CR 0.3mm Kit Tutorial

[Guest]

Chaps

I've just run up a quick tutorial on how to change your Iwata CR from a 0.5mm to a 0.3mm needle / nozzle setup.

You will need the 0.3mm kit from John and some bees wax:

Remove the 0.5mm Needle Cap, Nozzle Cap, Needle and Nozzle (these can be put aside for later conversion back to a 0.5mm if need be). Then remove the Trigger and Needle Chucking Guide:

At this point you may want to give the brush a good clean.

Now the tricky bit, you have to "Nip up" the packing screw a little. This is the advise given by The Airbrush Co. You can actually get a new 0.3mm Needle Packing Set if you like. I may do this myself, I'm not sure tightening up the screw will have a good long term affect on the Teflon seal. If you look into the rear of the brush (from the handle end) you'll see the flat head screw:

I had to turn mine clockwise about 1/4 a turn. Try adjusting then put the needle in (lightly oil with SuperLube first), you need to feel a little friction when the needle passes through the Teflon seal. This took me about 5 mins to get it just right.

When you are happy with that you can then put the brush back together. I start with the Trigger (note, there is a cut out in the Trigger, this faces the rear of the brush) and Needle Chucking Guide parts then the needle (smear the needle with a little SuperLube first), this I put in from the front and then slide it back until you can see the tip in the paint cup, this avoids any possible damaged to the tip when fitting the Nozzle. I then put the nozzle on, this is where the bees wax comes in. Smear a little on the thread and then screw into place. Hand tight is fine. The wax stops you getting bubbles in the paint pot.

Next put the Nozzle Cap and Needle Cap back on, I use a little wax on these threads too.

The last thing to do is slide the needle all the way home and replace the handle.

I suggest you do a dry run now to see if everything runs smoothly, then give the brush a good run through with cleaner to get rid of any surplus wax etc.

Don't forget to give the outside a nice polish too!

Hope this helps.

Rick.

PS. Sorry about my reflection in some of the shots, I used the studio gear set-up from the last job!

[Guest]

That is spot on Rick. I have to admit, I would not have thought of tightening the inner screw, I am surprised that they do not supply a .3mm packing set with the needle. I assume that if this is the advice they give then it must be OK. However, I do see long term problems if you keep going from .5 to .3 and back again.

I do think when I finally get round to fitting the .3 needle set, it will stay there, I cannot see where I would need the .5 over the .3 enough to make it worth re building the AB all the time.

Have you done any work with the .3 yet? I would be interested to know just how much easier it is to do fine line etc. In theory, fine lines should be possible with the .5 by getting the pressure, paint thickness and pull back control. Just wondered if it is easier to do with a .3

Thanks for taking the time to do a tutorial on this, superbly illustrated to, much appreciated.

[John]

I've decided I'm going to grab a .3mm needle myself, I've been putting it off for far too long

[Guest]

Hi Graham.

Yep, if I was to keep changing needles I would get the 0.3mm packing kit. They suggest that when you have tightened up the .5 to fit the .3 you maybe able to use the .5 needle with no adjustment back. No chance, I tried that, you'd need a hammer!

I haven't done much with it yet, house + small lad + overflowing sink = damaged kitchen ceiling to deal with!

I had a quick blast on a 1/72 Spit and hand camo is nearly possible now. I need more practise though, I've only had the brush for a week and just got back into modelling in the last month.

I'll let you know how it goes.

Rick.

[Guest]

Listen to the voices in your head John, you know they make sense!

[Guest]

Cheers Rick. Me to John, those voices have been in my head for too long now, may have to be an early December purchase

[Guest]

The reason you don't get a different teflon seal is that the needle diameter should be fairly consistent regardless of the nozzle size, the difference is where it's ground in the taper and point sections.

One of my brushes came with a 0.2, 0.3 and 0.5 needle / nozzle set, i've switched between the 0.5 and the 0.3 a few times and occassionally I nip up the seal grub screw as the seal does wear, comparing the needles in a micrometer shows very very close tolerances in thickness.

You shouldn't have to force the 0.5 needle in if the 0.3 needle fits.

Also, if you fit the needle from the front, (an invaluable tip from Geoff Illsley), draw it back slightly to fit the tip, nozzle and cap before seating the needle, it's all too easy to bend the tip of it while fitting the nozzle or cap.

Changeover BTW is as quick and easy (for me as I strip and clean after every session), as cleaning and the 0.5 is hands down better for large area coverage giving a larger spray circle allowing faster coverage and overlap which is essential for Acrylic gloss as it dries up faster than a puddle in a furnace and maintaining a wet edge for a gloss finish becomes an art form in it's own right , I tend to use it for main priming of kits and large area solid colour work.

I've never yet used the 0.2 and frankly don't see where i'd need to, even on 72nd scale stuff

[Guest]

m1ks

I agree on most points there OM. Now I've slept on it, I think the pictures of the needle cap fitment are a little mis-leading as it shows the needle extended. In truth the needle was fitted as you suggest, from the front then drawn back slightly. I was lazy and fitted the needle then drew it back with the trigger to fit the caps. This is a bit dodgy as you can actually let go of the trigger at the wrong point and, well, you can guess what could happen! I'll PhotoShop the images and repost tonight.

As for the seal, if you tighten the screw until you feel slight friction on the .3 needle, then the .5mm is too tight a fit with way too much friction, I've tried it (this needle was also lubed when testing). Mind you, this is a new brush so tolerances could be tight still.

I also suspect that the needle diameter is larger for the .5 than the .3, I didn't micrometer it at the time, I'll have a look later. Iwata also list, in the parts Cat', a smaller Teflon seal kit to go with the needle/ nozzle set, so I guess there is a reason for that.

All good fun, off to work another day another headache...

Rick.

[Guest]

Quick update chaps

I've just checked the diameter of the two needles and here's the findings:

0.5mm 1.1mm dia

0.3mm 1.0mm dia

The 0.5mm needle will not fit, even under pressure, with the packing adjusted to 0.3mm

I guess Iwata didn't intend the brush to be changed very often. Maybe a way of making peolpe buy the BR as well as the CR :1newwink:!

Rick.

[Guest]

Right, I've updated the tutorial a bit. I hope it'll not cause anymore confusion.

Just a quick comment though, this is how to replace the .5 with the .3, not a general guide on how to rebuild your brush, we may all have our own ideas on that!

[John]

.3 needle kit ordered

[Guest]

Oh O',Don't blame me when the missus' finds out!

[Guest]

No problem, just mentioned drawing the needle back as in the pics, (as you say yourself), it's protruding, the method you used, drawing back with the trigger also gets it out of the way and something i've done myself though as you also say, not good practise.

don't worry over photoshopping them, i wouldn't expect you to go to the trouble, just a pointer for people as i've bent needle tips by doing similar silly things and the slightest kink affects the spray performance.

Re the needle thickness, I reckon that's Iwata playing cheeky buggers, 0.1mm difference with these tolerances isn't much and the teflon seals don't compress that much either, as you mention, I suspect it's their way of having to change the whole setup costing more for bits or get another brush.

The brush I have is a spraymaster and i've not used an Iwata but I just assumed that, as the SM is more or less a copy of the Iwata, as are most of the DA brushes scattered about, they'd work on the same principal, if they do list seperate seals for 0.3mm and 0.5 then they are clearly aware of the needle thickness difference, (i do know the Iwata needles are thicker than the SM ones as I bought a couple thinking they'd work as replacements in mine but they don't go anywhere near).

I'd certainly get a seal to go with the setup for changes as too many swaps and the 0.3 needle won't seal properly.

[Guest]

NP m1ks, well the plot thickens!

I've just been in touch with a very helpful chap at this company:

2 X Needles To Fit Iwata Airbrush Model BR 0.3mm on eBay (end time 01-Dec-10 15:43:23 GMT)

And he explains that the needle size as far as he's concerned is the same, just the end is ground/polished to suite the nozzle size. Just as you thought m1ks.

This doesn't add-up. Has Iwata changed how it does things or is it something else? Work of the Devil/ marketing dept? I've just sent an email back to this company to confirm a few things and I'll post my findings. I basically hope that the company is right and I can buy a .3mm needle from him and swap between the two sizes easily without tatting about with the packing!

Rick.

[Guest]

You certainly should be able to but at these sizes 0.1mm is a massive difference.

Incidentally, the link you posted are the needles I bought as I wanted to see if the polished tips really made a big difference, unfortunately they're a thicker needle than standard Chinese AB stock size, (at the time of purchase I only had my basic chinese DA which came with the compressor).

They look a good needle if you/re thinking of getting some BTW