My Take on Machining Wheels

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Dick_Morris
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My Take on Machining Wheels

Post by Dick_Morris » Fri Feb 18, 2011 5:52 pm

Pipescs asked for a source for a form tool for turning wheels. I'm not a fan of the form tool for my own use for several reasons. (1) I'm cheap, and the form tools aren't. (2) My 50-year old 12" Atlas wasn't rigid enough to use a form tool. In fact, to turn the radius where the flange and tread meet, I have to pull it over by hand to cut the last few thousandths to avoid chatter. (3) When the form tool wears out, you have to get a new one, so the first operation of the unmachined cast iron should be with another tool to avoid wearing out the form tool too quickly. My "new" lathe is a 35-year old 12" gear head Asian lathe. It's much more rigid and the form tool might work with it, but I'm still cheap.

There are a couple of good descriptions of wheel turning - Dave's on Youtube at http://www.youtube.com/user/trainman460 ... 6Ld15IVTEg and another at http://www.jghtech.com/html/wheel-turning-1.html. While Dave's gave me some ideas, my machinery wasn't up to it and I didn't need the level of production that he needs. The other used a lathe with a turret attachment. I don't have a turret, but picked up a lot of ideas from it.

My method was to rough drill the wheel castings on the drill press because it was quicker than using the lathe, face the back of the wheel castings in a three jaw chuck and bore and ream the hole.

I then mounted it on a fixture. The nut is a flange nut with the bumps machined off the back side. The mandrel was a grade 8 bolt that was only .006" small. It is Loctited into the fixture. Some equally spaced pips with an automatic center punch made it the wheel fit without a rattle.
Attachments
wheel holding fixture (1).jpg
wheel ready for tread cut (2).jpg
Last edited by Dick_Morris on Sun Feb 20, 2011 3:19 am, edited 2 times in total.

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Dick_Morris
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Re: My Take on Machining Wheels

Post by Dick_Morris » Fri Feb 18, 2011 6:52 pm

An Aloris tool holder and an adjustable carraige stop allowed me to do the various operations fairly quickly. I turned 32 wheels during most of the evenings during one week.

The front face of the rim was done with one tool/tool holder, the OD of the flange, rail side of the flange, and tread were turned with another.

I found that a TNMA-666, C-2 grade for cast iron would be a good choice for a cutter. These have a 3/32" radius - correct for the radius on the wheel. They have a hole through them making them easy to mount. They are 3/8" thick and if they didn't have the radius, each side would be 1-1/4"wide. A box of them was found on Ebay at a reasonable "buy it now" price.

The holders to fit this tool are for much larger lathes and cost a fortune, so I made my own. The bits don't have any rake so this had to be built into the holder. Since I was going to cut on the left and front edges, the holder holds the cutter so that it is lower on the front, left corner. I think I used about a 6 degree angle. The left edge of the bit is also twisted clockwise a bit from 90 degrees so that it will cut the correct angle for the rail side of the flange.

Here are photos of the tool holder and tool and turning the OD of the flange.
Attachments
Big ugly cutting tool.jpg
wheel flange to size (3).jpg
Last edited by Dick_Morris on Fri Feb 18, 2011 7:40 pm, edited 2 times in total.

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Dick_Morris
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Re: My Take on Machining Wheels

Post by Dick_Morris » Fri Feb 18, 2011 6:59 pm

Next, the tread is turned. I used the carriage stop and a spacer to control the end of the cut. The spacer was used because the first cut with this tool went farther to the left to machine the OD of the flange than was needed to machine the tread and side of the flange. The tread took two cuts to get to full depth.
Attachments
wheels carriage stop and spacer (5).jpg
wheel tread cut (4).jpg
wheel tire (6).jpg
Last edited by Dick_Morris on Sat Feb 19, 2011 1:46 am, edited 1 time in total.

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Dick_Morris
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Re: My Take on Machining Wheels

Post by Dick_Morris » Fri Feb 18, 2011 7:30 pm

I don't have a photo of it, but the taper on the tread was cut with the carriage solid against the carriage stop. The compound rest had been set at the correct angle and the the tool was backed to the right using the compound. The scale on the compound was marked with a Sharpy so that it could be put back in the proper place before starting on the next wheel.

I made a form tool from a HSS tool bit to put the radius on the OD of the flange. I used an angle grinder for the rough shape and a diamond cutter from Dremel to get the final form. To get a bit of clearance I put the diamond cutter in the drill press and used a ceder shim (the kind used to install a window) on the table of the drill press with the tool bit on top of it when I did the final shaping. To machine the flange I just set the location of the form tool on the flange by eye.

The final operation (no photo) was to hold the wheel in a three jaw by the flange and face the center of the outside face.

I made lots of notes on speeds and other relevant information and put marks on the dials with a Sharpy to remember where to stop. Even on wheel number 30 it's easy to forget what comes next. Once I was comfortable I didn't make any measurments except as a double check every few wheels. Even with this limited mass production I couldn't have done it without the quick change tool post and carriage stop.
Attachments
radius cutter (8).jpg

Harold_V
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Re: My Take on Machining Wheels

Post by Harold_V » Sat Feb 19, 2011 4:29 pm

Nice setup, Dick.

Harold
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ScaleModeler1974
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Re: My Take on Machining Wheels

Post by ScaleModeler1974 » Sat Mar 05, 2011 11:46 am

I have a friend that has two smaller lathes that wants to use one for the rough turning of the flange and tread diameter and the other for the final tread angle and fillet radius.......

He has about 40 or so wheels to turn.

After reviewing the wheel turning vids that Dave S. has done it makes me wonder if I could just make a tool to turn the flange angle, fillet radius, and the tread angle all in one shot?
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steamin10
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Re: My Take on Machining Wheels

Post by steamin10 » Sat Mar 05, 2011 1:38 pm

Not with a 'small' lathe. The final cuts that are over an inch wide (7.5 wheel) with a form tool, will present a heavy demand on the machine. It may do any of a number of unwanted things, from stalling completely, to initiating chatter marks, right at the finish dimension.

My 9 inch SB wont do it on iron wheels, but ok on steel, if the setup is tight. So it is give and go. I have more success with tread first, and then a shape cut for the flange to final.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
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ScaleModeler1974
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Re: My Take on Machining Wheels

Post by ScaleModeler1974 » Sat Mar 05, 2011 6:08 pm

Yeah that's kind of what I meant Dave.........

Machine the tread and flange diameter.....then do the tread angle, fillet, and flange angle.
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steamin10
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Re: My Take on Machining Wheels

Post by steamin10 » Sat Mar 05, 2011 9:12 pm

Um, I work the tread and bring out the fillet, then tread taper. I set a form tool for the flange and plunge down to finish. By working from the base of the fillet, I get a true (er) diameter. A little blue or felt market or whatever will give a good visual read on the fillet.

This is all after you work to a mandrel of course.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.

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