Lack Enclosure, ringing, rubber feet  

Re: Lack Enclosure, ringing, rubber feet

[...] My concept is a 1/2" steel plate drilled at foot locations, and then attached to the MK3 using t-nuts and felt-pad insulators between. A half-inch plate of approximately 12x14 would ring in at about 25lbs, and the MK3 would remain at approximately the original height.
I'm reading conflicting information about the importance of platform stability. My Mk3 is on an end table with several years of magazines stacked up on the lower shelf. It's very solid and I'm getting good results. I've read up on the paver approach, and considered doing something similar.

Recalling my days working with hifi and turntable stability, I immediately thought about some of the solutions we used back then. I was looking into the use of inverted cones to concentrate all the weight into a vary narrow surface to lock the platform into place. Then I read some material indicating that some flex between the printer and platform is desirable. They described the importance of a car suspension when keeping a platform steady on rough roads. In this case, the printer is the origin of the vibration, but according to the article, some play in the suspension (feet) is desirable for overall dampening. Give it something to absorb the vibration.

I'm curious about the hard rubber feet with felt, but I'm going to hold off on anything more dramatic.

One thought on your steel plate: If offered in the Prusa online store, I wonder what shipping would be? Perhaps something more practical like the sand-filled bases like those used for portable basketball hoops?

Re: Lack Enclosure, ringing, rubber feet

One thought on your steel plate: If offered in the Prusa online store, I wonder what shipping would be? Perhaps something more practical like the sand-filled bases like those used for portable basketball hoops?

I'm not suggesting Prusa offer this, shipping would be absurd! Sand filled is a good idea. But I am thinking of making this for myself -- my preference of this over a simple paver (and sand would be similar) is that it is much more dense and wouldn't raise the printer higher in the enclosure and be easily drilled, unlike a paver.

Re: Lack Enclosure, ringing, rubber feet

[...] it is much more dense and wouldn't raise the printer higher in the enclosure and be easily drilled, unlike a paver.
I'm definitely not an engineer, nor a materials expert. It seems to me there are 3 approaches:

In the recent Prusa blog post, he mentions that the solid feet with felt approach shows promise. Stabilizing the platform is always a good thing, but I wonder how much it improves actual prints?

Re: Lack Enclosure, ringing, rubber feet

Maybe screwing it to 3/4" plywwood and then piling weights on either side of it would do just as well? Seems a little easier than procuring and drilling 1/2" steel, and it would remain not too heavy in case you needed to move it.

Re: Lack Enclosure, ringing, rubber feet

Maybe screwing it to 3/4" plywwood and then piling weights on either side of it would do just as well? Seems a little easier than procuring and drilling 1/2" steel, and it would remain not too heavy in case you needed to move it.

Except in my case I have a friend with a machine shop and a waterjet capable of cutting 1" stainless. This is probably' gonna be one-of-a-kind.

Re: Lack Enclosure, ringing, rubber feet

Except in my case I have a friend with a machine shop and a waterjet capable of cutting 1" stainless. This is probably' gonna be one-of-a-kind.
Hah! If you've got that available, go big! Print the entire platform as hunks of steel! Bonus points if you rivets or use big ugly blued welding marks to make it look like a 1930's iron works product. Rig up some LEDs to make it look a Bessemer furnace when you open the doors. Totally overkill, but man would it look good!

Maybe I'm getting carried away...

Re: Lack Enclosure, ringing, rubber feet

Except in my case I have a friend with a machine shop and a waterjet capable of cutting 1" stainless. This is probably' gonna be one-of-a-kind.
Hah! If you've got that available, go big!

Well, I'm actually trying to go small. Steel sheet is 1.5" shorter than the popular paver.

Maybe I'm getting carried away...

Perhaps a trifle. 😉

Re: Lack Enclosure, ringing, rubber feet

Perhaps a trifle. 😉
Maybe just welder's goggles when you open it up?

Re: Lack Enclosure, ringing, rubber feet

When I got my first MK2S last year I saw that some people were putting them on pavers/blocks to help reduce the vibration. I, however, went another direction. I had a large mouse pad - approximately 1/4" thick and 12" x 20". I placed the printer on that and not only did it reduce the noise of the printer, I had very few issues with prints. Usually the prints I had issues with were 99% cause by me/bad settings.

I now have 2 MK2S, and 1 MK3. All 3 units are on 1/4" thick rubber padding. The weight of the MK3 is enough so that parts of the frame, in addition to the feet, make contact with the rubber padding.

Re: Lack Enclosure, ringing, rubber feet

When I got my first MK2S last year I saw that some people were putting them on pavers/blocks to help reduce the vibration. I, however, went another direction. I had a large mouse pad - approximately 1/4" thick and 12" x 20". I placed the printer on that and not only did it reduce the noise of the printer, I had very few issues with prints. Usually the prints I had issues with were 99% cause by me/bad settings.

I now have 2 MK2S, and 1 MK3. All 3 units are on 1/4" thick rubber padding. The weight of the MK3 is enough so that parts of the frame, in addition to the feet, make contact with the rubber padding.

Can you post a link to the padding that you're using?

I think some of it may depend also on how sturdy/massive your table is. If its not rock solid, maybe the extra mass helps some.

Re: Lack Enclosure, ringing, rubber feet

[...] I think some of it may depend also on how sturdy/massive your table is. If its not rock solid, maybe the extra mass helps some.
That's what I'm thinking. You want the platform stable so as not to transfer vibration from the surroundings or resonance in the platform itself back into the printer frame. No shimmy and shake. I've got my end table loaded with 3 feet of old magazines underneath and it's sunk pretty well into the carpet.

The foam would work independently, isolating the printer from the platform and vice-versa. Deadening any vibration. I think this is where the foam or cork recommendations come in.

If I'm understanding things correctly, the issue with the existing feet is that they simply isolate the printer frame somewhat, but don't really dampen very well, resulting in a bit of wobble.

Re: Lack Enclosure, ringing, rubber feet

I went with a paver on top of a bicycle inner tube. Before I did so my printer and the worktable it is on shook like mad. Very little vibration remains in the printer and table now.

Regards,
Martin

Re: Lack Enclosure, ringing, rubber feet

I went with a paver on top of a bicycle inner tube. Before I did so my printer and the worktable it is on shook like mad. Very little vibration remains in the printer and table now.

Regards,
Martin

Interesting. Does your MK3 still have the regular Prusa feet, or did you switch them for something else?

Re: Lack Enclosure, ringing, rubber feet

It still has the regular feet. A few months back I think it was February/March there was several topics on the subject of vibration and means of reducing it. One of the conclusions that came up was that the rubber feet did not absorb much of the vibrations at the frequencies that were shaking the printer and instead transmitted it to whatever the printer was standing on. As a result placing the printer with the feet fitted onto a paver effectively added mass to the base of the printer thus reducing the vibrations. The inflated innertube acts as a damper and isolator damping the remaining vibrations and reducing the amount that is transmitted to whatever it is standing on.

Regards,
Martin

Re: Lack Enclosure, ringing, rubber feet

When I got my first MK2S last year I saw that some people were putting them on pavers/blocks to help reduce the vibration. I, however, went another direction. I had a large mouse pad - approximately 1/4" thick and 12" x 20". I placed the printer on that and not only did it reduce the noise of the printer, I had very few issues with prints. Usually the prints I had issues with were 99% cause by me/bad settings.

I now have 2 MK2S, and 1 MK3. All 3 units are on 1/4" thick rubber padding. The weight of the MK3 is enough so that parts of the frame, in addition to the feet, make contact with the rubber padding.

Can you post a link to the padding that you're using?

I think some of it may depend also on how sturdy/massive your table is. If its not rock solid, maybe the extra mass helps some.

here's the stuff i'm using on the 2 MK2S that I have at work.
https://www.amazon.com/gp/product/B001FZTO06/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

the MK3 is on the oversized mouse pad. Basically this stuff above with a thin layer of spandex.

Re: Lack Enclosure, ringing, rubber feet

I would be surprised if changes in the oscillation of the whole printer (amplitude or frequency) by changing the systems “standard feed on a good massive table” would actually improve the print quality more than marginal.

The quality of the print is getting worse if the vibrations of the print table/plate are “different” than the vibrations on the extruder head. And the weakest connection between the table and the extruder are probably the belts.

Re: Lack Enclosure, ringing, rubber feet

This morning I put a paver stone under the MK3. Wow! It runs much quieter than before. I hadn't expected such a big difference in sound output.

Re: Lack Enclosure, ringing, rubber feet

Yup, it makes a major difference. There have been a few occasions when I have fallen asleep watching the TV with the printer in the same room and it has not woken me up.

Regards,
Martin