Author Topic: VERTICAL TURNING on SHERLINE  (Read 895 times)

Offline Davis2x1

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VERTICAL TURNING on SHERLINE
« on: March 06, 2017, 07:58:17 PM »
Has any one tried a set up as shown to true a 7" diameter fly wheel on a SHERLINE mill?
Dave
Sherline Mill and Lathe

Offline wagnmkr

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Re: VERTICAL TURNING on SHERLINE
« Reply #1 on: March 06, 2017, 08:41:24 PM »
That is an interesting question. I will be watching for the answer.

Tom
I was cut out to be rich ... but ... I was sown up all wrong!

Online crueby

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Re: VERTICAL TURNING on SHERLINE
« Reply #2 on: March 06, 2017, 08:49:59 PM »
Gotta say that I never even thought of that solution!

Guess we'll find out if it is rigid enough to do the cuts. Whenever I was doing a larger flywheel, I always did it on my Sherline lathe, with the headstock turned 90 degrees to let the flywheel hang out the back side.

Keep up posted on how it works!

Online AOG

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Re: VERTICAL TURNING on SHERLINE
« Reply #3 on: March 06, 2017, 09:02:56 PM »
I played with doing something similer and I ran into problems. I had no issues cleaning up the hub but the rim was a disaster. With no support it just flexed and rang like a bell. I ended up trashing the casting. The lesson learned is that you need something like a face plate to add rigidity and support the turning loads on the rim.

Tony

Online b.lindsey

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Re: VERTICAL TURNING on SHERLINE
« Reply #4 on: March 06, 2017, 09:16:00 PM »
Tony is correct. The same situation arises with the riser block on the lathe too. The castings just need more support to stop the chattering.

Bill
« Last Edit: March 06, 2017, 10:38:23 PM by b.lindsey »

Online crueby

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Re: VERTICAL TURNING on SHERLINE
« Reply #5 on: March 06, 2017, 09:17:03 PM »
I played with doing something similer and I ran into problems. I had no issues cleaning up the hub but the rim was a disaster. With no support it just flexed and rang like a bell. I ended up trashing the casting. The lesson learned is that you need something like a face plate to add rigidity and support the turning loads on the rim.

Tony
Do you think that adding a support plate to the setup, to help hold the spokes/rim rigid, would make that setup work? I'm wondering if the mill column would be rigid enough?

Online AOG

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Re: VERTICAL TURNING on SHERLINE
« Reply #6 on: March 06, 2017, 09:33:05 PM »
Up to a certain size I think you could make it work. You would have to turn it pretty slow and you will still not get a great finish with that set up. My recommendation is to flip it around. Put the part on a rotary table and use a conventional end mill to do the cutting. Please be aware that you will still need to properly support the rim to get a good finish. I learned that the hard way when I trashed a second casting while building my Elmer's number 50. Of the two setups I've tried, the rotary table is certainly the more rigid.

Tony

Offline Flyboy Jim

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Re: VERTICAL TURNING on SHERLINE
« Reply #7 on: March 06, 2017, 09:34:45 PM »
I played with doing something similer and I ran into problems. I had no issues cleaning up the hub but the rim was a disaster. With no support it just flexed and rang like a bell. I ended up trashing the casting. The lesson learned is that you need something like a face plate to add rigidity and support the turning loads on the rim.

Tony
Do you think that adding a support plate to the setup, to help hold the spokes/rim rigid, would make that setup work? I'm wondering if the mill column would be rigid enough?

I'm wondering the same thing. When I turn the flywheels for my P & W, I'm thinking about making a support plate that bolts to the Sherline face plate and then the flywheel would bolt to that.

Jim
Sherline 4400 Lathe
Sherline 5400 Mill

Online b.lindsey

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Re: VERTICAL TURNING on SHERLINE
« Reply #8 on: March 06, 2017, 10:39:36 PM »
I think that is a good idea Jim  :ThumbsUp:

Bill

Offline AussieRoy

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Re: VERTICAL TURNING on SHERLINE
« Reply #9 on: March 06, 2017, 11:12:53 PM »
Has any one tried a set up as shown to true a 7" diameter fly wheel on a SHERLINE mill?

You might get away with using that mill by reversing the setup shown in your photo. 

Mount the flywheel (PM-1B1 is it ?) on the mill table with some spacers under the spokes to bring the flywheel as close as possible to "square" with a DTI to minimise the amount of metal you remove.  This will ensure that the flywheel is mounted a securely as possible.  Clamp onto the spokes with the clamps bearing on the spokes directly over your spacers to ensure that you don't bend or break a spoke.   Then make up a purpose built cutting head (or maybe two heads) that will allow you to bring a cutting tool to bear on the face and sides of the wheel rim, and on the face and sides of the hub.  The beefier you can make this purpose built cutting head, the more rigid it will be.   You'll probably only use that cuttting head once, so keep the design simple/basic.

That will leave the rigidity of the mill column as being a possible limitation, and one way around that (apart from ensuring that the X, Y locks are secured and the Z Gibs are well adjusted,) is to use very light cuts.  If you can't slow the mill down enough to be able to use a HSS cutting tool on the rim, you could try using a carbide tool.   

Mill the face and sides of teh flywheel, followed by the face and sides of the hub.  Then drill and ream the centre hole so you maintain concentricity, before flipping the wheel over.   

When you flip the wheel over to machine the other side, you'll be able to sit the machined surfaces of the rim on parallels.   If you clamp onto the unsupported spokes, be sure to not over-tighten the clamps.  You can use the reamed hole in the centre of the wheel to center the flywheel under the mill, and can then use a DTI on the machined rim to double check that your cuts on the second side are concentric with the reamed centre hole etc.

If you're in doubt about whether your set-up will work, rather than risking ruining your casting - do a trial run using a suitably sized disc of free machining steel (or maybe even a suitably sized piece of brass). 

Hope that info helps.

Regards,

RoyG


Offline Davis2x1

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Re: VERTICAL TURNING on SHERLINE
« Reply #10 on: March 07, 2017, 03:53:26 PM »
After reading all the good advice I think I found a solution that I can handle.
 
First I'll mount the flywheel on my mill. Level and machine the face of the hub, locate a center and drill and ream the bore to size.
Second I'll make an arbor with a slight shoulder to fit the bore. Drill and tap the end for a hole to hold the wheel on the arbor.
Third rotate the lathe head toward the rear and face off the rim.
Finally remount and level on the mill and face off the remaining hub face.

Many of the large sprockets and gears I have used during my  career only had the faces of the hub machined. I think this should be "OK"

I knew Roy would want to reverse the operation cause he's standing on his head anyway.

Regards to all.
Dave
Sherline Mill and Lathe

Offline Flyboy Jim

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Re: VERTICAL TURNING on SHERLINE
« Reply #11 on: March 07, 2017, 06:11:40 PM »
After reading all the good advice I think I found a solution that I can handle.
 
First I'll mount the flywheel on my mill. Level and machine the face of the hub, locate a center and drill and ream the bore to size.
Second I'll make an arbor with a slight shoulder to fit the bore. Drill and tap the end for a hole to hold the wheel on the arbor.
Third rotate the lathe head toward the rear and face off the rim.
Finally remount and level on the mill and face off the remaining hub face.

Many of the large sprockets and gears I have used during my  career only had the faces of the hub machined. I think this should be "OK"

I knew Roy would want to reverse the operation cause he's standing on his head anyway.

Regards to all.

Sound good. Keep us posted on how it goes.

The only thing I might add, unless you've already thought of it, is to locate the center hole so it enables the inside of the rim to run true. The outside of the rim can be machined so it runs true, but most of the time the inside is left as it is and will really show up if it doesn't run true.

Jim
Sherline 4400 Lathe
Sherline 5400 Mill

Offline Chipswitheverything

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Re: VERTICAL TURNING on SHERLINE
« Reply #12 on: March 07, 2017, 10:23:03 PM »
Might interest readers of this topic to see a few pictures of a related flywheel job that I had to do using my Senior mill a few years ago.  The flywheel had been turned on a large lathe that was no longer available to me, but the rim had been left too deep, and needed trimming by about 1/8" all round.   
  I didn't have a decent sized rotary table, just a 4" one to the design of George Thomas.  So the rim needed support very close to where the milling cutter was operating.  I rigged up a steady that closely fitted the rim, and made a succession of cuts down to the final depth.  The set up was fairly stiff to turn, and feeding into the cutter rotation was quite feasible by grasping the flywheel rim.  Took a long time on the 14" dia flywheel, but it did it...  ( apologies the old photos are not great...)

Dave

Offline Davis2x1

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Re: VERTICAL TURNING on SHERLINE
« Reply #13 on: March 18, 2017, 09:27:32 PM »
Finished my flywheel per RoyG's instruction. Thought I would share with you my method of fixing the flywheel to the shaft. I used to use this method of using a key for fixing rollers to shafts. The key is a 1/4 X1/8 bar attached with 2-56 socket head screws. The photo shows a mock up of the connection 
Dave
Sherline Mill and Lathe