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Zundapp KS601 - Making The Battery Strap

   The friend who I bought my KS601 from received the Zundapp with the toolbox cover hinge pin bent all to hell and the cover hanging by only one knuckle, all but ready to simply fall off and be lost forever. Everything was so distorted the cover could not be closed (after dealing with the keyless lock) and to try to force it probably would have resulted in it ripping off all together. It's a miracle the tool box survived intact. When I bought the bike from him, one of the first things I did was remove the cover to preserve it from being further damaged or lost. But now I want a useable toolbox, so it's time to fix that hinge.

In the image to the right you can see that one knuckle is completely detached from the hinge, having neatly cracked off. In addition to being broken, the hinge was also nearly torn free of the toolbox, all but one of the three spot welds having failed.

You can see that I lightly stitch welded the hinge back onto the box. I was concerned about burning the paint and, while I hate to admit it, my TIG skills had degraded somewhat at that point from a lack of practice. I would be a tad bolder now, having gotten back into the groove to a large degree but, under the circumstances, I decided it was best to take the safer route and went pretty light with the welds, maybe too light, but I figured all I had to do was equal the strength of the original spot welds. Well, maybe slightly exceed, considering they failed. We shall see as time goes on.

Alas, probably at least partly due to the cover hanging agape for untold years in a barn, the inside of the toolbox was rusty as hell. I am not a real fan of sandblasting, despite the friend I bought the bike from running his own sandblasting business. So I got down, applied a fair amount of elbow grease, and wire brushed the hell out of the worst of the rust. May not look like it, but it made a substantial improvement. Actually looks better than the pictures would suggest. Oiled it later. It will improve.

But now, time to re-attach that hinge knuckle. You can see how clean the break was. Almost looks like the folded over side of the knuckle in the picture.

Used to be I'd revel in the challenge, but you recall those rusty TIG skills. Took a really conservative approach to sticking that little bugger back on. Didn't want to have to drill the pin out or ream the ID afterward. Again, the welds are maybe a tad lighter than I would have liked to see but I think, with me being the one who will be using it, it'll hold up just fine for the duration.

Another issue was no key for the damned lock. I made a quick and dirty torsion bar and rake out of some wicked aircraft stainless welding rod, then fooled around for awhile patiently picking it so the cover could close. I was quite proud of myself when the lock opened. Discovered in the process that it had four tumblers, all apparently set to the same height. I don't know if that's true for all Zundapps or KS601's. Something to check out at the next meet.

The Zundapp KS601 tool box hinge, exploded view.
The Zundapp KS601 toolbox hinge, dismantled, tack welded
into place, showing the knuckle that cracked off.
The Zundapp KS601 hinge assembled, awaiting welding.
Toolbox hinge, assembled and held in position, ready to weld the knuckle.
The Zundapp KS601 hinge, successfully welded.
The hinge knuckle welded back on, hopefully for the long term.
   If the tumblers truly were set to the same height, I figured even I could make a key for it. I have billions of old keys and sorted thru them trying to find one with the correct profile. Nothing was thin enough, so I figured I was screwed and would have to pay the pros to do it. Took the cover and lock to a locksmith. Dude cycled the lock closed, took out some tools and picked it in, no shit, ten seconds. Felt my pride in having gotten it open deflate like a popped balloon. He says, I do it all the time, and shrugged. True, I suppose, but still. Ten seconds. I spent damned near ten minutes.

Well, they dug around looking for the correct blank for quite awhile. Finally said, heh, nothing is thin enough. They had one of the correct profile, but it was expensive as hell. They were quite apologetic and searched the internet looking what the current prices were on them, about $15 as I recall. Sold two of them to me at their cost, then took a belt sander to them to thin them down. Sure enough, all the tumblers are at the same height, so the key is straight as a ruler. Works very nicely and I have a spare.

Last updated 11-16-17
Email:  mechanique at wmol dot com

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