Hotend/duct not moving smoothly X axis (left to right)

[Buurman]

Hi,

I have two Vorons, slightly different but both Formbot kits, my first two Voron builds.
One Voron make a bit more noise than the other, and I am starting to investigate why.....

I switched out motors, since they were a slightly newer model on the second voron, but that didnt change the situation.

I feel that on the silent Voron, the hotend is moving easier and without difference in fraction.

On the "loud" Voron I feel differences in fraction, not mechanical, but like motor resistance, but not constant, like every 7cm it gets a little more resistance, that you need to push through, and then it start over again. This is not the rail, I removed the belts, and without belts its smooth as a baby butt  (I can say that as a daddy, I hope)
It does this with motor wires off, since its never good to move your axis (faster) with wires connected.

Anyone having a idea where this might come from? nothing is loose, nothing seems out of center...

Things I may check still:

• are the belts the exact same length (for XY), they look the same, but need to fully take them out to check. (and can this cause this?)

Anything else.. dont know.. again, motors swapped already... belts double checked...

[smirk]

23 minutes ago, Buurman said:

baby butt  (I can say that as a daddy

Course you can but I always find it an odd analogy to use given what we all have found hiding in nappies (and on floors, hands, on their baby-grows, up their backs.......) Unless you're subconsciously observing about the state of the printer. Perhaps you need to do a  sniff test?

On a slightly more sensible note, perhaps the idlers or bearings? I guess we do run these things on threaded screws (for their axles) and under tension when the belts are tightened. If they're not running entirely smoothly then might exhibit as noise or "stickiness".

[Buurman]

Well, yeah right now its deep shit  hahaha, maybe I did mean something with it..

Yeah, I checked the bearings, but like you said, maybe under tension, so I will try to test them one by one with a belt under tension...

Lets see if I can find out what this weird issue is... It prints fine, but it can never be good this uneven feeling...

[Buurman]

Thanks SMIRK!

To be exact, it was the left bearing (with teeth) on the X gantry.

Strangely, it is moving freely without belt, but with tension of the belt, it got "grippy" somehow, and caused this very strange bumpy feeling.

Loosened both sides to be sure, really not even close to being tight, I think about 3/4mm lose from feeling grip, they just function as axis anyhow.

I will be looking for a version with very little screw length, and mostly being smooth, I want to prefend this in the future.

Edited August 1, 2022 by Buurman

[smirk]

41 minutes ago, Buurman said:

I will be looking for a version with very little screw length, and mostly being smooth,

If (when!) you find  the appropriately sized shoulder bolts let us know. Occasionally I go on a quest to find some and I've never yet found the perfect combo: Long shoulder/shaft and minimal screw. There's generally too much screw or not enough shoulder.I guess I could hack-saw off the excess screw but I'd prefer to have the right size.

 

Probably worth checking the bearing inside the toothed pulley, on the few printers where I've switched to shoulder bolts, I've found the inner race/bearing of the pulley has been shot - in no small part cause I'd used cheap ones, can't blame the threaded screw for everything.

[Buurman]

Yeah I checked the bearing and it seems ok, rolling it with some force it seemed good.

now I need to make it my life mission to find these smooth bolds

[Buurman]

This could be an option maybe @smirk, rather had them in M5 x 40/45 but longest is 35mm.

This would still be ok I think, leaving enough length in the top to keep it strong and centered.

[Buurman]

Or these, I ordered them both to give it a test... 

And new toothed bearings/idlers, seems still like its coming back slightly.. so new ones...

[smirk]

Daft question, those first ones (with the small threaded but). Don't they need a flange at the top to act as fasteners (hold things together)?. If they're only axels (as it were) and not fasteners then fabby..

[Buurman]

The screw currently holds no function at all, not keeping things together. The other screws do that.

i think they are solid, just axis nothing special.

if you would insert the first ones, I think it will work fine, the trick is ever getting them out again

again, it can fail, I will try it

Edited August 1, 2022 by Buurman

[smirk]

1 minute ago, Buurman said:

the trick is ever getting them out again

Magnets (although they do look stainless steel so might not be magnetic depending on the "variety") and assuming you don't have them enclosed, but definitely sounds like it could work then if they're only axles.

Thinks aloud......Actually I wonder if the design was enclosed (no holes to thread in bolts) if you could get away with round "pins" to act as axle, but there again there might be wear if the pins moved/rotated over time. At least with something that is screwed in it shouldn't rotate and start enlarging its own hole

[mvdveer]

7 hours ago, Buurman said:

Thanks SMIRK!

To be exact, it was the left bearing (with teeth) on the X gantry.

Strangely, it is moving freely without belt, but with tension of the belt, it got "grippy" somehow, and caused this very strange bumpy feeling.

Loosened both sides to be sure, really not even close to being tight, I think about 3/4mm lose from feeling grip, they just function as axis anyhow.

I will be looking for a version with very little screw length, and mostly being smooth, I want to prefend this in the future.

 

Have you considered the pin mod. I am, but first want to get the printer going.

 

 

Most recent version here:

https://github.com/VoronDesign/VoronUsers/tree/master/printer_mods/hartk1213/Voron2.4_Trident_Pins_Mod

 

 

[smirk]

9 hours ago, mvdveer said:

Have you considered the pin mod.

Now that is precisely what I was thinking of, that would definitely do the trick and avoids threaded screws as spindles.

[mvdveer]

6 minutes ago, smirk said:

Now that is precisely what I was thinking of, that would definitely do the trick and avoids threaded screws as spindles.

Wish I came across it before I printed all the parts for the current build. Once I get this current machine/build purring, I'll do the mod

[smirk]

12 minutes ago, mvdveer said:

current build.

This the never ending build? I think we're going to have to call you Sisyphus. Except, instead of a rock, it's a 2.4. Clearly I'm down here in Tartarus with you, the beardy old troll that comes across to torment you and ask "Whatcha doing? Ooooo, did you mean to do that?"

[Buurman]

11 hours ago, smirk said:

Magnets (although they do look stainless steel so might not be magnetic depending on the "variety") and assuming you don't have them enclosed, but definitely sounds like it could work then if they're only axles.

Thinks aloud......Actually I wonder if the design was enclosed (no holes to thread in bolts) if you could get away with round "pins" to act as axle, but there again there might be wear if the pins moved/rotated over time. At least with something that is screwed in it shouldn't rotate and start enlarging its own hole

Only the very last part has thread, the rest is without, the last 5mm or so is threaded.

If the axle will spin, I agree, it may wear, but I think it wont, otherwise a little Loctite should help.

1 hour ago, mvdveer said:

I printed all the parts for the current build

Are you building a printer???   

1 hour ago, smirk said:

"Whatcha doing? Ooooo, did you mean to do that?

Hahahaha!

[Buurman]

11 hours ago, mvdveer said:

Have you considered the pin mod. I am, but first want to get the printer going.

Most recent version here:

https://github.com/VoronDesign/VoronUsers/tree/master/printer_mods/hartk1213/Voron2.4_Trident_Pins_Mod

Looks promising to be honest... ah crap... now I need to test 2 things...  Ordering pins/dowels today, but I think about taking it one step further.. going for CARBON shaft and cut it myself, still need to think about this idea, but I like the weight saving and I know they are very strong...
Since I am still also thinking about using a carbon X axis, not that I care a lot about speed, rather quality, but, its the experimental guy in me... @mvdveer you know what its like...

[mvdveer]

24 minutes ago, Buurman said:

not that I care a lot about speed, rather quality, but, its the experimental guy in me... @mvdveer you know what its like...

Oh don't I just...

[smirk]

26 minutes ago, Buurman said:

CARBON

Granted the spindles wouldn't be long but would there be a certain amount of flex in carbon spindles?  I'd also read/seen somewhere that the Carbon fibre (guess it's really the weave with the epoxy) softens at a relatively "low" temperature (by "low" I mean something you might see in a printer's chamber). Sorry, I'll need to find that reference otherwise I'm just in hand-waving speculation mode (again!)

[Buurman]

14 minutes ago, smirk said:

Granted the spindles wouldn't be long but would there be a certain amount of flex in carbon spindles?  I'd also read/seen somewhere that the Carbon fibre (guess it's really the weave with the epoxy) softens at a relatively "low" temperature (by "low" I mean something you might see in a printer's chamber). Sorry, I'll need to find that reference otherwise I'm just in hand-waving speculation mode (again!)

Well, I didnt think about that, so that a good thing to bring up...

But you see these CF Axis for the X gantry ... I mean, these only work if they can handle heat well.. without bending... 
I wonder if I can find anything about their heat resistance...
The FLEX would be non existing I think, since none of the axle is out in the open, it has no space to flex...
And again, I worked with it before in building large prints like my Witcher 3 Swords and loved the stiffness of them... will they wear? I dont know... but dont think so..

[Buurman]

These could also be an option, but I dont really like the price tag of it
But the mechanics of it is perfect... 

https://www.aliexpress.com/item/1005004502239524.html?spm=a2g0o.cart.0.0.683738daYaSH8I&mp=1

But I think, looking at them, you cant mount your end stop switches to it... so they are useless to me.. 

[smirk]

9 minutes ago, Buurman said:

I wonder if I can find anything about their heat resistance

Well so far I've failed to find the reference I'm talking about, few academic papers though. From what I can determine it's really the resistance of the epoxy/glue used to hold the stuff together (the carbon itself will survive several thousand C). Perhaps I stumbled across really cheap'n'nasty CF that's held together with butter.

[Buurman]

Every time I look at this print quality, I start to drool a little... I still have some work to do I see... pfff
But I am printing them. going for it... 

So I will test 3 things I guess.. 

In current XY joints I will test several replacements for the M5 bolt, 2 different pins, and maybe Carbon rod.

And then on newely printed PIN XY Joints, I will test Stainless pins AND carbon rods.

 

[smirk]

Just now, Buurman said:

I still have some work to do I see..

Being old, I always like to point out "no matter how good you think you are, there's always someone/something better", but also being old (and wrinkly with apparently a funny complexion) I appreciate sympathetic lighting and good camera angles.

[Buurman]

The older I get, the less I care I always say  

Now closely approaching 50, sooooo, lets say, I care about 50% less  

 

Still.. its a damn smooth print... or.... creative photography  

Edited August 2, 2022 by Buurman

[Simon2.4]

1 hour ago, Buurman said:

These could also be an option, but I dont really like the price tag of it
But the mechanics of it is perfect... 

https://www.aliexpress.com/item/1005004502239524.html?spm=a2g0o.cart.0.0.683738daYaSH8I&mp=1

But I think, looking at them, you cant mount your end stop switches to it... so they are useless to me.. 

Those do look sweet, however, IMO alot of the Voron's "personality" comes from it's printed parts. It's esthetics of course and very personal, how it their weight compared to the printed parts @116gr a pair ? This, for me, would be the biggest factor to consider. Their price is not too bad considering this is billet machined.