Split wafers Roger Shoaf

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Geo, Mercedes Benz, BMW.

Haven't done cars for a while, but BMW and Mercedes Benz aren't really "split tumblers" - per-say. They use sidewinder keys. Different principle. Two separate tumblers - one on each side of the key (that could - in theory - operate independently of one another).

Geos ARE (for all practical purposes) Toyotas

BMW does use split tumblers.Also not all Mercedes are sidewinders.4-track sidewinders will have four tumblers. They use sidewinder keys. Different principle.

OK Bob, other than convention, what would prevent someone from puttting two cuts of different depths in a Toyota lock and cutting the key accordingly?

While I have never done it, I can't see why it would not work. Also if you took a Mercedes or a BMW and laid one of it's half tumblers side by side with a Toyota half tumbler you would be hard pressed to tell the difference in function, just like if you were to take a Ford 10 cut ignition tumbler and a GM tumbler and subject them to the same.

By this I mean that the same general shape is there even though there is a difference dimention.

The Toyota tumblers ride on the top (and bottom) of the blank. To do what you are suggesting and have say a #1 half tumble on one side and a #3 tumbler on the other side, you would have to make the cut go only half way across the top (or bottom) of the blank.

Mercedes and BMW sidewinder keys, OTOH, have the "cuts" running along the sides of the blank. So you could theoretically, have a #1 tumbler on one side and a #3 "cut" on the other side and just have the key cut differently on each side (but the key could only be operated one way - you couldn't flip it over and have it still work)

Again, GM and Ford sidebar tumblers ride on the top of the blank as opposed to along the sides.

If so, I stand corrected. Never did much work on the high dollar German cars. Was just going from memory of what I'd read years ago (when I was still reading car articles).

Yes that is correct. The only difference between that and a Mercedes or a BMW side winder is that the key has a partition running down the middle.

Of course to do this you would need to use an end mill to cut the deeper side but it should work just fine especially if you cut the deeper cut about .010 past the centerline.

Sure it would. The lock would not know the difference as long as you cut the key the same on both sides. The half cuts opperate in the same space but they hit the key blade only on one side, whereas the standard tumbler rides all the way across the blade.

Roger Shoaf wrote: <snip>

Actually it shouldn't work unless you did something else, like Vidmar, etc. to make the different tracks different. After all, every tumbler rides all the way across the key if the cut will let it. If you have a

1 and a 3 in the same position on the same side of the key then the tumbler will always ride to the three depth. If it is a one length, that won't work. BBE.

No it won't, the tumblers are split, and only interact with half the key. Each half tumbler opperates independantly from the other tumbler in the same cut position.

Again I disagree, the theoretical circumstance I was referring to was if one were to cut a left and a right cut in a position that had split tumblers and then keyed the lock accordingly.

I understand fully what theoretical you proposed, what you don't understand is my reply that it would not be reversible. If there are different cuts in the same position on opposite sides of the key, all would be well. If you wanted the convenience of putting the key in either way up, that isn't possible. If you are having trouble visualizing that, make one to see it in effect. BBE.

I don't have a Toyota lock plug handy to double check, but from my sometimes feeble memory the split wafers in any particular space have the springs on a single side so the part of the tumbler that hits the key does so on the same edge of the blank.

I suspect you might be thinking of the newer style Toyota lock that does not use split wafers, but rather has double cuts like a VW (VB series) or the old Capri. I don't recall the exact code series for the split wafers but if I remember correctly it could be distinguished from the newer series because the older (split wafer) had 8 cuts and regular spacing and the newer series has 10 cuts, and irregular spacing.