Examined in some detail in THIS post but entered here in the Stove Reference Gallery for the record. A brand with Swedish heritage certainly, but the stove itself was assembled in Romania with components made in China and marketed by a Swiss company. Recapping a little on the post I’ve linked to above, my stove is of a batch recalled by Katadyn because of a handful of examples of gas leakage from the built-in gas regulator, this black box housed in the body of the stove. There’s no leakage from the component in mine, which has seen considerable use by a previous owner and I’ve thoroughly inspected parts … However, the connector to a gas canister doesn’t incorporate a shut-off valve. The Mk2 Gemini rectified that omission by having one that does, and a shut-off valve there is essential to ensure that if a gas leak does occur at the stove - whether from the gas regulator or perhaps an O-ring on one of the control spindles, or if the gas supply hose were to spring a leak - then the gas can be isolated at the gas canister, remote from the potential fire. On my Mk1 Gemini I’ve overcome the lack of a shut-off valve in the canister connector by making use of an MSR ‘Low Down’ accessory, more usually seen to convert this configuration … … to this It works well, with the additional benefit of distancing the gas canister further from the stove and keeping the supply hose low down and well away from hot zones. A further refinement is my fabrication of this connector. Coupled to a standard connector for a Camping Gas butane cylinder I have a source that suffers less from evaporative cooling than smaller disposable canisters. It’s possible too with that hose to supply the Gemini with a 1 bar regulated propane supply by substituting this for the Camping Gas valve. John
If I may offer a suggestion, this "Rothenberger Maxigas Regulator for The Roxy Kit 120 - Maxi Regulator" could be used in this case, instead of the MSR ‘Low Down’ accessory: Brand Rothenberger Model Number 035723E Global Trade Identification Number 04004625357231 Item Weight 0.09 Kilograms Part Number 035723E ASIN B00M2TN3TC I should point out that I have no commercial ties to them—I wish I did .
Thanks @chiorpo but it’s about the price of the MSR device and is made of an aluminium alloy, which makes it unsuitable for silbrazing to it the necessary male and female lindal fittings to make it compatible with the stove’s hose connector and a gas cartridge.
I’ve never seen what it’s actually like, but it has a 7/16 threaded inlet valve at the bottom and a 7/16 threaded outlet at the top. I’m buying one now to see what it’s really like; I think it’s made of brass, like other Rothenberger items I own.
@chiorpo Agreed, the illustration suggests brass. I had taken the reference to alloy from a retail source description. I’ll be interested to hear your findings.
From the photograph of The Roxy Kit 120, it looks like it has a female port on both sides, so you would need to find or make a double-male 7/16"×28 UNEF adapter. As for using a large cylinder I have a Weber 8486 adapter, consisting of a gas pipe and a pressure switch to use the italian gas cylinder with the Q1000, Go-Anywhere gas, Performer Deluxe Gourmet models. I'm not a welding wizard like you.
While looking for a male-to-male adapter, I came across another solution—perhaps a cheaper one. By combining these three Chinese-made parts, you achieve the same result.
I’m grateful for your thoughts and interest @chiorpo Since you said that you’ve no commercial involvement with Rothenberger (!) I’d best confirm that neither do I with MSR, but their ‘Low Down’ device works well in the Optimus Gemini (Mk1) example in providing the essential shut-off valve at the gas canister otherwise absent. Additionally though, it accomodates the height of a large canister, which without it tends to raise the stove’s hose into a warm, if not hot, zone. The arrangement seen here with a Robens Fire Finch stove.
I really appreciate everything MSR produces, it is certainly reliable, but it is also fun to play around with other similar items: Markill 92489 Alocs CS-G07 but at this point, we ought to start a new thread about three-legged adapters. I first got interested in this type of adapter as a way to replace the alcohol burner in my Trangia, but then I caught the "stove bug"—and I still haven't recovered.
The Markill one appears not to incorporate a shut-off valve in its gas canister connector, which isn’t what’s wanted for the Optimus Gemini application. The Alocs one looks good, but I can’t find it on AliExpress or other source.
… the only device I could identify on AliExpress with any relevance, but unsuitable because of the lack of a shut-off valve.
The various pieces I ordered arrived these days. The cheapest solution I've found is these three pieces made in China. the tube has two O-rings on each side and seems pretty secure to me. The Rothemberg piece has a 7/16 threaded inlet valve at the bottom and a M8x1 threaded outlet at the top, but I'll play with it anyway, it has the same thread as the air valves on car tires. I'm sure it could be useful to someone for a Frankenstein-style creation.
