SIS - Seismic Isolation System for A1 mini

Project Overview

Welcome to the SIS project! 

The “SIS - Seismic Isolation System -” project aims to achieve superior vibration and seismic isolation performance for Bambu Lab’s 3D printers, specifically the “X1” and “P1” series.
 

This project was inspired by @thrutheframe’s “HULA,” which features a sliding isolation bearing structure using thrust bearings.
This structure is a highly reliable technology that has been widely adopted in Japanese buildings to protect them from earthquakes.

Traditionally, implementing seismic isolation mechanisms in 3D printers required the use of ball bullets, which made miniaturization difficult.
However, by utilizing thrust bearings, “HULA” successfully achieved significant downsizing—an impressive accomplishment.
I would like to express our sincere respect to @thrutheframe and the “HULA” project.
 

The SIS project, like “HULA,” adopts a sliding isolation bearing structure with thrust bearings, and is designed to achieve the following features:

• A more compact body design
• Improved seismic isolation performance
• Enhanced cushioning capability

Important note on A1 mini version

There are some important points to consider when using the A1 mini version.
Please be sure to check the following.

The A1 mini is a very compact 3D printer and therefore weighs very little.
It is also a bed slinger type, so its weight is not evenly distributed over the ground surface.

It is important that the SIS body does not move in order to achieve 100% SIS performance.
This requires a certain weight, but the weight of A1 mini does not meet that criterion.

Therefore, the use of TPU mats is not recommended for SIS for A1 mini, and the use of Earthquake Proof Gel mats is strongly recommended.
If you must use a TPU mat, please use double-sided tape or other means to secure the mat in place.

SIS Family

For SIS other than for the A1 mini, check the following.

for X1/P1 Series : https://makerworld.com/en/models/915508

for A1 : https://makerworld.com/en/models/1081524

Seismic isolation performance of SIS

Using the iPhone’s accelerometer, we compared the vibration levels of SIS with both the stock feet and Bambu Lab’s anti-vibration feet.

SIS reduces the printer’s body shake to approximately two-thirds of the level seen with the stock feet.

By absorbing and dispersing the vibrations generated by the printer, SIS improves both print quality and noise reduction.

Here are the test results for SIS.

Here are the test results for Stock Feet.

The stock feet recorded a vibration level of 1.23 m/s², exceeding the allowable threshold of 1.0 m/s² shown in the graph.
 

However, the Bambu Lab’s anti-vibration feet sold by Bambu Lab significantly increase body vibration.

Although they provide a similar level of noise reduction to SIS, they may negatively affect print quality.

Here are the test results for Bambu Lab’s Anti-Vibration Feet.

The vibration caused by the Bambu Lab’s anti-vibration feet is so intense that it cannot be properly compared using the standard graph scale.

When the Y-axis is extended to 2.5 m/s², the full extent of the vibration becomes visible.

I recommend discontinuing the use of AVF and switching to SIS instead.

The vibration test is conducted at a maximum printing speed of 500mm/s.
In terms of max volumetric speed, this equals "40mm³/s," a speed that most commercially available filaments cannot handle.
In actual use, the vibrations would likely be much smaller.

The vibration test was conducted under the same conditions using the smartphone app “phyphox.”

You can check the details of the app on the website below.

https://phyphox.org

What you will need

The following items are required to print SIS.

• PLA filament
  The body of the SIS should be made of a rigid material with low toughness and no shrinkage.
  Therefore, PLA filament is suitable, not PETG or ABS.
  Any general PLA filament can be used.
   
• TPU 95A filament
  SIS anti-vibration dampers use TPU 95A filament.
  However, there are differences in hardness among manufacturers, so if you are concerned about this, please use the following Overture Highspeed TPU.
  https://amzn.to/3yKCeCb
   
• M3 6mm bolts
  The main body of the SIS is divided into a lower cover and an upper cover. 
  Two or four M3 6mm bolts should be prepared for each body to secure it during assembly.
  Two bolts are sufficient if they are fixed diagonally, but four bolts are recommended.
   
• M3 4mm bolts
  Axis Feet for A1 mini must be bolted by design.
  Two bolts are used per foot.
   
• F8-22M thrust bearing (11 ball model)
  Like HULA, SIS uses a sliding bearing type seismic isolation mechanism.
  Like HULA, four F8-22M standard thrust bearings are required.
  There are various numbers of balls on the market, but SIS is designed to fit an 11-ball model.
  If the support in the center of the bearing is 20.2 mm in diameter, there is no problem.
  https://amzn.to/3Va6YE6
   
• Earthquake proof gel mats (Highly Recommended)
  Use Earthquake Proof mats whenever possible.
  Fits 40mm x 40mm x 5mm gel mats.
  Details of the mats, including where to purchase them, are described separately below.

About SIS Features

SIS involves precise measurements and design to control bearing behavior and maximize its effectiveness.
The design, adjusted to micron-level precision, ensures excellent sliding performance, smooth operation, and no wobbling.

This precise design ensures that the bearing washers and Cage & Balls do not contact the parts and operate properly within the maximum operating range.
This provides even better seismic isolation.

The dampers are specially designed with a thickness of 0.5mm using TPU material.
They feature eight ribs connecting two circles, providing moderate elasticity and damping force.
Prior to reaching this design, nearly 50 dampers were created and tested iteratively.
 

TPU mats optimize modeling options to maximize effectiveness.
The thickness of the top and bottom surfaces were adjusted and the wall surfaces were removed to bring out the flexibility of the TPU.
This contributes slightly to the seismic isolation effect.

Additionally, SIS is compatible with superior commercial noise and vibration-resistant gel pads compared to TPU.
The 40mm x 40mm x 5mm gel pads provide even more powerful vibration isolation capabilities.

You can get four of these pads in Japan for only $0.64.

DAISO is AMAZING !!
https://jp.daisonet.com/products/4549131944020

Higher-performance gel pads, which serve as an alternative to DAISO products, can be purchased on Amazon.

If you’re aiming for top performance, the ELECOM TS-F006 is highly recommended.
https://amzn.to/3PfIVRP

I was given information about the mats sold on Aliexpress.
You can purchase them below.
Thanks for the info! @alexloe
https://www.aliexpress.com/item/1005007409323784.html

Updates

Version 1.2

The bearing’s range of motion has been further optimized.
Additionally, since the hardness of TPU can vary depending on the manufacturer or material aging, we have added a softer damper model.

I recommend trying the standard damper model first, and if you feel the shock absorption is too stiff, please try the soft version.

The print profile has also been updated.
Previously, due to a bug in Bambu Studio that caused the first layer of the damper to fail, Arachne was specified for outer wall generation.

However, with a new approach introduced in this update, we’ve confirmed improvements.

Left : New Print Profile , Right : Old Print Profile

Print quality has been verified, but if your print fails, please manually switch the relevant parameters back to Arachne.

SIS Assembly

Please refer to the following instructions for assembling the SIS.

1. Attach Housing Washer to Bottom Body
   
   
   
   First install the “Bearing Housing Washer” in the red area of the Bottom Body.
   The Housing Washer should be installed with the smooth surface without grooves facing up.
    

2. Fixing Top Body to Bottom Body
    

   
   
   Align the Bottom Body with the Top Body and secure with M3 6mm bolts.
   Fix at least two M3 6mm bolts diagonally, or all four if possible.
    

3. Place Cage & Balls on Housing Washer
    

   
   
   Place the bearing Cage & Balls on the Housing Washer.
   Be careful not to touch the bearing balls with bare hands, as they will not slide smoothly.
    

4. Storing the damper in the body
    

   
   
   Push the damper into the body and store it.
   The top body has a slight return to prevent the damper from coming off, but the TPU damper can be inserted without any problem.
    

5. Assembling Axis Feet
   
   
   
   Assemble the Axis Feet using M3 4mm bolts.
   Align the screw holes in the base with the holes in the foot parts and bolt them together to secure them in place.
   
   The characters on the foot parts indicate the following meanings.
   FL: For Front Left
   FR: For front right
   R: For rear (for both left and right)
    

6. Attach Shaft Washer to Axis Feet
    

   

   
   Push the Shaft Washer of the bearing into the red area of the Axis Feet.
   The Shaft Washer should be installed with the smooth surface without grooves side down.
    

7. Place Axis Feet on the body
    

   
   
   Align the Axis Feet with the center of the TPU damper.
    

8. Attach the mat to the main body
   Finally, attach an earthquake-proof gel mat or a TPU mat to the recess on the bottom surface of the bottom cover.
   
   
    

   If you’re using a gel mat, since it is adhesive, remove the film on one side only before attaching it.

   Peel off the remaining side when fixing it to the installation location.
   Repeat steps #1 through #8 a total of four times to complete all SIS.

Installation Notes

When installing SIS on the A1 mini, remove the rubber feet on the bottom of the printer.

The SIS is designed to fit on the appropriation when the rubber feet are removed.
To improve stability, this correspondence must be made.