Sticky Sap Sawmill - 1/3 Scale CASE 65

[steamin]

Picture #1 & #2 are overall views of what my wife and I display at steam and tractor shows across North Carolina and adjacent states. The i/4 scale sawmill is based on the construction articles that ran in ModelTech magazine many years ago. Castings were not available for the various components. So I pre-machined CRS stock and TIG welded the pieces together and then machined the assembly as if it where a casting. The main frame is made of donated black walnut wood. The main frame breaks down into three 5" sections that stack on top of each other. The center section has wheels on it so the whole rig can be pulled in and out of the trailer. The husk frame and carriage were made of cherry. The carriage has four heads blocks. We can cut a log 4"-5" in diameter by 5' long. Anything larger in diameter has to be quarter sawn. I am using a Frued 12" diameter, 24 tooth thin kerf rip blade. The sawmill was constructed back in 2000-2001, about 3 years after I had finished a 1/4 scale CASE 65. We needed something for the little steamer to do and the sawmill was perfect. The 1/4 scale CASE had to be sold for personal reasons,but I did invest in castings for a 1/3 scale CASE 65. That is what you see in the foreground. The 1/3 CASE was completed in April of 2009.

Picture #3 is a bit of a close up of the CASE and water wagon. The water wagon is actually cherry wood that was cut on our sawmill at a show in Ohio in 2004. We raided the slab pile of a full size sawmill at the show and came up with a lot of great pieces to cut on our mill.

The pictures were taken this past weekend at the Farm Days show at the Boys & Girls Home at Lake Waccamaw, NC. It was our first show of the season.

Anyway, thought maybe some of you might be interested in some slightly larger models.

 

[kf2qd]

SWEET!

 

[steamer]

Sweet indeed!

Any pictures of the Case build? th_wwp

 

[steamin]

Yes, I document the build via pictures. I will be glad to post them. I did start a blog about the machining and construction of the CASE. It went by the wayside when our son was in a very bad motorcycle accident and I never did get back to it.

 

[steamin]

I have hundreds of pictures of the 1/3 CASE 65 build. I will be glad to share any and all and any information I may have. I will begin with the boiler, because everything mounts to it like the main frame of a vehicle.

The Boiler ! The heart and soul of any portable or traction engine. When built right and maintain properly it will give years of service. When approaching the design of a model boiler it is very important to remember that water, steam and thermodynamics do not scale down. There is a series of engineering calculations one must go through to determine the parameters that the boiler must be built too. Maryland has a very good section in their Boiler Codes pertaining to model boilers.
Here is the link: http://www.dsd.state.md.us/comar/09/09.12.01.33.htm This will give you an excellent over view of what is entailed in designing a model boiler.

I must say that boiler design and construction should be left to those who are experienced and have the proper welding credentials. Pressure Vessel Quality (PVQ) materials must be bought and used through out the boiler construction. The weld joints must be properly prepared and welded in a special manner to obtain full pentration. Bob Oliver of Oliver's Boiler and Jonas Stutzman of Middlefield, Ohio would be excellent starting points to have a professionally build boiler made for your larger scale steam project.

Knowing all that I still decided to pursue building my own boiler based on my 45 years of machining and welding experience. I had already jumped through most of the hoops when I fabricated the boiler for my ¼ scale CASE.

The original boiler design for the 1/3 CASE was based on a flanged and riveted boiler. These boilers are a thing of the past and North Carolina Board of Labor would not begin to work with me on such a construction or even approve its operation. So a new boiler had to be designed for my project. I had a piece of 10” seamless pressure tested schedule 40 pipe of the right materials just begging to be used as a boiler. So with that piece of pipe and the engineering calculations I started to develop a design for my 1/3 scale CASE. I discussed my design with the NC Board of Labor Boiler Division Bureau Chief and several professional boiler makers. What I am suggesting at this point is too gather as much information as you can so you can have a well-conceived and sound design. I purchased the necessary PVQ materials and the cutting, drilling and weld joint preparation began. I used the TIG (tungsten inert gas) welding method for all my weld joints. There is no weld spatter to clean up and you can control the heat of the weld very precisely.

Picture #1 shows the 10” seamless pipe up on the surplus K&T horizontal milling that I was ale to acquire. All the penetrations into the outer shell were made using the K&T via drills, end mills, boring head and slugger cutters.

Picture #2 shows the outer shell laying in a piece of channel iron that was used as a jig. 1-1/2” square tubes were welded to the outer sides of the channel for threaded rods and clamp bars as can be seen to the far end of the pipe. At this point I am establishing the horizontal centerline of the pipe.

Picture #4 shows the pipe with the vertical panels and throat sheet welded in place. I used the huge welding table at work for all the initial welding.

Picture #4 shows the completed outer shell for the 1/3 scale CASE 65 traction engine.

 

[steamin]

This posting shows what took place to generate the firebox.

Picture #1 shows the front and rear pieces of the firebox tack welded to a piece of channel at the appropiate distance apart. The channel was clamped very firmly to the welding table. Then the crown sheet was tack welded at its mid-point to the front and rear sheets of the firebox.

Picture #2 shows that a lot of heat was applied to the crown sheet to wrap it around the outside of the front and rear sheets of the firebox. Bar clamps were used to aid in the wrapping process as well as holding the crown sheet in place for tack welding.

Picture #3 shows the bottom of the fire box and how the mud ring had to be ground to provide for a root weld and then the fillet welds. The welding process for this project entailed a root weld, fillet welds that required anywhere from 4 to 6 passes depending on the width of the weld area and then a cover weld. It was a very time consuming process, but a great challenge and the out come was most gratifying.

 

[Dan Rowe]

Hi Larry,
Photos of the Case build will be very interesting. I have a set of 1/4 scale plans in my stack of plans.

The link to the Maryland Model Boiler Code has changed to:
http://www.dsd.state.md.us/comar/comarhtml/09/09.12.01.33.htm

Dan

 

[steamin]

Thanks for the update Dan on the Maryland code site.

A few more pictures of the firebox for the 1/3 CASE 65.

Picture #1 shows the entrance way to the firebox and the weld prep that had to be done.

Picture #2 is a side view of the firebox with the stay bolt holes. At this point I am hoping that they will match the holes in the outer boiler shell. Boy, did I do a lot of measuring and rechecking.

Picture #3 shows the firebox inserted into the boiler shell. I used the stay bolt holes to locate everything together.

The weld prep for the joints required a 45 degree angle to be ground on each mating piece except for a right angle weld. The edges were ground until there was about 0.06" to 0.09" flat left. A root weld was performed by just fusing the two mating pieces together. Then multiple passes were made with filler rod. Each pass overlapped the previous pass until the groove was entirely filled. Then a cover weld was performed. This is when you roll the rod with the torch from one side of the weld area to the other. When finished, it looks like a single weld was performed.

 

[steamin]

A few more boiler build shots. Next posting I will get into the construction of the contractor box. By the way the contractor box and canopy were extra when you ordered a traction engine. The canopy was considered for protecting the mechanics and not necessarily the operators.

 

[IronHorse]

Now that's a boiler, great job


IronHorse

 

[steamin]

Greetings,
It is time to move on to the "Contractor Box" of the CASE 65. I had a 1/4 scale CASE 65 for almost eleven years. During that time I built 3 contractor boxes for that little CASE. The bottom kept rusting out on me even though I would drain it and dry it out after each use. So this time I decided to go to the extra expense of building the 1/3 scale box from stainless steel. The following pictures in this posting and the next reflect the progression of the fabrication process. Again, TIG welding was used throughout the build. All the holes are for fake rivets. You will not believe what I finally used to hold the rivets in place. Super Glue Yes super glue. Any heat applied to a flat panel of stainless steel will cause it to warp. So I would run a very light bead of super glue around the hole and drop the rivet in. Da-dum and wall-ah the rivet was held in place. In a test piece I had to use a hammer to break the rivet loose.

I hope you enjoy and if you have any questions I will be glad to answer and share any information I may have.

 

[steamin]

Continued from previous post about the "Contractor Box".

 

[steamin]

Bull Gears - Part #1


The bull gears were the next big things that I tackled. I knew that this would be a very time consuming machining operation and that once set up could basically run on its own while I worked on other component parts for the Tractor. The bull gears have a 16” pitch diameter. My lathe will only swing a 13” diameter. So this is where I put the 55 year old Kearney and Trecker (K&T) universal horizontal milling machine to good use. When I purchased the machine several years ago, I was very fortunate to get all the attachments that went along with the machine, especially the powered rotary table. I basically turned the machine into a horizontal lathe. Instead of a tool bit, I used end mills to do the cutting. The attached pictures show some of the various processes involved. The rotary table is powered via the table power feed through a special gear box mounted on the end of the table. I made a fixture that looks somewhat like a 4-jaw chuck and mounted that to the rotary table. Before mounting the casting I found the center of the bull gear in relationship to the spokes. This is where the excess material on the OD did come into play. The gear blank was not cast symmetrically, so some concessions had to be made. I made sure one surface was relatively flat for a reference surface. Once the center was found, a hole was drilled and reamed 0.501” diameter for a locating dowel pin. I had a similar hole in my fixture that was located on the center lines of the rotary table. The gear blank was place in the fixture over the locating pin and clamped in place by the four bolts like using a four-jaw chuck. As the bolts were tighten, the locating pin was pulled in and out to make sure the gear blank was not favoring anyone particular direction in the fixture.

I proceeded to use a 2” diameter roughing end mill to remove the excess material within 0.050”- 0.060” of the finished dimensions. A ball end mill was used to make a nice fillet towards the face of the gear. A standard 4-flute end mill was used to produce the final finished surface. One picture shows how much material had to be removed from the spokes. The gear blank started out at 57 pounds. When all the machining was done, it weighs a mere 26 pounds. Why the gear blanks were cast with so much excess material, I do not know.

In any case, while the K&T was doing its thing, I was able to work on the front and rear wheel hubs.

 

[steamin]

Bull Gears - Part #2

Once the sides of the gear blank were machined to size, the gear blank was clamped to the table of a Bridgeport milling machine. The original dowel pin hole was used to find the center of the gear blank and the digital readout (DRO) was zeroed for both axis. Using x-y coordinates, the location of the eight mounting holes were found and drilled. A special block was machined to mount to the top of the rotary table via the “T” slots in the top of the table. This block had a ½” diameter dowel pin in the center and 8 corresponding tapped holes to bolt the gear blank firmly in place. A large 4-flute end mill was used to machine the blank to the appropriate outside diameter for the gear tooth cutting process.

The actual gear tooth cutting process is not black magic nor should it scare you from trying it. There are cutters that have the exact shape that is needed for any given pitch diameter and tooth size. They are called “involute” gear cutters. . An involute cutter cuts the root of the gear tooth and the sides of adjacent gear teeth. The main concern is not to cut too much metal at one time.

The K&T was set up as a typical horizontal milling machine and the rotary table was disconnected from the power feed. An indexing plate assembly was mounted to the rotary table so the gear blank could be rotated in precise increments. A 1/8” wide slitting saw was used to remove a major part of the material where the root of the tooth would be. This lessens the amount of material that the gear cutter has to remove. Two passes were made with the gear cutter to reach the desired depth and profile. The K&T has a power feed on the knee. So I would index, flip the power feed lever to up, the stop would trip the power feed handle out. Then I would rapid traverse the knee down and start the process all over again. Meanwhile I would work at something else for the tractor. I guess you would call it multi-tasking. Believe it or not, when I finished machining the two bull gears, I almost had a full 5 gallon bucket of cast iron shavings.

 

[steamin]

Good Evening,

The rear hub castings and keepers are fairly straightforward machining operations. I did run into a dimensional problem. The outer recess that the keepers go into was cast a little to deep. So by the time I machined a good flat bottom for the keeper to ride against and machined the keeper to size, I had to put a thick washer between the two in order to have clearance for installing and removing the taper pin that holds the keepers to the axel shaft. This was the case for both sides. The hubs were pretty rough castings in that the two halves of the mold were not aligned properly and the castings were not cast systemtrically. So I used a hand grinder to dress things up as best as possible. I did not drill and tap through the spoke holes on the otter edge of the hubs. I made those blind holes as well as the rear spoke mounting holes.

The spokes were mad from 5/16” diameter cold roll steel bar stock. My wife, Karen, cleaned and cut the bar stock to length. She dressed a 45 degree angle on one end for the threading. A geometric die head was used in the lathe to chase threads on one end of each spoke. A forming die was made to hot forge the flat head on each spoke.

The rims were made from ¼” thick hot rolled steel. I had a local fabricator power roll the 8” wide flat sheet into a 24” circle. The ends were cut and then TIG welded together for a completed wheel band. I took a piece of 8” wide brown wrapping paper the same length as the circumference of the wheel band and made a full size layout of the spoke holes. The layout was then tapped to the outside of the wheel band and the center points of the spokes were center punched at their appropriate locations. A piece of flat stock was clamped to the mill table over hanging the front edge 10”. It turned out that the rear rim wrapped itself around the knee of the milling machine. Thus allowing me to rotate the rim and re-clamping for drilling and counter sinking the holes for the spokes.