So one of my nits about my Badger SOTAR has been how incredibly stiff the air valve spring is. It takes way too much force to depress the air valve IMO, enough to it's tiring and makes it harder to control the trigger as precisely.
I had in the past tried to clip the spring from my spare SOTAR to see if that would lessen the tension, but it didn't do so to a degree I found meaningful. The spring is very short to begin with, so there's a limit to how much you can remove and stretch before it no longer seats properly, and unfortunately that limit is reached before the tension is reduced even to the level of stock Iwata trigger.
But yesterday I thought "Well I do have a spare Zsolt spring, might as well see if it's compatible if clipped to size". This should have occurred to me long ago, and I feel a bit of a doof that it didn't. I removed the (unmodified) spring from my SOTAR and compared it to the Iwata spring, and they're the same diameter, the SOTAR spring is just way shorter. I carefully measured and clipped the Zsolt spring to the same length as the Badger spring, and it works!
My SOTAR now has a trigger that depresses by the weight of my fingertip alone! It basically feels like there's no spring in there at all, except when I take my finger off the button, it pops back up like it should. With the needle tension dialed down, my brush's trigger moves practically by thought alone.
This also appears to have alleviated the "gritty" feeling I'd previously experienced with my SOTAR triggers. I think having to cram the button down like that was making it more prone to twisting and rubbing harder against the sides of the body cutout, but now that I don't have to use hardly any force at all it's free to exhibit more relaxed stability during movement.
Anyway, for those who have a Badger brush and are interested, all you need to access the air valve spring is a T6 Torx screwdriver/bit. If you look closely at the bottom of the air valve stem, you'll see the little hole the air passes through is also a Torx socket. Stick your bit in there and you can unscrew the cap off the end of the valve spring compartment. It's easy to not realize there even is a cap, as the seam blends in with the end of the hose thread.
These springs are pretty cheap, so IMO it's a very easy and worthwhile upgrade.
I had in the past tried to clip the spring from my spare SOTAR to see if that would lessen the tension, but it didn't do so to a degree I found meaningful. The spring is very short to begin with, so there's a limit to how much you can remove and stretch before it no longer seats properly, and unfortunately that limit is reached before the tension is reduced even to the level of stock Iwata trigger.
But yesterday I thought "Well I do have a spare Zsolt spring, might as well see if it's compatible if clipped to size". This should have occurred to me long ago, and I feel a bit of a doof that it didn't. I removed the (unmodified) spring from my SOTAR and compared it to the Iwata spring, and they're the same diameter, the SOTAR spring is just way shorter. I carefully measured and clipped the Zsolt spring to the same length as the Badger spring, and it works!
My SOTAR now has a trigger that depresses by the weight of my fingertip alone! It basically feels like there's no spring in there at all, except when I take my finger off the button, it pops back up like it should. With the needle tension dialed down, my brush's trigger moves practically by thought alone.
This also appears to have alleviated the "gritty" feeling I'd previously experienced with my SOTAR triggers. I think having to cram the button down like that was making it more prone to twisting and rubbing harder against the sides of the body cutout, but now that I don't have to use hardly any force at all it's free to exhibit more relaxed stability during movement.
Anyway, for those who have a Badger brush and are interested, all you need to access the air valve spring is a T6 Torx screwdriver/bit. If you look closely at the bottom of the air valve stem, you'll see the little hole the air passes through is also a Torx socket. Stick your bit in there and you can unscrew the cap off the end of the valve spring compartment. It's easy to not realize there even is a cap, as the seam blends in with the end of the hose thread.
These springs are pretty cheap, so IMO it's a very easy and worthwhile upgrade.