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I hear a lot of folks say "I never used calculus after college", but if you work as an engineer, then you use the knowledge constantly. Its like saying "I learned to read in school, but I have never written a book, and so I don't use that skill". But then you become a chef, and read a book that...

The flywheel rim was turned from several glued layers of birch plywood, cut round on the bandsaw. I used a router mounted on the lathe toolbit holder, and turned the lathe chuck by hand. This prevents a flywheel snag/explosion when you try to rotate a wood piece normally in the lathe chuck. I...

3D printed patterns lend themselves to a two-piece pattern, since that gives you a way to start the pattern with a flat side. I have pretty much transitioned 100% to 3D printed patterns, but I do know how to manually make patterns too. .

Here is my oversized Cretors-replica flywheel casting, compared with an original Cretors No.02 flywheel, and also compared to a Cretors No.01 flywheel. This was just a proof-of-concept thing, to see if this method would work, and I did not expect to see any sort of quality in the resulting...

In the cast of this flywheel, looking at my photos, it looks like I actually made half the mold just by pressing the pattern down into the sand, and so I did not make a follower. But this is how you make a follower. This was sodium silicate bound sand. I needed some risers on the rim to avoid...

Casting the individual spokes. The single wood spoke pattern was cut from a flat sheet of birch plywood, and then hand carved using a Demel with a long straight bit in it. The spoke blank had a centerline around the entire piece, and I just worked 1/4 of the piece at a time, down to the...

I have toyed around with making larger scaled up replicas of Cretors engines, and made a pattern for an enlarged Cretors No.01 flywheel. I have probably posted this previously somewhere here. The method I used to make the follower was to fill a shallow flask half with sodium-silicate sand...

I always thought that patterns were generally two-piece, or more, split-pattern type, until I visited Bob Pearson's shop and saw the original Cretors patterns. All of the Cretors patterns for the popcorn engines, and popcorn wagon cast parts are one-piece. The cretors patterns appear to be made...

Opinions on how to approach making a casting for the Chenery Gnome Rotary will vary. I can offer one way to do it. A photo of what I think the casting would look like is at post #22 here: https://www.homemodelenginemachinist.com/threads/les-chenery-rotary-engine-1-5.31718/page-2 Assuming the...

It is really interesting to read about other people's foundry experiences. There is so much to learn, and so many different ways to do the same thing. It took me about six years to get a good handle on casting gray iron. Many things that I was told about it turned out to be myths. I really...

I was lucky to lock in a seat of Solidworks for a one-time fee ($4,000), with no annual subscription. This was in 2012. There is no way I could afford an annual fee. Diddo for AutoCad 2004; perpetual license; no annual fee. If you don't need the yearly upgrades, then you can save a ton of...

We had 4 semesters of calculus, the last one being differential equations. Many people have asked me "Do you solve calculus equations in your everyday work?". The answer is "No". It should be understood though that calculus is the language that describes how things function in the...

Welcome Gunny, glad to have you in the group. This is an adictive hobby for sure. I have known many who have been at it much of their lives. My dad started building model engines when he retired, and ended up building 38 engines. I was very busy with life until about 14 years ago, when I got an...

Welcome, glad to have you. Looks like you are into some interesting hobbies. Please share photos. Pat J. .

And I have farmed out 3D printing for pattern making too, to a commercial firm that had a high-end printer, and the results were outstanding. Once you get an engine into a 3D model, there are many options available at that point. I think more and more options will emerge over time. The 3D...

If I ever get a slight break in my workload, I am going to start 3D printing the patterns for this engine, 1/2 scale. With the effort put into making an accurate 3D model, then a 3D printer allows repetitive accurate pattern making. A 3D model can also be shared with others, and then they too...

Luckily 3D modeling programs and printer prices have come way down over the years, and more and more people are embracing these tools. It was very difficult for me to learn 3D modeling, even though I was very good at 2D CAD. The difficulty with 3D modeling (in my opinion) is not that 3D modeling...

Looks very good so far. Nice stack with the brass work. .

More downloadables from the Prusa site. Note: I am not shilling for Prusa, and have no connections to that company, but I do notice that not only does Prusa make nice 3D printers, they also offer a large number of what I call "spin-off" printable items, many of which could be used in this...

I get updates from Prusa from time to time concerning new developments/methods using the Prusa XL multi-material/multi-head 3D printer. The 3D printing hobby is getting really impressive, with some fantastic new trends, as follows: 1. Prusa's 3D model download page had some impressive models...