Relocating head on round column mill

[Mike Ginn]

Does anyone have any really good method(s) of re-location the mill head when it has been moved on the round column mill. It is quite easy to get it into the approx same position but how can that accuracy be improved. I'm thinking of using accurate dial indicators but I haven't got a clear plan. Any help would be appreciated.

 

[stevehuckss396]

There was someone years back that permanently installed a laser on the mill head. Then a line was drawn on the wall across from the mill a good distance away. When the head was raised or lowered the laser was turned on and the head swiveled so the laser was back on the line. He claimed good accuracy if done with care. I always wondered about it but if the line on the wall is far enough back I dont doubt it can work.

 

[SmithDoor]

I put torque arm on my mill.
Very happy no more head moving when going up and down.
I loaded to download here.

Dave

Does anyone have any really good method(s) of re-location the mill head when it has been moved on the round column mill. It is quite easy to get it into the approx same position but how can that accuracy be improved. I'm thinking of using accurate dial indicators but I haven't got a clear plan. Any help would be appreciated.

 

[SmithDoor]

See download
https://www.homemodelenginemachinis...s-grinders-with-torque-arm-add-to-mill.29461/

 

[goldstar31]

This has been answered a long time ago. I have a round column mill drill and I probably recalled how lasers were used whilst damaged cars were being' pulled out'. I did a City and Guilds as a 'manure'
student.
Long before this, as a 16 year old , my line boss was the Signals Officer in RAF 617 ( The Dambusters) Squadron and they used TWO lights to align the height of the bombing runs. It's in the film!
During the War, the Luftwaffe aligned its targets in the UK by sending out two radio beams and at. the intersection, the bombs were released. until, that is Alexandra Palace 'bent' the beams. It was one bit of British 'cloak and dagger' that went on some years after hostilities ended.

I bought a couple of cheep cheep lasers. One of which is a sort of rotary table and both have lots of ' bubbles', magnets and - as I said-- very cheap.

The other gadget or gadgets comes from Geo Thomas yet again. This time it is in his Workshop Techniques and is or are merely two bits of mild steel round and a packet of cigarette papers. The two bits of metal are halved PRECISEDLY in a similar way that D Bits are fashion Once the Two flat faces hold a slip of paper, one is only a thou out. Great things to set up all sorts of things- not just mill drills.

Maybe someone will be interested?

 

[SmithDoor]

Here is few photos of how fix the rotation.
It simple and accurate

Dave

 

[Mike Ginn]

Guys. Thanks for your ideas. I really liked the laser idea. I have tried it using cheap straight line laser unit with a mag base. I attached it to the pully cover and used a reflective tape 3m distant. With a dial indicator it was easy to relocate to within 1/2 thou. I made me realize that the relocation could in fact be easily achieved using only the indicator. I found the mill head was easily adjusted the last few thou with a rubber mallet. Since I don't need to do this often I will stay with the indicator and not consider the extensive mechanical solutions which look very elegant. Thanks again.

Happy days!

 

[SmithDoor]

The laser uses a spot, so is only good as your eyes.
This why I use a torque arm
It will give a very high accrues and fast
About same as a knee type mill.

Dave

Guys. Thanks for your ideas. I really liked the laser idea. I have tried it using cheap straight line laser unit with a mag base. I attached it to the pully cover and used a reflective tape 3m distant. With a dial indicator it was easy to relocate to within 1/2 thou. I made me realize that the relocation could in fact be easily achieved using only the indicator. I found the mill head was easily adjusted the last few thou with a rubber mallet. Since I don't need to do this often I will stay with the indicator and not consider the extensive mechanical solutions which look very elegant. Thanks again.

Happy days!

 

[Dusty3v0]

"Winky's workshop" on YouTube converted a round column drill press to square. A great idea but impractical on a mill or or milldrill.

 

[SmithDoor]

That lot of work for a keyway.
You can use rake as a keyway which I have done on drill press.

I am surprised he did not address belt slipping.

Dave

"Winky's workshop" on YouTube converted a round column drill press to square. A great idea but impractical on a mill or or milldrill.

 

[packrat]

Fix for the round column mill/drill

 

[peterl95124]

if you don't have far to go, put a dial-test-indicator in the drill chuck
and set it up to indicate the side of your vise, then raise the head and
lower the quill to keep the indicator on the vise, adjust the head
twist so as to keep the indicator from changing. QED.

 

[SmithDoor]

In video it looks like he planing on use the rake as a keyway.
The downside to a keyway is the head still moves.
You need to put a lock on the keyway too.

But will work I did to drill press I not care if table moved a little.

Dave

Fix for the round column mill/drill

 

[Balta]

Does anyone have any really good method(s) of re-location the mill head when it has been moved on the round column mill. It is quite easy to get it into the approx same position but how can that accuracy be improved. I'm thinking of using accurate dial indicators but I haven't got a clear plan. Any help would be appreciated.

Mark Lecuye (That lazy machinist) used the laser with a vertical line method on one of his videos. I have never done it but it occurred to me that if you put a mirror on the other end of the room and make the laser hit the same spot back on the mill head, you would double your accuracy without the trouble of setting up the line, and set up is almost trivial.

 

[goldstar31]

Long time ago but vehicle alignment with lasers was 'turned' with prisms- and onto graticules.

Balta- you are actually repeating the lights on the RAF 617 ( The Dambusters) Squadron Lancaster bombers! It was copied from the stage spotlights - in this case, a London theatre. I guess that it was the Windmill-- with all the saucy nudes.

 

[awake]

The laser uses a spot, so is only good as your eyes.
This why I use a torque arm
It will give a very high accrues and fast
About same as a knee type mill.

Dave

Hmm ... eyes are actually quite good at discerning very small differences. I've forgotten the numbers I've seen, and don't know if they are based on research or intuition ... but let's postulate that the human eye can reliably distinguish a difference of .25mm / 0.010" - I suspect it is much finer than that, but let's go with that. Now shine the laser on a wall that is, say, 3m / 10' away (yes, not an exact conversion - rough ball park is fine for this thought experiment). If the alignment is within .25mm at 3m, what is the error on a head that extends, say, 300mm from the round column? Maximum error would be .025mm, or around .001". That may sound like a lot, but then again, a typical Bridgeport is not considered to be capable of consistently reproducing much finer than that. And if you double the distance the laser travels, or halve the error that the eye can discern, you double the accuracy - quadruple it if you do both.

 

[Cessnadriver]

Check the magazine Home Machinist there was an issue where a gentleman walks through the making of a device (with plans I believe)that will keep the head in alignment once moved on the round column import mills. From what I remember reading it kept very accurate and he also converted a drill to run it up and down. I will dig around and see if I still have that issue. Might be able to look on line as I know the magazine is still sold in book stores.

 

[packrat]

I have a lot of the Home Machinist magazines, I would like to read that issue, if you find what year and month it was in.
I may be able to find the issue if I spent some time looking though all the ones I have...

 

[DanP]

Maybe I'm missing something. Are you talking about the rotation of the head around the column? You are not talking about "sweeping" the table, correct?

 

[SmithDoor]

I was looking something fast to do over and over that would hold accrues of most knee mill (± 0.001). Which would do for any work I ever need to do.

After building and installing the torque arm I test the mill head going up and down using a Angle plate and a dial indecatar .
Then lock the torque and column it was repeat less than (± 0.001).
I was very happy with outcome.

This solve two problems
1) This first is very heavy cuts the head DOES NOT MOVE.
2) I could move head up and down and would hold accrues.

Dave

Hmm ... eyes are actually quite good at discerning very small differences. I've forgotten the numbers I've seen, and don't know if they are based on research or intuition ... but let's postulate that the human eye can reliably distinguish a difference of .25mm / 0.010" - I suspect it is much finer than that, but let's go with that. Now shine the laser on a wall that is, say, 3m / 10' away (yes, not an exact conversion - rough ball park is fine for this thought experiment). If the alignment is within .25mm at 3m, what is the error on a head that extends, say, 300mm from the round column? Maximum error would be .025mm, or around .001". That may sound like a lot, but then again, a typical Bridgeport is not considered to be capable of consistently reproducing much finer than that. And if you double the distance the laser travels, or halve the error that the eye can discern, you double the accuracy - quadruple it if you do both.