Tachiara 4x5 cam locks

[Ulophot]

I posted recently about my first experience with the used Tachiara I recently purchased. Maris Rusis, especially, has been very generous with his expertise and comments in private correspondence, for which I am grateful. My remaining issue at present is that the front toggle cam locks, more on one side than the other, are not fully locking. I have purchased and tried both 0.2 and 0.1 mm shims, having found that the thicker, older ones (one of which was missing altogether, were causing problems.

The shims are steel; the old ones appeared tobe brass, but I can't really tell. The new back ones lock well and have freed up the back movement when not locked. When "locked" they stick up at about 45 degrees, leaning backward.

The front ones, which "lock" at, respectively, about 20 and 35 degrees (also toward the back) just don't get a firm hold, though the latter one would, I think, be fine if the lower one didn't loosen so easily. I don't know if perhaps something else is contributing to instability on that side. I have 0.1 in the front at present; 0.2 worked no better.

I do note that the screws in both cams are slightly bent. If someone knows the size and thread, I'd be grateful for the information.

Any ideas?

[Barry Kirsten]

I've had two Tachis over the years and thankfully no issues with either of them. I'd suggest replacing the bent screws. I'd say they bent due to pressure from the locking cams over the years. I think that if replaced you'd find that no or thinner shims would be required. Sorry I can't help with the size of the screws

[Ulophot]

I just found a post from 1998 saying that Tachiara had started using nylon washers in place of the metal shims. I'm off to track some down; the local hobby store where I got the steel ones doesn't have them.

[Richard Wasserman]

If you can't find the washers locally, Mcmaster-Carr has what you need. https://www.mcmaster.com/#nylon-washers/=18s5n5g

[Ulophot]

Thank you, Richard. That's the most promising source so far.
I'm surprised that, since Tachiara had started using nylon shims in '98, no one else mentioned it when I identified metal ones. Anyway, it will be interesting to see if the nylon solves the problem; it's compressibility suggested that it would.