Just throwing this out there.........

[resto]

I don't know what it is with me and tank badges, but I am already looking for something to do this winter and would rather work with aluminum instead of plastic.

Started out hoping to design something generic that would screw directly to a Special style tank but it is challenging since the mounting holes and indentations are not symmetrical from side to side. I may still go back to that though as I like the idea of removable badges.

Since I already have a spare Special tank that has the indentations and mounting holes filled in, I thought I would use that as a starting point.

Here's a quick rendering I've come up with and would like your opinions on it. I intend to come up with a dozen or so variations of it. I am hoping to get away with using 3 inch x 6 inch x 1/8 inch aluminum plate (so it can be polished) and have it match the curve of the tank. I'd also like to keep it as simply as possible too. The hole in the emblem could hold a stick on insert, e.g. the Yamaha tuning forks or something like that.

Looking at the pic, ignore the white portions, and envision the green portion as polished aluminum.

Let me know what you think.

 

[gggGary]

Cool concept.

I just got some OEM 73 badges they have separate left right part numbers but I ended up with 3 lefts.....
ANYWAYs the painted and chromed pot metal, aluminum, what ever it is is soft enough that I was able to rebend the left to fit the right side perfectly. Just warmed in my hands with gentle steady pressure did it. I don't know aluminum but a very soft type should be hand formable? especially if the back is relieved so it is thin?

 

[nj1639]

How about a tank badge that says XS650 printed in the Baskerville italics style, similar to the cam end cover 650 of the '82 and '83 Heritage Specials? Winner winner chicken dinner.

 

[resto]

Dammit Jim, I'm a retiree not a magician...........

 

[jd750ace]

With the curvature required to match the tank, here's my thoughts. Being .125 thick, it would have to be pressed into a form with significant over travel to allow for spring back if the aluminum had any temper to it at all. Annealed aluminum is a pain to machine, as it's difficult to clamp the soft material, and it does not cut as clean as solution heat treated material. If I were attempting this for myself I'd simply do it in 3 steps and cut it from 6061T4 bare plate, anneal it, press form it to fit the tank profile, then re-do the solution heat treat and straighten it before polishing. That's a lot to go through, but the spring back of the tempered material can vary from sheet to sheet and with the grain direction in the finished part, and getting it to lay down good from part to part would be a challenge IMO. If you COULD get consistent results pressing it at T4 (solution heat treated condition) It would greatly simplify things, but that's a pretty tough sheet to press. You would need a negative and positive of the tank with over travel in both to allow for the spring back.
Not a terrible idea though. If you made your press block set from something with high resilience and very high shore hardness (nylon 66 immediately comes to mind) you could do probably 100 sets or more without it deforming. Hard to do more than about a half dozen press parts with hardwood, and unless you monitor the pressure closely, it's very easy to split your blocks. I have a fair amount of experience breaking form blocks.

 

[resto]

jd750ace,

Thanks for the valuable feedback. Your suggestions are pretty much the way I was going to go about it. As it turns, the .125" aluminum plate is 6061 (from eBay) but the "T" number is not stated. I will be using .75" aluminum billet bottom block, machined (filed?) to initially match the curve of the tank where the badge will be (to be determined) located. Didn't know how much spring back to expect though and was just going to keep putting in more arc on the bottom block to compensate for that. Was hoping to avoid annealing as I don't have an oven hot enough to do 6061 properly. That was one of the reasons I put the hole in the badge design, to make it easier to press.

I like your idea of nylon press block, it's easier to machine and shouldn't mar the surface of the badge as much as a metal press block would. Even considered using really hard rubber. Have a lot of old hockey pucks around..............

Depending on how it goes, I may have to pick your brain more on annealing. I haven't had much luck doing it consistently with a torch. Always got some warpage, but it was very thin gauge aluminum.

 

[jd750ace]

I guess your ebay metal does not have the mill stamp on it anymore? Sometimes folks wash the mill ink off when they receive the metal. I'm not a fan of that. Never know when a piece might get mixed up and that ink stamp saves you from buying another sheet when you have a useful bit laying around. In aircraft sheetmetal shops, we mark our cut-offs with thickness, alloy, temper, and purchase order number and put them in a cutoff bin so we get the maximum usage out of a sheet.
On annealing, a proper full anneal of 6061 would be at 760 degrees for 2-3 hours, followed by a cool down rate of 50 degrees per hour down to 400, which can continue to room temperature or it can be pulled from the oven at 400. That's per MIL-H-6088G. Problem is you would have to bring the temper back up with a solution heat treat before you tried to polish it.

Hot forming temps, which have a temporary softening effect on heat treated alloys (but necessitate temperature stable tooling) for 6061 alloy is 300-350 degrees, preferably soaked at that temp for an hour. You can do that in the kitchen with enough accuracy, and it will reduce your forming pressure and spring back. The material naturally age hardens back to it's previous state at room temperature. Perhaps that's a good way to go for you. You can download that Milspec (and mountains more) from here:
http://www.everyspec.com/specifications-standards-search.php

 

[resto]

That 700 degree temperature is definitely out of range for my toaster oven (hmm, unless I rewire it for 220V.....). Good to know about the softening at 350 though, but that would exclude using a nylon press block though. Guess I'll see to what extent I can shape it with just blocks that have the curvature over exaggerated and take it from there.

Thanks for the info and link. Will post some pics once I get started in a couple of months.

resto