Enlarging holes

Looking to buy a machine to enlarge holes in thick steel would a mill/drilling machine be the best choice using a boring bar set up?? Looking for a source for bushings and pins too. Bob

I don't know the specifics of your work, but if it can be chucked in a lathe, that would be your best bet. If not - a fly cutter on a milling machine.

there is a lot of ways to do what you are wanting to do,if you have a lot to do of the same type work look at ironworks, they can do the jobs fast.

It's hard to say without more information. Basically, what machine you need will depend more on what exactly your doing. That said, a mill with a boring head will more than likely fit the bill in all but the most odd ball setups.

Need more info. How big of holes and how accurate do they have to be? How thick of steel? You might not need a fancy machine at all. A circle cutting attachment, a clean proper size tip and a cutting torch will make a pretty nice holes.

A drill press should be your last option, so go from there.

A drill press should be your last option, so go from there.

Steel from 1 1/2 thick and up to 2 1/2 diameter and need to be accurate for cyl pins

Portable boring jigs are easy to make and pretty flexible. Depending on the size of your piece it can be faster too, as long as you don't mine tack welds on the faces of what you're working on.

Are we working on a back hoe or loader boom? Drills are out and so are reamers unless you have some huge machine tools available with the right tooling. More info would again be nice but if this is what you are indeed workng on the best/easiest way is far from cheap to buy, a portable pin bore welder/boring machine. Lots of guys doing it on a portable basis, at least around here. We bought our own about ten years ago, as I remember it was $12K by the time we were done. The guys who do it portable are in the neighborhood of $200 per hour. An alternative is to enlarge the bores with the portable bar and make bushings on a lathe, saves you a lot on the machine purchase and this is how we started, didn't last long once we priced out the materials and shop time on the lathe so we purchased the bore welder attachment. You can also save by welding the bores manualy but it's not the hot set up if you have many to do. I am not trying to turn your project into gold but as has been stated here before there just plain is not a cheap way to do it right. You must either pay the freight, or half arse it. The average guy would be best served by hiring it done on site, we have lots of machines to take care of.

Our machine is a Climax, there are others.
Climax

I have parts that are off the machine and small enough to be clamped in a machine, what kind of machine and bit to use??

Depends on how many holes. I"ve cut pretty good "one off" hole just using a carbide burr, template and file. Wouldn"t want to do many that way.

We do those hole sizes in those thicknesses in my mold building shop installing the guide pins and bushings. We use a mill. Before the CNC just used a standard Bridgeport mill. Most of the time drilling thru two or three thick plates at the same time. We drill the hole as large as we can or needed and then use a boring head and boring bare to suit the need. We also have to cut pockets for cavity inserts that need to go thru thick plates using the boring head.

All mill work below on the plates. My mills are my right hands when it comes to cutting large holes.

Using a mill, you can also make some nice holes just using a nice end mill. If you want the proper way to do it, I'd have to suggest a bushing, or ID grinding the hole after its been to the mill, and grind stock was left in the hole.