Machining metal parts

[wdchyd]

Metal work is like simple arithmetic:
Add……..welding
subtract……machining
Multiply…….cnc
Divide……….cut off saw

A decent vertical turret Bridgeport type mill and a metal lathe will help with the subtraction.
And once you have a mill your old drill press will become a dust collector.
Lots of good advice above, especially on considering hiring a machinist to inspect a potential mill to purchase, lots of junk out there for sale that I would not put in my shop.
I have two vari speed mills and 1 CNC Hurco. My not so old drill press holds my coffee cup

 

[Fallon]

https://youtube.com/c/Blondihacks has some good intro to machining videos for the lathe & mill. Great place to start.

So many machining things you don't even conceive of until you start learning or doing. Fun like dozens of pounds of mild steel is not nearly stiff enough. Followed by hundreds or even thousands of pounds of cast iron isn't stiff enough. Or everything is a spring no matter how stiff you think it is.

 

[jthibodeau89]

Yeah, my ACRA mill is 3400 lbs. Stiffness and vibration damping are key to accurate machining. The small square column mills can be improved by filling with epoxy granite.

I built the Fitch RPC. Very easy. Single push button to start and push button to stop. Can have a remote start/stop buttons and indicator at each machine, if you like.

 

[AWSubie]

These four YouTube channels I found to be very informative.

MrPete222

Frank Hoose

H&W Machine Repair and Rebuilding

Joe Pieczynski

I started out on the journey u are about to begin roughly six years ago and I’ve enjoyed every minute. Here are some thoughts:

A mill and a lathe are complementary to each other. Each has certain tasks it does very well and each can do tasks the other does but not quite as easily.

A digital read out (DRO) on both the Mill and the Lathe reduces the effort required to keep track of tool position and makes your work go faster.

My shop space (single car garage) is limited. I had difficulty finding an American made small lathe that wasn’t beat to death. My solution was to buy a Precision Matthews (Chinese) 12” lathe. I couldn’t be happier.

If you can find a Bridgeport mill in decent condition (and can afford it) buy it. I looked at several that were in miserable condition and several more that were nice but the asking prices were so far above my budget I couldn’t begin to negotiate. I ended up getting a circa 1980’s Taiwan clone.

As far as spindle tapers, for the mill I don’t think it really matters what u get. If the mill you buy lacks tool holders, eBay has plenty of tool holders at reasonable prices for just about any taper. For the lathe, you only need to understand that a threaded spindle has safety concerns when working in reverse. Keyed and cam-lock spindles are somewhat more versatile.

An alternative to rotary phase converters and digital phase converters is to re-motor with a DC motor and controller.

Happy hunting!

 

[3Ts]

Thanks, to everyone.

Budget is a significant factor.

I only have single phase available. I checked on cost to bring in 3 phase and it was not going to happen. I’m aware of the phase converters and the delta and Y configurations for 3 phase but have never done any wiring with them. Plenty of single phase and signal wiring.

As for adult ed classes – there aren’t any, i’ve already checked into them. The one course in welding specifically stated that it was for degree students only and not continuing education. (I know there’s a way around that, but being over 70 I’d have a hard time convincing anyone I was changing careers.)

Just so you have some background, I have a full woodworking shop and make cabinets & furniture from time to time now that I’m retired.

I expect to see the machinist tomorrow and see what he says about letting me shadow him at his shop. With the holidays coming up, I really don’t expect anything to happen until early next year.

I appreciate all the information.

 

[ultrarunner]

The era of Covid has changed much…

Traditionally, community college is open to everyone…

I have used a simple idler 3 phase motor to run my 1hp J head Bridgeport.

Never did anymore than give it a twist of the wrist with one hand and plug in the cord with the other.

This setup has worked with zero issues since the mid 1980’s and took about 10 minutes to set up…

 

[LD1]

The era of Covid has changed much…

Traditionally, community college is open to everyone…

I have used a simple idler 3 phase motor to run my 1hp J head Bridgeport.

Never did anymore than give it a twist of the wrist with one hand and plug in the cord with the other.

This setup has worked with zero issues since the mid 1980’s and took about 10 minutes to set up…

Yup. 3ph motors will run on single phase....just got to get them started. Once running, voltage is "induced" into the third leg....thus you can now run a mill.

ITs not perfect.....Maybe 240v on the two legs you are feeding and 180v on the generated leg. Dont matter, it just needs something to be able to "start" your mill or lathe.

Purpose built converters do some things to better balance voltage. Like more windings on the 3rd leg and capacitors. They also use capacitors to start so you dont have to give it a twist of the hand..


To anyone wanting machining equipment and their holdup is 3PH power......Id say dont let that stop you. Between a RPC, Static, build your own, VFD, etc etc.....you can have three phase power pretty affordable to run a mill or lathe

 

[3Ts]

There is a term for 3ph motors that are "inverter rated". What does that mean? If I'm understanding 3ph motors correctly, they all will work off an inverter. The only concern that I see is that the inverter changes frequency to control the motor speed and cooling could be an issue at lower speeds.

 

[LD1]

There is a term for 3ph motors that are "inverter rated". What does that mean? If I'm understanding 3ph motors correctly, they all will work off an inverter. The only concern that I see is that the inverter changes frequency to control the motor speed and cooling could be an issue at lower speeds.

You got it.

They all don't work off am inverter. I fact I'd say most don't in an average industrial setting.

Motors are designed to work at their nominal rpm at 60hz. With a freq drive you can vary this but not much if you want longevity.

Try to run a non inverter motor at load at 5 or 10hz it will burn up shortly.

Inverter motors take extra steps to ensure cooling. Fan design, cooling fins, heavier windings and insulation, etc

 

[metalbender]

Avoid the round column mill-drill like the plague. Been there, much frustration, no T shirt. Now have a Grizz square column bench top unit, big enough for most needs.