Modified Coleman Xtreme Stove

[Bill Fornshell]

Coleman Xtreme – Phase 1 Complete

I am posting this now so at least one Phase of the Coleman Xtreme’s “Diet” can go into my “Year 2005 – Done Box”.

I made 5 or 6 Stove/Pot Stands trying to keep the overall weight of both the Valve Assemby/PowerMax Canister Connector and the Stove Stand/Pot Stand at or under 7 ounces. I milled most of the extra metal off the Valve Assembly and cut down the stock gas on/off knob, The overall stock weight of the Xtreme is 11 ounces. For the different Stove Stands I made several trying to find the lightest but stable stand to support a larger size cook pot while melting ice/snow for water. The Xtreme w/PowerMax Canister is really great in low temperatures and maybe better than anything else on the market. At low temperatures things need to work easy and work well with light gloves on so that was my goal..

I worked on the Xtreme as a two part piece of equipment. The Stove/Pot Stand and the Valve Assembly/PowerMax Canister Connector.

For this version (I call ver. 3.0.1):
– the weight of the Stove/Pot Stand is 3.25 ounces.

– the Valve Assembly/PowerMax Canister Connector is 3.67 ounces.

This brings the complete Xtreme ready to burn at 6.92 ounces.

Things to note when looking at the pictures:
1. I used light nylon nuts to hold the Aluminum rod for the legs. These will be replaced by light metal nuts and even lighter “push nuts” where heat might melt the nylon. The weight of the stove reflects the weight of the final nuts used.
2. I used 1/8″ aluminum rod instead of the 1/8″ titanium rod I had because the aluminum rod was just a little lighter and a lot less expensive. The aluminum is also a lot easier to work with. The aluminum rod costs $0.17 a foot and the titanium with shipping and cut charge was about $0.89 a foot. I can buy the aluminum local.
3. For Roger A. – The Stove/Pot Stand required no special tools but I did thread some of the aluminum rod. The thread “die” costs about $5.00.
4. I did mill the Valve Assembly with skills I first learned in a “shop” class back in Jr High, about 50 years ago. The milling saved almost 1 ounce. Changing the stock stove legs saved 2 ounces.

[Ryan Faulkner]

Dang Bill,

I wish you had a windpro so we could see what you could do with that.

Good job on the new stand :-)

[Bill Fornshell]

Thanks Ryan F.
I like the MSR WindPro but it has a big problem when trying to lighten it. It has a heavy burner head. If I adapted the Coleman Xtreme to burn off a regular canister the new gas line plus the modified Xtreme would be lighter than Mike’s modified WindPro. Mike’s WindPro is 5.1oz I believe. The stove part of my Xtreme only weighs 3.25oz. I could take the gas line off a WindPro and and use the Xtreme with a regular canister and be well under Mike’s weight.

I think that before I buy a WindPro to modifiy I want to have a close look at the Brunton Optimus Crux a sit on canister type stove at 3.1oz. It might be eaiser to convert to a remote canister and it is really light to start. the Coleman F1 UltraLite out of the box is 2.7oz and I have one of them.

I may have to get a WindPro to use for parts and then see what I can do with it later. I can buy just the gas line but it costs $40. I think I would be better off buying a new stove. I could then adapt the WindPro to the PowerMax canister and use the WindPro gas line on the Xtreme and other stoves to convert them to a remote regular canister.

This is of course all for the sake of science.

[Ryan Faulkner]

Bill,

what I think could make for the lightest stove would be a windpro, with the smaller burner head modifacation, and the metal fuel line cut at both ends and then welded back together so there is less than an inch of metal tubing. Then the flexible fuel line shortend a few inches.

so it would end up with a smaller burner head, almost just attached to the flexable line with a half inch or so of tubing.

I dont think I explained this well, but you may be able to understand it.

[Bill Fornshell]

Ryan, I understand.

I used the smaller burner head from the Coleman F1 on the modified Xtreme. I am not sure I would even call it an Xtreme anymore. Coleman still mostly yes. The burner head is from the F1 and the connecting tube is home made, the Mag casting while still the Xtreme unit is very much modified from the stock unit and the complete stove stand/legs are home made. I tried using the pot stand from the F1, they are nice but they are to heavy.

I do like the way the WindPro has the screw in the top of the burner head. That gives you a great way to attach the legs/pot stand.

I don’t know what would happen if I drilled a hole in the top of an Xtreme or F1 burner head. I have also thought about trying to make my own burner head.

If we could pick and choose parts form stoves currently being sold I think we could come up with a really light stove. I called Coleman about buying a few parts and they really didn’t want to sell them. I was told they didn’t want folks modifing their products. This was said politely but a no is a no. They said if my stove was broke I could send it in for repair.

Hey Coleman supply us with some parts. We like the Xtreme and PowerMax Canister but just want it lighter. I would love to have you sponsor what I am doing for your stove. Sorry Ryan hope that doesn’t get me in trouble.

[Ryan Faulkner]

I found this repair parts page on the coleman site, for the Xtreme.

[Mike Barney]

Great article Bill, thank you very much. If you were camping in warm weather, would you really need the casting at all? (that you did such a great job of machining down!)

MikeB

[Bill Fornshell]

Thanks Mike, I am going to make an adapter that will allow me to use the Xtreme without the PowerMax and connect to a regular canister. The reverse of that has already happened. I have an adapter that will let me connect my old Rapid Fire remote canister stove to the PowerMax Canister.

I am not sure what you would save in the summer or warmer weather by going to a regular canister. The regular canister empty weigh is more than the PowerMax I think. I would defer to someone like Roger Caffin, Michael Martin or one our other smarter folks for that answer. If you want to use the PowerMax canister you have to use the casting.

[Mike Barney]

Thanks. I had heard elsewhere that the purpose of the casting was to insure in cooler weather that the gas temp was not too low, hence the idea of not needing the casting for AZ in the summer.

Per your other note, where can we find out more info on using a PowerMax canister with an existing IsoPropane stove?

Thanks for the contribution,
MikeB

[Ryan Faulkner]

Mike B

MSR Stove-PowerMax Fuel

[Mike Barney]

By the way, if you’re part of any nonprofit (they specify churches, scouts and schools, plus Red Cross and many others), you can get a smoking deal on an Xtreme stove directly from Coleman for $37.08 vs. the original price of $59.95
You can register at their non-profit site,(below) and they will send you the password for access to the nonprofit site.
They also allow “Civic Groups” (owners of Honda’s?) and “Other” as qualifying groups.

http://www.coleman.com/coleman/promotion/youth_camping2.asp

Hope that helps!
MikeB

[Bill Fornshell]

Thanks Mike, I have a Coleman Outlet Store near where I live and they sell the Xtreme for $40 or so. I have been lucky and have saved a little more during one of their many “sale” weekends.

Thanks Ryan F. for posting the link to the MSR to PowerMax information.

[Michael Martin]

Bill-

Beautiful work! You’re truely an inspiration to me.

It looks like those legs might fold up. If so, would you be kind enough to post a photo?

Best Regards,

-Mike

[Bill Fornshell]

Mike Asked?
“looks like those legs might fold up. If so, would you be kind enough to post a photo?”

Yes, the legs fold, you might say they are spring loaded and need something to help keep them folded like a rubber band. Sorry I didn’t weigh the rubber band.

The stove will fit with a little extra space in my SP Ti 700 mug.

[Bill Fornshell]

From Coleman:
===============================
NEW ADAPTER EXPANDS FUEL OPTIONS FOR X-STOVE OWNERS Coleman® Exponent® X-series stoves are getting new fuel canister alternatives. The ingenious Powermax® Fuel Adapter allows any X-stove to run on conventional, more readily available butane-propane fuel canisters. That gives traveling adventurers the option of powering their stoves with either Coleman’s proprietary Powermax fuel or standard, threaded butanepropane blended canisters.

The innovative new adapter also effectively converts the LP canisters into a liquid-withdrawal fuel system to mimic the performance advantages that the Powermax system and X-stoves delivered – namely consistent performance throughout the life of the fuel cartridge including strong performance at higher altitudes and in below-freezing temperatures. The Xstoves broke important performance barriers often associated with butanepowered stoves and conventional vapor-withdrawal systems.

The lightweight aluminum adapter attaches to an X-stove fuel connector and two swing-out legs provide a stable platform for the fuel canister. In a 180-degree departure from standard usage, the threaded butane canister is inverted and attached to the adapter upside-down to allow a liquidwithdrawal method of fuel-feed to the burner. (Historically, LPG canisters of butane or butanepropane blended fuel used in conventional upright position rely on vapor withdrawal. There is pressure inside the canister. When the stove valve is opened, it allows the vapor to pass to the burner for combustion. Colder temperatures decrease pressure and degrade performance. A liquid withdrawal system draws the blended fuel in liquid from the pressurized canister, carries it via a copper fuel tube to a regulator that passed above the burner, which heats it and converts it to a vapor before feeding the vaporized fuel to the burner. The system results in reliable performance when temperatures drop below freezing, and it is less affected by altitude than vapor-withdrawal systems.) The Powermax Fuel Adapter will be available for the ’06 season with an MSRP of $23.
===============================
The following is my comment on this product:
This adapter should open up a lot of possibilities for the MYOG folks. A comment has been made that it looks a bit over engineered. They should have asked us to help. The price is right and I hope to get one as soon as they are available.

[Rick Dreher]

Hark, is that the sound of a milling machine warming up? :-)

They at least deleted an unneeded leg and made it a bipod rig. I have to say, it’s nice knowing you could now take a 450 g canister and an X-stove winter camping–at first glance an attractive proposition. We’ll have to await the adaper’s weight before crunching the total weights (e.g., 450 g cartridge + adapter versus two large Max cartridges).

However it plays out, my guess is the Max cartridge days are numbered.

[Bill Fornshell]

Rick: Yes, but think about the difference in weight between the Steel standard canister and the weight of the Aluminum canister used on the PowerMax.

A bought a dozen of the large PowerMax canisters for $2.99 each. That gives me a good supply if Coleman decides to discontinue the PowerMax. I would save them for very cold weather hiking.

On a different note, there is a much eaiser way to adapt a standard canister to the Xtreme stove. I have done this without using the PowerMax “Mag” casting. I just went with a different canister control valve and gas line. Unscrew the PowerMax gas line at the Xtreme stove and screw in the replacement that is made to connect to the standard canister. The weight was even a little lighter.

The plot gets thicker. I made two stoves like Son of Balrog, one for the PowerMax and one for a standard canister. I will just take which ever I think I need for the Temp I think I will be in if I want a canister stove.

I am happy to see Coleman doing something new and I does give us more “parts” to play with. The best part is the price of the Coleman stoves. Most are less than the competition.

Coleman also has some really great pictures of this stuff.

[Curt Peterson]

This is neat – at least someone’s thinking about different ideas – but I’d rather see the opposite: a way for screw-on canister stoves to run on PowerMax fuel. It’s the lighter cartridge that I’m after – not more options on the same canister. I think you’re right-on that this probably means the end of the PowerMax cartridges. I know a semi “secret” place that not only has them, but has them cheap. Might have to go clean them out…..

-Curt

[William Siemens]

I guess this is nice, but honestly I feel disappointed that Coleman seems to be backing away from their powermax concept. Not only is the liquid withdrawal method a more sound system, but the gas mixture is better for cold weather than the “other” cartridges. An MSR cartridge hooked to an Xtreme stove will make for easier access to fuel, but will NOT be as good as a powermax cartridge. Bill

[Rick Dreher]

I tried and failed to Google up even one retail source of Max cartridges. I’m sure they’re out there, but it should be much, much easier. For that matter, I can’t even find them on the Coleman.com website.

My local REI stocks them but rei.com does not. Their market penetration seemed to peak five or so years ago when Coleman was selling a line of Max-powered car camping equipment. I could even find them at WalMart.

They’re the Betamax of camping fuel.

[Rick Dreher]

If I don’t include the adapter weight, steel doesn’t suffer too badly in the comparison–about 6.5 oz for the 450g canister versus about 3.2 oz for a 300g Max cartridge, which extrapolates to 4.8 oz for a 450g equivalent. The adapter weight definitely hurts the steel option.

Aluminum’s easy field crushability is another big plus in its favor.

[Bill Fornshell]

I would not use the adapter with one of my stoves if I needed a stove for cold weather. I would just go with a non-Coleman lighter option.

[Craig Shelley]

Our local Walmart had all the Powermax cylinders on clearance last week. The guy in the department said that he understood it was being discontinued by Coleman.

Craig Shelley

[Michael Martin]

Curt writes:

>> I’d rather see the opposite: a way for screw-on canister stoves to run on PowerMax fuel.

I think we’re unlikely to ever see this kind of adapter from Coleman because of the liability issues. Some Yo-Yo is sure to to hook up a stove with no pre-heat tube to the liquid-feed Powermax cartridge and turn his Pocket Rocket into a Pocket Rocket. ;-)

-Mike

[Bill Fornshell]

Mike, I don’t know of any of the ultra-light “sit on the canister stoves” that has a pre-heat tube. No pre-heat tube/loop or what ever and you would not get the benefit of the PowerMax fuel. I think.

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