Fairbanks Morse Type T Replica

[raveney]

I saw a lot of really nice hit and miss engines last year at a local event. One that I had never heard of is the subject of this build. I have researched online and hadn't seen a set of castings or plans so decided to have a go at it from scratch.

The engine pictured is of unknown HP, but I am aiming at a 2 HP version. Some engines were paired with a cooling tank on a wagon and labeled "Jack of all Trades". I really like how the flywheel hubs are split and bolted to the shaft.

Vintage Machinery has good quality printed catalogs that were used to make a jpeg image and import into CAD. I then made some ratios to scale it to several constraints that I have for this project.

1) flywheel must be able to be turned on a 9x20 lathe. 8" nominal is good size on a faceplate.
2) cylinder size should be close to 1 inch, so I can use my existing honing equipment and boring bars.
3) cylinder jacket and crankcase should be close to nominal pipe sizes so I can fabricate using scrap metal I have access to.


I plan to silver braze or TIG braze the most difficult part: the crankcase. I modeled these dimensions off a buildable crankshaft with 1/2 journals and 3/4 stroke. The original engine uses a cast iron crankshaft, but I will likely fabricate one from mild steel.

I think I can use 3 inch nominal sch 40 carbon steel pipe and 3/16 steel sideplates to makeup the crankcase. The fillets will be JB welded after the parts are brazed or welded in place. E-bay has an original part that the seller had many pictures of so I was able to reference all of the features and attempt to figure out how it should function as I go. I plan on sharing the drawings for each part on this build and look forward to having others share the build experience or offer recommendations.

 

[raveney]

Design
update on the CAD work so far. We have the crankshaft, connecting rod, piston, wrist pin and end plate modeled and swinging about without obvious issues. Images of the connecting rod that I've seen on ebay differ from the nicely drawn picture in the manual. The bottom half appears to be bronze with a upper shell half bearing also bronze. The rod's upper body appears to be cast iron. Neat idea. Probably make the piston from grey cast iron and the wrist pin will be secured with #4 set screws from underneath. The pin looks to be oiled from a countersunk hole at the very top. The oil is splashed using a strip of metal on the bottom of the rod journal.

 

[GreenTwin]

Awesome build topic, and very nice 3D work !
.

 

[raveney]

Thank you for the kind words.
I believe I have enough to get started, and I also think that the crankcase may be the most difficult part to make. I am choosing the fabrication method using TIG welding, but silver brazing would also work. I will keep the drawings offline until each part is made, and then share as-builts. No promises on the quality as I struggle with overcrowding dimensions.

The main component used as a basis for the engine is a piece of 3" sch 40 steel pipe. I cut it 1-1/2" long and squared the ends to a final 1.400" dimension. The one side has a maintenance cover/bearing support for removal of the crankshaft. I used 1/4" steel plate for this and tack welded it on the inside circumference. Then removed the excess OD, radiused the corners to 3/8" and faced a mounting area using a radius bit of tool steel. Started to bore it out for the crank. This opening should allow me to tack weld the opposite side plate which will be a 3/16" plate.