Saturday, February 28, 2009

day 12

i just wasn't feeling right about how the exhaust was looking, it was too understated so i decided to add to it, this is what i came up with. i am liking this allot better now, it doesn't get over powered so much by the battery box i am building under the seat. speaking of that... 
here is a rough cardboard pattern that i whipped up to simulate the profile of the box.
this shot shows the pattern lay ed out on the .040 al sheet. the space in the middle of the traced pattern lines is the material needed for the bend radius on the front of the box. to get that number i knew i was gonna bend it over a piece of 1.125in tube so i found the circumference of the tube then divided it buy 3.
i radiused the edges of the box the same way i did on the saddle bag using a hammer and dolly clamped in a vise.  stay tuned for more.

Tuesday, February 17, 2009

day eleven

i decided that sisnce i am going to be riding this bike i want to have a saddlebag on one side. i did some sketches the made a pattern. i traced the pattern to this sheet of .040 al, then i added 3/4in around the outside to allow for my radiused corners that i am going to do on this box.

here i am test fitting the side panel to the frame making sure i have proper clearance all the way around.
i just used a scrap of 1 1/8in tube as a dolly to hammer the edge over. having a tight radius bend in the dolly makes the corneres on the pattern bend nicely.
here it is all radiused. if you work your bends slowly as you more around the part you will end up with out wrinkled corners like you would if you were to hammer each area to its full arc before moving forward.

on the second side i desided to try starting out my bend with a flanging tool(aka cresent wrench) this helped allot to define the edgeand keep my flange height more consistant. i use this method all the time.
i am going to jazz this bag up a bit with a grid pattern of swedged holes like the ones i did on the plate mount. here i am laying out where they are going to end up. i center drilled them with a 1/8in pilot. i will wait untill the box is hammer and dollied after welding to swedge the holes. straightening the box with a bunch of swedged holes would make for a tricky job so i will treat the holes once the box is square.
cleaco your part down flat and scribe and cut  an even line around the edge so that your part has an even flange height. this will make the center strip easyer to cut and hopefully make your box have a better chance of ending up square.
tack all around the box before doing any final welds, if you can do any hammer and dolly work before sewing the box up.
when your done welding do any hammer and dolly work you need to to straighten out any warpage due to welding, then you can use a grinder and a body file to take the welds down.
here it is sitting on the bike, next up building the top for the box and choosing a latch.

Monday, February 2, 2009

day ten?

in this section i am building a license plate mount that attaches to the rear axle. its layed out on .080 6061 al sheet. the axle hole is 20mm .
here it is with all three holes drilled and the sides folded up. i used a small pan brake to bend the sides up. make sure to allow for your bend radius
i built this swedging die that you clamp down on the sheet metal to give it extra strength and cut weight.
here is the mount all welded togeather for the plate backer i used .032 al to cut weight since its not really structural. i will be selling these in the pangea speed store soon, feel free to email me and i will whip one up for you if your interested.

day nine

here is the pile of tubing i recived in the mail, you can get mandrel bent tubing for pretty cheep off of ebay.
i had to machine off about .050 off of the i.d. of the exhaust clamps to allow for the larger tube dia.
here is a shot of the lathe doing its thing. i just ran a boaring bar back and forth a few times and it did the trick.
i had an idea of how i wanted the exhaust to run but wasnt set in stone on anything. its alway nice on a setup like this where you have really loose requirements that you have to meet.
here are the first few bends all layed out. when i was doing my aprenticeship a guy named gary kendall showed me a trick that really helps out allot when working with tube. when laying out a cut fold a piece of paper in half and wrap it around the tube and make sure that the paper lines up even on both sides then mark it with a sharpie. what this does is makes sure that your keeping a straight line around the tube and if your working on a bent tube it helps to reduce the chance of "cheating the bend". allot of people like to substitute tape for the paper but tape is designed to bend around a corner so it doesnt always give you a straight line.
here the pipes are tacked togeather and seam to be fitting up well.
this is basicly how the tips are going to sit i am going to extend them a little bit to clear the frame but you get the idea.
another shot.