quick question re. round collumn mills

[Matt McColley]

Why is it that round collumn mills don't appear to be as popular to convert to CNC?

This mill looks VERY robust.... and with the free shipping and included angle lock vise appears to be the same cost as their X3 clone?

https://www.grizzly.com/products/2-HP-Mill-Drill/G1006

Do you have to lock the head to get the needed rigidity on this style mill?

I have no personal experience to draw on with any other kind of mill than a manual feed knee mill.

[Bobbyr70]

I have a round column mill and I like the little critter for what it is.
It is tougher than the x3 because it is larger (I used to own one). And that means you can do larger work take heavier cuts etc.That is it's Primary advantage.
Round Column means every time you need more head room for a different tool say you want to use a drill chuck after you just milled out a profile with a 1/2" tool . You have to re-zero the machine or pick up an edge for reference. With the square column machine you can just raise and swap tools and you don't loose your place on the x/y.
It's a pain to set up for multiple cuts and have to reset everything. It's not the end of the world but it does consume more time.

[philbur]

Also you have to CNC the quill for the Z-axis which is not good for stroke length and rigidity. Also if you get a mill with a sloppy quill you are stuffed.

Phil

Why is it that round collumn mills don't appear to be as popular to convert to CNC?

This mill looks VERY robust.... and with the free shipping and included angle lock vise appears to be the same cost as their X3 clone?

https://www.grizzly.com/products/2-HP-Mill-Drill/G1006

Do you have to lock the head to get the needed rigidity on this style mill?

I have no personal experience to draw on with any other kind of mill than a manual feed knee mill.

[Torsten]

The description from BOBBYR70 is pretty much right on.
Yes you have to lock the Head on this Machine to do any kind of milling operation.
And then you have about a little over 5 inch of travel on the quill so you need to plan the operations concerning toollength to stay within carefully.
To get to a different range in Z you have to loosen the Head and reposition which will result in you having to pick up position again.
Not that big of a deal really once you get good at it will only take a few minutes.
Overall the ranges on this Machine will give you greater capabilities at the cost of slight inconvenience once in a while.
Good Luck

[Bubba]

Kind of late to jump in, but I have been running my round column RF35 since about 2002. I have been well pleased with it and can say it does what I ask of it.
Yes, you have to pre-plan what and how you are going to do things to hopefully eliminate the head movement problem and in most instances, I have been able to do it. Some of it involves creative tools (for example use of stub drill in a collet rather than a screw drill in the drill chuck). Yes, I might have to take lighter cuts because of the rigidity, but I spent a lot less for it than a square column mill (and I don't remember even seeing them when I got mine).

Bottom line, would I do the round column again knowing what I know now? Tough question because there have been a few operations that I did BECAUSE I could rotate the head. I think it would boil down to the time of day, what was on sale, how much money I had and because I am hard headed, whether or not somebody told me that day that conversion of a round column was stupid and a waste of time! That would be enough to make me do it just to prove them wrong:})

It all boils down to personal choice (Ford, Chev, or Dodge)?

[Bobbyr70]

one of the things I did to my mill to make the z axis work was to fab an imput right into the hand/miro adjustment hole in the front of the head. only issue is lots of back lash. for some reason it has not been a big problem so far. I just make sure the safe Z is high enough to back it up off the material and keep the quill lock squeezed a bit. I get what I pay for sometimes.

[philbur]

My experience with trying to run say an half inch end mill with the quill extended towards maximum is not good to say the least.

A CNCed round column is very restrictive. If you already own a manual round column is one thing, but to buy one in order to CNC it is quite another.

Phil

[pete from TN]

I just recently acquired a used round column milling machine for a great price. I used it for about three months. I sold the machine because I had a fella that really wanted it and I was able to get into a much larger knee mill. The reality is that having used it pretty heavily for that couple months I have a newfound respect for these mills. Mine was an rf31 model I think and that machine could cut some metal pretty nice. The belt drive is also very quiet. I also have a Lathemaster larger milling machine that I am converting to cnc right now. My take on the round mills is this. If you are not gonna spend a lot of money and get into a larger type of square column milling machine like the lathemaster or the Industrial hobbies or even the grizzly or jet equivalents then I would rather have the round column than one of the X series of machines. The reason being that the round mills are pretty heavy duty and have some decent table travels. Yes the head position upon raising and lowering the head is a bit of a pain but if you were to get into the tormach tooling which is much shorter than the R-8 and supposedly more rigid you would not have to move the head as much. The machine weighs around 750 lbs and the table and saddle are pretty rigid. The fact is that it really comes down to what you intend to do with the machine. To me the machining envelope is real important. You will realize that the first time you have to machine a part and you have to spend a lot of time moving things around just to get the part where you can make the cut you need. My lathemaster mill has some decent travel for a benchtop machine and I still find myself wishing it was larger. When I bought this mill I had never even heard of Industrial hobbies and this mill was the best my money could buy. I think about the engraving possibilities of the cnc and if you wanted to make a sign let's say. On the smaller machines you will quickly run out of room to make the sign on and your size will be dictated by the limits of your travels. Another nice feature of the round column machines that one might not think about is that since you can rotate the millhead on the spindle you can actually machine a nice mount for a router or other high speed spindle off the main spindle and not have the thing way out on the right or left of the head out of the main area of the tables travel. With the round head you can swing the head over and have the router spindle directly over the center of the table..... Anyways, having owned one for a little while I really do not see the bad press they seem to get because they are a decent little mill. JMHO.....peace

[mark c]

OK, I'll chime in here too. I have a RF-31 and I love it. Yes you do need to plan ahead in your setups, but for the money it's a heck of a machine and very important for me, the RPM is higher, 3000 to 1970 or so. I had planned to CNC it, but decided not to.

HTH
Mark

[ckirchen]

I CNC'd a round column mill a few years back and I will echo that it is a decent machine.

It had it's quirks, but where I really came to dislike the round column was when I was reaming larger holes. First you spot (short tool), then you drill (little bit longer), then you come in with the reamer (extends well into the work piece). So you have to raise the head and touch off X/Y again. But wait, the reamer is long and the probe is not. Oh joy. I quickly came up with clever ways to find X/Y again, but it became tiresome fast.

Now I have machining centers and it is so nice to be able to kiss the work piece with the spot drill and then bring the head all the way up for the reamer.

Like I said, a round column mill is a decent machine, but reaming large holes was something I did a lot of back then, so I outgrew the machine fast.

I will also second the comment about the sloppy quill. My machine came with one, so I ran it with the quill lock on slightly, but surface finish suffered and there was nothing I could do about it.

Chris Kirchen