[UM2] [UM2+] - Reduce plate vibration

[Melka 57]

Hi,

Let me preface this by stating that I'm not an engineer, probably a dumb dude and very new to the 3D printing world.

I witnessed quite a lot of vibrations on the build plate of my Ultimaker 2+ and I think that it has a detrimental effect on the quality output.

I was wondering if we could put two small steel bars as an attempt to rigidify the whole plate and limit those vibrations.

I checked with my local hardware store and they supply flat bars of 35mm wide and 6mm thickness.

Here is a quick model I did, based on the source files of the plate shared on Github (thanks btw :->.

I calculated that each of those bars weight ~500g, so I would be adding more or less 1kg to the current plate.

A quick check with a 1kg spool filament showed me that the motor seems to lift the plate pretty well, not sure if the Z-accuracy is conserved though.

Do you think that adding those bars would help with the vibrations ?

Thanks for your help !

Edited October 19, 2016 by Guest

[neotko 1,417]

Looks good, any chance to use the existing holes to clamp it so there's no need to take everything out? Yea it would need to disassemble the bed, but if there's no need to drill the plate it might be easier to install (and less problems while doing it).

[Melka 57]

Here how the current plate looks like.

As you can see, there is a single hole that we could use.

Currently, there is nothing using that hole, at least on my model.

I'm not sure that this single hole would suffice to clamp the steel bar really tight, and I agree that it would ease a lot the overall project.

Plus, no original parts would need to be modified!

Edited September 3, 2016 by Guest

[neotko 1,417]

Yea it's complex to find the spot I bet. For me the best option atm it's

https://ultimaker.com/en/community/21649-pib-polybenzimidazole-isolator-coupler?page=2&sort=#reply-151749

But the mod need's some hard to make m6 stuff I think.

[Melka 57]

Hmm... But the rods are attached to a printed part screwed on the Acrylic panel where "Ultimaker 2" is written, no ?

That doesn't seem very rigid to me. Am I missing something ?

Edited September 3, 2016 by Guest

[catohagen 41]

would be better to use an 'L' shaped aluminium profile, 10x10mm with 1-1.5 mm thickness should stiffen enough, i would guess just gluing it with strong epoxy glue or similar would be enough to stop the vibrations.

[eldrick 64]

You are adding enough weight that I'd expect the whole plate to resonate at a slower frequency, i.e. it might not damp down to zero before printing of the next layer begins, and could give "echos" from that delayed motion.

[meduza 191]

If i were to stiffen up the bed, i would go with two C channels rather than trying to do it with those heavy steel bars.

I have been thinking about using a pair of DIN Rails (used for electrical installations, they are cheap and easy to come by, and especially the 15mm thick one is pretty stiff) to stiffen up the bed, but i have not tried it.

Edited September 3, 2016 by Guest

[Melka 57]

Hmmm, in my original idea, I planned to put the bars ABOVE the plate.

But... actually is much easier (and quite obvious!) to simply put it underneath the plate, with longer screws

Good idea Meduza! Seems straightforward to do!

Edited September 5, 2016 by Guest

[IRobertI 516]

Don't forget to adjust for the reduced travel if you put something underneath the platform, it's pretty tight under there.

That said, I've been wanting to do this myself for a long time but never got around to it. Will be interesting to see how much of a difference it makes.

[Melka 57]

Don't forget to adjust for the reduced travel if you put something underneath the platform, it's pretty tight under there.

 

The steel plates I plan to use are of 6mm height.

I think it won't touch the chassis of the machine as there seems to be around 1cm of gap.

I really hope it works, it would be cool to finally have a stiff plate

[meduza 191]

The thinner DIN rails i was thinking about using are 7.5mm high, and do only weigh about 300g/m (so less than 200g total added weight), the 15mm ones are slightly heavier.

[jhertzberg 19]

Here how the current plate looks like.

As you can see, there is a single hole that we could use.

Currently, there is nothing using that hole, at least on my model.

I'm not sure that this single hole would suffice to clamp the steel bar really tight, and I agree that it would ease a lot the overall project.

Plus, no original parts would need to be modified!

 

You also can have access to the rearward holes just forward of the four holes surrounding each of the linear bearings. You would just need to swap in a longer M3 screw.

[Melka 57]

Hey guys!

I said I will be back !

I made this modification a month ago:

Sketch:

Photos:

 

Stuff you need:

 

Steel bars

Width: 35 mm

Length: 305 mm for each of the 2 bars

Thickness: 3 to 5mm

Note that here, I used some steel angle of 3.5mm thick (8 euros for 1 meter...).

Please do not use that, as I had to cut quite a bit of the depth of my steel angle so it wouldn't touch the bottom of the printer when the bed is homing (Thanks Robert :>.

And I'm pretty sure flat steel bars are perfect.

 

Screws

Some M3 x 15mm and M4, long as well (sorry, don't remember the exact size)

 

How to do it:

If you want to do it yourself, you'll need a powerfull drill. The trickier hole is the 14mm one, start with smaller diameters and work your way up!

The easy way would be to simply laser cut those bars from a shop. I know https://pro.john-steel.com can do it in Europe. It's around 30-40 euros, I think. It will save you the hassle.

You'll have to be able to disassemble your printer to reach the plate and add the bars. It's pretty easy and takes around 10-15 min.

Note that there are no permanent modifications of your printer, so you can put everything back as before.

 

Results:

Overall, it adds around 500g to the plate and I didn't see any negative effects of that added mass. I used the machine 100+ hours after this modification. Z-hop works fine as well.

Previously, I experienced huge wobbling in Z of the complete bed when printing either at high speed, with some specific movements or when the print is at the front of the plate. Very often, I observed amplitudes of 1 or 2 mm, pretty sure it affects the output quality.

Now, I'm completely sure it drastically reduced the vibration. Though, I do not performed an actual scientific test to quantify that reduction. I have some Ultimaker 2 at hand that do not have this modification, I could make some video to compare.

There is still some very minimal flex, but it's due to: 1. 12mm bearings and 2. fitting of the 12mm axis in the frame of the printer. Anyways, those vibrations are not affecting my sleep anymore, I am reborn.

That said, it's still a huge design flaw. Why didn't you Ultimaker Gurus add some 12mm rods in the front of the printer to support the bed ?

My modification may even give a stiffer bed than the new plate on the Ultimaker 3. This new plate looks like a profilé, but it's probably still made of aluminum... and that metal is not really rigid.

Edited October 19, 2016 by Guest