10-31-2012, 05:10 PM
You know what you could do...
Hollow out the wood tank & put an aluminum one inside. Wouldn't that jack with people's ideals...
10-31-2012, 05:48 PM
Actually, in the latest BMW Motorcycle Magazine, a guy in Japan who fabs the coolest racing/cafe beemers, price no concern, hollows out standard tank, makes it into a flip up unit skin, covering an aluminum square type low volume tank. Maybe you saw it? I'm actually riding behind an a goldie type tank, in my mind, called dreaming on into the winter.
11-01-2012, 01:18 AM
Seriously? 12ga? wow. you're a stud. 16ga would have been fine man, but hey, they're your arms.. lol
what type of al are you trying to work with? 6061? 7005? aluminum has a pretty narrow range to work with before it gets too brittle.
Last edited by beater; 11-01-2012 at 02:07 AM.
11-01-2012, 01:24 AM
Maybe TMI, but this is the walnut forming stump, with nice groove for pounding sharp curve, dimple for shrinking, a taper for whatever and a rolled edge for bigger outer radii.
11-01-2012, 01:28 AM
Sometimes have to pound around simply the bench edge.
11-01-2012, 01:34 AM
Also helps to have a good solid wood/maple anvil to pound on. Also cut one end of square mallet to a V shape, very handy.
11-01-2012, 01:37 AM
So late today started on the middle of the left side tank bottom.
11-01-2012, 01:40 AM
11-01-2012, 01:44 AM
Pound around fer awhile, a couple hours go by.
11-01-2012, 01:46 AM
Sometimes the most obvious tool is useful.
11-01-2012, 01:55 AM
Just in time for supper, leftovers, and it's almost about right. Still have big doubts about this project, when the six pieces are about right, they git welded, and then I'll know a lot more about it. Just can't spring for the welding rig. Not going to pay more for a welder than for the bike. Can't ride a welder.
11-01-2012, 02:25 AM
I'm using 63 thousanths, or about a 16th of and inch. Next jump up was 80 thou, and that stuff was thick. 3003 grade. Could'a went with a 5000 grade, more corrosion resistant marine grade, but couldn't see the upside. 3000 grade is pretty malleable. Don't know anything really about doing this. Never done it before. The grades of aluminum start at 1000 and go on up to 7000, each with its own characteristics and applications. Cyclists know a lot about these things. My partner thinks it's crazy and will blow up?, and it's illegal. I said I'll git a fire extinguisher when I go riding. Not sure the tensil strength of the steel tank is much more. Or, we could just sit in a rest home watching TV? This is hard, don't know if it can be done, don't recommend it.
11-01-2012, 03:34 AM
3003 H14 is what you want. The strength will come from making the tank itself. You could anneal it to make it easier to form, then it will work harden. Check out this guys site:
11-01-2012, 12:18 PM
sorry - I misunderstood. I thought I saw that you were using 12ga (.080). 16ga is still overkill, and yes, the strength will come from having the finished shape. The trick will be to make sure you are evenly planished to make sure that you have aligned all the grain and gotten the material as uniform as possible.
I know you're not there yet, but when it comes to welding on the tabs, remember that that this will be the weakest point of the structure from a vibration and cracking perspective. You will most likely need to form a "dissapation zone" on the mount areas. meaning, slightly thicker stock welding over the tabbed area, (usually 2-3 times the tab surface) to have the tab attached to that, then the plate to the material.
I am sure you will source a quality welder, but make sure that you discuss heat treatment of the base material around the welded zones "if" they are in load baring areas.
Do you have a stick or basic mig? I could show you how to make some basic tucking tools that will save you a ton of time if you do, out of drum brake tools. my other recommendation is to get a bag and hammer assortment for plannishing and forming, simple but effective.
I'll go back to my hole now. Oh, and not only is steel "real", but it's easier too! lol
Originally Posted by 8ninety8
11-01-2012, 04:11 PM
I think you're correct, when the various bulging pieces are connected a massively convoluted monocoque (sp?) shell appears. the pieces of which, each with their own propensity toward retaining a unique shape. The weak points should be where all the weight will bear, the front socket and the rear posts fixture, each of which will be completely gussetted to the top underside, completely gussetted forming non-distorting structure.
I've watched, utube, 3003 welded and then deliberately bent, and the weld does not bend. It can be hammered, but looks much tougher than the metal next to it, guess it's, well, thicker than even 80 thou. and tempered after heating. It's all new, for me it's a small opperation, will power, non-deep pockets with the lower than 500 pound UK price tag in mind. Thanx for the tips about tools, an empty shot bag is around 40 bucks, the shot 6 bucks a pound, so I'm using a couple layers of old carpet and the 11 dollar HF double ended nylon dimple mallet. It's like the canoe, make one, been there done that.
Thanx for the click to Fournier site, very much info.
Last edited by 8ninety8; 11-09-2012 at 04:20 PM.