International Plant is down!!!

Great balls of fire, driving to work this morning every light I came to turned red. That was a first. Things like that do not bother me, in fact I was laughing after the last light was red.

I got to work on time. As soon as I walked in I noticed the boss (owner) was in the back of the shop with the large door open and his truck & trailer backed in. From that point 7:30, till 10:15 it was working in overdrive. What had happened was a large company in the area, the whole plant was shut down due to a large shaft was messed up. We're talking $1000's a minute were being lost due to this main shaft.

The shaft was 19 feet long, and the diameter was a little over 9 inches. On each end of it are smaller dia. ends. Think of a rolling pin, if you remember those. On these smaller ends are where the bearing are. These large bearing and the housing they are in allow the shaft to be attached to a stationary place while the shaft can turn in the bearings. One of the ends on this shaft was all messed up. Maybe when it was running in got hot and the bearing failed or maybe the bearing just wore out. In any case it messed up the bearing surface on the shaft.

To fix it we got this large thing in our large engine lathe. We indicated it in several places to assure it was running "true". Now my boss started turning the messed up area to a smaller size which he told me he would tell me later. I started making a sleeve that the inside diameter will end up being .003 (thousands of an inch) smaller then the part the boss is turning. The outside of this sleeve I'm making, the outside dia. will be larger than the finished size for the bearing fit. Have I lost you yet?

Now you may think, if the sleeve I'm making is smaller then the shaft I need to put it on, how is that going to work? Well, now comes the fun part. We have both spent time getting to this point, about 2 hours. The people from the plant kept calling in a panic mode. So what we do is: light a cutting torch and start heating up the sleeve. This is done with care to insure the part heats up uniformly. Back to 8th grade science class, what happens when you heat something? I'm sure you know, it expands. So this very hot, but not red hot, this hot sleeve is very quickly slid onto the shaft and you hope and pray it is going to go all the way on. In this case it slipped right into place. Now you wait...

What happens when this metal cools down. That's right, it shrinks. Since it was made smaller then the shaft its on, once its cool there isn't anyway it will come off unless you cut it off. Now once it is cool it can be turned to the correct size it originally was (80mm) and its good to go. It was then driven to the plant around 10:30 and I'm sure they were very glad.

One more note, sometimes the dang heated up sleeve doesn't slide all the way and that is just a bummer cause I need to cut it off, make another one and repeat the process. We are talking seconds to get it in place.

The rest of the day was spent by me making a couple of smaller shafts for a local chicken company, you may be able to guess their name. Its a short week, maybe there won't be any more surprises but you know what? I don't mind a few surprises. It is also a good feeling to "get her done" and help in a rather big way I must say, it kept a company from maybe having to send people home or any number of things...

Large Bolts

This week at work I made 7 rather large bolts. I started with 3.25 diameter 22 inches long, round shaft material. It was 415 type steel. First in a large manual engine lathe I faced and turned one end of the shaft back about 1.5 inches to a finished Dia. to 2.812. Next I turned the shaft around and faced the other end to finished length and center drilled it. I did this to all 7 parts and they are a bit heavy.

Now they are ready for the CNC Lathe. In this lathe I clamp in the chuck on the turned 2.812 dia. I type in M23 and push start and the tailstock moves into position. So now the center of the tailstock is inserted into the centerdrilled hole I drilled earlier. It is ready to machine into a Bolt.

I had run these before so the program was already done, all I did was reload it to the machine control. I rough turned the part, it is always exciting to watch through the window the metal just being peeled away by the carbide cutter. The specs of cutting it: 439 SFM, feed rate .017 ipr, depth of cut .15 .

After roughing I used another tool to finish turn it. Next I needed to put on the threads. For that I use a threading carbide insert. It is shaped like a V with the tip doing the cutting. It takes many passes to get to the finished size of the thread. The thread is metric, 15m x 1.5. I have a nut to screw on to make sure the threads are good.

I deburr the part and it is done. I cut alot of metal on this job which I like...I'll post photo's on my Facebook page...