Flywheel with integrated fan

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Brian Rupnow

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I wish I could build a flywheel like this. The flywheel would revolve clockwise. Air on the far side of the flywheel would be pulled thru the angled holes and blow onto the air cooled cylinder on the near side of the flywheel---I think. Looks like it would be a job for cnc. Might be kind of a pig to build with manual machines. The flywheel shown is 6" diameter made of steel or brass.
38jXEj.jpg
 
I just had a look at Dale Dietrich's four cylinder engine on Youtube. That flywheel is a beautiful thing. Far more work than I would want to invest, but it sure is pretty and functional.
 
I suppose you could build a center hub, then set it up and gash it 8 places at 45 degrees, then solder in the blades, then trim the end of the blades and solder on the outer rim. Be a lot of work, but gives a pretty end result. If you google "Dale Dietrich engine youtube" you can see where he has made a four cylinder engine with that style of flywheel. The mass of the hub and outer rim would suck up an awful lot of heat before the solder would flow. Maybe Dale made his from steel and then tig welded it together. tig is very easy to control. My A.C. welder and mig welder would get it done but would leave some big ugly welds.
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I do keep thinking about buying a TIG welder set-up. I went to my local welding gas supply company, and they will sell me a tig for about $1500 plus tax. I do love this hobby, and there is a lot of really neat stuff I could do with a tig. Other side of that coin is that I'm 73 years old. I already have AC stick welder and mig welder and oxy acetylene.
 
Could the first flywheel be made with a tilted rotary table?
 
I suppose if the holes were big enough if might work. Would be interesting to try. You could almost machine one up from a cheaper aluminium or even plastic to test the air movement.
 
Could the first flywheel be made with a tilted rotary table?

Without tilting a rotary table, I don't see another way to do it other than 5 axis CNC. I have 4 axis and tilting the rotary table is how I'd do it.

The problem with 5 axis CNC is getting the CAM files. Only the professional (BIG $$) CAM programs do it.

EDIT 2020 EST - Changed the first paragraph to help clarity. I wrote it and I wasn't sure what it meant.
 
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Hi All
In the downloads section under Draw Tech there is a a 5 inch diam.
flywheel as you describe. Very well drawn and detailed.
It is for a Knucklehead motor bike engine.
It is in KH-1 folder.
Graham
 
No need to tilt the RT. Center punch the hole locations. Mount it on a shaft held at an angle. Bore one hole rotate on shaft to bring next center punch under spindle. Repeat.

I had the same idea to test my radial that needs a 20" propeller. I am not trilled to fiddle with the carb with a 20" propeller spinning and was thinking of replacing with something to provide fly wheel effect and some airflow.

I am not there yet but will use the described method. If one use the tilt table the shaft length can be reduced and the hole path arranged to "miss" the table.
 
I'm going out today to look at tig welders. I have every kind of welder there is except for tig. Tig welders are capable of laying small, controllable weld beads, and would be perfect for fabricating things like the flywheel. Brass and bronze have become so expensive to buy that all of my future builds may have fabricated steel vane type flywheels.
 
Without tilting a rotary table, I don't see another way to do it other than 5 axis CNC. I have 4 axis and tilting the rotary table is how I'd do it.

The problem with 5 axis CNC is getting the CAM files. Only the professional (BIG $$) CAM programs do it.

F360 does 5-axis tool paths doesn't it? I'm pretty sure that the Pocket NC folks include a 1-year F360 license with their bench top 5-axis mill.

Mike
 
Today I bought a TIG welder. I looked at Lincoln--best price with taxes was $3000. Looked at Miller---same thing. Drove up the road 25 miles to Orillia and bought a TIG with all the bells and whistles for $1412.00 including taxes--And it comes with a free helmet with adjustable darkening lens. Made and sold under the Solidweld brand. It has AC output, High frequency start, 35% duty cycle, foot pedal, and all the hook-ups for a gas bottle. 220Volt. It will weld steel or aluminum. I'm going to make a few of these fabricated fan/flywheels and perhaps sell some.
 
Brian, if you have done O/A welding, you will have no problem with TIG welding. And I was going to suggest taking a look at an import. I have used the Everlast brand with good results; in fact, just upgraded from my DC-only Everlast 3-in-1 (TIG, Stick, Plasma cutter) to an AC/DC Everlast 3-in-1. The bells and whistles are fantastic, especially pulse control. Not what I would recommend for a professional, but for a hobbyist, it is a great machine.

The biggest challenge you will have with using TIG on those flywheels is getting into the tight corners. You may find it helpful to watch some of Welding Tips and Tricks videos on You Tube - no affiliation, but I find them enormously helpful. Based on those videos, I think I can already tell you what Jody would recommend - a gas lens cup that lets you extend the electrode way further out than an ordinary cup.

In terms of machining the flywheel as drawn in the OP, I was also thinking along the lines that others have suggested. To me, this doesn't look that hard to accomplish with manual machines, depending on the capabilities of the machine. Unless I'm seeing it wrong, these are straight-through holes, just cut at an angle. If that is right, there are at least two ways to skin this cat. I have a dividing head that can tilt, so one solution would be to set it to the right angle, use an endmill to cut a flat, then drill through, then index to the next location, then repeat. But probably better in terms of rigidity would be to use a rotary table mounted flat (horizontally) on the table, with some sacrificial material under the flywheel, and tilt the head of the mill rather than the dividing head. I think even the smaller import machines can tilt (rotate) the head, at least in one axis? I have a Bridgeport as my main mill, so tilting AND nodding are both available - hardly ever used, but invaluable when you need it.
 
Mauro, what type of machine do you have? In addition to the BP, I have a very sad mill-drill of a type that was not very popular, which among its other faults does not tilt or nod. But I had thought most other designs did - looks like I was mistaken!
 

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