Here is an brass Optimus 930 300cp. I found this lantern on a fleamarket in Normandie,France. It was missing the globe. The hood has a big dent, but it was in good condition. I was lucky to find an original half frosted globe on Tradera.
I really appreciate the existence of this "community" - I've been trying to fix the air pump check valve on my model 930-300 CP. The photo with the exploded diagram and suggestion for simply making an extraction tool was great, attached is my own version. I succeeded in getting the valve out, but the tiny little rubbery stopper has become too brittle, so I'm trying to figure out how to fabricate something else that works. Has anyone tried using a tiny ball bearing instead? Thanks
A little check ball instead of the rubber was an interesting idea! They are often used in fuel systems for engines. Like in my hot bulb engines, where they are used in three places; two in the fuel pump and one in the fuel injector, and they work great. I have used small ball bearing balls meant for bicycle hubs, and the seats are brass just as it would be with the NRV here. I'm not convinced that it would work for our NRV's though, since the pressure on the ball against the seat isn't by far as large as in fuel systems (the spring is mainly there to keep the ball seated, not for the actual seal) but it would absolutely be interesting to give it a try. If so, I think the brass seat need some machining first so it won't be so thin. When I change a ball in a fuel pump or injector, I always put a new bearing ball in place, tap it firmly with a hammer to re-form the seat. Then that ball is discarded (they are really cheap) and a new one is installed.
Carlsson- yes, I was assuming some form of shape-tuning would be needed. I'm now also considering using a tiny rubber/neoprene ball instead of metal ball bearing. Will dig around and see what works, promise to share. Thanks again.
Alternatively, go to www.base-camp.co.uk/Petromax/Petromax Spares Price List.htm and look for this item: 17 Check valve cone with packing £ 0.80 Another alternative : britelyt.com/product/new-part-10-pump-valve-complete/ O.K. it looks a little different but it will screw straight in. Henry.
I found a lamp yesterday that needed a ball instead of a rubber seal. This was a mid 1920s Welsbach lamp and the pump kept pushing out at me. It had worked before OK so I never investigated but I found a spring and a rubber seal which was flat and a bit too small for the tube but the tube end was just a hole. No spigot. I tried a new rubber which didn't work but then engaged brain and shoved a 5/16 dia SS ball in there. It wouldn't work without the spring but now I get a perfect seal. Those spring loaded Primus type pump NRVs will probably work fine with a ball. Might have to experiment with the ball size and the spigot end will have to be squeaky clean but worth a try for sure. ::Neil::
