Paul T's Voron 2.4 Build

[Paul Trautner]

I purchased a fystec voron kit off aliexpress which I planing to build with some modifications. 

First mod is using a 30:1 harmonic gearbox for the z axis. This should give higher resolution, no z droop, and no backlash to affect z hop and bedmesh moves. For this mod I used the galileo 2 z-drive files with some minor modifications.

Second mod is to the stealthburner tool head by adding the idm scanner with can, the hgx larger gear extruder, and modified components to remove weight.

Post any other modifications you think I should look at during the build. Below are some of the pictures so far

[Paul Trautner]

Made some good progress and as hoped there is no gantry motion when force is applied so gantry sag should be solved. Next is to wiring the electronics and get it moving 

[YaaJ]

Harmonic gearboxes still are a bit expensive (much less than 15 years back, and some cheap ones on Ali...) Where did you get them from ?
The toolhead mod is gorgeous !

 

[Paul Trautner]

10 minutes ago, YaaJ said:

Harmonic gearboxes still are a bit expensive (much less than 15 years back, and some cheap ones on Ali...) Where did you get them from ?
The toolhead mod is gorgeous !

Similar cost to the new galelio z drive but with better resolution, little to no backlash, and no gantry sag.

[YaaJ]

Thanks !
Completing a 2.4/350 project, I'm a bit worried with the gantry sometime dropping... Even had to increase the limits for the leveling, one corner dropping a bit too easily.
Will consider this mod in the future !
Didn't know about the Galileo Z drive : until now, thought it was an extruder...

[claudermilk]

11 hours ago, YaaJ said:

Didn't know about the Galileo Z drive : until now, thought it was an extruder...

It's a bit confusing. There's a Galileo2 extruder and a Galileo2 V2 Z drive mod. I'm not sure why they named them the same thing.

[Paul Trautner]

Made some progress on the electronics. With this layout would you move the fans to the back of the printer? With the harmonic drives the fans don't fit on the side bit I also think with this layout the back is better 

[Dirk]

17 hours ago, claudermilk said:

It's a bit confusing. There's a Galileo2 extruder and a Galileo2 V2 Z drive mod. I'm not sure why they named them the same thing.

I had been seeing the Galileo name often recently. Like you, when I saw @Paul Trautnerpresent his 'galileo' z-drives, I browsed a bit and finally found out a bit about a piece of information which will be probably documented in the 'ages of voron history'.

I am no Hans Christian Andersen or a university lecturer, but here is why and what and how...

The 'inventor' of these galileo z-drives, is a guy called Jared and he is from the Voron Design Team. He was the one who signaled a simple but very effective design by a guy named Robert Lorincz on Thingiverse. It was a concept of a so-called planetary-gear design (I am also not an engineer) for an extruder. Jared liked the concept so much that he popularized the extruder in the Voron community.

From this popularization the Orbiter 1.5 was also released on thingiverse. An extruder which can be printed and made with a few extra simple and cheap parts to use in the Voron Afterburner, to replace the Clockwork-1 extruder. The name Orbiter, because apparently the central gear rotates while the 3 smaller gears rotating around it within a case. Like a solar system with only 3 planets.

He himself used the same concept to design his own larger planetary gears which he used as the Z-drives for the voron 2. Out of respect for Lorincz, he named his planetary gear system - Galileo- You know... this italian scientist we know, from the 1600's who was trialed by the catholic church because he said the world was orbiting the sun, and not the other way around

Anyway, the z-drives he designed, are a complete replacement mod for the z-drives and the skirts of the Voron 2. You need to buy parts for +- 5 euros to build each.
At the heart of these z-drives lies still the design of Lorincz with a 7.5:1 gear ratio.

Galileo version 2, which is a more stable version, where the powers are better distributed over the gears and over the central gear, by using a 9:1 gear ratio. Galileo 2 is actually only the name of the gear system, the planetary design. Their project is still at the beta stage.  Using the Galileo it implements a stealthburner clockwork-2 replacement, a stand-alone replacement to use with non-stealthburner systems and the z-drives. 

The galileo-2 z-drives are very compact and light, with the pancake motors driving the gears to produce more than enough power and resolution. That is why they are also being used already in the Micron as a mod above the official version (not in the mods folder, so maybe even considered to be part of a future micron version).

Even in beta stage, the manufactured galileo kits are all sold out on all voron parts selling shops over the world. The price is even higher than the exorbitantly expensive orbiter 1.5 / 2.0, while it can be printed / made once the cad is made public.

A search of galileo extruder on my favorite shop, aliexpress shows kits, and when you read the details, they are just orbiter 1.5 DIY kits that are sold for 4 times the price (7.5:1 gear ratio, not 9:1) of the orbiter 1.5.

So... less exciting than Hansel & Gretel, but that is how the planetary rotations of a thingiverse design centers around the revolving worlds of  the orbiter 2.0, galileo extruder, galileo-z-drive and the kits that are sold out. 

I decided to wait until the cad comes out and I can print and assemble my own Galileo-2

Edited December 29, 2023 by Dirk

[Graymattor]

The Harmonic gearboxes have certainly peeked my interest.. 

However, looking on Aliexpress they are not cheap to the UK! £100 each - ouch!! The Galileo 2 Z drives are £37 each but they are only 9:1.. 

There appears to be a few printed options  

https://cults3d.com/en/3d-model/tool/3d-printed-strain-wave-gear-harmonic-drive

Edited December 29, 2023 by Graymattor

[atrushing]

2 hours ago, Graymattor said:

The Harmonic gearboxes have certainly peeked my interest..

There appears to be a few printed options

They piqued my interest as well from a video of the very design that you linked. How To Mechatronics has a great writeup explaining the design of strain wave gears including a download link to Thangs.

I started designing an harmonic extruder but that has been put on the backburner for a year already.. The ball bearings keep things aligned better but the needle bearings allow for a thinner and more flexible strain gear.

[Paul Trautner]

4 hours ago, Graymattor said:

The Harmonic gearboxes have certainly peeked my interest.. 

However, looking on Aliexpress they are not cheap to the UK! £100 each - ouch!! The Galileo 2 Z drives are £37 each but they are only 9:1.. 

There appears to be a few printed options  

https://cults3d.com/en/3d-model/tool/3d-printed-strain-wave-gear-harmonic-drive

You won't be able to fully print the galelio2 because it's a custom motor with a different pinion. The teeth are also pretty small which make them hard to print accurately with fdm. 

[Paul Trautner]

1 hour ago, atrushing said:

They piqued my interest as well from a video of the very design that you linked. How To Mechatronics has a great writeup explaining the design of strain wave gears including a download link to Thangs.

I started designing an harmonic extruder but that has been put on the backburner for a year already.. The ball bearings keep things aligned better but the needle bearings allow for a thinner and more flexible strain gear.

What gear ratio did you have with your design? I downloaded the cults nema 17 harmonic drive with a 30:1 ratio and it works but the wave generator produces too much heat and melts on long fast moves. I wanted to redesign the mechanism with 1 module gears which would half the ratio to 15:1 but when I modeled with involute gears they did not mesh correctly. I was also going to change the design from the balls in the wave generator to 2 small ball bearings thinking that it would help reduce heat generation. I wanted the z axis to move at 10mm/s but if you limited the speed to 5mm/s or less with the parts printed in nylon the design on cults should work for this application. After my printer is built I plan on trying to make a better design with a 15:1 ratio in the attempt to get 10mm/sec moves with a 3d printed harmonic drive

[atrushing]

21 minutes ago, Paul Trautner said:

What gear ratio did you have with your design?

I used a 36t circular spline and a 32t flex spline so it ended up with an 8:1 ratio. With the steel needle bearings it seemed to have too much friction so I am planning on rebuilding it with PTFE bearings. I think I need to make the strain gear more flexible as well. I found that the design is very dependent on good tolerances and it took a lot of trial and error getting a good fit.

I did get the drive spinning well enough but I never did any endurance testing.

[Paul Trautner]

31 minutes ago, atrushing said:

I used a 36t circular spline and a 32t flex spline so it ended up with an 8:1 ratio. With the steel needle bearings it seemed to have too much friction so I am planning on rebuilding it with PTFE bearings. I think I need to make the strain gear more flexible as well. I found that the design is very dependent on good tolerances and it took a lot of trial and error getting a good fit.

I did get the drive spinning well enough but I never did any endurance testing.

I did a 30 and 32 and there was not enough clearance for the gear to flex with the mating teeth. Maybe with the larger gear teeth you need to have a larger delta between the two gears. Might try 30 and 33 for a 10:1 

[atrushing]

48 minutes ago, Paul Trautner said:

I did a 30 and 32 and there was not enough clearance for the gear to flex with the mating teeth. Maybe with the larger gear teeth you need to have a larger delta between the two gears. Might try 30 and 33 for a 10:1 

Let us know how it goes. I am trying to get it to work with a Nema 14 stepper so it can fit better into my small printer design.

[Graymattor]

3 hours ago, Paul Trautner said:

You won't be able to fully print the galelio2 because it's a custom motor with a different pinion. The teeth are also pretty small which make them hard to print accurately with fdm. 

Appologies, the Galileo 2 Z drives are the LDO kit so come complete 

[Paul Trautner]

Was able to switch back to the original Z drive for the printer and it was working as expected, no issues with the idm scanner from ali-express, scanning and input shaping work well. Build plate from fystec is really bad so I am going to try lapping with a surface plate to improve the flatness but overall the rest of the kit was of good build quality. Just need to finish printing the rest of the parts so I can put the enclosure on 

[Paul Trautner]

Did not make much more progress on the printer but I did tear apart the harmonic drive to look for the source of backlash and I think I found it and can print a part to resolve it. I have made one sample and just need to make a test fixture to try it out before I modify all the others. It seems like the ellipse that flexes the bearing was not large enough to get the teeth to touch on both side. I have added about 1mm to the long dimension and it seems to respond to input motion much better. 

[Dirk]

Why don't you contact the AliExpress seller and confront them with this fault?

I think you have paid enough to expect a decent product.

[Paul Trautner]

On 1/13/2024 at 4:37 PM, Dirk said:

Why don't you contact the AliExpress seller and confront them with this fault?

I think you have paid enough to expect a decent product.

I don't have much hope that they will resolve the issue but I may contact them to see what they say

[Paul Trautner]

First print

 

 

[Paul Trautner]

0.4mm nozzle with 0.2mm layer height. Turned out good for the first print. Need to calibrate pressure advance and dial in my hole compensation.

[Paul Trautner]

And a 16 minute speed benchy. Happy with how the printer is working.

 

 

 

[Paul Trautner]

I started printing PA-CF parts for work and quickly found out that my bambu clone hotend was not able to keep up. I swapped my Rapido V1 in the printer and it's working great but now I need another. Stick with rapido but go to the V2? If so upgrade to the UHF? Other options?

[atrushing]

1 hour ago, Paul Trautner said:

Stick with rapido but go to the V2? If so upgrade to the UHF? Other options?

It depends on just how much plastic you want to push or how fast you are trying to go. That plus your budget..

The Rapido/Dragon UHF versions as well as the VolcoMosq require shrouds that are 8.5mm longer. The Dragon ACE and the T-Volcano (requires some assembly..) are more compact while still having a lot of heater block mass. I will be trying out the CHCB-V V6DM soon, it has a 70W ceramic plate heater and a taller melt zone and is pretty low cost (~$40). The Dragon HF is supposed to be able to do 30mm^3/sec and is the same size as a Dragon ST.