TMWT: The machine work thread

[weejub]

Alright, let's talk wiring.

This mill has three, three phase motors; in-column coolant pump, x-axis power feed, and of course the head. Running each of these off of a separate VFD doesn't make sense, too expensive and wasteful. The side of the mill has a GE motor start switch with replaceable "heaters". This is a breaker switch, not a magnetic starter switch, that can handle up to 18A by use of replaceable "heaters". Think of this as a breaker in your house electrical panel. Instead of replacing the whole breaker to upgrade amperage for a circuit, you can replace just the current trip mechanism, which even in your household breaker is a heat element.

This is what it looked like when I pulled it open the first time:

You can see lots of failed insulation, and that the head motor was wired directly to the 3 phase line.

Inside cover:

Heater comparison. Heaters with the thick wire are the 6.4A ones:

Rewired all three motors to the load side of the switch, with the 6.4a heaters:

@CruizerHound , you were right, with this setup, the 7.5a output VFD didn't like being line power. Original thinking was to buy a larger VFD that wouldn't mind as much, but in doing research, I discovered static phase converters. Ended up buying an American Rotary digital static phase converter from Wolf Automation (link in post #51). Very slick device.

Cover off:

Internal wiring:

It's a 1-5hp model. Low on the toggle is 1-3hp range, high on the toggle is 3-5hp range. I'll operate this in "low" range.

She just sits on the wall and looks pretty

So, with that phase of this project done, I turned my attention to cleaning and got the column sump cleaned out. Pumped out 15 gallons of the nastiest, most disgusting, rotting-carcass smelling sludge oil mix I've ever experienced. Had to breathe through my mouth, even with the respirator on, to not vomit. In lighter news, that chapter of my life is over (thank god) and I even started cleaning the outside of the machine:

Long story short, static phase converters are cheap, and are very simple to hook up and use. VFDs are a good alternative when your load would better be suited to a rotary phase converter, as VFDs are dramatically cheaper than rotary phase converters. If you want to be able to control your motor speed, a VFD is the way to go.

**MIND BLOWN**

I just love to look at that even though I have no idea what it can do, what you are doing etc Its just a work of art let alone whatever it does.

 

[GLTHFJ60]

First project! Milling out, then tapping, the casting on a @Trollhole carb to retain the factory return line on @Fort Knox 's 77 fj40. Borrowed a tap drill and tap from @S4Cruiser .

 

[Fort Knox]

I can vouch for how incredible it is to just eat away metal a fraction of a millimeter at a time with this beast of a machine.

 

[RedHeadedStepChild]

Fraction of a mm?
You guys need to take bigger cuts. Bury a hog out mill and watch the blue chips fly! Then you're having fun!

 

[S4Cruiser]

Seems like a good deal here if needling a bunch of collets.

Great deal on Jet 35pc 5-C Collet Set. - The Garage Journal Board

 

[GLTHFJ60]

Coolant pump had to be disconnected because it got too hot, and my x-axis power feed started smoking earlier so it got switched off, but I started making a thing today! Called a mini-pallet, for clamping small things to the mill.

Trammed the vise, squared up the sides, cut slots to fit in the vise jaws, flattened the top, scribed a grid with a hardened and sharpened punch, then drilled and tapped the center hole. The rest of the holes in the grid will get drilled and tapped as well.

 

[GLTHFJ60]

 

[lt1fire]

well this is all kinds of awesome

 

[RedHeadedStepChild]

Good fun.
Bend up a piece of lexan and you can those chips at least a bit contained.
Personally, I'd skip the gloves while you've got that thing running. In the shop we require cut resistant gloves for most operations, BUT anywhere with an exposed rotating cutting tool gloves are forbidden.

 

[GLTHFJ60]

Heard Jim, thank you

 

[cruisermatt]

Couldn’t let @GLTHFJ60 be the only one contributing...
machined a big speed hole in one of my motor mounts.
I’m still amazed I acomplished the trapezoidal shape without shooting anything across the shop

Also, the bolt hole is 18mm in diameter. Good luck finding an 18mm still bit! I drilled to 11/16” and bored it the rest of the way. Forgot to take a picture unfortunately.

 

[GLTHFJ60]

How'd you cut the trapezoid shape on the mill, specifically how'd you clamp the non-parallel edge in the vice?

Perfect job for the mini-pallet I'm building

 

[cruisermatt]

How'd you cut the trapezoid shape on the mill, specifically how'd you clamp the non-parallel edge in the vice?

Perfect job for the mini-pallet I'm building

Actually, yeah that mini-pallet thing would have been awesome.

Let’s just say what I did was a poor example of shop safety

I put the outside straight edge along the vice jaw (on parallels) and closed the vice until it contacted the part, and then jammed a big chunk of aluminum stock in there. And cranked down on it hard

I cut the outside shape with a cutoff wheel.

 

[GLTHFJ60]

I don't think this is how it's supposed to work.

Note to self: learn the difference between climb milling and conventional milling, lol

 

[RedHeadedStepChild]

Bummer, but it could have been worse.
You'll want to check to be sure your head is still true.

 

[cruisermatt]

What depth of cut??
Also, 4 or 5-flute is going to be a lot better for steels.

 

[cruisermatt]

Also, are you milling the edges of that steel that you cut with your plasma cutter? If so, I’d highly recommend you hit it with a sanding disc first. When you plasma cut without shielding gas (like most do in home shops) you basically nitride-coat that cut surface, which is super hard and will wreck your tooling.

I learned this the hard way a few times using a CNC plasma to make hole patterns and trying to drill those holes out. Just didn’t work and destroyed a ton of drill bits.

 

[S4Cruiser]

Also, are you milling the edges of that steel that you cut with your plasma cutter? If so, I’d highly recommend you hit it with a sanding disc first. When you plasma cut without shielding gas (like most do in home shops) you basically nitride-coat that cut surface, which is super hard and will wreck your tooling.

I learned this the hard way a few times using a CNC plasma to make hole patterns and trying to drill those holes out. Just didn’t work and destroyed a ton of drill bits.

Is this why it seems dross is harder to grind? I always try to knock it off but it all never co Es off this way.

 

[cruisermatt]

Maybe. Not completely sure though.
I usually use a hammer and chisel. Works good.

 

[GLTHFJ60]

What depth of cut??
Also, 4 or 5-flute is going to be a lot better for steels.

1/4"

Also, are you milling the edges of that steel that you cut with your plasma cutter? If so, I’d highly recommend you hit it with a sanding disc first. When you plasma cut without shielding gas (like most do in home shops) you basically nitride-coat that cut surface, which is super hard and will wreck your tooling.

Yes, and I did. Was climb milling, pushing it kinda hard, and this garbage two flute endmill bent like a pretzel!