Sunday, June 2, 2013

Heavy duty lathe steady rest

Recently I started a large (secret) project for my wife that will take the better part of a year to complete. Right away I realized there were some missing infrastructure items that would be required that would be hard to built right in the middle of the larger project. The first tooling deficiency I ran into was my lathe steady rest.

The large Yam lathe I bought last year came with a significant amount of tooling. A three point steady rest was one of the tooling pieces. Initially everything looked pretty sweet. My large secret project has need of several long large diameter shafts which is one reason I chose this particular lathe. I figured get the big Conan lathe first and hold out for the sweetheart deal on a really nice smaller lathe when it appears in my machinery shopping sights.

During the secret project design phase I made a decision that was connected to the lathe acquisition. Since it is so long I decided to increase the basic size of the project considerably. Hey, if you're going to go to the trouble and expense to build your own secret project then go for the gold medal. Who the heck wants a bronze anyway?

So it turns out the steady rest that came with my lathe is way too small. It can pass 7.85 through the frame and I need to pass at least eight inches through. So this is how a tooling project is born. A steady rest is a pretty straightforward project in a machine shop. There is nothing too fancy or critical to the proper functioning of a steady rest so if your lathe is missing one I encourage you to go ahead and make one.

First order of business was to take some measurements of the stock Yam steady rest. The only semi important number is the center height off the ways. From these measurements its easy to develop the larger size I need.
For the new steady rest I wanted anti friction roller tips instead of the bronze tips that the stock Yam unit has. I figured if I was going to build one I'd make it slightly different and better just for good measure. Roller tips mark the work less but have a nasty habit of sucking chips between the roller and the work. Non rotating tips generally don't allow chip between the work and the rip but at the the expense of marking the work more and with higher friction. Its a common and simple enough matter to make a thin plastic shield to keeps chips from finding the roller tips.
Measuring the vee way depth on the stock steady rest. I got lucky that it was a ninety degree angle instead of some oddball thing.
The large steady profile was cut from the electronic layout you see above. Material used is one and a half inch thick steel plate. I added some extra material in the center and at the bottom so I could cut the profile in half and still clean up the machined surfaces and end up with a proper circular opening.
Check out the awesome oxy fuel cutting provided by Nowell Steel in Antioch. These guys do all my heavy steel cutting. Talk to Ted or Chris if you need some steel cut.
I scribed the base block directly off the stock steady rest. This was just for the roughing of the vee groove. Once I was close I started taking measurements for precision depth.
When the groove was shallow I had to use my multi-anvil micrometer because the pin was above the surface. These handy versatile micrometers have the ability to measure from a flat surface up as well as a multitude of other measurements. Once the gage pin was below the surface of the block the normal depth micrometer could be used with more stability.
I used the trusty Doall vertical band saw to split the profile. It took about ten minutes to make the split I left material between for machining the ears to thickness after the saw cut. I still have to make the latch and hinge for the two halves. All the time I was sawing the profile I was wondering which way it would spring. This is one good reason to cut a profile as a closed shape. In particular if you use a heat producing process. If I would have waterjet cut this I most likely would have cut them as halves with a small amount of material for machining. On this thickness of material the oxy fuel process is faster and cheaper. My time is free in my shop.
This is the clamp plate that secures the steady rest to the underside of the lathe. The bolt will pass through the bottom of the steady rest and be tightened from topside.
This last weekend I worked on the roller guides. There was quite a bit of work in these puppies. Early on I thought I wanted a single side support with a stud type cam follower. I was looking at one of the lathes in the main shop the other day and it had a very nice roller setup on its steady rest. The lathe was a Cazeneuve. Once I decided to make the support double sided it doubled the amount of work in these parts. My milling machine looks like a steel sliver bomb went off near it.
 The axels for the cam followers are made from the hardened shanks of shoulder bolts. The shaft is clamped in the roller support tightly for minimum vibration.

I have been documenting the build with video. Check out the Oxtoolco YouTube channel if you want to see some live machine shop action on this project.

Thanks for looking.




14 comments:

  1. Great post - very interested to see the final piece! Just recently discovered this and read the entire site through in a few days time. Love people who show how to build what they are passionate about.

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  2. Thanks for the nice comment. I checked out your blog and just wanted to encourage you to keep it up. I was going to write an article about accuracy, precision, resolution, and repeatability but you beat me to it.

    Regards,

    Tom Lipton

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    Replies
    1. Tom, you must be the one guy reading my stuff!

      I wasn't going to go too deep into the level of measuring that you do because, frankly, I'm not near your level! However, I'd like to get people accurate to at least a sixteenth for the home hobbyist.

      With that said, would you care to collaborate? I'd be happy to handle the crude stuff if you'd like to take it a little deeper.

      Keep it up, I wait for your stuff like a dog waits on dinner at the bowl!

      Delete
    2. Well we should start off with your first name. Or I could just call you "engineer dude" your choice.

      I'm game for some kind of collaboration. Maybe throw out some project ideas on your blog. Perhaps a tool technique or process that is of general interest to all the lurking gear heads and interesting to you personally. I take suggestions all the time. Here are a couple of things on my list for articles.

      Momentum and inertia lessons learned the hard way.
      Corded drills versus cordless.
      Sharpness Determining and specifying

      Kick it around and let me know what you think.

      Regards,

      Tom Lipton

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    3. Tom - gladly. Howdy, my name is Marshall Whitney.

      If you care to, shoot me a mail or send me your contact info. I can be reached at whiskeytrader@gmail.com. I really like your first topic - it reminds me of coiling my extension cord the other day and which resulted in the plug end making high speed contact with my eye resulting in sudden negative acceleration. And blood. :) Always a good time in the shop!

      Delete
  3. Come on... This is worse than always having to wait for the next episode of Breaking Bad!

    I check out you page each morning before work, and nothing...
    I am telling myself, that you are working on something REALLY cool, and are in the process of doing a mega post!

    Love your work, keep it up!

    Ian Bee

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  4. The pressure is killing me. All those people out there waiting with such high expectations. Now you compare me to a spectacular series like Breaking bad. How can I ever pull myself up to that level?

    I may have to reveal the secret project just to keep the sharks at bay. Its like climbing a sand dune.....

    Thanks for your addition to the pressure.

    Tom Lipton

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  5. Dear Mr Lipton,

    I have recently discovered your blog, but am a regular reader of your column in CTE magazine, and am currently reading your book: I'm up to the section on CNC Lathe. In the book, you suggest people contact you but you don't give an email address (that I could find). Could you please email me so I can send email back. I promise I won't be a pest. philip@fliptronics.com (A phone number and when is an acceptable time to call would be appreciated too)

    Thanks,
    Philip Freidin

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  6. Tom,

    I read your column in CTE and it's by far the one that I never miss. Obviously I happened on this post because I need to build myself a steady for a newish lathe the company was so kind to get for me. They want me to make a solid pulley row (15 vee's spaced evenly for wires to be guided by in a dry-drawing process) 18" long 11 1/2" dia. out of cast iron. Steady that came with the lathe is good up to 6 1/4" or so and I don't like the idea of chucking on maybe an inch and leaving 17 hanging out! The only reason I need the steady is because it needs bearings in either end and a clearance hole for a shaft (supported by pillow blocks) to pass through.

    Anyway, the point is you got me on Ebay looking for a nice old Mul-T-Anvil and I bet I'll find all kinds of good uses for it, so thanks for the new tool idea!

    Putch

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    Replies
    1. Hi Putch,

      Sounds like a fun job. I did some similar work for a steel wool making machine for the SOS pad company back a ways. This job will depend on the vee geometry. If they are big vee's which is sounds like they are. What is the through hole size? I would be inclined to do this between centers if the through hole is decent size, say two inch or larger. Are there spokes on the pulley? or can you add a tapped hole off center on the ends for a drive dog? Barring that if the center hole is pretty big take a look at keyless bushings. Trantorque is the brand name www.fennerdrives.com These will clamp your pulley to the center shaft and you're off and running with no steady rest. Let me know how it turns out.

      Regards,

      Tom

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  7. Hi Tom, Just wondering where can I find pictures (or video) of the finished steady rest?

    Thanks,
    Jason

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    Replies
    1. Hi Jason,

      I shot some videos of the fabrication and machine work for the steady rest. Check out my YouTube channel oxtoolco and look for the playlist called heavy duty steady rest.

      All the best,

      Tom

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