Author Topic: Steam engine (Tiny vertical w/reverse)  (Read 26154 times)

Offline NickG

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #30 on: August 24, 2012, 01:55:01 PM »
This is brilliant George - when I saw it I thought, another Stuart, I won't bother ... then noticed the scale of things! I thought the column was fabricated too, some interesting machining operations there  :ThumbsUp:

Nick

Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #31 on: August 25, 2012, 07:16:12 PM »
It's time for the next installment.
Today I will be making a flywheel.
As with the base and column the flywheel is 12L14 steel. The O.D. is .900 and the width of the flange is .150.
I started by chucking up a piece of 1.00 steel, facing and turning the O.D. to size. On one side the hub sticks out .038 so I cut this with the facing tool I had installed. On the second flywheel I realized I could cut this hub with the necking tool so I eliminated this step.

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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #32 on: August 25, 2012, 07:21:48 PM »
The next 2 steps were to center drill and drill the crankshaft hole. I drilled it undersize followed by the finish drill which has never been sharpened so with a little cutting oil gives a nicely sized hole.
This diameter is .089.
The next step was to part it off leaving .01 for finishing to size.
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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #33 on: August 25, 2012, 07:28:20 PM »
The next step was to make a step collet to hold the flywheel for facing and counterboring the other side.
I had an aluminum disc in my scrap box so I chucked it up, faced and bored it to the O.D. of the flywheel. You'll notice a reference mark on the face of the collet and the chuck jaw. I have found that when I make these types of collets if I register the collet with the chuck when I take it out to split it and reinsert it the runout will be negligible.
The blank was then inserted and the collet clamped. The second side was then cut to the proper width and the recess cut.
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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #34 on: August 25, 2012, 07:38:16 PM »
I finished the second flywheel and then went to the mill for the next machining steps.
First up was to indicate the rotary table.
Next was to clamp the collet with flywheel installed into my small 4 jaw chuck. I use this chuck strictly for rotary table work. The chuck is mounted to an aluminum plate with a flange that extends about 1.00 beyond the chuck, this way I can hold irregular pieces and offset them for radial cutting.
I left the clamps loose and inserted my conical mandrel into the spindle. I then located the flywheel by inserting the mandrel into the crank hole and then tightened the clamps. I have found I can get within .001-.002 by this method. If it's something that needs to be exact I will follow the mandrel with a dial indicator.
I had already made a location chart for the holes so it was just a matter of going to the proper coordinate and center drilling and drilling the corner radii.
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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #35 on: August 25, 2012, 07:45:27 PM »
The next operation was to cut the material from between the spokes.
I inserted a .062 high speed 2 flute endmill and started cutting. My new mill goes to 2500 rpm which isn't exactly fast enough for this size cutter but given the thickness of the web it wasn't a problem.
I roughed the material out staying about .005 away from my finish dimensions. First was to cut along the spokes from the inside to the outer radius on both sides of the spokes. The next step was to cut the radius using the rotary table. With all the webs cut out I then went to my finish dimensions and cleaned up the spokes and radius.
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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #36 on: August 25, 2012, 07:49:43 PM »
The final step were to chamfer the corners of the spokes and the radii. I used a very small white grade conical mounted stone in my Dremel grinder flex shaft followed by small files and emery cord. All that remains is to drill and tap for the set screw, oh yes and to finish the second wheel.
gbritnell
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Offline Dean W

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #37 on: August 25, 2012, 10:53:13 PM »
I really enjoy watching your work, George.  The machine work, of course, but seeing and reading how you finish
off a piece like the flywheel, too.  Makes all the difference.
Dean
In beautiful N. Idaho, U.S.A.

Shop Projects:
http://www.deansphotographica.com/machining/projects/projects.html

Online Don1966

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #38 on: August 26, 2012, 02:00:59 AM »
George, you are a true master. It is a joy to follow you with your project. You make it look so easy and you photos and documentation is superb. Keep um coming.


Don

Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #39 on: August 29, 2012, 01:01:50 PM »
This installment will cover 3 parts, the shift link, the cylinder and the steam chest.
When making small parts, even those that would normally be made from a sheet of steel, I prefer to make them out of a piece of round or rectangular stock. This way there is always something to chuck or clamp onto. The profile or drilling is completed and then the part is sliced off or parted of depending on how is was made.
With the link I I used a piece left over from making the base and chucked it into the 4 jaw chuck that was still set up from the earlier operations. I drilled the link holes and the corner radii deep enough to get 3 pieces. I then removed the extra materiel with a .062 end mill and then sliced them off with a .025 slitting saw.
From here it was just a matter of filing to put the corner radii on. As all of the fasteners on this engine are 1.0x.25mm the link slot is .04 wide. The thinnest file I have is .047 so I took an older one and ground the back side away till I got it about .034 thick. This allowed me to file the curvature into the link.
gbritnell
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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #40 on: August 29, 2012, 01:09:31 PM »
Next up was the cylinder. As mentioned I started with a piece of round stock large enough in diameter to encompass the external shape of the of the part. I chucked it in the lathe, drilled and bored the bore (.300 dia.) and then transferred it to the mill where I had remounted my vise and dividing head.
I indicated the part to get it concentric and then milled the valve face first. Next I rotated the part and cut the 2 side angles. From there I rotated the part and cut small facets around the curvature. These were filed smooth before the piece was parted off in the lathe.
In the last picture you can see that the upper and lower heads had already been made. I didn't show the steps for these as they were just turning exercises.
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Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #41 on: August 29, 2012, 01:29:48 PM »
There was an operation that I did before removing the 4 jaw chuck from the mill. That was to drill the mounting holes into the lower part of the column legs. The parts still had the chucking lug so I clamped it into the chuck, indicated and drilled it.
Here's an aside to the drilling of this part. On my initial setup of the rotary table and 4 jaw chuck I had indicated the center of the rotary table and set my digitals to -0-. When I cut the spokes in the flywheel I naturally indicated the wheel blank to center.
Now to drill the legs on the column I clamped it into the 4 jaw and with an arbor inserted into the crosshead bore I indicated it to center, first. I then rotated the rotary table to get the sides of the legs parallel to the axis of the mill. That seemed like the proper progression. The only problem was in moving the jaws in and out to clamp the part the true center of the chuck wasn't on the true center of the rotary table and longer. It was only when I got ready to center drill the first hole that I noticed it looked out of place. How could that be? I had indicated the bar true and set my digitals. It then occurred to me that I should have indicated the part square first and then picked up the center because by doing it the other way the part had rotated off center when I squared up the legs.
Calamity averted.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #42 on: August 29, 2012, 01:37:24 PM »
The final piece in this posting is the steam chest. Once again I started with a piece of round stock. The valve guide hole in the chest is offset so the needed diameter was calculated and chucked. I drilled the guide holes but didn't show the steps, center drilling and drilling.
From the lathe it was over to the mill and chucked into the dividing head.
The outside flats of the chest were cut first followed by the drilling of the mounting holes and inside corners of the chest. The remaining stock was removed with a .062 endmill working out to the pre-drilled holes.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #43 on: August 29, 2012, 01:39:36 PM »
On the sides of the steam chest are 2 holes, one for the steam/air inlet and on the opposite side the mounting hole for the reversed lever. These were now drilled.
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Online Don1966

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Re: Steam engine (Tiny vertical w/reverse)
« Reply #44 on: August 29, 2012, 01:41:36 PM »
George you have been a busy fellow, that is some superb work and love how you show the setup.

Don