Gorton 2-28 milling machine

"Lloyd E. Sponenburgh" fired this volley in news:XnsA1A674010C614lloydspmindspringcom@216.168.3.70:

Sharpe... I know the diff, just can't type. LS

Filed for future reference. Thanks.

Larry Jaques fired this volley in news: snipped-for-privacy@4ax.com:

???

I generally program a ball end mill to hemstitch the angle onto the workholding fixture using X Z or Y Z stepover.

Takes a while but comes out dead nuts.

You taught me something new, so I saved it, Lloyd.

Yep! I did get it back-asswards, but I thank you for your understanding.

I put my money where my mouth was when I made my purchases. I've purchased two BP's, both new. What I really wanted was a Gorton---but the money wasn't there.

I fully agree on the flexibility of the BP machine--that (and its relatively low price) is what made it so popular. It certainly isn't known for it's rigidity, but it is one of the handiest of all drop spindle mills to operate. With care, some very good work can be accomplished.

I did a lot of tooling work in my productive years. A great deal of it was for Litton Guidance and Control, building tooling for the guidance systems used in military aircraft. I served them for 16 years. All of it was accomplished with a BP mill, without benefit of a DRO. In skilled hands, they are quite capable----but they are not, nor will they ever be, the equal of machines that outweigh them by 1,000 pounds. That's been my point right along. You can't get rigidity without mass---and BP has a bare minimum.

Harold

A great deal depends on the shop in which a machine is used. Some may dedicate given machines to altering head, ram and turret positions. In my shop, there was but one machine at any one time---it served all purposes.

I've altered all of these setting time and again, and continue to do so even in retirement. They allow dealing with pieces that otherwise wouldn't be possible.

Make no mistake---the features of a BP mill are exceedingly valuable---that's the reason they've been so damned successful. It certainly isn't because of their high quality. In fact, they aren't even scraped. They are a very nice machine for the money, but they are not of high quality. Never have been.

Not scraped, you say?

Please---I'm not open to discussion on this particular subject. Flaking, which has been provided for aesthetics and oil control, *is not scraping*. The only portion of a BP that is scraped is the knuckle on which the head mounts. All other way surfaces are ground.

Look closely. They are ground, so please don't argue. (Not aimed at you, Gunner. I think you know it, too!)

Harold

Indeed. I fix em when they break.

Gunner

That's dandy for production work, but for those of us doing a one or two off part for our own projects we usually aren't doing CNC and we also can't afford to be making dedicated fixtures we'll never use again.

news:516ff7c6$0

Uhm...tooling fixtures usually are one-off, same as any other one-off job.

You didn't get the memo ?

I can't afford to indicate each part if there is production involved.

Apparently not, I still use standard vises, angle plates, clamping components, etc for one off jobs, just like every other home shop machinist does. Dedicated fixtures are for production or at the very least commercial work where there are funds to cover the cost of those fixtures. Those of us doing personal projects don't like to waste perfectly good material on a one off fixture.

Indeed, production, for-profit, not home shop work. I made fixture plates for a project where I was making around a dozen parts, and I still didn't like using that nice hunk of 3/4" 6061 plate off my meager stock rack.

"PrecisionmachinisT" fired this volley in news:Zs6dnVe8RsCbGezMnZ2dnUVZ snipped-for-privacy@scnresearch.com:

Yeah... I make fixtures for one-off jobs almost every day; not always for locating the work, but often just because it's the only way to hold the work and machine it all-over.

LLoyd

"Pete C." fired this volley in news:517189f8$0 $11243$ snipped-for-privacy@ngroups.net:

Fixtures can be as simple as a waste plate with a few bolts through the workpiece. If it changes for every new workpiece layout, it is - in a sense - a "dedicated fixture".

Lloyd

jon_banquer fired this volley in news:01e13f3b- snipped-for-privacy@pd6g2000pbc.googlegroups.com:

I don't have enough room around my machine for a vise crane, and I'm old enough that I really don't like hoisting a 120lb milling vise on and off the table, so I don't do a lot of soft-jaw holding. It works, though -- especially for thin parts that have to be machined all over the top surface.

For those of you who don't understand what this is all about; you mill a negative of some of the perimeter of the part in the jaws so the part fits snugly into the profile. You mill that profile shallower than the material's thickness such that you can do your machining on what projects above the jaws.

When it gets really thin or clumsy to hold, you can even ditch the 'above the jaws' strategy, and just machine the jaws along with the workpiece.

But I don't like to move my vise any more than absolutely necessary, and it's not _usually_ on my mill, since I 'fixture' almost everything.

LLoyd

And if I'm not mistaken, you have cnc...which is why I mentioned using cnc and a ball end mill to produce an angled surface.

As to why Pete seemingly got his panties into a wad, I really don't know--personally I think he's simply just looking for an arguement, and probably needs to see about getting on medications.

--because if he's truly trying to inform me about what "home shops do to get the job done" well, he's barking up the wrong tree....although most of my equipment today is indeed cnc, like many others, I started moonlighting out in my garage, about 35 years ago....my first lathe was an Atlas TH54 and shortly afterwards, I bought a Taiwanese R8 knee mill that was labled as a "Huskey"...

a ball end mill to produce an angled surface.

know--personally I think he's simply just looking for an arguement, and probably needs to see about getting on medications.

the job done" well, he's barking up the wrong tree....although most of my equipment today is indeed cnc, like many others, I started moonlighting out in my garage, about 35 years ago....my first lathe was an Atlas TH54 and shortly afterwards, I bought a Taiwanese R8 knee mill that was labled as a "Huskey"...

You perhaps missed the personal projects part of what I said. While you may run a commercial operation from your home shop most of us don't. As for CNC, I have several CNC machines and I do on occasion make fixtures when I will use them more than once, otherwise I'd rather spend the extra 15 minutes clamping and indicating than waste $20 in material on a one time fixture. Perhaps you are rich, I am not and while I'm not poor I am frugal and try not to spend where there is little benefit.

My initial comment was directed only towards Lloyd, just in case the option of using cnc to mill a slanted surface for use as a baseplate instead of having to set up a sine plate had never occurred to him.

He has cnc and pretty sure he does some production work.

It's not that I'm rich, it's that when I quote a job, I factor in the costs of any cutters, tooling plates etc. that will be needed.

Oftentimes the workholding fixtures are then scrapped, I don't worry never finding another use for it sometime down the road..it's already been charged to the customer...

If someone doesn't have cnc then obviously for them it's not an option.

--further, if someone wants to do it some other way, it's perfectly fine with me...one reason is as good as any another.

"PrecisionmachinisT" fired this volley in news:rKSdnaclGqbgd-zMnZ2dnUVZ snipped-for-privacy@scnresearch.com:

PT, I've done that before; I have two reasons not to normally do it:

1) My CAM package makes it very clunky to set up an angled side profile like that, because it is primarily a 2.5D package, and 2) I'm not really happy with the time vs. surface finish tradeoffs of that method. It takes a really long time to make the tiny stepovers and depth increments to produce a reasonable finish.

But yes. It works OK. There are times when it's just not practical to move a piece around on the angle plate, and then so-called "side- profiling" is the way to go.

"PrecisionmachinisT" fired this volley in news:U5mdnREn5Ob7ZezMnZ2dnUVZ snipped-for-privacy@scnresearch.com:

Ummm.... sorry.... I COMPLETELY missed that! I read your suggestion to mean milling the finished surface on the part, not the baseplate! (slaps head!)

Please ignore my prior post on this, and accept this one as the real response.

While it's difficult to get my CAM to set up for precise start and end points on a sloped 'side', it's easy as heck to set up a precise angle, so long as you don't care about the start/end points within a few thou.

So, yes... that would be faster than setting up a sine plate, most especially for setups I'd be using more than once.

The surface finish doesn't matter much, so long as the overall angle is held monotonic over the whole surface.

LLoyd