Wrong way fly cutter

[deverett]

I needed to make some washers with one concave side. The easiest way was to use a fly cutter to scallop out the concave face on the end of a bar.
So, a piece of 1-1/4" bar was quickly fashioned into a fly cutter using a piece of 3/16" HSS as the cutter.
Only when it was finished and inserted into the chuck did I realise I had made the fly cutter the wrong hand.

Fortunately, my milling machine has reverse gear and I was able to do the job intended.

I'm not the first to make a wrong handed tool, and no doubt will not be the last. Tool makers beware!

Dave
The Emerald Isle

 

[Sprocket]

Must be why they make machines run both ways...I've done it too.
Doug

 

[tim9lives]

I’ve done that too. It’s one of those….” Duhhh moments “

 

[RonGinger]

I once made a tap, I think it was a 10-36 for a spark plug. I made a right hand thread, but cut the flutes for left hand cutting. It took me a minute or two to understand why it was not cutting threads.

 

[chrsbrbnk]

think of it as evening out the wear on the quill splines. or compensating for a surplus of either left or right lathe bits?

 

[kwoodhands]

I made a wood lathe years ago. Went well, and tried a bit of turning. Being left handed I thought if the headstock was to my right instead of the usual left it would be more practical for me.
I turned the lathe 180° and reversed the motor so it would turn toward me. This worked fine till I decided to use a chuck instead of spindle turning with a lathe split center.
I turned the lathe on, the chuck undid itself from the 1x8 threaded spindle. The chuck flew past me ,landed on the floor and rolled out the open door. The chuck stopped against a fence in my garden.
I ran out and grabbed the chuck before anyone could see what I had done.
Turned the lathe back to original position and same with motor direction.
mike

 

[Sprocket]

It’s hard being a lefty in a right handed world. We’re just better at adapting.
Doug

 

[Ken I]

Doug - Spot on - lefties live in a right handed world and have to learn to cope.
I began on an old fashioned drafting machine - it never even crossed my mind that working with my arms crossed was "wrong" - years later I was given a reversible drafting machine - I set it up left-handed and found it impossible to use. Ah-Well!
When we switched to CAD I had to share a station with several right-handers and was forced to use it right-handed and continue to do so.
As a left handed designer of machinery, I have to be careful not to design machine "left-handed" - unfortunately I have missed a trick or two occasionally and only on installation has someone commented "why is it left-handed".

As an extreme example I once bought a pair of German "Rems" cut off lathes - they were left-handed - when you stood at the controls the headstock was to your right - even I found that baffling.
When I visited the company - sure enough, the designer was a leftie - he was apparently perplexed, I was the first person to point this out to him. Subsequent machines were built the "right" way around.

Some things are right handed that even some lefties don't realize :-
Playing Cards (lefties fan mostly to blank corners - give a right hander a set of left handed playing cards and all he will get is blank corners)
Fishing reels
Scissors
Padlocks and combination locks
Vegetable & paring knives (beveled sharpened edge on the wrong side for lefties and dig in instead)
Micrometers and Verniers (if you hold it in your left hand the scales are away from you).

Que lefties to add to this list......

Regards, Ken

 

[Steamchick]

Mike, Doug, I am strongly right handed. But my Father's lathe (was his Father's before him!) was bought in the 1920s. A small 3?" swing treadle lathe. This was made with right-hand threads for all the lead and feed screws. I.E. to the left tightens-up, to the right slackens off.... - It wasn't until a few years after being taught to use the lathe that I found ot (at school) that all the modern tools had "left-handed threads" for feed screws! How Odd, that I had to learn to wind everything "backwards"! But it made me ambidextrous on machines... As I have a "modern" lathe (I.E. post 1930s) (my 6th lathe) my Sister and Bother-in-law now use the "old" lathe... She is left handed and has never used a "right makes it tight" machine, and he has never been trained - except by her , on the "left makes it tight" machine...
So does that qualify as a machine for sinistral people? - The headstock is still on the left of the operator...??
K2

 

[SmithDoor]

I know when making one from a bar you do look at right way it turns.

They either made for a a special job or it was a error so sold for lower cost.

If look in download section I have uploaded drawings and photo of my fly cutter. The angle of fly is low for a smother finish and can be made on most small mills.

Dave

I needed to make some washers with one concave side. The easiest way was to use a fly cutter to scallop out the concave face on the end of a bar.
So, a piece of 1-1/4" bar was quickly fashioned into a fly cutter using a piece of 3/16" HSS as the cutter.
Only when it was finished and inserted into the chuck did I realise I had made the fly cutter the wrong hand.

View attachment 131825

Fortunately, my milling machine has reverse gear and I was able to do the job intended.

I'm not the first to make a wrong handed tool, and no doubt will not be the last. Tool makers beware!

Dave
The Emerald Isle

 

[Richard Hed]

Doug - Spot on - lefties live in a right handed world and have to learn to cope.
I began on an old fashioned drafting machine - it never even crossed my mind that working with my arms crossed was "wrong" - years later I was given a reversible drafting machine - I set it up left-handed and found it impossible to use. Ah-Well!
When we switched to CAD I had to share a station with several right-handers and was forced to use it right-handed and continue to do so.
As a left handed designer of machinery, I have to be careful not to design machine "left-handed" - unfortunately I have missed a trick or two occasionally and only on installation has someone commented "why is it left-handed".

As an extreme example I once bought a pair of German "Rems" cut off lathes - they were left-handed - when you stood at the controls the headstock was to your right - even I found that baffling.
When I visited the company - sure enough, the designer was a leftie - he was apparently perplexed, I was the first person to point this out to him. Subsequent machines were built the "right" way around.

Some things are right handed that even some lefties don't realize :-
Playing Cards (lefties fan mostly to blank corners - give a right hander a set of left handed playing cards and all he will get is blank corners)
Fishing reels
Scissors
Padlocks and combination locks
Vegetable & paring knives (beveled sharpened edge on the wrong side for lefties and dig in instead)
Micrometers and Verniers (if you hold it in your left hand the scales are away from you).

Que lefties to add to this list......

Regards, Ken

I'm right handed but do own a left handed monkey wrench. I have to use it once about every 5 years or so.

 

[Bentwings]

The lefty operation is interesting . I have to admit I’ve never given a thought to it
Operating a machine tool just seemed natural . Bridgeport’s had handles on both ends of th x table ant the knee was lefty designed. It was just plain natural way to do things the spindle handle was righty as were speed controls. I never gave I a thought . Thanks for pointing it out. Operating our shop lathe, it only cuts right hand threads and cuts towards the church . Not a good idea. There is not an easy way to reverse the lead screw. Left threads aren’t common. I didn’t really become hand conscience untill my left knee got blown out in sports. It stopped running overnight and started years or life long issues blowing was one of my favorite sports. Lefty had advantage due to oil conditions. It’s probably one of the only sports where it’s mechanically possible to develope opposit have I did start this and was sort of successful but went back to senior baseball I’m just to old and sight impaired to play now I throw right an bat right but lefty has some advantage batting left as it gives nearly two full steps head start to first base. I taught my two youngest batting left . The older just finished his town ball league with second high batting average ant top on base percentage he throws right but writes lefty. Other son is ambidextrous. But he is pro bike racer and ballet dancer so handedness doesn’t mean much. Older son flys giant scale Rc warbirds. Radios have two modes but neither favor handiness. While I was driving race cars I tended to steer with left hand but shifted righty other controls ere divided for closest hand right foot has always been gas or power pedal and clutch is left while brakes can be either . In very early days some cars did use left foot for power but it evolve to today’s configuration now keys or start switches have moved around . Right has always been my choice but there were push button shifter in merc and Chrysler cars . So I’ll start looking at handed ness for my new hobby… steam engines so fr I haven’t noticed any differences . In full size I think the big steamer had a “ Johnson bar throttle right hand but I’ll have to ask about this. How do toe shovel snow? My booster shovel is ambushed. As is my mower but this iPhone is either as is my iPad and computer. Mouse wore either. On off computer I hard to get to with either hand. Most important device at this age is coffee cup either hand as is coffee pot and medication box. My cat seems Amy to but dog training dog heeled on left most of the time until K9 training when it was left,right,front or back most of the time I used leash control with both hand working but how you use control is up to you and dog. Cat doesn’t matter she chooses where she wants to be . I just looked over at the fridg. Lefty is the normal way I open it but he handle is on the right . Door knobs are which ever way you are used to I think mine open either way but key is to left while mail box is tight Circle track racing is left turn except road racing Now you have me looking at everything .LOL.
byron

 

[SmithDoor]

Try this for left and right.
Try find a left handed by looking at how they use a computer mouse.

Now try to find a right handed person using the with left hand.

Both my wife and my self are right handed but we use a the mouse on the left hand keep the right had for the number keys.

The first time we both saw a mouse being the person was using left handed.

Dave

I'm right handed but do own a left handed monkey wrench. I have to use it once about every 5 years or so.

 

[Bentwings]

Try this for left and right.
Try find a left handed by looking at how they use a computer mouse.

Now try to find a right handed person using the with left hand.

Both my wife and my self are right handed but we use a the mouse on the left hand keep the right had for the number keys.

The first time we both saw a mouse being the person was using left handed.

Dave

I’m down to using a stylist now as my fingers jut don’t wor well on iPhone actually it’s not too hard but still seeing two of everything is difficult.
byron

 

[dnalot]

Both my wife and my self are right handed but we use a the mouse on the left hand keep the right had for the number keys.

Me too. Also frees up my right hand for drinking coffee and using the TV clicker

Mark T

 

[Bentwings]

Me too. Also frees up my right hand for drinking coffee and using the TV clicker

Mark T

Uh,hi. You have a right handed coffee cup too!
Byron

 

[stragenmitsuko]

Always wondered why there are no left handed angle grinders .
Would be so handy in certain situations .

Same for calipers . Altough they seem te be avilaible now .

Pat

 

[GrahamJTaylor49]

As an apprentice tool maker we were taught that there are three hands, Right hand, Left hand and cack hand. This was for all those bits that were made the wrong hand when we wasted time remaking them the opposite hand. Engineering, what a bloody silly game.

 

[Ken I]

I like to design or un-hand a design so that it is ambidexterous - like this laser cut part of a more complex welded assembly.

The castellations fit into other laser cut parts for welding. The large hole is for a cable access - the "red" hole is redundant to unhand the part otherwise some dolt is going to weld it together backwards which could ruin the entire assembly.
Of course I could add a lot of explanatory notes - but dolts seldom read them - so its just cheaper to make it fool-proof.
Just 2c worth.
Regards, Ken

 

[JLaning427]

Ken,

That is a great example of Poka-Yoke. Designing something so that you can't assemble it wrong is something most designers should but often don't consider.

Another option would be to make the castellations or other features such that it obviously doesn't go together right when you put it together wrong.

I used to work in sheetmetal and there was always a chance you (or the shop floor guys) could bend the part inside out. And sometimes you could design that out of the parts / assembly. And sometimes you can't. Sometimes you can put centerpunches or similar features in (using the machine) to be able to help know which side is which. But sometimes the turret was full and that wasn't a choice. But thinking through the process was important.

James