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Flat Sheet "Y"s...
Posted: March 26th, 2010, 9:13 am
by AlisoBob
soliD was asking about them....
Heres one....
Chachi did one,
Are there others?
Posted: March 26th, 2010, 11:02 pm
by CR500R7
A member by the name of _joshua_ ( from Nice, France ) was fabricating one similar to those examples and also had a picture of someone else's "y" in his build thread.
His first post for his build was on the 5-23-2009 at 7.43 AM and his last post was on the 5-30-2009 at 2.26 AM.
I have no idea if he has finished it or not, I would like to see how it turned out though.
You can checkout his short build thread here,
http://www.bannedcr500riders.com/board/ ... highlight=
Posted: March 28th, 2010, 7:38 pm
by asteroid500
They look great, but with most of us trying to get a OEM look the flat Y was never an option....but they do look good though

flat sheet y
Posted: October 3rd, 2010, 8:20 am
by riverman
I'm getting ready to start chopping the 04 CRF250R. I have been educating my self from this site and the other one. Do you think there are benefits to doing the flat sheet y versus the other method of moving the stock y section up and repalcing the sections of the 1 inch tube?
I have concerns about reducing the down tube to fit the y section seems to be a stress point weakness by grinding the tube down. Could be strenghtened by adding some small fish plates front and back.
I have the ability to draw the flat sheet out in cad and have it laser cut. But this would add alot more welding. So is it worth the extra time and effort?
The other thing it is blowing my mind what some of the guys on here are paying to have there frames welded.$$$$$$$$$$$ I have been welding for 30 years I'm thinking 2 hour max and it would be done, certinly if you just had the cradle to handle.
Thanks for sharing your knowlegde
Tim
Posted: October 3rd, 2010, 10:37 pm
by bearorso
I like flat sheet Ys, but the few I've done have been full flat sheet cradle/Ys - the first one probably 7 years ago out of 6061, and the most recent last Xmas for a mate who I foolishly showed that picture posted here. That was done in 7020 / 7005.
With flat sheet Ys, you are making something with damned near the whole piece being one continual HAZ . Weakening the Whole piece. So with 6061 I've had the whole cradle / Y piece heat treated as a unit before fitment to the main frame. The 7000 series fabrications required no solution heat treatment, as that's what 7000 series was developed for.
I then just do a basic artificial aging in a oven I have that will just take a frame, after the cradle/Y fitting, if the frame is being put into use straight away.
Because the 'side plates' are cut out, with only a gentle bend going to the downtube , and the bottom and top plates have just the forward bend in them, (with non bent sections at RAs to them) the plate cradle / Ys don't distort much during full solution HT, though I made a simple jig to keep the rail gaps as they should be, and just a top Y steady as a precaution.
Doing it with a full y/ cradle is a lot of work, with a Lot of welding, but it looks fantastic, and is as strong as you can get. You can tailor the thickness of different sections. Though it Did cost my mate a small fortune for the 7020 / 7005 sheet/plate to cut it out of.

Posted: May 23rd, 2011, 7:37 pm
by coley13
Bump
Posted: May 23rd, 2011, 7:47 pm
by coley13
That first picture confuses me, looks like genuine lower rail plus mount yet there is no seam/ join to flat sheet Y on the outside. Grinded flush maybe? Anyway just bumped the thread. Thinkin of using flat sheet method.
I like the first one butt welded, would it be fair to say it should have an insert at the Y. Or better off fillet welding the flat sheet to the outer side of down tube?
Does that look like a mig weld?
Flat Sheet "Y"s...
Posted: May 24th, 2011, 5:52 am
by cryzsurfer
It's probably TIG but they fuse over the filler as opposed to dabbing it to make the row of dimes look. There's also an automatic wire feeder that can be hand held which I tried but didn't like or a wire fed TIG torch which I also thought sucked. Both of those builds look sweet IMHO.
Craigus
Posted: May 24th, 2011, 8:48 am
by AngryShawn