Iwata HP-BH Modification

M

Madbrush

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After the recent purchase of my new airbrush, despite being absolutely over the moon with it, the only thing I didn't like was completely closed nozzle protector cap so I just had to do something about, I normally always work with the cap off, however as you all know this puts the needle in danger of being bent, because I finally have a decent tool to work with, I don't want to work without the cap, but I do want to see the needle the whole time I work, so I did the following modification;

Before I go any further, I do know it's been done before, I do know it's not my idea and I do know that the following mod is probably available commercially, but, I wanted to do it myself and save some cash as well as being able to say "I did it".

when I started out airbrushing, I bought a load of cheapies to get me started, I still have these and they still all work, but since these are nearly always copies of Iwata products, the crown protector fits perfectly on my new brush.

With a small hacksaw, I cut away two sides of the crown leaving behind two prongs, I made these prongs a little more streamline with the use of my modelling files and at the same time removed all sharp edges and buffed it all with some 1000 wet and dry, most of it is now brass, i.e.. no chrome left over, but as long as my needle is protected at all times, that's not important.

The first photo shows the original cap which will be replaced for storage, the second photo is the new pronged protector with an unmodified crown next to it.
 
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Nice neat work Malc. I must do this for mine, i'm just a bit half soaked in doing anything at the moment :)

Lee
 
Nice job, saved yourself about 19 euros doing this yourself…that's a few bottles of paint.
 
Thanks guys, It's always nice to save a little money, it's always a little over for more important things as Trem says, but it's also a nice feeling if you can do something yourself, I'm well used to having to improvise thanks to building my planes and stuff, I have a vast collection of tools specifically for my models, but they become handy for anything at all intricate such as this, I also love trying to solve problems, in fact I always say there are no problems, only tests and challenges and I like both;)
 
How did you manage to hold something so small and file the sides down so accurately? Did you leave it on the original 'Iwata copy airbrush' and file it down still attached?
 
How did you manage to hold something so small and file the sides down so accurately? Did you leave it on the original 'Iwata copy airbrush' and file it down still attached?

Yes Trem, That's exactly what I did, when I first started airbrushing I bought four copies of different sorts, the first one I used I dropped it on the floor then stood on it and bent not only the needle but the body as well, lol, I kept it for parts in case any of the others needed them, but since I now have a decent brush, I'll probably never use them again, so I just screwed all the parts onto the front body and then put this into a small bench vice I use for my models, this left me with both hands free so I could hold the saw and guide with the other hand, after that just tidied it all up and shaped the prongs with my fine modelling files, all this while it was still on the body.

I removed it from the body to polish it and get rid of any sharp edges left over with as I said 1000 wet and dry sandpaper, to be sure it wouldn't scratch anything on the new brush a ran a screw with same size threads back and forth a few times to ensure it would still fit, then applied a little machine oil on the threads.

The little crown I used was one of four, I tried them all on to find one where the prongs were exactly top and bottom, the rest were at different angles, when I work freehand, I get in close and generally look at the needle from the side, but is need be I can put a little this rubber ring between the crown and the brush so that I can turn it one way or the other for a better view of the needle, but I'll try it out first to see if I need that
 
Yes the commercial ones have a small rubber 'o' ring, so that the crown cap can be twisted to the right angle, vertical, horizontal or diagonal. I used to think it was to seal the cap to the head but it is not is it? It's so that you can position it to the desired angle.
 
Yes the commercial ones have a small rubber 'o' ring, so that the crown cap can be twisted to the right angle, vertical, horizontal or diagonal. I used to think it was to seal the cap to the head but it is not is it? It's so that you can position it to the desired angle.

Thanks Trem, although I don't think I need it, I'll still throw one on.
 
You do not need any seals because no air goes anywhere near the threads.

To cut it, it is recommended to keep it on the head. Here in SA You can not buy the cheap caps alone, only complete heads. Also before you cut, place it on your gun and Mark the prongs that you want to remove. If you really want them square, either vertical or horizontal, then you can sand the base until you get it right.
 
You do not need any seals because no air goes anywhere near the threads.

To cut it, it is recommended to keep it on the head. Here in SA You can not buy the cheap caps alone, only complete heads. Also before you cut, place it on your gun and Mark the prongs that you want to remove. If you really want them square, either vertical or horizontal, then you can sand the base until you get it right.
The part is already made Andre, I have some super thin rubber washers I get with my servos which are not always used, these fit nicely over the part where the crown goes, the idea is to be able to slightly turn the prongs of the crown if I need to.

Before I cut prongs I already did just as you described, but I cut it and shaped it on the head of the cheap brush which trashed it, I certainly wouldn't risk that on the new brush, lol
 
Good job Madbrush!!
It looks better than my modified crown caps which I have made for all my Iwata's. I also bought a few of the cheap crown caps so I could match the 2 prongs for top and bottom but now I prefer diagonal or horizontal because I can see the needle better. So I'll be doing some more work on them soon. It's a great feeling to do things yourself eh? and I haven't bent a needle since. Now I wouldn't dream of airbrushing with the cap off :)
Another option to hold them when your working is to put the Crown cap in a wooden clothes peg and then in a vice. Here's some photos of mine:
Dremel 2 prongs off.jpg
Hand file.jpg
 
Good job Madbrush!!
It looks better than my modified crown caps which I have made for all my Iwata's. I also bought a few of the cheap crown caps so I could match the 2 prongs for top and bottom but now I prefer diagonal or horizontal because I can see the needle better. So I'll be doing some more work on them soon. It's a great feeling to do things yourself eh? and I haven't bent a needle since. Now I wouldn't dream of airbrushing with the cap off :)
Another option to hold them when your working is to put the Crown cap in a wooden clothes peg and then in a vice. Here's some photos of mine:
View attachment 29128
View attachment 29129

Thanks Mel, it is indeed cool when you can do stuff yourself, the clothes peg trick is very clever but had I thought of it I would have been stumped, we only have plastic ones, lol, my wife thinks the wooden ones soak in dirt, but I'm going to buy a pack for my hobby room, they will come in handy for my models too.

Thanks for the tip:thumbsup:
 
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