'78 KZ1000 makeover

Nice to see you working on your bike. I have one question. Where is the removable joint for the upper part of the subframe going? As it is right now, you won't be able to remove anything with the end of the lower piece welded to the top tube. I assume that you will put a second set of joints in the top tube forward of that weld. Am I right? If so you may need to throw your seat on there and check for clearance. It gets tight in a hurry when the seat is latched.

BTW did you try my suggestions on drilling out those stainless bolts? I guess that makes two questions.

what 79 mkII said!
oh yeah and what testa said,also!

:laugh:

leon

Last question first- Yes, I took your suggestion Josh and slowed the lathe down. It helped quite a bit, until I learned that you can't drill a pilot hole that's only 1/8" smaller than your final hole. The stainless still chews up the outer edge of the bit ahhh well, at least I know now :dry:

:blink: you mean my subframe ISN'T removable yet?!?! Be still my heart! All kidding aside, my plan is to make and secure the bottom mounts before cutting the top. I want to try and keep things as straight as possible. I don't want my subframe tweaked to one side like some fat chick rode it side saddle :laugh:
MKII, Leon, thanks for the support

we are here for ya buddy! :laugh:

pat on the back,kick in the a$$.
you know whatever it takes, .

leon

looking good Adam.

Again, thanks guys. I need to finish preping my right sidecover later today, then I'll take the right brackets off and shorten them and cope the down tube. I'll be happy if I can get that much done today, that way I can do the left side tomorrow. This weekend, I'll make the right sidecover mold :woohoo: and in between I can cut the top of the subframe off and start working on those connections. Then it's a matter of finishing up any left over welding, and...... well I didn't really think I'd make it this far!

I shortened the brackets and coped the top of the tube and tacked it into place

This is going to be the final spot. I'm happy with it...as much as I can be. The guy that bent the tubes over bent them just a tad, so it doesn't follow the lines of the sidecover as perfectly as I would have liked, but it's only a few degrees off and it's not that noticable sooooooo I'm gonna roll with it.

I did the left side this afternoon:

It was much simpler since I did all the figuring out on the right side.

This is what it looks like from the rear

I tried to make the tubes as symetrical as possible. I will put a couple of longer welds on the tubes so that it can withstand me screwing with it while I cut the top subframe tubes.
Some may notice I used the old maier sidecover for the mock up. The next time I post a pic of the left side, I'll throw on one of the carbon fiber ones. Maybe I'll drag ou the frame and throw on the tank and tail for a better visualization for everyone, including myself!

testarossa wrote:

Ok Adam, I'm sure that we can get a good hole in those bolts. When you first said gun drill I got scared because when I think of a gun drill I think 0.094" diameter hole that is 5" long. 1.5" deep shouldn't be too much trouble. That drill bit is a cobalt drill which is about as good as you can get from the hardware store. The thing about cobalt is that they are tough, but you don't want to spin too fast. That looks like exactly what happened. Corners of the drill are wiped out which is a classic sign of too much surface footage (rpm.)

As best I cant tell f593c bolts are either 304 or 18-8 stainless. General purpose stuff. One quick check is to see if the bolts are magnetic. No I'm not crazy, there is magnetic stainless. It's called martensitic, look up 410 or 420 if you don't believe me. Now if it is the magnetic stainless then it can be heat treated to be quite hard. In that case I would take my spindle speed recomendations and cut them in half.

Now, assuming that we are dealing with 304 or 18-8 we want to stay under 50 surface feet. This means 750 rpm for the 1/4" drill and 375 rpm for the 1/2" drill. Actually on an engine lathe, my gut feeling would be to run about 400 rpm for the 1/4" and probably 250ish for the 1/2". It's important to know that regular stainless is not particularly hard, but it is very tough and it doesn't like to break into small chips easily. Those long, stringy chips are not great for your drill. They prevent the flow of coolant and concentrate heat at the cutting area. Not good.

Before you even start drilling holes, lets take a turning tool and skim the face of that bolt. Not a heavy cut, just enough to clean up that surface that you are drilling into, and most importantly, make sure that it is nice and square. You don't want to try and start a deep hole into an angled surface if you can avoid it.

Next, get yourself a #4 center drill. Start the hole with that, and if you go just deep enough it will give you a nice chamfer at the top of the hole. If you drill 0.297" down with the center drill, it will give you a 0.015" chamfer at the top of your 1/4" hole.

Now, start the hole with the shortest drill possible. If you can get a screw machine drill that is 1/4", then thats the best bet. The flutes on a 1/4" screw machine drill are just shy of 1.5" long, so if you are careful, then you can finish the hole with that. Just for reference, the drills that you usually get at the hardware store are jobber drills and they are the next size longer than a screw machine drill.

So, lets recap. Start the hole with a #4 center drill. Drill as deep as possible with the screw machine drill. If necessary, finish the hole with a jobber drill. Personally I would get that last 0.100" or so with the short drill, but you just have to push the drill a short distance, then pull out and clear chips, and repeat. The secret is that once the flutes are buried, they load up with chips fast. You don't want them to load up, BAAADDD! Only after I drilled the 1/4" hole, would I start the 1/2" counerbore. As for coolant, you are probably fine, just drill a little, pull out, clear chips, re-apply coolant, and repeat until you reach the bottom. This isn't a 2x4 and you aren't going to get the hole all the way down in one shot. At least not with a twist drill.

Hope this helps.

the stainless used for silver ware tends to be of the magnetic variety

I have some 1" cube rare earth magnets, and they were readily attracted to my hardware store stainless bolts. I have some 316 stainless hardware which has a negligible attraction

testarossa wrote:

Now if it is the magnetic stainless then it can be heat treated to be quite hard. In that case I would take my spindle speed recomendations and cut them in half.

Remember what I said here. That explains why you had a hard time with the full size drill after drilling the pilot hole. The edges of the pilot hole are work hardened by drilling. If the stainless is magnetic then it contains enough carbon in the alloy to allow it to be hardened unlike the austenitic/non magnetic stainless. My recommendation for spindle speed would be something like 300 rpm for that 1/4" drill and don't drill the pilot hole. I would still start the hole with a center drill, but only drill about 0.300" deep. Then just go for the finished size with your 1/4" drill. Make sure that you get plenty of that cutting oil that you are using for coolant in there.

As plummen stated cutlery is made from magnetic stainless since it can be made harder than regular 304.

BTW it looks to me like the angle that the tube is bent to is pretty close, but the bottom of the side cover is not a straight line. I doubt that anyone will notice unless you are painting the frame some wild color. It almost looks like the right side tube is kicked out a little more at the bottom than the left in the back view. It could just be the angle of the picture.

One more question. Is there room for your quarter turn fastener in the area of the original bottom tab on the side cover? Will the fastener be in the original location or are you moving it slightly?