOD
0.00xx <--- only 00, 25, 50, 75 work in these digits.

EDIT3:
From that page you linked about minitaures

Stepper Motor Step Angle: 7.5°
Steps per full rotation: 360°/7.5° = 48 steps

I totally didn't know the monoprice mini didn't microstep. That's crazy!

Mk3 has a 1.8° motor, with 16 microsteps.
Essentially 0.1125° step angle.
And 3200 steps per rotation...
vs 48... haha... ... haha... ouch.

EDIT4:
That article is a treasure trove of "how to fix your cheap printer"
I would honestly say 2/3rd of what that article says, is IRRELEVANT.

And what it DOES say, it does not tell you how.
Basically all 3D printers made in the last 3 years that aren't "super ultra cheap" won't have MANY of the issues this guy is "struggling" with.

I'm writing these snarky comments in "response to the author", not anyone on here. Just more amusing that way.

Resin has some disadvantages too. It’s generally a little more brittle than PLA or ABS so you may need to be careful when designing minis with thin cross-sections.

So is it more brittle than PLA, which is quite brittle... or more brittle than ABS, which is *NOT* brittle? There are "flexible" resins out there. I don't think "brittle" would be a good descriptive word for them. Apparently this guy knows nothing of his intro paragraph.

At most you should be aiming for 30mm/sec. This is probably half the speed you’re used to. It will seem slow if you watch every layer building, so don’t! ‘A watched kettle never boils’ as my Gran always said.
The mk3's default speed is 35mm/s on outside perimeters. Not sure what kinda printer you have that's got a default 60mm/s outside perimeter speed, but unless you paid ~10,000$ for it, I bet it's more "false marketing" than "reality". I find on my Mk3, the 35mm/s outside perimeters are slow enough for everything but the smallest things. (which I would drop down to 20mm/s on)


The secret to you getting the right layer height is not falling into the trap of presuming smaller is better.

No. Smaller is better. As long as your printer can do it.

Every 3D printer has a ‘Magic’ layer height. This is related to the stepper motor resolution and the pitch of the z-axis lead screw thread.

Nope, just cheap printers.

The first layers that your printer lays down are called the initial or bottom layer and they contain 100% infill. They help with bed adhesion and compensate for any unevenness or a poorly leveled bed.

If you have non-self-leveling bed, it's your own fault for it being poorly leveled. LEVEL IT. Stop trying to gloop down a .4mm first layer to fix YOUR failure. You can't even blame your cheap chinese junk for that. LEVEL YOUR BED... Or even better, don't buy a printer based off a 4 year old printer, and get one that has some kind of mesh bed leveling. (don't have to be automatic)

As the setting for the initial layer is often a number of layers, is important to increase this when you are using very thin layer heights to print your miniatures.

So uhhh... I have no idea what you are talking about here. I know Slic3r, Cura, and S3D do NOT do this... ... Are you by any chance using Cura 15? Cause that's like 3 years old... let me guess, it came with the printer?

Ideally, you should aim for at least a 0.5mm thick initial layer. if you’re using a layer height of 0.04mm this would be at least 12 layers. Your default settings are more than likely set to something like 5!

NO. NO. NO. NO. NO. NO. NO. NO. This is a LIE. You are WRONG. You will NEVER EVER EVER EVER get a good first layer, that is TALLER THAN YOUR NOZZLE IS WIDE. In fact, the general rule is with a 0.4mm nozzle to NEVER EVER EVER print a layer thicker than 0.35mm.

You may be tempted to increase your minimal layer time. This will allow time for each layer to cool before the next layer is printed. Unfortunately, this has the problem of your nozzle dripping excess filament whilst it waits before commencing the next layer.

Are you sure you aren't using Cura 15? On Slic3r, Cura and S3D, it will simply slow the nozzle down, down to a minimum speed, to increase the layer time. I've never seen the nozzle just go "chill" someone else for a few moments.

This blob of filament on the end of the nozzle then finds its way onto your print and makes a mess. Or worse it will have time to set. And then as the nozzle passed over your model it knocks it over.

Did your nozzle's heater turn off while waiting? How in the world did the filament cool and harden at the base of the nozzle? Then knock your model over? Really? Recall what I mentioned about first layer height? I worry more about breaking things on the printer, than "popping" my models off the PEI sheet...

Say No to Oozling

Nice article saying oozing is bad.
Next time explain how to fix it, rather than make it sound difficult to fix.
Also, you can NOT retract "molten" filament. There is no "sucky sucky" going on. Only releasing the "pressure".

As you can see there’s nothing here that’s massively complicated. Take a few hours to work through this list and you’ll be rewarded with perfect 3D printed miniatures.

You sure make it sound hard. Also. Hours? Try WEEKS for a cheap chinese printer, and DAYS for a high end one.

And best of all optimizing your 3D printer with all these settings will not only give you the best quality miniatures. It will improve the quality and reliability of all your 3D prints.

These settings? The only settings you gave were SPECIFICALLY for monoprice printers, and some mystery slicer that was most likely Cura 15, which was originally released January 2015. Every "setting" you provided is USELESS to 90% of 3D printers on the market, and more than likely 100% of slicers current out.

Seriously. That article is so full of garbage.

It's crap like that, that gets people to buy 3D printers and think it's easy... except this article is TOTALLY WRONG.

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Veröffentlicht : 22/04/2018 7:54 am
Rocky79 gefällt das
Kwaad2
(@kwaad2)
Honorable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


it s 3 days long i m loocking for the default steps per unit in to the firmware but i could n t find anything .

do you know any value i could use on the prusa calculator Mostly for X and Y axis ??

For the mk3 the default settings from the firmware are.


// Steps per unit {X,Y,Z,E}
#define DEFAULT_AXIS_STEPS_PER_UNIT {100,100,3200/8,280}

X = 100 steps/mm
Y = 100 steps/mm
Z = 400 steps/mm
E = 280 steps/mm

(I don't know why it's 3200/8, rather than just 400, for the Z)

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Veröffentlicht : 22/04/2018 8:20 am
reid.b
(@reid-b)
Reputable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

EDIT- nevermind, thought you were referring to extruder axis.

Veröffentlicht : 22/04/2018 10:31 pm
joshua.w6
(@joshua-w6)
Eminent Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?



The first layers that your printer lays down are called the initial or bottom layer and they contain 100% infill. They help with bed adhesion and compensate for any unevenness or a poorly leveled bed.


As the setting for the initial layer is often a number of layers, is important to increase this when you are using very thin layer heights to print your miniatures.


Ideally, you should aim for at least a 0.5mm thick initial layer. if[sic] you’re using a layer height of 0.04mm this would be at least 12 layers. Your default settings are more than likely set to something like 5!

Before I begin: I didn't read the article, only your comments, so I'll reserve judgement on the author/article.

One thing I noticed in your quotes though, is the original author is using the term "first layer" when he should not be.

He keeps saying "first layer" when he really means "bottom horizontal shell"

Look below, i've edited your quotes with the proper term, it makes a ton more sense:



The first layers that your printer lays down are called the [bottom horizontal shell] and they contain 100% infill. They help with bed adhesion and compensate for any unevenness or a poorly leveled bed.


As the setting for the [bottom horizontal shell] is often a number of layers, is important to increase [the number of bottom horizontal shell layers] when you are using very thin layer heights to print your miniatures.


Ideally, you should aim for at least a 0.5mm thick [bottom horizontal shell] . if[sic] you’re using a layer height of 0.04mm this would be at least 12 layers. Your default settings are more than likely set to something like 5!

Veröffentlicht : 23/04/2018 1:42 am
Kwaad2
(@kwaad2)
Honorable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


Before I begin: I didn't read the article, only your comments, so I'll reserve judgement on the author/article.

One thing I noticed in your quotes though, is the original author is using the term "first layer" when he should not be.

He keeps saying "first layer" when he really means "bottom horizontal shell"

I've never known of anyone/anything that changes the walls on the first layer.

I know that for example, Slic3r, has a setting for "first layer thickness as a percentage".

I know that OLD slicers did it that way.

I don't know of ANY slicer that adjusts the first layer shell.

I'm just laughing. I know my way around Slic3r, and Cura, and played with a "trial" of S3D. (which if anyone has a spare copy, I would be much obliged)

3D printing is what I would call an "advanced" hobby.
It's kinda VERY similar to owning a old Manual Lathe, or Milling Machine.

It's not as simple as "carving", "drawing", or "painting".

Working with creating your own designs requires fairly advanced computer skills, and knowledge in CAD. This also requires an "artistic" mind. Meaning if you are good at Drawing, and art stuff, you will pick this up fairly easily.

Optimizing the software on your printer is pure MATH. This requires a mathematical mind. It is VERY rare for someone to be "gifted" in both of those, enough that "both" would be "easy".

Optimizing, and troubleshooting extrusion, mechanical problems, temps, etc, requires a VERY analytical mind. This is someone who is "gifted" with diagnostics. You know, that guy that you've heard of, that can listen to your car idle for 2 minutes, and tell you that your piston wrist bearing is going out on cylinder 3, without using any tools, or even touching the car... That's me. But I struggle with math, and just fight it out. CAD... Nope. I've tried, and tried, and tried. I'm getting better, but it's like pulling teeth. It's just not "natural" to me.

I had an issue with my printer, I asked for help. Everyone told me to do what I either "ruled out" or "already tried". I tried again, cause that's the kinda guy I am. I said "It's my heatbreak." and eveyone was like "no way." Guess what? Replaced it, and I'm 24 hours of print time in, without a single extrusion hiccup.

I am superb at diagnostics.
I can do math, using the proper software, to do it for me.
I can NOT design.

The day that all 3 of those, are EASY for everyone. (regarding using a printer) Is the day 3D printers belong in the home.

(My first printer was actually a Monoprice Mini V2, My second printer was a Monoprice Mini Delta)
I knew within a week of getting my first printer, that printers are NOT as "simple" and "easy to use" as 90% of youtubers make it out to be.

I expected it to be difficult. At that time, I worked with automation in automotive, as a Maintenance Engineer. I personally find messing with my printer EXTREMELY enjoyable.
I have replaced my extruder now, about 4 times, and when I had the jam, I had pulled it apart about 10-15 times.

But even as Josef Prusa himself has said, the hardware is there. There's "little to fix" regarding hardware.

Printers need to be able to automatically calibrate the first layer. Printers need to be able to automatically adjust extrusion multiplier, and automatically adjust speeds when needed. Until printers can do these things, it's not fair to market them (or talk about them) in such a way, that any 6 year old child, can simply press "print" and it prints. When it runs out of filament you put more in it. Imagine a Laser Printer. They just WORK... Unless there's a mechanical failure, at which point, you DO NOT TRY TO FIX IT YOURSELF. You pay someone some serious $$$ to fix it for you. Why would you ever say, a 3D printer, which is MUCH more complex than a laser printer, is something you are ENCOURAGED to work on, because it's "easy".

If I show you this.

And I said "It's easy to work on, no big deal, ANYONE can do it." would you believe me? No. You wouldn't.
I find 3D printers no easier to work on, than that specific machine.

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Veröffentlicht : 23/04/2018 3:56 am
reid.b
(@reid-b)
Reputable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

You aren't getting it.

The question was centered around how thick should the bottom shell be. 1 layer, 2 layers, 3 layers, etc? Obviously the thinner your layer thickness, the more bottom layers you want, and perhaps top layers as well. It's as simple as that- don't make it all complicated and explained by all your experience.

Veröffentlicht : 23/04/2018 5:36 am
joshua.w6
(@joshua-w6)
Eminent Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

Edited for clarity:
Wow, alot to unpack there. Firstly, text only communication is terrible for conveying emotion. Please read the below with a smile on your face, I am writing it in good spirits and only with the intent to pass along some of my thoughts. This is not meant to be arguementative, and definitely not meant to cause greif. I'll do my best to keep my choice in wording pleasant too! 🙂



I've never known of anyone/anything that changes the walls on the first layer.

I know that for example, Slic3r, has a setting for "first layer thickness as a percentage".

I know that OLD slicers did it that way.

I don't know of ANY slicer that adjusts the first layer shell.

I'm just laughing. I know my way around Slic3r, and Cura, and played with a "trial" of S3D. (which if anyone has a spare copy, I would be much obliged)

With regard to the article, I agree with:

The question was centered around how thick should the bottom shell be. 1 layer, 2 layers, 3 layers, etc? Obviously the thinner your layer thickness, the more bottom layers you want, and perhaps top layers as well. It's as simple as that- don't make it all complicated and explained by all your experience.

The original author [edit: of the article which we were quoting, not the original post in this thread] is talking about how many layers are required for the bottom (horizontal) shell.
These two settings in slic3r are tied together, is all the original author meant, just with terrible terminology usage:

Smaller Layers, higher layer count for the same thickness

3D printing is what I would call an "advanced" hobby.
It's kinda VERY similar to owning a old Manual Lathe, or Milling Machine

I agree completely here. Buying a lathe or milling machine really highlights how little you know about milling and turning, 3d printers have very much the same learning curve.

It's not as simple as "carving", "drawing", or "painting".

Working with creating your own designs requires fairly advanced computer skills, and knowledge in CAD. This also requires an "artistic" mind. Meaning if you are good at Drawing, and art stuff, you will pick this up fairly easily.

Optimizing the software on your printer is pure MATH. This requires a mathematical mind. It is VERY rare for someone to be "gifted" in both of those, enough that "both" would be "easy".

Optimizing, and troubleshooting extrusion, mechanical problems, temps, etc, requires a VERY analytical mind. This is someone who is "gifted" with diagnostics. You know, that guy that you've heard of, that can listen to your car idle for 2 minutes, and tell you that your piston wrist bearing is going out on cylinder 3, without using any tools, or even touching the car... That's me. But I struggle with math, and just fight it out. CAD... Nope. I've tried, and tried, and tried. I'm getting better, but it's like pulling teeth. It's just not "natural" to me.

I had an issue with my printer, I asked for help. Everyone told me to do what I either "ruled out" or "already tried". I tried again, cause that's the kinda guy I am. I said "It's my heatbreak." and eveyone was like "no way." Guess what? Replaced it, and I'm 24 hours of print time in, without a single extrusion hiccup.

I am superb at diagnostics.
I can do math, using the proper software, to do it for me.
I can NOT design.

The day that all 3 of those, are EASY for everyone. (regarding using a printer) Is the day 3D printers belong in the home.

[...]

Printers need to be able to automatically calibrate the first layer. Printers need to be able to automatically adjust extrusion multiplier, and automatically adjust speeds when needed. Until printers can do these things, it's not fair to market them (or talk about them) in such a way, that any 6 year old child, can simply press "print" and it prints. When it runs out of filament you put more in it. Imagine a Laser Printer. They just WORK... Unless there's a mechanical failure, at which point, you DO NOT TRY TO FIX IT YOURSELF. You pay someone some serious $$$ to fix it for you. Why would you ever say, a 3D printer, which is MUCH more complex than a laser printer, is something you are ENCOURAGED to work on, because it's "easy".

One major thing to keep in mind is that when it comes to 3d printing, others have already done the work of tuning, which is the same as paper printing. It's only easy as someone has done the hard stuff already. Look at Prusacontrol. It has so few settings you can count them on one hand. Literally upload an STL, pick a few cookie cutter setups, and hit export. It really is darn close to laserjet, since someone else has done the hard stuff for you. (like laserjet, it would take a good long time for me to build one from scratch using no prefab printer parts, but there is no need. 3d printing is close to this same degree of public knowledge.

I definitely see what you mean about being a numbers person vs an artistic type. I personally found that 3d printing came to me pretty easy on both sides. I am definitely more of a numbers guy, but I have always been a software person. I am just the right age that I always had a computer, and always spent my spare time at a computer. Now I work for a living at a computer. I'm not a super wizard or anything, but I do consider myself a "pro software user / figure outer"
As such, my experiences in life did make picking up 3d printing pretty quickly, and my CAD skills are getting better and better. (Again, I'm not modeling the statue of david or anything, but I am beyond a beginner CAD level, and it wasn't very hard)

Maybe there are two categories as well as other experience related factors too. Numbers folks, artist types, and experience with software or other hardware.

Your background running CNC I'm sure was very helpful to learning to 3d print, right? There's alot of crossover with Gcode editing and the likes, which I am sure at least conceptually smoothed the learning process.

If I show you this.

And I said "It's easy to work on, no big deal, ANYONE can do it." would you believe me? No. You wouldn't.
I find 3D printers no easier to work on, than that specific machine.

Haha, talking to the wrong guy, I completely beleive you. If you can run a 3d printer, operating a slant bed isn't too much different really.
--> Like 3d printing, the CAD and CAM is what will cause troubles for a beginner.

On that note, the 3d printing community is super cool about helping each other out. You ever see what happens when a hobby metal worker asks for help at practical machinist [.com]? That crowd is brutal to beginners, lol.

Veröffentlicht : 25/04/2018 10:29 pm
Kwaad2
(@kwaad2)
Honorable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


You aren't getting it.

:mrgreen:


Anyone know what the Z step angle is and pitch of the screw? Looking to set my layer height. Are they 1.8* and .8mm?


Basically set the best layer height (ie .1978 or whatever it is instead of .2). A good explaination is the Layer Height section here: https://io3dprint.com/tips-for-3d-printing-miniatures/

Having experienced a Monoprice printer, Alan's second post means so much to me. It tells me that he is interested in finding the "magic number". Which yeilds the best results. For example on the Monoprice MIni V2.

As mentioned in that article. Every "step" on the Z axis is 0.0145833mm.
Many slicer's ROUND, and this cause MAJOR issues.

For example, let's say you want to print at 0.2mm layers.

0.18958333333
0.20416666666

So, to say it bluntly, you can NOT print at 0.2mm layers on that printer.
His question was, what is the equivalent of 0.04375/3 for the mk3?

The answer was 0.0025
🙂

So to answer his first post.
He asked is it a 1.8° step angle.
That is correct. Kinda.
It's actually
1.8°/32=
0.05625°

And he asked is the lead screw pitch 0.8mm. Which is wrong, the actual pitch was 8mm.

He never actually asked about the first layer. 🙂

I then went on to do the math to find the "magic number" for the mk3. Which is 0.0025mm. And in "practice" any 0.01mm layer height is TOTALLY FINE. 🙂


One major thing to keep in mind is that when it comes to 3d printing, others have already done the work of tuning, which is the same as paper printing. It's only easy as someone has done the hard stuff already. Look at Prusacontrol. It has so few settings you can count them on one hand. Literally upload an STL, pick a few cookie cutter setups, and hit export. It really is darn close to laserjet, since someone else has done the hard stuff for you. (like laserjet, it would take a good long time for me to build one from scratch using no prefab printer parts, but there is no need. 3d printing is close to this same degree of public knowledge.

Your background running CNC I'm sure was very helpful to learning to 3d print, right? There's alot of crossover with Gcode editing and the likes, which I am sure at least conceptually smoothed the learning process.

Haha, talking to the wrong guy, I completely beleive you. If you can run a 3d printer, operating a slant bed isn't too much different really.
--> Like 3d printing, the CAD and CAM is what will cause troubles for a beginner.

On that note, the 3d printing community is super cool about helping each other out. You ever see what happens when a hobby metal worker asks for help at practical machinist [.com]? That crowd is brutal to beginners, lol.

People have done the work, but the issue is every spool of filament is different. Every brand is different. Every color is different.
I've seen prints from Prusa Control, and it's BAD. Unless you only buy EXPENSIVE filaments... Don't expect your Prusa to yeild good results with Prusa Control. I hate saying that, but... yeah.

I know for a fact the default settings on the mk3, are TERRIBLE for what I print with. It's really mostly the "filament settings" and "infill speed". are the "disasters" in default configurations.

There needs to be some kind of automatic tuning, of those parameters, before 'anyone' can use it.

You are thinking of the "operator" side of CNC. I never did that. I was always Maintance/Engineering.

But my understanding of how to BUILD a 100,000$ CNC lathe... Transfers nicely in how to build a 1000$ 3D printer.

Yeah, the "community" is why I bought a Prusa. Hands down it's the best, and after my first "Cheap" unsupported disaster of a printer... I could easily dial in the mk3, and with the help of the community, I knew, I would have a "top tier" quality printer in no time.

Yeah, the CNC community is a little bit like... "Yeah. No. Do it yourself, or pay me 100$/hour."

Hi, I'm Sean. I used to work on CNC machines.
I try to not make mistakes, but the decision is YOURS.
Please feel free to donate to my filament/maintance fund.

Veröffentlicht : 25/04/2018 11:55 pm
joshua.w6
(@joshua-w6)
Eminent Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

Edited for clarity:

Agreed on all counts, sorry for the confusion, my other posts in this thread were chatting about that article which was linked to, not the original post here. I totally see why I may have caused confusion.

Monoprice select plus was my first printer, same struggles there. Loving Prusa living now adays. 🙂

Veröffentlicht : 26/04/2018 12:06 am
SilenTree 12th
(@silentree-12th)
New Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?


Anyone know what the Z step angle is and pitch of the screw? Looking to set my layer height. Are they 1.8* and .8mm?

I was reading into this issue now for hours and here's what I learned and could confirm. First off:

The rods are TR8x8(P2). This means they're 8mm in diameter and have a lead of 8mm (z lifts 8mm per full rotation). P2 stands for a 2mm pitch with 4 starts (irrelevant for your question but the more you know).

The motors have a 1.8° movement per full step with 16 microsteps inbetween. That results in 3200 steps per revolution with 200 full steps (which are relevant for the cause)

What you're looking for are the so called "magic numbers". The idea is, that those 200 steps have the full holding force contrary to microsteps which COULD (it's a very big COULD) lead to inaccuracies (I believe it's called z-wobble) when certain layer heights are printed.

The math is easy, confirming the specs was difficult:
8/200 = 0.04

One full step results in 0.04mm z-movement, so the layer height should be dividable by 0.04.

For example, if you want to print at 0.1mm layer height, you'd be better with 0.12mm or 0.08mm.
If you want to print at 0.15mm, it's better with 0.16mm.

In theory, this makes perfect sense, in reality however, nothing guarantees you that the printer doesn't home on microsteps (probably it does) and I have absolutely no idea how much inaccuracy you can get with two motors running on 24V at the same time. But my guts tell me, that it should improve print quality (at least in a miniscule scale). I will give it a try and check my results under a microscope.

However, I'm perfectly satisfied with my Mk3 and the quality I get. I just like to fiddle around and see what happens.

Veröffentlicht : 07/01/2019 5:34 am
Asraff Amzani
(@asraff-amzani)
Estimable Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

I've been wondering about the optimal layer height that mk2 and mk3 has with the given tr8*8 leadscrew.

Optimally, one would use 0.04 layer step up or adjustment when printing, hence having 0.04,0.08,0.12,0.16,0.20mm layer height options.

But prusa printers specifically, uses 0.05 layer step or adjustment, having 0.05, 0.1, 0.15, 0.20mm layer height options.

I had confusions over microsteps that I might get better resolution with higher microsteps but its just there to smooth out the motor movement which is to convert square wave to be as close to sine wave as much as possible.

I am looking an answer as why the original prusa able to use 50 micron or 0.05mm steppings instead of conventional 'open sourced' 40 micron or 0.04mm steppings in most other 3d printers?

Veröffentlicht : 02/04/2019 11:52 am
HMPoweredMan
(@hmpoweredman)
Active Member
Re: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

So what is ideal layer height for the MK3?

Divisible by .04 or
Divisible by .0025?

Veröffentlicht : 09/04/2019 9:53 pm
phmalcontacts@gmail.com
(@phmalcontactsgmail-com)
Eminent Member
RE: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

Tks every body, but,  HELP, I am lost like @kyle-s37.

I do not understand where the two calculations become different.

For the MK3S, and only  for the MK3S , what is THE magic  layer height number  :

Divisible by .04 or
Divisible by .0025?

 

ps :

 M503 code generate : on my MK3S 

echo:Steps per unit:
echo: M92 X100.00 Y100.00 Z400.00 E278.80

Veröffentlicht : 22/05/2019 7:05 am
lonnie
(@lonnie)
New Member
RE: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

You may find a good explanation here ReplicatorWarehouse.com about 3d printer for 28mm miniatures.

Veröffentlicht : 25/03/2020 10:16 pm
johnwilson6798
(@johnwilson6798)
New Member
RE: Motor step angle and screw pitch for MK3: 1.8* and .8mm?

Hi alan-e2,

You can check the specs below:

  • 2mm pitch, 4 starts, 8mm lead
  • High torque nema 17 stepper motor, 400mN.m/57.1 oz.in, 42mm, 2 phase 4 wires
  • Come with a brass nut and 1M (39.37") motor wire
  • NEMA 17 Stepper Motor with Integrated 100mm Tr8x8 Lead Screw, much stable than shaft coupling connecting
  • Great replacement for the Z axis of prusa i3 3d printers

For more information, you can also visit 3D Printers Point.

Veröffentlicht : 18/11/2020 4:22 pm
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