Three phase guru's?

My new acquisition seems to like three phase. I am told a rotary converter is not impossible to build. This might be easier than completing my generator project. I know the majic smoke goes in the motor from the wall… and is not supposed to get out. Seems 240 can fill two cylinders so to speak of a three cylinder motor, and once spun majically makes the three phase. I’ve read some good web pages, and see the need for the equalizing and normalizing and starting caps. Have dryer on hand for donor motor, or old washing machine, or any number of spare craftsman and the like from various tool yard sales.

Hive does have 3phase access I think.

It isn’t hard to make a split phase (single phase) to three phase converter, the mostly mechanical versions are called motor-generators, and the mass of the monster will be an advantage when you do finish the generator, but keep this in mind;
The conversion is lossy, you’ll get 60% efficiency at best, so if you need two horsepower out, you need to put more than three horsepower in.
The electronic versions are fairly inexpensive, but they need to be matched to their load, and they don’t like sudden changes in that load.
All things considered, it would probably be cheapest to put a single phase motor on your acquisition, they come in standard configurations from both the electrical and mechanical perspective.
How big is the motor? Most 3 phase stuff isn’t small, and the motor generator I built for a friend in KY was larger than the lathe that he needed it for (he restores lathes and mills in Maysville).
If you want assistance, I’d be glad to help out - my credentials are 3 years experience in the Army as a 52D10 and D20, generator mechanic.
Steve J.

I love you guys already… but I don’t think there is room for 0-16A Gorton in there… and I already hauled it home :slight_smile: Although it is still trailerized. Now, most all my other machining projects are 120/240 :slight_smile: I could use a hand with a cnc lathe, it’s a desktop. We’d have to work out some details. If you are really up for a project, I’d like to refit/recondition a 32 inch metal shaper… (not for lumber, it’s the real deal and about 7k lbs)

On the shop mill… the round column can lose position, best modification is an over thick column with an oversized triangular gib. Would be a cool project. Add in expoxy granite too? Wow factor :slight_smile:

Now if you guys want to acquire some old iron projects in three phase… I still have chains and binders, and will travel. CDL B too, no truck. Turret lathes go cheap, and stripped down Hardinge head stocks are pretty common. That would be almost an ideal donor for a slant bed project in 5C, or a smaller chuck. No I am not a machinist… I play one on tv.

That sounds grand. It is an odd spindle speed combination, it’s lowest is 700 or so rpm. It is more that the main function was duplication, and the mill part was a side effect. The semi extreme high rpms were to get cutting sfpm on small cutters. I am not ashamed to admit the magic smoke mystifies me. Will try and grab some motor specs from under the tarp.

It’s a Master AC multi speed motor Serial cn949 style 226527 type PB, 220 volts 1.5 hp and 3450 rpm @ 4.8 amps and .75 hp and 1725 rpm at 2.4 amps. It is about the size of a basketball, a little larger.

The spindle pulley pair produces ten speeds, the motor multiplies this.

1-a 1400 rpm
2-a 1800
1-B 2900
2-B 3700
2-C 5000
3-B 6000
3-C 7500
3-D 8600
4-C 10000
4-D 12000

That’s the high speed, the lower is half the rpms.Given the spindle is sized for 1/2 inch max collets… odds are sizing a single phase motor to drive single insert cutters say max of 5/8 and variable speed with a tach display would be the way to go. Odds are I need pull out my speeds and feeds charts and thinkerize :slight_smile: Is my understanding that pulse width modification keeps the hp but drops the speed? Not that you’d need 1.5 horse at 12k rpm… that’s really high speed for really small single flute cutters.