Wednesday, January 16, 2013

Empire State Express – Now, Get Back to work!

The thing that had made me procrastinate as much as I did about getting back to finishing the Empire State Express was the daunting task of having to make all of the wheels for the tender.  I hate doing anything that is repetitious and turning 8 small, boringly identical wheels on the lathe just didn’t thrill me at all.  The set for the loco (8 wheels, 2 sizes) took me an entire afternoon to turn.  But, at one point last Saturday afternoon I stood up and marched down to the lathe determined to get them out of the way.  
As it turned out -- no pun intended -- once I figured out the technique, I was able to zip off 9 of the little rascals in just a bit over 90 minutes without even breaking a sweat.  In fact, it was so much fun that I went down to the lathe again a day or so later and made one more and took photos for this blog article.

So here is my simple, step-by-step procedure for making small wheels for any sort of model that won’t make you procrastinate like I did.

The first thing that you have to understand is that the grain must run across the face of the wheel so that it maintains at least some sort of structure strength.  You “could” cut the wheels out of a dowel rod of correct diameter but the problem there is that the grain would run through the wheel not across.  Even though the dowel rod might be made of maple any stress on the wheel would still snap it in half.

Now you may have a better chuck than I do or, even better, a steady rest for your lathe.  If so, you can start with a smaller cross-section block than I could.  But in order for me to grab the billet tight enough to allow the turning of a long, spindly, wheel blank, I had to start with a larger (in this case about 2-7/8” square) block (about 5 inches long) that I attached to my smallest faceplate.  The wheels are only about 1/8” thick so even including the material lost in parting off the wheel you can see that I was expecting a lot of rejects.  As it turned out, I only had one failure and in a pinch I could even use that one.

I turned the block round and the “free end” down to my desired 1” diameter.  Once it was round, I left the drive end of the block at nearly the original size to provide a nice solid support base to minimize vibration.  For the heavy roughing out, I supported the “free end” with the live center in the tail stock.  By the way, for best results, keep your tools as close to “scary sharp” as possible.  Basswood is so soft that you need sharp tools to keep from tearing the wood.

After backing the tail stock out of the way I drilled a 1/8” hole into the end.  From this point onward I kept the speed down to about 50 or 60 RPM to avoid excessive vibration in the block.  If you have a steady rest for support you probably don’t have to worry about that and can probably run faster.

To start making the wheel, face off the end of the block so that it is smooth and flat.  A round nose scraper worked best here for me.  

Switch to a small spindle gouge to cut the “Cone” of the wheel.  At this point you could make careful measurements but as I discovered, “eyeball” measurements are close enough for this sort of thing.

Next, switch to a Skew chisel to cut the face of the wheel.  Gently move the tip of the Skew in to produce the rim of the wheel.  Here you are using the skew like a scraper because you are shaping the entire surface of the wheel at once. 


 Here you can see the finished wheel face.

The next step is to use a standard parting tool to define the wheel flange and begin to shape the cone of the next wheel to be cut.  This shot is a bit fuzzy but you can see how the second wheel is already starting to take shape and we’re not even done with the first one yet!


This step is probably going to raise eyebrows with wood turners.  I am positive that this is not considered to be orthodox lathe operation, but it works -- at least at the low speeds that I am using.  I first did this because my parting tool is wide and I didn’t want to waste any more available block length than was absolutely necessary.  I held the teeth of a hacksaw up against the back of the wheel flange and used it as a parting tool. 

It quickly cuts a very narrow groove.  You can see how narrow it is in this photo.

Finish parting off the wheel.  The back side of the wheel will be very rough but a few seconds on a piece of 100 grit sandpaper will smooth it right out. 

So the first wheel is done, short of a little sanding with 220 or 320 sandpaper.  Best of all, the next wheel is already about half done.  Face off the block, dress up the cone (if necessary) then face off the wheel and part it off.  Like I said, I did 9 in 90 minutes.  You can, too.  Here they are: 

One for the Bench

Promise only what you can deliver. Then deliver more than you promise. - Anonymous

‘Til next time…Keep makin’ chips!

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