E-gad, he’s making another one of those crazy pop-up things

[scc]

I've loved these engines since I saw one running some time ago   But not wanting to make one I am content to watch and enjoy your excellent work,             Terry

[90LX_Notch]

Some great machining going on here Craig, well done.  I’m enjoying this build.

-Bob

[Don1966]

You did wonders with those gears Craig. I ..........likeeee.........



 
Don

[Art K]

Craig,
At this point there's probably any number of thing you could start on next. Everything looks great!
Art

[Craig DeShong]

 Thanks for stopping by; a special thanks to Terry, Bob, Don, and Art for your comments.   Don, thanks again for the gear spreadsheet, it makes figuring gears a breeze!!!

Lots of comments lately; and I certainly appreciate all of them.   Maybe the thread discussing a lack of comments has spurred more comment activity?   I’ll just say that for whatever reason you are inclined to comment, I appreciate them; ever the smiley faces and popcorn comments.

I thought I would get the flywheels behind me.  This is going to be a “slog”.   The castings, as delivered, will produce fifteen inch flywheels and I need flywheels with a diameter just over thirteen inches.  Also the castings are about 1 ¼ inches thick and the flywheels I need will be finished to a thickness of one inch.  I have LOTS of material to remove.  You might wonder why I purchased such large castings; and the reason is that these Victorian era engines are characterized by large diameter flywheels with thin rims.  To get that “look” I need to start with larger than normal diameter flywheel and reduce the rim thickness.  These particular flywheel castings meet “pretty much” (once finished) all the dimensions I need for a scale flywheel for this model.

My lathe is a 12 inch lathe; so I won’t be using the lathe to machine thirteen inch flywheels; I’ll be doing them on a turntable.  I have a friend who has a 12 inch turntable he says he will loan me (it’s nice to have friends with “stuff”).  The good news is it’s a 12 inch turntable; the bad news is it weighs 150 LB.  Ten years ago I would have picked it up from the bed of my truck and carried it across the shop to the mill.   Now there will be no “carrying” this turntable.   I have a hydraulic lift table and my plan is to slide it off the truck bed and then transport it to the mill where I will again slide it onto the mill.  The next post will show how well this plan worked.

Firstly, however, I can start reducing the thickness of these flywheels.  Below I’m taking 1/10th of an inch off the side.  I’m just trying to remove stock with these operations, not “hit’ a finished thickness.  Below I’m just getting started on the first side.


And below is a view of that first side, completed.



Now I’ve turned the casting over on the mill and am performing the same operation on the reverse side.



It’s taken the day, but I have the thickness of this casting reduced to around .050 inches over the final dimension.  I’ll finish this on the turntable.

[Craig DeShong]

Thanks for stopping by. 

I don’t think this 12 inch turntable weights anywhere near 150LB.  It was easy to move, though I did use my hydraulic lift table to transport it into the shop and onto the mill. 

I centered the turntable under the mill quill and then located the flywheel on the turntable.  I’m using three of the spokes to hold it in place.  I don’t want to stress it crooked, mill the flywheel, and then have a wobbly flywheel when the stresses are relieved.

Once I shimmed the flywheel to get it level with the inside rim, I went around the top to get that side of the flywheel to the final dimension I need.

Next I needed to reduce the diameter of the flywheel by around two inches.  That is a lot of material to remove and I’ve tried several ways; all have been very slow.

First I tried milling the outside diameter, that was very slow going and I was only able to remove around .020 inches per pass. 

Next I then tried plunging down from the top and milling around the circumference from the top; more slow going.  In addition, I was using a one inch end mill for all this and this one flywheel was going to wear that end mill completely out in the process.   



One inch end mills don’t grow on trees, so I moved on to “plan-B”.  I thought I’d chain drill around the rough outer diameter of the finished flywheel, and then use a smaller end mill (maybe a ¼ inch) to remove the stock between the drill holes.  This might wear out a drill and a ¼ inch end mill, but the cost of replacement of both pales in comparison to replacing the 1 inch end mill.  This is still slow going.  I’m at the point where I can start with the ¼ inch end mill.

[kvom]

Plan B makes sense as drilling gives a better MRR than any other milling type.

[Jasonb]

I'd get an endmill a bit bigger than your holes (5/16" ?) and plunge down alternative ones so the cutter breaks through into the two holes either side. As you will be using the outer edge of the cutter it will cut better than if you plunge over the webs where the ctr of the cutter is hardly moving and you will also have to do all the webs.

Usually when I stitch drill I use a stub length drill so it does not wander and space the holes at the drills diameter, then they join themselves and teh waste drops off.

[crueby]

While doing all that drilling, have you thought about what you will use the outer ring for? Shop-elf-hula-hoop?

Quite a lot of material to remove, coming along well!
 

[propforward]

That's a mighty fly wheel. It's just one of those days when you wish you had a VTL.

[Craig DeShong]

Thanks for stopping by. Kirk, Jason, Chris, Stuart; thanks for your suggestions and comments.
Jason, your suggestion makes perfect sense; unfortunately, I’d already used the ¼ inch end mill to break through.  I do have another of these to do, so I’m going to try your suggestion on the second one.

Actually, the ¼ inch end mill passed around between the drill holes fairly quickly.  I was able to use a depth increment of 2/10th inch per revolution so it didn’t take too many passes to cut the outer ring off.

Chris:  A bit large for an elf hula-hoop!  I have no need for this thing, can’t imagine for what I would use it.  If anybody out there want’s it let me know.  It’s yours for the shipping; (actually there will be two!)


So as I stated, I plunged down into the inner diameter with a ¼ inch end mill and by taking 2/10th inch steps, cut the band I show above away.


Below is a view of the flywheel with the outer band removed.


The next step was to face the outside rim at full depth, taking about fourty thousandths of an inch off the diameter until I hit my assigned diameter.  Then I drilled, bored, and finally reamed the center hole.

[90LX_Notch]

That’s getting it done Craig.

-Bob

[Kim]

That's a lot of metal to remove! Your chain-drilling method seems to have worked well.

You should save the outside elf hula-hoop for a fly wheel on another engine!  All you have to do is add spokes! 

Kim

[Craig DeShong]

Thanks for stopping by.  Bob and Kim; thanks for taking the time to comment.
Kim:  you have an idea there… I’m always looking for a flywheel with a thin rim!

Just one photo for you today.  The first flywheel finished out great.  Just the tiniest bit of wobble; but you have to look REALLY HARD to see it.  For making it on a turntable, I’m quite pleased.


One down and one more to go.

[kvom]

Given the known size of the wheel, we can see how large the engine really is.