View Full Version : Disassembling Toyo 45A front standard

2-Aug-2010, 13:42
I've just purchased a Toyo 45A which has a pretty serious light leak. It looks like it is coming from a piece of fabric or rubberized material in the front standard. I've removed the clips that hold the lensboard in place (four flathead screws). It now looks like the front standard consists of a U-shaped piece into which a metal rectangle fits. There is a groove where the rectangle sits, but I can't slide the rectangle out. It looks as though there is some glue or caulk from a previous repair.

I don't mind paying for repair, but don't have the time to send it off to a shop and would like to take care of this myself. Anyone have experience doing this? I could also just glop a bunch of neoprene cement, but that seems sub-optimal.


Dave Hally
2-Aug-2010, 16:14
I've repaired my 45A several times, including completely disassembling the front standard. There are only three ways that you could get a light leak from the front standard.
1. if the lens board doesn't fit correctly (wrong or DIY lensboard)
2. a light leak where the bellows is screwed to the back of the front lensboard carrier (bent or tweaked front bellows frame- I don't know how that could have happened).
3 a leak in the bellows itself.
When I replaced the bellows on mine, I used a thin layer of black silicone sealant where the bellows contacted the back of the front standard.

There should not be any other piece of cloth or fabric in the front standard, maybe the PO tried to seal a light leak in the bellows?
Good Luck

2-Aug-2010, 16:24
Dave - the standard appears to be made of two parts, one which fits into another which in turn sits in the two arms attached to the rail. The larger piece has a channel rabbeted out into whcih the second piece sits. At the top of the standard, where the second piece sits in the first one is a 1/8 thick piece of foam rubber, about 3/8" high and which runs along the top edge. I'll post some pix in a few minutes.

2-Aug-2010, 16:41

3-Aug-2010, 09:10
Have disassembled the front standard. Looks like the leak was from the PO having assembled it with a small gap at the top. Am going to re-assemble this evening. Any recommendations on what glue to use?

Dave Hally
3-Aug-2010, 10:37
That looks different from any 45A front that I've ever seen. Maybe someone modified it? Anyway, If it will need to come apart in the furure, then I would wipe a thin layer of black silicone seal on one side and a thin wipe of oil on the other and reassemble it. The silicone should seal the light leak, and the oil should allow it to be disassembled in the future. If it doesn't need to come apart, then just use the silicone on clean surfaces. You can get replacement parts from the MAC Group(Google Mamiya America Corp.). They are reasonable. I tried to attach a picture of what mine looks like but the file was too big. Good Luck

3-Aug-2010, 16:41
Many thanks Dave. When I googled toyo 45 before, I got lots of different images of the front standard. I think it's been through some revisions through the years. The dealer tells me that it is <quote> faux pax leather placed to conceal the metal, its same/similar material that Toyo use on the sides of the rear standard to conceal the metal. Wista does the same thing in faux pax wood that it glues on the sides of the camera. </quote>

Dave Hally
3-Aug-2010, 17:30
OK, it looks like you've got it covered. I really like mine, except it gets a little heavy sometimes. Be aware that the base of the front standard is not as heavy duty as the rest of the camera. Where the front swings , the base has only two thin sections of cast metal where it moves over the pivot plate. It breaks fairly easy if it sustains a hard impact. DAMHIK (x2). If you get a longer lens, and need an extended lens board, ping me and I'll let you know how I made one.