Disassembling an Iwata TR1

[John R]

I suspect the sealing ring (item 7A) needs replacing but I am unable to remove the slide cam (item 29) to get at it. There seems to be an internal obstruction which I suspect is the valve rod (item 27). How does one remove the valve rod? The drawing seems to imply that it goes through the hole in the top of the body but at no point does the hole open when the slide cam is moved. It looks as if the only way to remove it would be to pull it downwards through the air supply hole.

Can anybody help please?

John

[Jetblast]

Part 27 is stacked on top of the air valve plunger & to get it out of the way, remove the air valve assembly (33) & just push the cam (29) rearwards. The cam has a ramp on it that will push 27 downwards & out of the way & allow cam removal.

 

[little-cars]

Adding to that the order to remove the parts is as follows.

Firstly get an area to lay out the parts on a cloth to keep them in order.

 

Remove the air valve 30

Remove back handle 16

Remove parts  11 &10

Now remove the small grub screw 28 from under the body of the brush using a small flat bladed screwdriver  ( this secures part 30 in place) 

Use a flat screwdriver to unscrew part 31 that was held in place by the grub screw

[Note When reassembling make sure that the hole on the side  o part 30  lines up with the screw hole under the brush body, then screw in part 28]

Remove the spring 30

 

Now the cam 29 can be slid backwards.

 

While the body is empty I usually check for any paint contamination on the cam and inside the brush body.

This can happen when the needle o ring  7A is worn.

If it's bad it might be worth changing the needle seal O ring 7A  while the brush is in pieces.

 

Reassembly us just reverse of assembly, remembering to put the air valve piston part 27  in from the top of the rush before part 29 goes in but best to have a copy of the parts diagram to make thing easy

 

Not the simplest design, but you shouldn't need to take it apart very often.

 

Ta, Paul

 

[John R]

Thank you both.

The problem is that cam (29) will not slide backwards beyond the normal range and it seems to need more force than I am prepared to use to shift it. I suspect that the inside is gunged up with paint so it is currently soaking in solvent to se if that helps.

Watch this space, as they say

John

[John R]

Success! Thank you again. It was left soaking for a few hours and after that the cam slid out smoothly. What I found raised my appreciation of what constituted 'gunge' was raised to a new level.

John

[little-cars]

Glad you've got it apart, sounds like you need a new needle seal !

 

You usually get a warning with smears of paint visible on the sliding cam. 

 

Paul

[John R]

Been there  - done that. I suspected that before taking it apart as I was getting bubbles in the paint cup. The old seal was pretty ropey.

Do you sell them? I looked under Iwata spares on your website but there were none there. In fact there was almost nothing there, if I remember correctly.

Should the seal be lubricated? I used one sold by Plumbers' merchants after finding the needle required too much force to put back in.

John

[little-cars]

John, We have some Iwata spares, but they aren't on the website yet.

 

Spares are on this link  https://airbrushes.com/parts_info.php?cPath=400_403_1_9_46&products_id=1850

 

From memory the TR-1 is a vitron rubber one, when it fails paint gets on the cam and it eventually glues it to the body.

 

Best to get the correct O ring.

 

Paul 

[John R]

OK. Thank you. I am OK for now. I got mine from aircraft-net, the one given by jetblast. Brilliant service - ordered one afternoon and it arrived the following morning

John

PS. Paul - when I clicked on the Modellingtools link in your post it took me took a page labelled HAMEX. Was this right?