American LaFrance Steam Fire Pumper

[steamin]

I feel like I lucked out on the pump casting. Usually my luck is to bore the final hole and find a big blow hole.

Anyway, I just had to share these pictures with all of you. I am sooo excited ! I want to take the assembly out of the fixture and put it into the main frame of the LaFrance. But I am going to wait till I get the major components for the top side machined and assembled.

Till later
Larry

 

[idahoan]

Wow that looks really nice Larry,

I have been following your build although not commenting on your progress as I should have.
Thanks for sharing your progress with us; your work is just outstanding.

I got to see a full sized one under steam and pumping water some years ago at Antique Powerland in Brooks Oregon; what a sight.

Dave

 

[rhitee93]

I like it

 

[steamin]

Good afternoon,
I had a chance to get back into my big lather this afternoon and play with the air chamber for the LaFrance. Since I do not have a radius turning attachment big enough to accommodate the radius required, I took a different approach. I made an aluminum template that resembles the profile of the air chamber. It was mounted to the tail stock of the lathe as shown in the below pictures. My magnetic base was mounted to the tool post with a indicator attached to it. The indicator rides on the template. The lathe is turned on and the carriage feed is place in gear. As the carriage moves, the trick is to keep the indicator on one particular number once you start the cutting process. I am running the lathe at 70 rpm and the carriage feed is as slow as it gets. With the slow speed and feed you can keep the indicator reading within a 0.001". Couple this with a round nose tool and a very smooth finish can be obtained and ready for sanding and polishing.
Again, thank you for your kind comments.
Till later, Larry

 

[rhitee93]

I'll give you a k point for that one. Very creative solution

 

[steamin]

Staring to look like an air chamber

 

[Shopguy]

That sir is one slick way to machine a profile. Beautiful work.
Ernie J

 

[kutzdibutz]

WOW- that really is a method to remember! K-point!!
Did you do something to the inside contour? I can imagine there is hardly a chance...
Will you support this in some sort of way? If this mass gets swinging there could be nasty cracks at the flange.

Cheers, Karsten

 

[vcutajar]

WoW Larry. I would have never thought of that method.

Vince

 

[ProdEng]

The air chamber looks fantastic and the method reminds me of a hydraulic copy lathe without the hydraulics!

 

[Runner]

Larry excellent setup, well thought out. But tell me how did you manage the curve nearest to the chuck? I note that your cutting tool had a rounded edge, was this sufficient to go all the way in a single pass?

Brian

 

[steamin]

Greetings, First, thank you for your kind comments and I am glad to share what I do with all of you. The bell was a bronze casting with a very, I mean, very thick wall. The inside follows the outside profile quit well, so I did not even consider machining the interior. The base was machined to size before I did any profile work except for a pilot hole that was reamed through the base smaller than the existing top hole. I used this hole with a mandrel to realign the bell in the chuck to machine the top boss for a live center. There was almost 0.200" to take off the diameter to bring it to size. The curve next to the chuck was blended into the already machined to size diameter. So I did not have to take the tool bit all the way to the chuck jaws. I used a 3/8" square high speed tool bit with a 3/16" radius. I have used this concept of profile machining several times, twice in a Bridgeport milling machine. The concept was not originated by me, but as pointed out, resembles a hydraulic lathe profiling attachment without the hydraulics. Many years ago I had the privilege to use one of those attachments on a Hardinge HLVH lathe. It made quick work of the task at hand. I guess I have covered the bases for all of you.
Till later, Larry

 

[steamin]

Greetings, started some work on the cylinders and steam chest. I generated a flat surface on the cylinder casting steam chest side using a carbide tip fly cutter; then clamped it back into the mill vise as shown in picture #1. Since there were no surfaces to clamp too with the movable jaw of the mill vise, I put a 1/2" diameter hardened steel dowel pin between the jaw and the cylinder casting. Then each end of the cylinder casting was machined with a fly cutter. For those who do not know what a fly cutter is, it is a tool holder that fits into the 1/2" diameter collet of the milling machine. The tool holder holds a regular lathe tool bit. The holder swings the tool bit in a wide arch cutting across the entire surface in one revolution. There are different sizes of fly cutters to accommodate different widths of surfaces to cut.

Picture #2 shows what I ran into with the final bore size. There are inclusions in both cylinders and oddly enough in the same relative position of each casting. So I am going to bore the cylinders out a little bit more and sleeve them.

Picture #3 shows the cylinder castings and steam chest in their position on the mounting plate. The two cylinders share the steam chest. The ports of the cylinders are off set from center to accommodate both slide valves. I will show that later when I get the parts worked up. The air bell is finished and polished up quit nice. I plan to have the air bell and the boiler stack nickel plated.

Till later, Larry

 

[rhitee93]

Larry, that thing is going to look amazing!

 

[ProdEng]

The pump on its own makes a fantastic model, love rotative steam pumps

 

[HaydenI.]

Hi larry that is ammazing finish on the cyl, im new to this and will have to do something like that soon but how did you get the steam chest cover side square in the first place??
Cheers Hayden

 

[steamin]

Hi Hayden, Thank you for your kind comment. Fly cutting a surface can give you an amazing surface. Be sure to put a small radius at the cutting point, 0.005"-0.010" should be plenty. Try the same thing by putting a small radius on your lathe tool the next time you turn something.

Now to your question; The side of the cylinder casting were pretty uniform and I was able to clamp on those surfaces with the surface in question pointing up. I took off just enough material to give me a flat surface to work with. Then I was able to clamp it in the vise as shown earlier. I would take a slight cut on one end and then inspect it to make sure that the other surfaces would fall into place when they were to be machined.

Hayden, I approach machining like playing a chess game. I am always planning my operations way in advance. I am always asking myself if I do this step now, will I be able to machine that other surface later and how will I do it. When I started my apprenticeship way back when my mentor had me write down the machining steps before I made any chips. It was amazing the mistakes i made on paper. Just some food for thought my friend..

I hope you will share your project with all of us.

Till later, Larry

 

[steamin]

Good evening, been able to spend a few evenings this past week working on the steam cylinders and associated pieces for the LaFrance. Picture #1 shows where I am at. I still need to drill a lot of holes in the caps and do all the steam ports in the cylinders. The steam chest is to size, but needs some holes, one for the steam inlet and two for the "D" valves push rods. Picture #2 is a close up of one of the bottom cylinder caps. I am trying to show the groove that the brass cylinder wrap will sit in. The top cylinder cover will hold it in place. More about that when I get the wraps fabricated. Then I can show you exactly what I have in mind. Picture #3 shows the components in position. Picture #4 is a close up of the cylinder caps and a special acorn nuts to hold them in place.
Till later, Larry

 

[SilverSanJuan]

Larry that's really beautiful work. A real classy lookin' engine.

Todd

 

[steamin]

Greetings, thought I would share a technique I use to hold a raw casting to machine those first surfaces flat, square and parallel to each other.

Picture #1 shows the "D" valve casting as received. As with any casting the sides are not straight due to the draft angle needed for the casting process.

Picture #2 shows my milling machine vise with a piece of 1/16" thick lead on each jaw. I bent a right angle to help hold the lead in place. Plus it gives a formable foundation for the casting to sit on.

Picture #3 shows the casting squeezed between the lead pieces. As I close the vise jaws I lightly tap the top of the casting with a soft face mallet to keep the casting seated against the top of the lead. Eventually the vise will tighten up and the casting will be secured in place. I machined around the perimeter first with a 3/16" end mill. FYI, use a small diameter end mill to keep the torque transfered to the work piece at a very low level. This helps to keep the work piece from climbing out of the vise; in this case, out of the lead pieces. The casting was secure enough that I was able to use a 3/8" diameter end mill to face the top of the casting.

Picture #4 shows how the lead was formed to the casting after clamping it in the vise.

Picture #5 shows the 5 surfaces I now have to work with. I will use these to machine to size the other side. Then the initial surfaces will be machined to their respective dimensions.

Till Later, Larry