Engines > From Plans
Pottyengineering Horizontal Mill Engine - Imperial - Mike's 3rd Engine
mikehinz:
I've made a start on my 3rd engine. This one is going to be the famous Pottyengineering Horizontal Mill Engine as originally created and drawn by Mr. Stewart Hart. Since I'm located in the US and Imperial fasteners and tooling is the most readily available, I decided to build the engine in Imperial measure and use the closest and most appropriate sized fasteners and stock. Additionally, in my seemingly unending quest to learn 3D CAD, I created a model using Fusion 360 and will generate drawings from that model as I go along.
I've linked a YouTube video that I just did of the animated model just showing that it all works and that there are no apparent collisions or other issues. I've also posted a couple of renderings of how I've been thinking about the appearance of the engine. My decisions to this point are to purchase a 4" cast flywheel from Martin Model & Pattern, some oil cups from PM Research and scale model fasteners from American Model Engineering Supply. I've also tried to use some brass parts for accent and plan to use a brushed type of finish.
I'm ordering the materials that I don't have on hand right now and will be starting a bit slowly as I'm in the process of making a few mods to my shop equipment including installing a DRO on my lathe. But I'm now at least making process on engine number 3!
http://www.youtube.com/watch?v=D6mlvtss7BY
Enjoy and follow along!
Mike
b.lindsey:
This will be a nice addition Mike. I will be following along.
Bill
Johnmcc69:
Looking good Mike.
I'm on board.
John
mikehinz:
An exciting day, I got started on the engine!
I decided to start with the aluminum base as there are a number of parts that have to fit on the base properly all have to align pretty closely. As per my previous post, I'd modeled this up in Fusion 360 and have started generating working drawings from the model. The engine worked in F360 so I'm reasonably confident things will fit, as long as I don't screw up the machining! I thought I had some 1/4" AL for the base but it turned out I didn't when I actually looked for it, so yesterday I made a trip to The Yard here in Wichita and picked up a piece of 1/4" scrap 6061 plate they had. Prices there for drops are extremely cheap, currently $1.70/pound and they have almost any size and shape of AL that you could dream of.
Anyway, on to the machining! First pix is after sawed a piece more or less to shape and then squared it up and brought it to the spec'd dimensions, 9" x 2.25". This is drilling the clearance thru holes for the #10 mounting bolts
Next pix shows what you (or at least what I did) when you don't have a proper counterbore tool on hand for 4-40 shcs. I just put a 2 flute 3/16 end mill in the drill chuck and plunged in with the quill at each required location to .115". It worked perfectly as far as i could tell.
Tapping 4-40 in 4 locations. I kicked the mill out of gear and simply rotated the chuck by hand while putting light pressure on the quill. I'd drilled for 75% threads and this process went smoothly. No broken taps and a test 4-40 shcs went in each hole with a good fit.
Here's the finished AL base plate on top of the drawing.
I also started on the crankshaft supports. The drawing spec'd 5/16" plate and I only had some 3/8" on hand. I cut a piece to rough shape then squared it up in the mill and brought it width. I then used a flycutter to take the plate down to 5/16". After getting to the required thickness, I cut that piece in half and the pix shows bringing them both to the required height fo 1.60". I did them both at the same time to get them as equal in height as I could. This pix just shows the final measurement. I used a 3/4" HSS 4 flute end mill. Worked well.
The last pix of machining today shows the crankshaft support pieces on top of the drawing. The next time I work on this I'll try to complete these pieces, being careful to get the bearing holes as exactly to the same height as closely as I can and will turn the bronze bushings and get them pressed into place.
And the final pix of the day is of some parts that arrived. I ended up getting a 4 1/2" cast flywheel from Martin Model and a small selection of scale model fasteners from American Model Engineering Supply. Both vendors had excellent service with extremely fast shipment and the quality of everything is extremely good.
All for today. I need to place another order for some raw material. I need a bit of drill rod and some 1/4" square stock for the crosshead slides as well as a few other small items. I'll try to get an order in tomorrow. I also need to work on a few more working drawings for the next parts I want to attempt. That always takes me a bit longer than I anticipate and I end up redoing them a couple of times generally.
Enjoy!
Mike
sbwhart:
Good Start Mike, I'll be watching with interest :ThumbsUp:
Stew
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