What *should* a Warco Super Major Milling Machine be able to accomplish?

SoD: I don't know what you're smoking, but it's probably illegal. Beware a visit from the boys in blue!

My Bridgeport, with an early varispeed head, has a 1.5hp (1.1kW) motor. Later versions had a 2hp (1.5kW) motor. Some of the clones had a 3hp (2.2kW) motor. But as far as I'm aware none had a 4kW (5hp) motor. My horizontal mill has a 5hp motor, but that weighs 3500lb, so not really bench mount.

Andrew

See, I just posted in another thread about the need to correct mistakes and here I am in the dock again. I plead Guilty. I've no idea were 4kW came from or why I typed it! It's not in the specification I quoted from. Seems I've got mental flatulence again.

Dave

Rigidity is what you want, and a Bridgeport or any column mill doesn't provide it.

Put the tool in the chuck, bring it up to the work but not touching, then get a DTI between the work and the cutter. Using finger pressure only push the cutter to and from the work and be amazed at how many thou movement you get. That is the play.

If you get 10 thou then buy a file, even a couple of thou is far too much. A real mill will only move a couple of tenths, that is what you need to get cutting.

Look at a real industrial mill, and the amount of cast iron in it.

Ho hum, that rules out just about any milling machine then. Even the big old K&T mills have a column. Likewise large bed mills have a column, not unlike small hobby machines. Even a plano-mill has a column, well two of them but they're still columns. May be the comment is a sort of reverse psychology selling technique so that we'll rush out and buy the A&S universal machine, and all it's cast iron, that is for sale?

Andrew

I think Andrew has it

Why practice being silly?

This is a home workshop forum, and the machines as used in such an environment. A column mill is the mill drill and similar mills, which took years before they bothered to put keyways or other anti rotation devices on the column.

Look at your wonderful Bridgeport, just how far is it from the tip of the cutter, through the head, down the column, into the knee then up to the vice? And how many joints and gaps are there? It isn't rigid. Do the finger and DTI test, but you won't, nobody ever does. Then you have the Senior mills, nice solid column but the table dovetails are square, as long as they are wide. This means that you can do nothing to stop the table twisting on the dovetails. This is not rigid.

Each machine has a limit to what it can do, to push that limit buy a Huron, for spotting holes and thin aluminium buy a Bridgeport. Most work is lightweight, works fine, unfortunately as a model engineer the work is far more diverse.

Just to clarify, my original question was:

What *should* a Warco Super Major Milling Machine be able to accomplish?

... because that's the machine I have. I just want to know what it can reasonably do.

I'm not in the market for a newer, larger machine.

Three tenths, using two fingers on the tool.

Andrew

Sorry Lee, I was trying to rank the Super Major relative to other machines.

The point is all milling machines cut metal, but that powerful rigid machines get results faster and generally make life easier for the operator. In particular it's more difficult to do accurate work with the lighter machines because they flex.

It's not as simple as saying a WM14 can only take light cuts in cheddar while a Super Major will plough through 12" armour plate. Rule of thumb for all machines is 1HP will remove about ¾ of a cubic inch of mild-steel per minute. So in theory an Super Major and a Bridgeport should do about the same amount of work in the same time. BUT a Super Major is lighter and less rigid than a Bridgeport, so in practice the operator has to adjust to maintain the same level of accuracy, because Super Majors bend more than Bridgeports. It doesn't mean a Super Major is a waste of space.

My initial contact with machine tools was discouraging. A combination of carp metal in my junk box and me not understanding tool options, depth of cut, rpm, feed-rate and the need to snug everything up caused the impression the machine was faulty. Not so. Once I got the hang of it, chatter stopped, tools stayed sharp longer, finish improved, and jobs got done faster. Bit like learner drivers mastering a clutch; who didn't start by kangarooing and smoking the clutch on hill-starts. There is nothing wrong with the car, you have to learn to drive it!

You have to get a feel for what a particular machine can do by using it. As a Super Major is a fairly big hobby beast, it's less restrictive than smaller machines like my WM18. But my WM18 does everything I need of it, and a Super Major is 'better' because it's bigger. The main limitation is the size of the table.

A Super Major would come unstuck if used for continuous production. It's sized for intermittent work allowing the motor to cool down, and it's lack of rigidity would cost too much in operator time and skill. But it should do a good job in a home workshop, better than my milling machine and streets ahead of a milling slide on a lathe.

Two common beginner mistakes are pussy-footing and Gorilla expectations. Nervous light cuts blunt tools very quickly. Tools must cut rather than scrape and rub. And beginners persist with blunt tools long after an experienced machinist would have changed them. Mr Gorilla is even worse; he may be brutal enough to damage the machine by overheating the motor and electronics, stripping gears, bending tools and causing excessive wear and tear. And disappointed because finish and accuracy are poor. The ideal is somewhere in the middle; moderately deep fast cuts within the capability of the machine. Let the machine do the work, and have it working hard rather than soft. I do it by ear: having selected a suitable tool and rpm, I adjust depth of cut and or feed rate until the motor is heard to be working without labouring.

Jason Bellamy's recent MEW series on Milling is an excellent introduction. Jason doesn't do anything in his write-up that isn't well within the capabilities of a well adjusted Super Major.

Dave

Not far off the 0.01mm (4/10ths) I just got on the SX2.7 using my thumb and with the tool 6" up from the table as having the head down low would have no doubt reduced the reading as the column waved about wildly.

Lee, I've sent you a private message. Look for the flashing envelope top left when you're logged in.

Andrew

Hola. Back again.

Sorry about the delay. Machining was deprioritised for a few months.

So had a big play today and guess what?

Well, a picture paints a thousand words:

TL;DR; Bolted machine down (didn't change much), faster speeds (1000RPM), faster feeds (250mm/m).

This is how I left it *after* changing to Arc's "known good" inserts - so much for high hopes:

Thoughts: maybe the setup is janky - too much flex:

Yuck. Change back to the vise, pronto:

Ooooo, faster (and don't let the trailing edge catch it):

Missing test, back edge was trashing the finish, so mill the other way:

The money shot:

Pretty:

Would the improvement gained by changing direction seem to indicate a problem with the tram of your mill? Assuming that the tram is adjustable.

Mike

As per Mike. You would likely find the surface is dished (concave). Perhaps not a lot but imagine a wide piece and cutting with a fly-cutter - it would be noticeable then likely preventing you squaring up th part, if that was what younwere wanting.🙂

I did see one article by Hass who said if the cutter is wide enough, do not run it central down the work. Slight offset gives a better cut. I do this now if the piece to be cut is narrower than the cutter, to allow such a cut.

Also when the trailing edge of the cutter comes along, does it show a arc on the work the opposite way. Meaning the cutter is touching at both ends.

Only from a amateur prospective of course.

Steve.

Yes, the trailing edge makes reversed arcs on the way through.

And yes, it must mean the head is out of tram.

Although when I checked it, it was about 0.02mm over 400mm, which I thought was reasonable.

I've since ordered a new DTI holder to re-check it.

Spot on tram will cut on the trailing pass giving an almost holographic look, best way to check if tram is out is to take a cut from both directions, if the trailing edge only cuts in one direction then you are leaning towards the leading edge.

As Stevie says you can get a smoother cut by offsetting the cutter as it will keep at least one tip engaged all the time this makes for smoother running particularly if you have any gears in the mill's head.

Annoyingly I like the current surface finish, so I'm at pains to tram to 100%.

The main issue for me is that it's trammed the wrong way.

I'd like the best finish to be a result from pushing the cut into the fixed jaw really.

I'd like the best finish to be a result from pushing the cut into the fixed jaw really.

Do you want a pretty-looking finish or a flat surface? JB’s pic is of a flat surface.