Modding HP-CH

[crewchief227]

So I love my HP-CH, it's really nicely built, sprays almost like a Micron, but I had one caveat. After being really used to my Microns as my primary brushes. The trigger is just so damn stiff in comparison. I have my Microns set with their triggers almost as stiff as they go (2-3 threads showing on the adjustment screw), and my CH set as loose I can go and still have the handle fully seated. I know I could probably ditch the handle and have it looser, but I don't like the balance without the handle. I could cut the spring, but that scares me for two reasons as their is no turning back, and I would be worried about the sharp end gouging the adjustment screw or chucking guide.

So my question is has anybody changed out their main spring on a HP-C or HP-CH with a Micron main spring? I could swap them right now as a "test", but then I'd be down a Micron, and it wouldn't be for any long period of time. I'm just wondering if the main spring is that stiff because a) they don't have thousands of hours of break in on it like my Microns, or b) the reason it's so stiff is engineering considerations where it needs to be to properly seat the needle back into the nozzle.

I always hear about people changing out or clipping their air valve spring, but I've never had a problem with this. Maybe cause I'm 6'4" 250 lbs. Army Vet that people say I have "He-Man" strength. But trigger sensitively really does effect technique. New micron springs are only $7 from Coast, but before the hassle of ordering is it just a waste of my time?

 

[Don Wheeler]

I think manufacturers overdo the spring tension to make sure the needle will seat even if the needle bearing is a little bit too tight. And, spring tolerances are kind of sloppy. I've modified or replaced the springs in almost all my airbrushes, both for trigger back tension and air valve.

Yes, the cut end of the spring can cause scraping if it is not bent square to the spring. A little work with needle nose pliers is often needed. I wouldn't mess with my only spring. I scrounge old ball point pens for parts to experiment with.

Don

 

[DaveG]

Pet Peeve of mine about the Eclipse, as well - have never really gotten a good feel for the trigger. I have gone to replacing the guts with custom pieces that allow for the exact same trigger adjustments available in a Micron. A softer, more compliant spring will go a long way to getting you closer...

 

[crewchief227]

Pet Peeve of mine about the Eclipse, as well - have never really gotten a good feel for the trigger. I have gone to replacing the guts with custom pieces that allow for the exact same trigger adjustments available in a Micron. A softer, more compliant spring will go a long way to getting you closer...

Dave you're a wonder at modding, and the exact person I'd hope would see this. So no problems with the needle reseating, or that dreaded invisible slow tip dry. You know when the needle doesn't seat just enough that you can't see any paint being released (unless you're purposely looking for it), but the needle gradually gets coated? And yeah being that the two brushes are identical from the trigger back I would love to do my CS as well.

 

[DaveG]

Dave you're a wonder at modding, and the exact person I'd hope would see this. So no problems with the needle reseating, or that dreaded invisible slow tip dry. You know when the needle doesn't seat just enough that you can't see any paint being released (unless you're purposely looking for it), but the needle gradually gets coated? And yeah being that the two brushes are identical from the trigger back I would love to do my CS as well.

I use a needle spring that is lighter than factory, as well as having the spring adjuster turned out a good bit so the trigger motion is light, yet still has enough feel to it to keep you feeling connected. A BIG part of the overall trigger feel is the adjustment of the needle packing. The teflon is not a very forgiving material, as it does not rebound back to position, just stays squished- It then takes time for it to start to wear in order to loosen the feel on the needle, which effects the trigger feel. If the packing is adjusted too tightly, you can not get away with a lighter spring, as you say, it will not return the needle to full seat. Our new needle packing O-ring is perfect for this application. Made from special compound, it will resist any solvent you throw at it, yet remain soft, and pliable allowing for a fantastic feel on the trigger, even if over-tightened slightly - it will also return to position if you then loosen the retaining screw up a little. If you are just using water based paints you can simply try a 1mmX1mm o-ring - you may have to replace them frequently, but they can be had inexpensively if not wanting to pay for the real deal.

 

[crewchief227]

I use a needle spring that is lighter than factory, as well as having the spring adjuster turned out a good bit so the trigger motion is light, yet still has enough feel to it to keep you feeling connected. A BIG part of the overall trigger feel is the adjustment of the needle packing. The teflon is not a very forgiving material, as it does not rebound back to position, just stays squished- It then takes time for it to start to wear in order to loosen the feel on the needle, which effects the trigger feel. If the packing is adjusted too tightly, you can not get away with a lighter spring, as you say, it will not return the needle to full seat. Our new needle packing O-ring is perfect for this application. Made from special compound, it will resist any solvent you throw at it, yet remain soft, and pliable allowing for a fantastic feel on the trigger, even if over-tightened slightly - it will also return to position if you then loosen the retaining screw up a little. If you are just using water based paints you can simply try a 1mmX1mm o-ring - you may have to replace them frequently, but they can be had inexpensively if not wanting to pay for the real deal.

Yes I have had so much trouble adjusting my SB. Usually I have a #1 screwdriver in my cleaning kit that is just long enough. On my other Micron the tension is right before the screwdriver slips. But my SB goes from packing just seated to dragging in an 1/8th of a turn. Then I have to "float" the needle down the body, and check the tension. Which runs the risk of dinging the needle I just spent time polishing. I have ultrasonic cleaned, and inspected the crap outa that packing over and over. So today to remedy that, I decided to give myself a Christmas present and ordered the iwata maintenance tool kit . It's something I have drooled over for a very, very long time. Should show up Friday!

 

[DaveG]

yeah, that tool kit has saved my arse a good number of times! A bit expensive for what you get, but the tools become priceless once you start using them. Enjoy!

 

[Squishy]

I love a stiff one. I prefer to have a bit of firmness when I pull back.

It's true though, . I am always surprised when I see folks wanting softer springs. It seems to be a common mod, so guess I'm just odd. I agree with Dave (and who wouldn't - he's the man) the needle packing plays a big part in trigger feel.

 

[Mr.Micron]

I love a stiff one. I prefer to have a bit of firmness when I pull back.

It's true though, . I am always surprised when I see folks wanting softer springs. It seems to be a common mod, so guess I'm just odd. I agree with Dave (and who wouldn't - he's the man) the needle packing plays a big part in trigger feel.

I am like you I wait a nice hard pull back due to I too am old and I feel I have better control over a soft spring even on the air valve.

 

[crewchief227]

I am like you I wait a nice hard pull back due to I too am old and I feel I have better control over a soft spring even on the air valve.

I don't mind stiff, I just mentioned in another thread how too many people are looking for feather light, I keep my Microns almost all the way adjusted down, I want that Micron like smooth pull, where it stays pretty consistent from just cracking the nozzle open to mid way (cause lets face it if you're spraying wide open, your flushing your brush ). It just seems like a more responsive spring. My CH is just really stiff getting that nozzle to crack open, which makes it easy to sustain that position, but not too good for more gestural work like really fine dagger strokes.

 

[Mr.Micron]

I don't mind stiff, I just mentioned in another thread how too many people are looking for feather light, I keep my Microns almost all the way adjusted down, I want that Micron like smooth pull, where it stays pretty consistent from just cracking the nozzle open to mid way (cause lets face it if you're spraying wide open, your flushing your brush ). It just seems like a more responsive spring. My CH is just really stiff getting that nozzle to crack open, which makes it easy to sustain that position, but not too good for more gestural work like really fine dagger strokes.

Yes that is what I am taking about being able to have enough tension on the trigger that you can feel it when it cracks open , The softer springs or lighter adjustment of them I would always end up opening it up too much. needing a stiffer spring I always felt was due to being a mechanic for decades.Well actually I will blame hand milking 20 milk cows as a child growing up that really builds hand muscles LOL . The life of an old farm boy .

 

[crewchief227]

Yes that is what I am taking about being able to have enough tension on the trigger that you can feel it when it cracks open , The softer springs or lighter adjustment of them I would always end up opening it up too much. needing a stiffer spring I always felt was due to being a mechanic for decades.Well actually I will blame hand milking 20 milk cows as a child growing up that really builds hand muscles LOL . The life of an old farm boy .

I was a mechanic too, an Apache Helicopter Crew Chief, and a F22 Raptor Fabricator for Lockheed. I'm also 6'4" 250 lbs., so yeah what might be tough for some is not for others.

 

[Squishy]

Well I have hands the size of a small ish child, and apart from the smell, there is nothing strong about me, so don't know why I like a stiffy, but I do.

 

[Robbyrockett2]

Well I have hands the size of a small ish child, and apart from the smell, there is nothing strong about me, so don't know why I like a stiffy, but I do.

Well, I'm glad Herb didn't phrase it that way.

 

[Mr.Micron]

Well, I'm glad Herb didn't phrase it that way.

Yes I did watch by phasing on that one cause I know my Squishy gal would of had a field day on it LOL

 

[Squishy]

Yes I did watch by phasing on that one cause I know my Squishy gal would of had a field day on it LOL

Little old me??? Don't know why you would think that herbypoos . Anyway if you want to blame hand milking for your super grip, then "we all totally believe you" I never once entertained the idea you might have whiled away the hours pulling and tugging on anything else .....Anyway, I don't think it's all down to grip, but also the wrist action, or so I've been told by other keen tuggers - building up a steady rhythm pulling, releasing, then pulling again with the perfect touch, until eventually reaching the full crescendo, and hopefully if you like to do it in a group, at the same time as everyone else. I've heard it's very satisfying finishing together, and sharing the moment as you all catch your breath. I wouldn't know though as I've never been into bell ringing.

 

[Mr.Micron]

Little old me??? Don't know why you would think that herbypoos . Anyway if you want to blame hand milking for your super grip, then "we all totally believe you" I never once entertained the idea you might have whiled away the hours pulling and tugging on anything else .....Anyway, I don't think it's all down to grip, but also the wrist action, or so I've been told by other keen tuggers - building up a steady rhythm pulling, releasing, then pulling again with the perfect touch, until eventually reaching the full crescendo, and hopefully if you like to do it in a group, at the same time as everyone else. I've heard it's very satisfying finishing together, and sharing the moment as you all catch your breath. I wouldn't know though as I've never been into bell ringing.

Nah I only tugged on utters being I could always find a fine lady who loved a good stiff one Oh yes I still hold my thrown in the gutter
But milking cows , moving hay , slopping hogs and gathering the eggs was just a normal morning before school for me as a kid.

 

[crewchief227]

Wow we really deviated from main springs didn't we

 

[Mr.Micron]

Wow we really deviated from main springs didn't we

we sure did but that is the moment you know your family is when we hijack your thread cause Squishy needs a good stiff one LOL