Machining metal parts

[jthibodeau89]

Round columns are fine if you you respect their limitations and properly plan your operations. Resetting column Z or heavy x cuts are the main issue.

 

[dstig1]

Where the round column mill-drills really fall down is if you are using end mills and drill bits interchangeably for different operations. The drill chuck sticks out a lot more than a collet and so there is almost no way to position the head at a height where you can do both without having to raise or lower the head due to the limit of quill travel. And for small home machine shop work, that is how you are going to operate. That is where either a square column or a knee mill saves you a ton of time and grief. I had a Rong-Fu round column for a few years and hated it for that main reason. Plus it wasn't solid enough to take any cut at all without chatter. But it was better than nothing. Now I have a Bridgeport that I refurbed this past summer and it is soooo much nicer to use it is like night and day.

 

[jthibodeau89]

When a part requires a change between milling and drilling, you can change r8 collet to the correct size for the drill bit.

 

[Jims1025R]

Round column machines are fine, within their limitation - you loose the position relative to the table if you raise or lower the head. There are tricks for this, but fussy. Round column mills are great if you need to mill or drill the end of something lone, as it can be clamped off the edge of the table, and the head swung around.

That said, I had one of each, and preferred the dovetail column mill for many reasons. You just need to understand how you'll use the mill, and which limitations may affect what you want to do with it.

If you choose a round column mill, one of these will be your friend:

Co-Axial Centering Indicators

From co-axial indicators to 3D centro position indicators, we have the setup tools that help your machinists to find the center point of a round workpiece whether operating on a manual or CNC machines, mills or lathes. Shop today and save big.

www.shars.com

 

[metalbender]

Yup, that co ax indicator is a true timesaver, with all mills.

 

[jwmorris]

Round column mills are great if you need to mill or drill the end of something lone, as it can be clamped off the edge of the table, and the head swung around.

You can do the same with a knee mill. There is a T slot across the front of the bed. I will say, about the only time I use it is when I am milling the slot for the extractor after I weld the lug to contender barrels.

 

[etpm]

You can do the same with a knee mill. There is a T slot across the front of the bed. I will say, about the only time I use it is when I am milling the slot for the extractor after I weld the lug to contender barrels.

The first shop I worked in had a repeat job that required drilling and tapping holes on the ends of 4 and 5 foot long stainless shafts. My boss had a concrete coring company cut a 5 inch diameter hole in the shop floor. We clamped the shafts in a fixture that held the shafts off of the front of the table. The ram was rotated and extended so the holes could be drilled and tapped. The shafts were lowered into the hole cut in the floor so that the end work could be done. As a learning project I came in one night and made a cover that resembled a manho!e cover for the hole because stuff kept falling in.
Eric.

 

[dstig1]

When a part requires a change between milling and drilling, you can change r8 collet to the correct size for the drill bit.

Collets are fairly limited in number of sizes and not many drill bits are going to successfully fit in them, but when you can, sure it can help. And most people who own a round column mill/drill are not going to have a collet set in 1/64's increments either... 1/8,1/4, 3/8, 1/2...are what you will probably have.

 

[TMGT]

Collets are fairly limited in number of sizes and not many drill bits are going to successfully fit in them, but when you can, sure it can help. And most people who own a round column mill/drill are not going to have a collet set in 1/64's increments either... 1/8,1/4, 3/8, 1/2...are what you will probably have.

You can use an ER collet holder with an R8 shank, will give you a wider range with fewer collets then using R8 collets.

Sent from my SM-G715U1 using TractorByNet mobile app

 

[LD1]

You can use an ER collet holder with an R8 shank, will give you a wider range with fewer collets then using R8 collets.

Sent from my SM-G715U1 using TractorByNet mobile app

Now you are gonna go an confuse new people.

There are literally dozens of different tool holder types.

R8 with drawbar seems the most common on the Bridgeport type Mills that a home hobbiest would be interested in.

Mine has quick switch tooling with er style collets.

Just going to an ER tool holder instead of directly in the r8 collet may be enough length that you can swap from Mill tooling back to a drill chuck without having to constantly raise and lower the table