Bike Forums - Blade bending blocks

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Quote:

Originally Posted by unterhausen (Post 15414586)

looks good

Indeed it does.

Looks like it might be easy to add a combo lever extension + handle, made from a piece of 2X4 lumber carved into ergonomic handle shape, secure the extension handle by driling to clamp it with the two pieces of all-thread.

I just used a 3' length of black iron pipe. They sell them at hardware stores for very little

Thanks. I have a lot of materials(pipe, angle, flat stock), I'll think on it for awhile. My only expense to date is for the wheel, and I guess the steel from the scrape yard @ $.10 lb, and a few sticks of 6011. Wood, bolts, etc. are from my accumulated "stock"(some might say junk). As far as my time, well, this is a hobby so it doesn't count:).

Brian

finished length(for now)

Played around with what I had this morning and came up with this. I had the flat stock cut to use for arms with the 6" radius block, but ran the block through the planer so now both blocks are the same thickness. No need for a separate lever, used that stock and added tabs from angle to the ends that pivot/engage the existing arms when pulled down for bending. I cut a piece of 3/4" pipe for a handle and it is used as a gauge on the distance between the lever arms for set up.

Bent some more 1/2" emt, way easier, probably over kill but I'll see how I like it with use(I have a cutoff wheel so easy to shorten). By using the bolts and all-thread it takes down quickly for flat storage. I know this is pretty rough compared to a lot of work here but its what I can do with what I have without putting a sh#tload of time in it. Major benefits: enjoy doing it, increasing fab skills.:thumb:

Brian

http://i1122.photobucket.com/albums/...ps4d06b365.jpg

remove the two outside nuts on the "axel" and the extension is released
http://i1122.photobucket.com/albums/...psc23104ee.jpg

http://i1122.photobucket.com/albums/...psa07b9f62.jpg

scrap pipe and all-thread handle
http://i1122.photobucket.com/albums/...psa1e38099.jpg

Quote:

Originally Posted by Cassave (Post 15358406)

Of course there's no need to make a constant radius block, or bend a constant radius curve in the blade. I made my bender with a block with an involute profile. An involute curve is a decreasing radius curve used on gear teeth. It's technically the path traced by a point on the circumference of a circle as the circle is rolled along a plane (for gear teeth that's important since there's no sliding contact) and incidentally it's a very "pretty" curve.

Cassave; Looked like a classic "French Curve" and maybe it is... But a quick Boogle to site below provides a layman's drawing and a simple step by step on how to draw one without any match beyond simple addition. Should be a "small brainer" to sketch one out on the side of the wood or metal slab one wants to make a bender from. Thanks for the correct name/term.

http://www.google.com/imgres?imgurl=...ed=0CCcQ9QEwAw

/k