But why? They could just let it protrude a bit? When doing a bit of calculation in my head, a 6 degree needle would protrude about 4,7mm from a 0.5mm nozzle, which might be a bit long, but only slightly over 3mm on a 0.33mm nozzle. I can see the point of having double taper on large nozzle setups, but not on anything less than 0.5mm.
I think it’s a balance of geometries. As you noted, an airbrush needle typically extends about 3mm past the nozzle. If you go much further, you might have air turbulence which could affect spray pattern. It’s also a function of trigger and rocker design. Usually, full travel of the trigger will move the needle from fully closed to fully open. Any more would be wasted. It makes sense to keep the same trigger assembly in an airbrush with different nozzle sizes.
I think you will find that double tapers are mostly used in larger sizes. In the Paasche VL, for instance, the medium and large needles have a double taper, but the fine doesn’t. In the Talon, only the large needle is double tapered.
Don
I have been checking my airbrushes tonight. Non has a double taper, but then, the largest nozzle size I have is 0.4mm. But the three 0.3mm or the 0.4 airbrushes ought to be similar enough to the Rage 0.33 to prove that it isn’t any real need of making it double tapered.
Trigger stroke length must depend on construction and physical size as well. Placing the pivoting point further down from the needle ought to make it possible to build for a longer stroke.
Badger, like most manufacturers, standardizes many parts to keep cost down. The Rage and Krome trigger mechanisms are basically Thayer & Chandler parts. They seem to work pretty well. People who need finer lines can easily convert to the smaller nozzle set.
Don
Do the needles for the 0.33 and the 0.21mm have the same angle on the first taper? I.e, the only one on the 0.21 needle.
You can see a picture of them side by side in my Krome review.
Don
The Badger Renegade Velocity superfine or Krome use Badger Parts # R-003 needle and the Rage uses Badger Parts # R-004 needle. Based on published data, the linear flow angles are 6.0 and 6.5 degrees respectively. Both are good for general modeling tasks.
Getting this picky is really useless. It will never be discerned by the un aided eye. Buy the Krome, Put in the .22 and know that other then maybe a Harder and Steenbeck infiniy, it is as small as you can go.
My thought was that if the Rage needle has the same angle taper in the first taper section as the Krome, you should be able to use a Krome needle with 0.33mm nozzle.
Since you have both, you could try it, if it would be of interest to you.
I’m always looking for new combinations to adapt my airbrushes to my own needs. “Problem” is that most high end airbrushes already are tuned to what the manufacturer consider be the best setting. But I believe that they sometimes don´t want to compete with their own products by making it too easy to adapt to other specifications. The Iwata Revultions are a good example. When they first arrived at the scene, Iwata said that the CR wouldn’t convert to 0.3mm. People played around with it, and came to the conclusion that the 0.3mm needle and nozzle setup for the BR would fit.
Today, there are “conversion kits” available as spare parts for doing this. And considering that the same kind of conversion can be made on the BR, but to both 0.2mm and 0.5mm, my guess is that they all use needles honed with the same angle, and because of that fit with either 0.2, 0.3 or 0.5mm nozzles. So why isn’t Iwata having this in their information? Probably because they rather sell one of each of these airbrushes, or maybe even more important, want people that are looking for better detailing capabilities to buy the HP-B instead of buying a 0.2mm setup for their CR.
On the other hand, just by changing the needle and nozzle on a CR to 0.2mm doesn’t make it an ideal detailing airbrush. It is too front heavy, too long, and probably has a bit too high angle needle taper to really compete with the HP-B.
A long, sharp, single taper needle can get damaged easier. Chopping of the slender tip by using a double taper is mostly a cost saving measure to the manufacturer. The compromise is a less precise spray pattern. It is less a concern with larger nozzle size.
I found that Iwata user are usually less concerned about the needle damage because the needle is more springy, thus less prone to damage or bending. Some knock-off needles are sharp with a single taper. But it is no favor to the user because it does not keep the shape very well.
I have 2 Powercat and one Neo for Iwata knock-off. So I know their needle quality first hand.
Iwata ship their airbrushes with good needles, as do most of the japanese brands. I’m not sure if they make their own, or buy them from some general needle supplier. The quality of the other brands I’ve tried is very similar. Even on the cheaper models. In my opinion this is one of the factors that still set them apart from the continously better chinese and taiwanese brands. And I would even go so far as to say that older needles often are better than the newer ones. I have a couple of old Iwata HP-C’s, a couple of really old Richs and a bunch of old Olymposes, and all of them have nicely polished sharp needles. A couple of them are 20 years old or more.