Building the 1/4-Scale 5 HP Red Wing: Part III


| January 2005

  • 1_4Scale5HPRedWing.jpg

  • Photo1.jpg
    'As long as the crankshaft is well-secured, cutting the keyway is fairly straight-forward. '
  • Photo2.jpg
    The governor arm bracket requires considerable machining.
  • Photo3.jpg
    Photo 3 (Left): Here you can see the completed crankshaft viewed through the cylinder.
  • Photo5.jpg
    The completed flywheel and governor assembly.
  • Photo4.jpg
    'Photo 4 (Above): The left side flywheel, complete with governor bracket and weights. '
  • Photos6.jpg

  • Photos7.jpg

  • Photos8.jpg
    'Photo 6 (Above, right): The raw casting requires a considerable amount of work to get it to look as it does in the following pictures. Photo 7 (Below, left): Yellow arrows point out the valve ports and the bores for the valve stems. Photo 8 (Below, right): Left arrow (blue) shows where air is drawn from the intake and mixer. Right arrow (red) illustrates where the exhaust flows out of the valve chamber and through the muffler. '

  • 1_4Scale5HPRedWing.jpg
  • Photo1.jpg
  • Photo2.jpg
  • Photo3.jpg
  • Photo5.jpg
  • Photo4.jpg
  • Photos6.jpg
  • Photos7.jpg
  • Photos8.jpg

Editor's note: This is the third installment in a planned four-part series on building the scale Red Wing engine.

Hello again! If you caught last month's article, you will remember that we covered milling of the large pieces. This month I want to expose you to some of the smaller and more difficult pieces to work with.

Step 9: Preparing the Crankshaft

The crankshaft is an interesting place to start. I had never made one before, but I was sure it would be a piece of cake. The crankshaft is made of 1/2-inch round material. The throw is 1-inch long and made of 3/8-by-5/8-inch flat stock. The throw shaft is 7/16-inch (0.437") round material.

The instructions call for silver-soldering the pieces together. I chose to braze the pieces and it worked very well. Here is a tip for those that haven't thought of it: The 1/2-inch crankshaft can be left in one long piece. The throw pieces are slid into place and everything is brazed. After cooling, the section of the main shaft that is not supposed to be there can be cut and removed. Leaving the main shaft whole helps to insure the finished crankshaft is straight.



The keyway can be cut one of two ways. You can use a 1/8-inch (0.125") end mill or a woodruff cutter like I did (Photo 1). Either way will give good results as long as the crankshaft is clamped in place securely.

Step 10: Completion of the Fuel Tank and Working on Small Parts

In the first article I talked about turning the bottom of the engine frame into the fuel tank. I milled a 1/8-inch recess at that time. Now is as good a time as any to finish the tank.



SUBSCRIBE TO GAS ENGINE MAGAZINE TODAY!

Gas Engine Magazine A_M 16Gas Engine Magazine is your best source for tractor and stationary gas engine information.  Subscribe and connect with more than 23,000 other gas engine collectors and build your knowledge, share your passion and search for parts, in the publication written by and for gas engine enthusiasts! Gas Engine Magazine brings you: restoration stories, company histories, and technical advice. Plus our Flywheel Forum column helps answer your engine inquiries!

Be sure to take advantage of the Square Deal Subscription Program.

  • No Missed Issues.

  • No Renewal Notices.

  • No Additional Cost.

The Square Deal Subscription Program is designed as a paperless transaction with automatic renewals at a preferred low rate.   With advanced electronic notification, a 100% satisfaction guarantee and an easy opt-out plan, the Square Deal Subscription Program is the best value, risk free, eco-friendliest way to subscribe.




Facebook YouTube

Classifieds