Showing posts with label Voron. Show all posts
Showing posts with label Voron. Show all posts

Sunday, April 18, 2021

Prusa MK3 vs Voron 2.4

Which is the better printer?

Recently I had an argument with Chris Warkocki the admin of the Prusa community group on facebook where he casted some aspersions on the Voron printer. so he claimed that every of his customer printers would print much better and faster than the Voron and the Afterburner would have a very bad cooling.

So there is a lot to unpack here. 

First, of course you cannot have an unbiased opinion about other printers if you have such close ties to Prusa and being the admin of the fb fan group. That is human nature and we know fanboys from other areas in life. But let us have a look at the substance of his claims and make some comparisons.

Costs

A stock Prusa MK3s as DIY kit comes with a price tag of 769,-€. As Chris already mentioned that his printers are heavily modded, let's add the most common mods. 

The bear frame kit without printed parts 89,99€

One spool of PETG for the printed parts 25€

Bondtech extruder upgrade 120€

SE Mosquito hot-end 160€

Seems he replaced the EinsyRambo as well and tried SKR and Duet boards, even is experimenting with klipper that requires and additional Raspberry Pi. So that could range from 100€ to 300€ for the electronics, but to be fair we just assume 100€.

That is a total cost of 1263,99€ for the heavily modded Prusa MK3. Not take into account other mods like Mitsumi, Vesconite LM8UU bearings or real linear rails, different stepper motors, larger frame (z height) etc. 

For my Voron 2.4 I have spent roughly 1400€ including LDO steppers, robotdig linear rails, 4Gb Raspberry Pi 4, Meanwell power supplies, panels with printed Voron Loge, prepared cabling harness from fermio labs and stainless steel bolts and nuts order in large quantity(hundred more than I needed).

I have also added some parts that are not listed in the BoM to have a more safe printer that pushed the overall costs to 1500€

So the Voron 2.4 is a bit more expensive than the modded MK3, given the doubt the no other mods are made. Still they are in the same ballpark in regards to cost.

Features

The official build volume for the Prusa is 250 x 210 x 210 mm that cannot be 100% utilized from my experience. 

My Voron has an official build volume of 300x300x300 mm that can be 100% utilized as the motion system has 350mm linear rails.

The heat bed on a Prusa is basically a PCB that is relatively thin compared to the 8mm aluminium slab I have on the Voron. The thick aluminum plate is not only more stable and precise(machined surface), it is also more resistant to warping with temperature changes, the aluminum has more mass and is a very good thermal conductor. So the bed temperature is more stable and more unified across the surface area.

Another advantage is that the Prusa PCB head bed is powered by 150W(24V6.25A), while the Keenovo heat mat on my Voron is has 400W (230V). It heats up quicker and does not stress the power supply or board electronics.

The Prusa motion system is still based on 8mm steel roods, 2 per axis. The Voron comes with linear rails, 4 for Z, 2 for Y and 2 for X. 

Also part of the motion system are the 5 1.8° stepper motors on the Prusa(2 for Z, 1 for X,Y,E each) while the Voron has 7 Steppers in total, 4 1,8° for Z that are reduced by pulls in a ratio of 20 to 80 teeth, 2 0.9° for Y and X movements and 1 for the extruder.

In numbers that means the Tr8x8 lead screw on the MK3 with the 1.8° stepper motors allow a resolution of 0.04 mm layer height. With the Voron also with 1.8° steppers and a GT2 fully with 16 teeth, but a ratio of 1:4 gets to the same layer height of 0.04 mm. But on the X and Y the 0.9° steppers on the Voron allow for more resolution that the Prusa.

Both design use printed parts, The Prusa comes with PETG parts, ABS is used for the Voron as PETG fails in a heated chamber.

I will not rub on the EinsyRambo board on the Prusa vs my 2 SKR V1.4 turbo boards as we included 100€ for a board upgrade in the Prusa in the cost calculation above. But I guess it is obvious that the combination of 2 SKR boards with Klipper doing the heavy lifting on a Raspberry Pi outperforms the old Prusa 8bit board.

Both can use steel sheets as build pate with PEI stickers or powder coating texture that are held in place by magnets. The Prusa has some needy magnets as inlays in the heat bed PCB( that like to fall off over time). The Voron uses a magnetic sticker on top of the aluminium bed. Both are rated up to 120°C before the magnetic force degrades.

Both printers have a inductive probe for bed leveling by default that require a steel sheet. But in addition the Voron has a probe for the nozzle. That means if you swap the nozzle or the hot-end(which is very easy on the Voron) then the nozzle probe can measure the new distance of the nozzle relative to the print bed and you don't need to adjust manually every time like on the Prusa(first layer calibration).

Per design the Voron has an enclosure. That helps with materials like ABS that tend to warp, but also keeps the fumes inside. The Voron even has a simple air filtering system. 

The Prusa uses 3 pin fans that allow the firmware to detect if a fan is not spinning which could lead to overheat in case of the hot-end fan. The Voron uses only 2 pin fans by default.

In terms of security features the Prusa has some self check abilities. The Voron has a thermal fuse for the heat bed by default that kills the power to the heat mat at 120°C. 

I have added a filtered C14 power inlet in my Voron that has 2 fuses. In addition I also added a 6A circuit breaker with built-in ground fault circuit interrupter. But that is not part of the standard Voron BoM.

Print Speed

I have to admit that I did no do my own tests yet as my Voron 2.4 is not finished yet. So I can only rely on information that other Voron users share. I guess a full video of a print with a clock running is a trustworthy source. 

Problem is that there was no real "standard" print. The often used bench boat does not say anything about size, infill percentage, material etc. The range of benchy times on a Voron 2.4 range from under 10 to 14min. I have seen videos from MK3 around 15min for a benchy, but again it is hard to compare as there is no standard for the benchy.

The actual speed you put into your slicer is a desired value. Just because you put in 800mm/s it does not mean your printer can do 800mm/s. Same goes for adjustments on the printer itself. 

So there are some videos from MirageC where he claims to print with 800mm/s with his HevORT CoreXY. Vez3D has a very fast coeXY, so does Anney_Engineering.

There is even a speed benchy contest on the Annex-Engineering discord channel. They have rules for the settings that lead to more comparable results.

One Voron 2.4 from joshmurrah (standard with afterburner) with 11:15min for the benchy and one Mk3 heavily modded with bear frame, linear rails, different hot-end/extruder and running klipper with 12:43min from Techromancer that looks a bit like cheating as he uses only one corner of the bed and thereby uses the advantage that the gantry if stiffer at the end as in the middle. And his MK3 is running klipper as well.

What I have not seen is a real fast benchy from Mr Warcocki. Not even a full video of his fast prints. Sometimes he shared short video sequences on FB and claimed a speed that cold not be verified in any way. 

To understand why the bed slingers like a Prusa Mk3 can hardly beat any CoreXY is very simple. There are physical limits. While the CoreXY design has the power of two stepper motors pulling at any X or Y movement, the MK3 design has a single stepper that must move the whole print bed plus the print itself(more mass).

Having that said the current best time is a delta printer.


Conclusion

To me the Voron 2.4 stock printer outperforms the Prusa MK3, even when the MK3 is heavily modded in many areas. You simply get a bigger, faster printer that already come with an enclosure.

When you want to opt for speed you can add a high flow hot-end from the beginning and don't have to throw money for a standard hot-end out of the window.

Changing the hot-end on the Voron works like a charm and is so easy. Compared to the mess on the MK3 where you have to completely disassemble the x-carriage and cabling to the board.

Why someone would spent >750€ on a printer kit, just to throw away most parts while replacing them and spend more money instead of directly building the printer of desire is a mystery to me.

I guess you have to be a real fanboy.




  






Sunday, March 21, 2021

Is EVERBODY building a Voron now?

It seems like a huge community is building a Voron now. It is really hard to get the parts.

I had ordered some parts from Fermio Labs, like the print bed, the LDI stepper motor for the Afterburner hope-end and the IGUS® cable chains.

Then a few days later some more parts where available and I ordered them. Unfortunately I did not pick the frame kit in black from LDO, that was then sold out in 2 days. But I got the LDO stepper motors for X any Y axis (0.9°) and picked the wire harness.

I have could make it by myself. But if you do the math. The complete harness costs me 114,90€. If I buy a 100 meter roll of the Helukabel Heluflon®-fep-6 in 0.25 mm² it cost me around 50€. The sourcing guide says you need 250 feet (or around 77 meters). Then I need the 0.5 mm² also, plus the JST and Molex connectors (just few cents) and the work I have to spent. They advertise that the connectors are properly labeled. If you don't have the tools(I got them) you would also need to spent a fair amount of money on proper tools for the Molex and JST connectors.

Well, I will report about the quality once I receive the harness. But that seem to be a fair deal to me.

The motors for the Z axis was nowhere to find, but then I stumbled across the hobby-store.pl . The had the LDO motors and I also ordered the steel shafts as they were cheap. I am not sure if I will use them as I also have a 5mm stainless steel rod here that I wanted to use. But cutting and grinding stainless steel is a pain.

I got the screws for my Voron as well. I try to use stainless steel bolts and nuts when possible and usually order them in larger quantities by 100, 500 or even 1000. So I spent round about 100€ for the bolts and nuts.

Some small parts arrived from Chine as well. The self tapping M2 x10, the JST connector set, the magnets and the Z inductive probe sensor.

I got the Mean Well power supplies both from Amazon for a good price.

I ordered the spring steel sheets from Energetic3D store. I am happy with the ones he provided for my Prusa clones and the Elegoo Mars 2 Pro printers.

So for know I can only wait for the resining parts like the frame, the heat mat and some others to become available again. 

Then I still wait for more parts to arrive from China, like the Bigtreetech SKS V1.4 turbo boards, the fans, the nuts for the extrusion profiles and the bearings. 

There are some electrical parts missing as well. But I plan to use proper circuit breakers and ground fault circuit interrupter for this printer. I am also thinking about some LED lights and some gadgets.

One would be a nozzle camera. 


Sunday, March 14, 2021

First Voron parts are coming in, best tools for threaded inserts

 So I have started to print the Voron parts from eSUN ABS+. After a little bit of fiddling I got the ABS+ to print fine on my Prusa clones.


I have also started to melt in the threaded inserts. Therefore I bought a cheap soldering iron for 8,99€ only on Amazon.



I doubt it is any good for any soldering applications, but the tip design and the low energy made it the right tool for my purpose.


So bought this set of special tips for threaded inserts on Amazon for 9,99€ that perfectly fit to this soldering iron.

With the soldering iron set to the lowest power (200°C) it is just enough to gently melt in the threaded inserts into the print. You don´t want this to be too hot, as then the plastic will melt like butter and it will be hard to get a good and strong bond between the insert and the plastic part.

The other parts that came in where the linear rails I ended up ordering directly from robotdigg.com. Ordering was easy and shipping including tax was cheap.



I am still struggling to the get stepper motors from LDO that I want. But I did order the build plate in 300x300x8mm, the IGUS® cable chains, the extruder stepper motor. So that I can at least build the Afterburner extruder.
The frame is also a problem. I cannot get it from a local shop like Fermio Labs as it is always sold out like the stepper motors. If I could figure out if the LDO frame kit is similar in the dimensions as the Mitsumi kit, I would have ordered this one. But the problem with cheap rails is often that the surface for the linear rails is much smaller as the linear rails touches the extrusion profile just on the edges of the linear rails.




Tuesday, March 9, 2021

Voron is coming !

 I have quite a range of Prusa MK3(s) clones now. I did not bother to build a Prusa Mini yet, as I don't have a use case for it. An advantage would be the smaller plate, as a lot of parts I print would fit and I would not have to wast so much energy to heat up a large bed. But on the other hand the design does not look sturdy to me and I don't like bowden extruders.  Honestly I still have 3 Ender 2 from Creality, that are very similar.

As many other I was waiting for a Prusa Core XY design, but I have lost hope on that. I guess it would be at least 2000€ if it every comes.

So I looked around for a nice Core XY design over the last months and found that the Voron Design has a lot of support. From CAD files to parts lists and even a sourcing guide. You can decide on the build volume, I choose to go with 300mm on all axis. What I really like is the approach to go with reasonably parts. They don't always recommend the most expensive option. They have a lot of parts from Aliexpress.

For example on the linear rails. For sure Hiwin makes good quality, if you manage to get original ones. But they recommend to buy from Robodigg. why? Because it is a 3D printer, not a CNC milling machine. I have seen a lot of Prusa modded MK3 with Hiwin rails and I always ask myself WHY? Why would you spend so much money for those expensive part if the rest of the printer cannot keep up with it?

Then of course there is the question why people buy Prusa printers in the first place if they anyway are going to replace the frame(Bear Mod), the linear rails, the hot-end etc. Why not simply get the parts and build a clone from the start like I did now many times?






Ok, but back to the Voron. I was looking for a printer that can print fast, but with high quality. Some of the videos I have seen on the Voron where quite impressive. I also looked into the HevORT, but that seemed to me like a lot of wasted money. Maybe good for someone who needs a huge build volume.

So my estimated budget for the Voron 2.4 is 1200€, this is what I have spent so far.

For Pulleys, idlers in anodized black and some timing belts I spent around 110€

For 6mm & 9mm GT2 belts and BMG Extruder parts from Triangle Labs I spent 80€

24V Fans for Hotend and Printcooling 15€

Washers, screws and magnets about 30€

Robodigg black Linear Rails  120€ 

MeanWell 5v and 24V Power Supplies 52€

2x BIGTREETECH SKR V1.4 Turbo 32Bit  86,79€

LP08 inductive sensor 5,82€

MINI12864 v 1,2 LCD Display 9,63€

I have problem to source some parts like the stepper motors. I want some quality from LDO, not the usual crap you get on aliexpress.

If you wonder about the quality of the printed parts. This is eSUN ABS+ printed on an original Prusa MK3 in an IKEA enclosure. There was no profile for ABS+ and all profiles for ABS did not work, but I got only ugly warped parts So I had to come up with something on my own to get started.



But in the end I got it running. I used the ABS profile as a base. Then I changed those values and got some good result

print fan to 15% min and 30% max, on all time and 

nozzle temp 240°C first Layer all other 235°C

bed temp 100°C first layer 95°C for all other layers

I change the extrusion with to 0.5 for the first layer. 

A new project "automatic cat litter box"

 I did not post any updates for a long time. I spent some time making some money with 3D printing to recover some of the costs from this hob...