I got interested in hot air engines earlier this year and wound up building the popular Moriya model designed by Dr. James Senft. I got lots of help and encouragement from the guys on the Home Machinist forum. There's a pretty lively discussion of the entire build here, including a link to a copy of Dr. Senft's original plans.
Sometime later I got interested in the Manson-style hot air engine, mostly due to its simplicity. Surprisingly, I wasn't able to find a complete set of drawings for a Manson engine, so I tried to come up with an original design. My first attempt was similar in a lot of ways to the Moriya engine, but it didn't run very well. The next effort was kind of a cross between the partially complete plans found here and the build log for yet another example found here. It ran much better than the first attempt, but still wasn't great. But once again, the guys on the Home Machinist forum came through with some great hints for improvement, and with them, a third engine very similar to the second one ran like a champ. There's even a video:
This file contains a Fusion 360 model for the third version, 2D drawings based on that model, photos of most of the parts, and a few miscellaneous notes. If you have any questions or comments about these plans, I'd love to hear them, either here or in a comment attached to the video mentioned above.
