Hey everyone. Does anyone have the Budaschnozzle and can write a short review ? Thanks.

Hey everyone. Does anyone have the Budaschnozzle and can write a short review ? Thanks.

I have the @LulzBot Budaschnozzle 1.1, which is practically identical to the 1.2. I’m very happy with it.

Here’s what i like about it:

  • Long melt zone - this makes the schnozzle well suited for fast printing (but not so much for slower machines, since it oozes quite a bit)
  • Aluminum nozzle, melt zone and heater block for good thermal characteristics
  • Different nozzle sizes available
  • Easy to disassemble
  • The heater block is fool-proof as the thermistor can’t fall out.
  • Metric design
  • Open Source
  • Made by an awesome company that cares about the RepRap
    Project and doesn’t just feed off of it

Here’s what i don’t like about it:

  • It’s huge and therefore only works on select x-carriages. I designed a custom carriage for my Mendel90.
  • The wooden plates break easily, but are not needed anyways. I threw them out (as well as the printed top part) and mounted the hotend against a piece of carbon fiber plate, which in turn gets mounted into my x-carriage.
  • It’s expensive (especially when compared to the QU-BD hotends, which vary a lot in quality)

All in all i can recommend the Schnozzle. Many community members are also very happy with their J-Heads, which i’d also suggest you to have a look at. While i disagree with many of the design choices that the people behind the J-Head made, it seems to be a pretty solid nozzle as well while being a good bit cheaper than the Schnozzle.

Edit: redacted the statement about the heater resistor. While it’s never happened to me on the Schnozzle, but once on a different nozzle, the Schnozzle can apparently burn up as well. At least when you’re in Spain :wink:

@Thomas_Sanladerer what design choices do you have a problem with on the J-head?

I have budaschnozzle 1.0, 1.0.2, 1.1 and 1.2. This last version has no flaws and it prints in a consistent quality. 1.3 has a better heatspreader.

I’e used a Budaschnozzle 1.2 from Lulzbot for ABS for about a month on my printer and have been very happy with it. I’ve run about 1/2 a kilometer of filament through it. I had one minor issue with a crimp connector which I resolved with a pair of pliers. I actually received a call from Jeff Moe looking for more details on the problem so they could log it, which I appreciated.

It is pretty big though compared to the J-head and the price is near $100. I’ve not had any problems with the plywood plates yet but I don’t have a huge amount of use on it. I replaced the top plate with a Buda to J-Head adapter to fit my printer’s extruder.

I also purchased a J-Head from http://hotends.com a bit after just in case the Buda didn’t work out I could swap over. They were both well rated in the forum threads and blogs I had read. The J-Head is slender, compact, very ‘efficient’ in appearance. the only thing I don’t like is that the nozzle is part of the heater block. With the Buda it’s pretty easy to maintain the nozzle by just unbolting it while leaving the hot end in place. I’ve only had to take the nozzle off once and that was by my own fault.

I haven’t run PLA on the Buda so I can’t speak towards that end of things. I know they changed the 1.3 slightly to improve performance with PLA but haven’t seen any comments about it yet.

@ThantiK three things:

  • Brass has poor thermal conductivity. At least the heater block should be made from aluminum.
  • The thermistor is a radial type, which might fall out (and has fallen out of two of the RepRapFab hotends, which are somewhat similar to the J-Head)
  • The nozzle is hard to swap out, as it requires the hotend to be removed from the printer and fully disassembled.
    I know these are kinda idealistic issues, and that’s why I still recommended considering the J-Head.

Aluminum has too good of a thermal conductivity. It pairs the readings with the heater too closely, and also has a tendency to wick away heat. Brass is the right application here. Aluminum would be a bad decision.

The other two issues, I agree with.

It pairs the readings with the heater too closely
Why is that an issue? When the thermistor lags behind the temperature of the heater block, that only introduces inaccuracies in the system, which will cause oscillations even when your thermistor reads a perfectly constant temp.

and also has a tendency to wick away heat
Where to?

It’s not that the thermistor lags behind the temperature of the heater block, it’s that the thermistor is paired too closely with the heater and not with the actual temperature of the filament.

Also, it tends to wick away heat into the air. Aluminum is very conductive of heat, and is a good material for removing it, that’s why it’s used in heatsinks. With brass, I can fan my print with a strong desk fan all day long. With aluminum, it removes so much heat, that the heater wouldn’t be able to keep up while strongly fanning prints. I’ve experienced this first-hand with the budaschnozzle 1.1 vs the J-head.

As it was explained to me, it also causes more hysteresis vs brass, so if you’re in a summer environment vs winter its performance differs on a larger scale.

Ah, I see your point with the fan.
But I’m still disagreeing with the coupling too closely argument.
A PID loop, the way we calibrate it, can only regulate the temperature of a single spot - in our case, the spot where the thermistor is mounted. Now, when the filament draws away heat, it will evenly draw it from all sides, but the heater will only heat one side - in the J-Head’s case, the opposite side of the filament. The heat will creep towards the filament (and then the thermistor), but as it reaches the thermistor, the filament has already sucked away a couple degrees. So your best case is going to be a continuous offset of the temperature on one side of the filament and the other. Worst case, with a imperfectly tuned PID loop, the heater will oscillate, and this oscillation will be much stronger than the thermistor reads.
With an aluminum block, the temperature throughout the heater block (and nozzle) will be almost perfectly even - so no hot or cool spots. Since it’s so excellent at conducting heat, it will easily get the filament up to the same temperature as the block, which is the same temperature the thermistor reads. No offset, no hysteresis, but since the heater’s heat propagates quicker through the block, it requires a faster PID loop. The Arduino has plenty of processing power for that and Marlin’s autotune will generally find suitable PID values which keep both the aluminum and brass block’s thermistors at a constant temperature. The difference is that, for an aluminum block, this temperature will be the same as the filament’s, while a brass block will heat up unevenly and oscillate while still giving perfect readings at the thermistor.