Climb milling

[ukracer]

I have posted before about having an issue when I have a choice of two things. In this case direction.
Strangely if the choice is from 4 things I have less problem remembering.

Anyway I struggle like hell to remembering which way climb milling goes.

Does anyone have a good way to remember it (apart from a decent brain)

As an add in I am assuming that the first time I cut a slot I can not get away from.climb milling. (One of the sides) irrespective of which direction I travel.

 

[Turbo]

The cutter is effectively trying to climb out of the hole it is cutting, hence the term 'climb milling'. In correct use the cutter should be trying to pull itself deeper into the cut.

Unless you have a very rigid setup it's probably better to cut a slot with a narrower cutter than the finished slot width. From experience trying to cut a 6mm keyway with a 6mm cutter usually results in the cutter pulling to one side.

 

[Agroshield]

In correct use the cutter should be trying to pull itself deeper into the cut.

Please could you review that comment as it seems to say the opposite to the way most other people would describe the situation.

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Think of a tablesaw. If you push the piece of wood into the blade from the front and stop pushing, the cutting stops and the piece of wood just sits there. That is the analogue of conventional cutting.

If you push the wood into the blade from the back, the blade catches hold of it and launches it across the room. That is the analogue of climb cutting.

You can see the same thing with an angle grinder on a flat sheet of metal. If you cut going away from your body and do not grip the grinder hard, it will pull from your hands and drive itself along the workpiece. That is climb cutting.

If you cut towards your body and do not grip hard, the grinder will just sit where it falls.

Hence, in milling, look at it as if the metal was not clamped down. If feeding the metal into the cutter would mean the cutter pushes the metal away from itself, you are conventional milling. If feeding the metal into the cutter would mean the cutter sucks the metal into itself, you are climb milling.

Another way to look at it is if you are going clockwise around the outside of something, you are climb milling. Think of a Mercedes CL. CL ockwise cutter rotation CL ockwise feed CL imb cutting.

 

[minimutly]

^^ Indeed. I would add that climb milling works best with nice new, rigid machines that have zero slop, and even then only for light finish cuts. If there is 30 thou backlash in the table it's quite likely that the cutter will pull itself into the work by that much. Cutting slots should be ok, but there is an element of unequal force - get shorter cutters and make sure they are sharp.

 

[Screwdriver]

Imagine you are using a Dremel with say a little drum sanding bit.

When the tool touches the surface, it wants to run along the workpiece since the sandpaper grips and tries to "drive the tool" in the direction of the "cut".

You always want to try and pull the tool in the opposite direction so that the motion is slowed down by the bit trying to drive the other way.

If you try to push the tool in the direction it wants to go, it will run away because there is nothing holding it back. That's a climb cut.

Another example might be a car sitting stationary on a hill with its tyres spinning. Gravity holds it in place and the spinning wheels impart just enough "drive" to keep it stationary against the slope. This is a snapshot of what you want to happen when cutting, the cutting teeth/sandpaper/tyre rubber is moving relative to the workpiece.

If you then push the car down the hill it will only move as much as you push because it is in equilibrium with the drive from the tyres balancing the pull of gravity. This is the normal direction. You have complete control.

Push the vehicle up the hill and it might "run away" in fact the spinning tyres might suddenly gain full traction and take off up the hill. That is climb milling.

 

[Beanwood]

It’s probably not helpful but I struggle to remember which way to feed my router table- until I put an arrow on the worktop indicating feed direction. Eventually it became second nature.

 

[ukracer]

It’s probably not helpful but I struggle to remember which way to feed my router table- until I put an arrow on the worktop indicating feed direction. Eventually it became second nature.

I am.going to print a little diagram. But this is the problem. I seem to have a problem in my brain where I struggle with 50/50 choice.
We have a parcel force guy who is brilliant. His name is Phil or Nigel and I can never remember which.
I know it's one of the two but not which one.

 

[ukracer]

^^ Indeed. I would add that climb milling works best with nice new, rigid machines that have zero slop, and even then only for light finish cuts. If there is 30 thou backlash in the table it's quite likely that the cutter will pull itself into the work by that much. Cutting slots should be ok, but there is an element of unequal force - get shorter cutters and make sure they are sharp.

I strangely know what climb milling is ( I even find I get a better finish from it)
But when the mill is in front of me my brain can't process which way to go.

I guess it sounds very weird to anybody with a normal brain function.

Another anomaly is being unable to remember words in a song. BUT I can remember titles of records from the 60's to the early 90s when I hear them. In many cases I can also add the singer.
It's rather ironic as I struggled to get to sleep last night. My brain was reliving my youth and would not shut down.

It started by my remembering a mate of mine who passed away a few years ago but he was a Genius. Made Air rifles in his shed on a knackered Myford. But he was the first to mention climb milling to me.
Anyway my brain started wandering and started to expand from a previous issue I have had where I started wondering what a previous girlfriend was doing now. Having never even thought about her for 50 years.

Last night this Expanded into me going through a list of girls I had dated, every one would be before 1979. Every time I tried to stop remembering I came back to thinking about climb milling.

It all sounds stupid but it's happening a lot more just lately and has coincided with me trying to come to terms with de cluttering , so if anything happens to me my son does not have to get a roll on ,roll off ,skip and bin the lot.

Sorry for digressing but I had to get it off my chest and for obvious reasons my wife is not the best person to run it past.

Climb milling has a lot to answer for.

 

[Beanwood]

I am.going to print a little diagram. But this is the problem. I seem to have a problem in my brain where I struggle with 50/50 choice.
We have a parcel force guy who is brilliant. His name is Phil or Nigel and I can never remember which.
I know it's one of the two but not which one.

Permanent marker on the table top is what I used (Sacrilege? I don't know - but this is here to be used and when I'm gone - it'll be in a skip or making someone else some money from a garage clearance)

 

[Guineafowl]

Just like light refracting through a prism - ‘blue bends best’. If you also try to remember ‘red bends least’ you’ll muddle the two in your mind*. Focus on the one thing.

Forget climb milling, learn only how to conventional mill - go anticlockwise round the part. (COnventional COunterclockwise?).

^^^ Always start from there, then you can work out (DON’T memorise this!) that an inside feature is the opposite, and for climbing opposite again.

* Our humourous physics teacher:
”Blue bends best.”
We all nodded.
”Although, you could say ‘red bends readily’, but that would be wrong”
*loud classroom groans and tutting*

 

[Agroshield]

It’s probably not helpful but I struggle to remember which way to feed my router table- until I put an arrow on the worktop indicating feed direction.

A router table is different to a mill in that the stuff being cut is generally always on the same side of the cutter due to the fence.

The arrow would be incorrect if you were hollowing out the inside of something.

On a mill, the cutter can be to the left or right or in front or behind the stuff being cut, so a single arrow will be correct 25% of the time, incorrect 25% of the time and irrelevant 50% of the time.

 

[ukracer]

A router table is different to a mill in that the stuff being cut is generally always on the same side of the cutter due to the fence.

The arrow would be incorrect if you were hollowing out the inside of something.

On a mill, the cutter can be to the left or right or in front or behind the stuff being cut, so a single arrow will be correct 25% of the time, incorrect 25% of the time and irrelevant 50% of the time.

Oh damn. I still don't understand it all then.

 

[Seadog]

You can still feed it from the wrong direction on a router table. If you're particularly stupid

 

[Beanwood]

You can still feed it from the wrong direction on a router table. If you're particularly stupid

Hence my arrow making me ‘less’ stupid

 

[Beanwood]

A router table is different to a mill in that the stuff being cut is generally always on the same side of the cutter due to the fence.

The arrow would be incorrect if you were hollowing out the inside of something.

On a mill, the cutter can be to the left or right or in front or behind the stuff being cut, so a single arrow will be correct 25% of the time, incorrect 25% of the time and irrelevant 50% of the time.

That’s what I meant when I said it may not be helpful. Even on a router table doing plunge cutting it would be wrong.
But making marks I thought may help OP?

 

[Chippie]

The way I remember, on a vertical milling machine, with conventional rotation of the cutter, feed the work piece into the cutter…..if the workpiece is fed from the back of the machine to the front, that’s climb milling…not good!

 

[m_c]

A picture is worth a thousand words-

Best way I find to think about it, is with climb milling, the cutter will want to 'climb' out of the cut.

Practically, you only want to be climb milling on something with next to no backlash, otherwise it's a recipe for damaged cutters and ruined workpieces, which can lead to even more damage.
I only ever climb mill on the CNC mill, as I know it's only got under 0.02mm of backlash, which for any cutter I'm ever likely to use on it, is negligible.

 

[ukracer]

A picture is worth a thousand words-

View attachment 409430
Best way I find to think about it, is with climb milling, the cutter will want to 'climb' out of the cut.

Practically, you only want to be climb milling on something with next to no backlash, otherwise it's a recipe for damaged cutters and ruined workpieces, which can lead to even more damage.
I only ever climb mill on the CNC mill, as I know it's only got under 0.02mm of backlash, which for any cutter I'm ever likely to use on it, is negligible.

Strangely whilst that pic does show it. It would make more sense to me to have a pic with the table direction altering and the cutter always rotating clockwise as that what going to happen in the real world.

I think this one will help me more.

 

[Seadog]

I don't know where this "conventional milling" came from. I suspect our cousins across the pond. It was always back-milling when I were a lad. And it still is, as far as I'm concerned.

And then there are drill presses, steady rests, etc., etc., etc.

 

[Johnnybravo]

Climb milling is easy to remember. You only have cutters that cut being rotated clockwise when viewed from above. If your cutter is situated to the left of the line/ contour you want to mill and it’s moving away from you, you are climb milling.

The other way to remember is which bit of material meets the cutter first? Climb milling is always cutting from the outside to inside. The milling cutter touches the outside of the material first. Conventional milling , the cutter contacts the inside of your material first, and cuts towards the outside.