Round Milling Machine Crazy Question (maybe)

[Tomc938]

Ok, so I admit I am a newbie, and my idea might be nuts, but I thought I would ask before I give it a whirl...

I have a King RF-30 clone. As I have heard, the Rond column is a drag when it comes to moving the head up and down as the whole thing pivots.

I am wondering if it would be possible to make a Tru-Line-8 type of alignment set up (

), but rather than clamping a large clamp to the bottom of the column, to make a fitting similar to the way the device clamps to the head, but on the base, UNDER the column. It seems that you would need to extend the arm until it is higher than where the column meets the base so you can have the right amount of travel.

This seems to me to be a much simpler way of firming up the head. I realize that this would mean that you could not use the attachment to keep things lined up if you want to rotate the head, but I'm not thinking would be rotating the head that often. Not an option for most milling machines in the first place.

If this description makes sense, and with your experience you can see a reason, or possible reason, why this would not work I would appreciate your thoughts.

If I do go ahead with the project, I would prototype with my 3D printer and make sure everything lines up before going into metal.

Thanks!

 

[historicalarms]

Quite frankly, after using a round column for more than 20 yrs , I don't really notice much of an inconvenience to round vs dovetail for vertical movement...no doubt dovetail is quicker and a dovetail quality machine is typically capable of much tighter tolerances than a round column....precisely the reason I don't sweat it much. Over the years, if I did have to adjust head height during mid operation, it was relatively easy to re-align to within the expectations I have of my mill-drill.

Edited to add....Also I have found the fact that i can swivel the head one way or the other quickly more advantageous than a dovetail column. Dovetail column head swivel ( at least the ones I have looked at) are limited by a slot cut in a collar) are limited in movement...mill drills aren't, 360 deg if required ( and I have , in one instance used that to my advantage).
More than a few times , when a long cut was required and with limited table travel, I have used the head swivel to gain up to 5" in cut length without having to re-mounting the work piece. If you know your going to need a slightly longer cut than bed travel allows....initialy mount your work as close to the inside of your bed that you can and still have column interference with movement, with head centered to mill column, make the cut your bed travel will allow...now swivel your head the direction needed to one side or the other so the cutter looks like it will still engage work piece. Now back your table up as much as needed, move in to engage cutter again and make a few more inches cut.

 

[CalgaryPT]

Quite frankly, after using a round column for more than 20 yrs , I don't really notice much of an inconvenience to round vs dovetail for vertical movement...no doubt dovetail is quicker and a dovetail quality machine is typically capable of much tighter tolerances than a round column....precisely the reason I don't sweat it much. Over the years, if I did have to adjust head height during mid operation, it was relatively easy to re-align to within the expectations I have of my mill-drill.

Edited to add....Also I have found the fact that i can swivel the head one way or the other quickly more advantageous than a dovetail column. Dovetail column head swivel ( at least the ones I have looked at) are limited by a slot cut in a collar) are limited in movement...mill drills aren't, 360 deg if required ( and I have , in one instance used that to my advantage).
More than a few times , when a long cut was required and with limited table travel, I have used the head swivel to gain up to 5" in cut length without having to re-mounting the work piece. If you know your going to need a slightly longer cut than bed travel allows....initialy mount your work as close to the inside of your bed that you can and still have column interference with movement, with head centered to mill column, make the cut your bed travel will allow...now swivel your head the direction needed to one side or the other so the cutter looks like it will still engage work piece. Now back your table up as much as needed, move in to engage cutter again and make a few more inches cut.

That's interesting feedback from a longtime user. Also a good example of how something that appears to be a big disadvantage can also be beneficial depending on your needs and the degree of precision required. Thanks for posting.

 

[historicalarms]

Just a word of warning tho that I should have included in 1st post.

When you do swivel the head out from over the table & it's base, make sure that that base is securely attached to your bench or stand and that stand is sufficiently wide enough in stance to accommodate the shift in overhang center of gravity. The warehouse foreman where I bought mine was very emphatic that the #1 reason for mill-drill damage was from unbalanced roll overs.

The scenario that arose for me to use the 180 deg swivel was for the farmer that does our land. during harvest a few years ago he had a big housing on his combine strip out a 1/2" bolt hole & the nearest $7000 replacement was still at the factory and 2-3 weeks delivery away....not a good situation in excellent harvest weather.
That housing barely fit under the quill sitting on the floor so the swivel was mandatory to do the job. There wasn't room nor enough metal on the attaching piece to just re-drill & tap a larger bolt so a much larger bore out and a big enough shim/plate welded in place & then drilled & tapped for the same 1/2" sized bolt. The biggest mill cutter I have is 1 1/4 " so thats what we cut out of the housing and i cut an appropriate 1/2" thick bushing to be welded in place. The size of the bushing allowed it to be welded without interfering in the hole site for the bolt.
Entire operation took us about 6 hrs from removing from combine to back on and harvesting....way-way better than the 3 weeks offered by the manufacturer. My payment for the job was a hand shake & a sincere thank you....and the fact that quite likely our own crop would get harvested before the snow flew...which it did 4 days after ours was harvested.

 

[Tomc938]

Quite frankly, after using a round column for more than 20 yrs , I don't really notice much of an inconvenience to round vs dovetail for vertical movement...no doubt dovetail is quicker and a dovetail quality machine is typically capable of much tighter tolerances than a round column....precisely the reason I don't sweat it much. Over the years, if I did have to adjust head height during mid operation, it was relatively easy to re-align to within the expectations I have of my mill-drill.

Edited to add....Also I have found the fact that i can swivel the head one way or the other quickly more advantageous than a dovetail column. Dovetail column head swivel ( at least the ones I have looked at) are limited by a slot cut in a collar) are limited in movement...mill drills aren't, 360 deg if required ( and I have , in one instance used that to my advantage).
More than a few times , when a long cut was required and with limited table travel, I have used the head swivel to gain up to 5" in cut length without having to re-mounting the work piece. If you know your going to need a slightly longer cut than bed travel allows....initialy mount your work as close to the inside of your bed that you can and still have column interference with movement, with head centered to mill column, make the cut your bed travel will allow...now swivel your head the direction needed to one side or the other so the cutter looks like it will still engage work piece. Now back your table up as much as needed, move in to engage cutter again and make a few more inches cut.

Thanks! Your voice of experience is much appreciated.

Just a word of warning tho that I should have included in 1st post.

When you do swivel the head out from over the table & it's base, make sure that that base is securely attached to your bench or stand and that stand is sufficiently wide enough in stance to accommodate the shift in overhang center of gravity. The warehouse foreman where I bought mine was very emphatic that the #1 reason for mill-drill damage was from unbalanced roll overs.

The scenario that arose for me to use the 180 deg swivel was for the farmer that does our land. during harvest a few years ago he had a big housing on his combine strip out a 1/2" bolt hole & the nearest $7000 replacement was still at the factory and 2-3 weeks delivery away....not a good situation in excellent harvest weather.
That housing barely fit under the quill sitting on the floor so the swivel was mandatory to do the job. There wasn't room nor enough metal on the attaching piece to just re-drill & tap a larger bolt so a much larger bore out and a big enough shim/plate welded in place & then drilled & tapped for the same 1/2" sized bolt. The biggest mill cutter I have is 1 1/4 " so thats what we cut out of the housing and i cut an appropriate 1/2" thick bushing to be welded in place. The size of the bushing allowed it to be welded without interfering in the hole site for the bolt.
Entire operation took us about 6 hrs from removing from combine to back on and harvesting....way-way better than the 3 weeks offered by the manufacturer. My payment for the job was a hand shake & a sincere thank you....and the fact that quite likely our own crop would get harvested before the snow flew...which it did 4 days after ours was harvested.

Very good point! As my machine was just recently lifted onto the stand, it is bolted to the stand, but will bolt the stand to the floor.