progressive hack

[makenzie71]

Well, we started with something like this...



I decided to do a little hacking for 3 primary reasons:

...it's ugly.
...it's a poorly built clusterfuck.
...seat height was too high.

So I took out a torch and cut this off...



See?  Clusterfuck.

I then around confused because I had approached without a plan and basically built the same clusterfuck again...and cut it back off after I realized I needed a plan  Went inside and broke out some paper and a pencil and started drawing.  I wanted to do something to clean teh rear up a lot and decided I'd use a solo tail I had lying around...a k2 GSXR tail.  Before long, though, I realized that a 13" hump really didn't fit the bike well.  So I cut off another subframe and started working around a K4 solo tail which matched the tank FAR more nicely.  So after about 84 hours of tedious labor I finally had this:



I spent part of that night in the shop cutting and welding shaZam! I ended up with a new clusterfuck...but a much more contained, low profile one.  Far superior...and about 14lbs lighter than the first attempt.



I think it really worked well for the bike as a whole.  Before long it'll be a nice looking, interesting ride...or another ratbike...whatever.



Just for perspective...I'm 6'2" and 150~ish:



I've got to say that the most diffucult thing I've delt with so far is figuring out where the hell to put the damn steering damper!  Such a pain in the ass bastard thing to figure out...I've got 6 dampers, all different sizes and designs, none fit conveniently until I ripped the overflow tank off...which is worthless anyway.






...more to come eventually...

[weaselnoze]

wow dude. im impressed.....







...ur only 150 and 6'2? damn

lol but seriously i like the new look! a lot! i wish i had the time and resources to make a frankenbike.  oh and the space!  u should see the 'hole' i have to squeeze my bike into, next to my dads zuma and misc car/bike parts and a sleu of road bicycles..

[makenzie71]

yeah I'm a light-weight.  I also do a lot of running and actual labor as part of my job so any effort to gain weight is usualy thwarted.

I really don't have the space to do this, either...that's why all the shots you'll see are either from my front yard, on a trailer or at work...lol.  I have a full shop at work and considering how tight it can get at home my little 6X8 trailer becomes my mobil work spce.  I've actually got a little bench that lays over one side of the trailer for tooling, a lift I made to either lift a bike while on the deck or I can pull it off, a frame rack and two 10 gallon crock-pots for tools and parts...it's pretty sad, sometimes.

[GeeP]

I think you have an interesting idea.  I'm glad to see you enjoy fabricating.  However, I have a problem with your welds and some of your basic design.  They worry me.  I don't intend this as a put-down, but as constructive criticism.

Several things define a proper weld.  First, the material must be properly prepared.  This means removing all mill scale, rust, dirt, and other contaminates from the weld area.

Second, the joint must be properly set up.  This means that the joint fits tightly, encompasses as much of the structural member as possible, factors in expansion and contraction during fabrication, and other variables.  This also includes welding equipment setup and selection of the proper consumables for the material to be welded.

Third, the weld must be performed properly.  Put simply, this means using proper technique.

What I see in your fabrication is a lack of forethought in the design, a lack of proper joint design (has to do with 1), and a lack of welding skill.  All of these things can be fixed in time.

I have a particular problem with the welds that hold the "subframe" to the frame.  Not only the quality of the welds, but the design on the subframe and joint.  You have no supporting strut below the subframe to support the load in compression.  The result is that the welds are subjected to large tension and compression forces.  This is a very critical joint, failure of this joint will result in a significant mess. 

I did a quick and dirty calculation to determine the loading on the subframe to frame joint.  This calculation is rougly worst-case.  I assume a load of 150 lbs at a station of 20" aft of the weld location.  Assuming that the joint acts as a plain lever pivoting around the center of the joint, the leverage ratio is 20:1.  This means that 3" of weld bead must support 3000 lbs of tension.  14 ga tube is .083" thick (Stub's wire gauge).  Therefore, 3" of tube, .083" thick must support 3000 lbs tension. 

Standard weld design for tube assumes a maximum penetration of roughly 70% for tube joints.  This means that the weld is only joining .058" of tube.  This means that .058x3"= .174 square inches of welded tube supporting 3000lbs tension.

1/.174" = 5.75 scaling factor to determine PSI

5.75 x 3000 = 17,250 PSI.

This is a MINIMUM figure, and only assumes a load of 150 lbs.  It also assumes a PERFECT WELD.  It does not take into account the strength of the frame tube, which very easily could be less than that of the square tube.

AWS 6013 rod has a tensile strength of 60,000 PSI.  This will occur at roughly 522 lbs at station 20.0 on your tail assuming PERFECT welds.  A safety factor of 2.0 is advisable as a bare minimum, limiting the maximum weight to 261 lbs per frame member.

With the lack of penetration, poor puddle formation, high liklihood of oxide inclusions due to dirty steel, and burn through, I would be suprised if the weld held half that.

The question here is whether you are willing to trust your life and that of your passenger's to those welds.  Personally, I would not.  I strongly suggest you make a trip to your local library and pick out a few textbooks on welding and fabrication.  Study them carefully and practice. 

Remember, you must be very conservative in your design practices.  As an example, most overhead lifting equipment will carry 7 to 10 times it's rated load before failure.  THINK ABOUT IT!  Please?

[ajgs500]

You go Geep!!!!!!!!

[makenzie71]

I think you have an interesting idea. ...etc etc etc... As an example, most overhead lifting equipment will carry 7 to 10 times it's rated load before failure.  THINK ABOUT IT!  Please?

First, Geep, I sincerely appreciate any kind of criticism when it's aimed at my safety.

Second, I'd like to congradulate you on your astounding abillity to judge the quality of my welds without having even seen a clear shot of them.lol Please don't take that the wrong way, but there's no way you can be a judge of my weld quality in the shots I've provided.  I've already ground these down, but I'll foward you some shots of some of my headers if you'd like to see what I do.

The spars are only 22" long at their longest possible measurement and the weight (161lbs with all components) is centered 10" from the base of the subframe and there's 6" of weld around each spar and it's propperly joined to the frame.  With just 2" of weld on either side, my frame machine couldn't bend the spars into propper alignment while they were still 34" in length and it has a 2000lb pull, with the chuck mounted at the end of each spar. The subframe tubing is 12g, the frame tubing is 14 I think.  850lbs has already been applied to each individual spar at 14" from the base with no ill effect.

If there's some kind of visual test you'd like to see performed that isn't absurd, I'd happily film it for you.

[makenzie71]

the tail light assembly...

[makenzie71]

~~OOPS!!

Each spar was loaded at 450lbs.  I loaded the pair to 850lbs.

Sorry about that.

[pantablo]

what the hell was it when you started? its gonna look badass painted krylon flat black.

[makenzie71]

what the hell was it when you started? its gonna look badass painted krylon flat black.

ya know I love that krylon flat black!

When it started it was a 1996 ninja 500.  Not sure exactly what it was by the time I got it...still basically a 98 500.  Now it's another ratbike.  somewhere in between it turned intoa  1993 Ninja 500...oddly enough...

[GeeP]

Second, I'd like to congradulate you on your astounding abillity to judge the quality of my welds without having even seen a clear shot of them.lol Please don't take that the wrong way, but there's no way you can be a judge of my weld quality in the shots I've provided.  I've already ground these down, but I'll foward you some shots of some of my headers if you'd like to see what I do.

The spars are only 22" long at their longest possible measurement and the weight (161lbs with all components) is centered 10" from the base of the subframe and there's 6" of weld around each spar and it's propperly joined to the frame.  With just 2" of weld on either side, my frame machine couldn't bend the spars into propper alignment while they were still 34" in length and it has a 2000lb pull, with the chuck mounted at the end of each spar. The subframe tubing is 12g, the frame tubing is 14 I think.  850lbs has already been applied to each individual spar at 14" from the base with no ill effect.

The reason is because I've spent 1,000's of hours looking at welds and structures, sometimes through an inspection mirror 1.5" in diameter.  I'm also pursing AWS certification, so I spend a lot of time practicing.  After enough time looking at welds certain things jump out at me.  It's also because I see certain joint setups and get a mental image of what's going on.  As an example, you say you watch cows.  I'm sure you can spot problems with cows from 500 yards.  It's likely I wouldn't know what you were looking at.

One thing that is a tipoff is that you say you ground down the welds.  This is poor practice.   A good weld should be slightly crowned.  Grinding off a weld will reduce it's strength.  Ground welds are not allowed in certified fabrications.

I am glad to hear that the structure has proven itself acceptable through load testing.  Proper load testing is always the best way to determine if a structure is suitable.  However, I still suggest that you study a text on welding and then reassess your joints.

If there's some kind of visual test you'd like to see performed that isn't absurd, I'd happily film it for you.

I suggest you practice your SMAW with 6013 on 1/8" or 3/16" flat.  Start with flat butt welds and work your way to overhead fillets.  You can check your penetration and inclusion content by performing bend tests.

The bend test is a visual test.  For example, prepare a "coupon" by butt welding two 4" pieces of 1/8" flat together on one side.  Now place the weld side down on your welding table with the weld just past the edge, clamp it down and beat the other piece till it folds over and the weld fails.  Note the penetration, inclusion content, burn-though, and any other defects.  Adjust your settings if necessary and try again.  For thicker material, a 20-ton or greater shop press comes in handy.

If a weld has been performed correctly portions of the base metal should fail with the weld.  This can easily be seen with 6011 or 7018 in plain carbon steel 1/4" thick.

I recommend you find a copy of "Modern Welding" by Andrew D. Althouse, Carl H. Turnquist, and William A. Bowditch.  ISBN 0-87006-279-4  This book covers all the common welding methods in a textbook format.  It includes practice exercises and performance requirements.

Welding is 90% practice, which is why AWS certified welders must show practical experience every six months to maintain certification.

Again, I'm not trying to rag.  I'm trying to impart information more than anything by pointing out errors, as we never learn from what we do correctly.  I think once you read the book you'll have a better idea about where I'm coming from. 

[Jake D]

Thems is little bitty pictures. 

But I like a good welding debate as much as the next guy. 

Bike looks cool, Mak. 

You need to paint it.   

[makenzie71]

One thing that is a tipoff is that you say you ground down the welds.  This is poor practice.   A good weld should be slightly crowned.  Grinding off a weld will reduce it's strength.  Ground welds are not allowed in certified fabrications.

It's something I do with anything visible externally.  I weld the joint, then lay a rather wide bead across my surface and ground down to give a little smoother apearance.  The same weld is still holding the joint thoroughly, it just looks a little nicer...since I only have access to CO2 it's a little difficult for someone with my skill to make a small "pretty" weld.  Common body-work practice.

I suggest you practice your SMAW with 6013 on 1/8" or 3/16" flat.

I don't typically do much shielded metal welding, mostly metal/inert gas or gas/tungsten.  Only places I really use a stick anymore is welding heavier stuff that my MIG machines have a hard time penetrating propperly.

I have a copy of Modern Welding somewhere that I chip away at from time to time.

I've done the bend test a lot.  I spent 3 years in the shop just sticking random things together and then beating them apart with a hammer to see what would give and how.  Despite the fact that my welds usually aren't as pretty as I'd like them to be, any more (as long as I pay propper attention to my settings) my welds tear apart the material instead of the other way around.  I also make it a point to spend time in the shop, at least a couple hours a week, building something just for the sake of practice.

As I said, though, I really do appreciate having things pointed out anytime someone feels they could be hazardous.  I'd do it for anyone else, and I certainly appreciate it being done for me.

Jake, paint's in the next week or so.

[Blueknyt]

I belive the welds and Joints Geep is Mainly refering to, and i would agree with the reasoning  IF this in fact isnt a machup to get an idea.
 

the the basic structure does indeed look unsound as it stands, Im a good one for eyeball engineering too, while my welds may look bad at times ive had em crash tested and know they hold up.   those Joints for the Batt box is a big redflag . thats why im wondering if most of this wasnt a machup before being redone with better cuts and jointwelds.    Other then that i have no issue with it.

[makenzie71]

It's hard to see in that picture but the seat braces aren't supported by those thin little tabs.  Those support the tail.  The seat brace is supported by the tank support.  I'll put more picures of it up later.

The battery hanger is just tacked on in that picture.  Still trying to get that perfect.

[makenzie71]

To go into a little more detail on the above picture:

I can't think of the propper term...gussets, I think...but I've used 14g steel plates on the sides of the battery hanger braces to support the weight...really did it "over-kill" considering that the hanger had a solid bead at the base of the braces and then all down the sides of that bent steel plate that I have the wiring harness and all sitting on.  I'm also making plate that will bolt on, instead, to block view of the mangled portions of the stock framework...I lack the patience to make it look pretty again, I think.

The tank support is made from the same piece that supports the tank on a stock EX, just trimmed it down to fit propperly and braced the sides to support a little more load.  The braces that support the rider weight are 16g 1" tubing, supported at the rear by a 1.5" long piece of rolled steel...9/16 or 5/8, can't remember.

There's a little tab you can see in the picture above with a eye in it beside the tank support.  That's a 16g tab built to support the tail cowl tabs.  The battery hanger supports the rest of the tail's weight...actually the battery hanger supports the battery, the tail and a tail lamp and that's it.

[makenzie71]

I got around to doing a little more work...mostly some finnish work on the subframe and body work on the tank, but I slapped some paint on.






Instead of my typical matte black, I chose a rubberized undercoating.  This is the stuff they use on cars in the north to keep the salts and crap on the road from dissolving them.  It's paintable, super tough and I don't think it looks half bad.

[RVertigo]

Well, it looks better than it did...  That's fo sho...