For them that like seeing some expert metal bashing

I have been watching some of the videos by this chap on youtube...

At first I thought, oh yes someone who can hack about with a lathe. As time progresses however and you get into a few more of them, there does not appear to be any job he can't do - impressive skill set.

A good starter:

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(how to you get a bog standard arc welding job turn out that pretty? ;-)

This one for inventive creation of tools along the way:

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Rings a bell:

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Reply to
John Rumm
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Easy, you turn off lots of the weld bead and try and convince yourself if it looks better it must be better.

He appears to have a complete lack of respect for basic H&S at the lathe. Poking fingers towards moving parts, wearing gloves, touching moving parts (such as when adjusting the fixed steady with the rollers) Removing swarf, often with fingers with the machine in motion is completely loopy.

Maybe no safety glasses too, or at least if they are they have no side protection.

Reply to
The Other Mike

I'm not sure how he gets a cylinder nice and true by swapping it end for end several times. I reckon there will always be a messy bit somewhere in the middle. However he does get a nice finish. I'm having trouble getting a good enough finish. I'm turning down some 2 inch high tensile steel to make bolts. The finish is good at the start but at one inch it's not as smooth. I've tried shifting the tool up and down with no improvement

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Reply to
Matty F

several times. I reckon there will always be a messy bit somewhere in the middle. However he does get a nice finish.

high tensile steel to make bolts. The finish is good at the start but at one inch it's not as smooth. I've tried shifting the tool up and down with no improvement

Have you tried increasing the lathe speed to get the same surface speed as you had at the start?

Colin Bignell

Reply to
Nightjar

Somehow I think no matter how much weld bead I turned off, you would never get down to a completely solid surface with no voids, slag inclusion etc ;-)

In one vid he does point out he normally pulls swarf away with smooth jawed and handled pliers just in case they every do grab...

Reply to
John Rumm

several times. I reckon there will always be a messy bit somewhere in the middle. However he does get a nice finish.

inch high tensile steel to make bolts. The finish is good at the start but at one inch it's not as smooth. I've tried shifting the tool up and down with no improvement

Yes I have, and no improvement. I guess the tool is not the right shape, even though it seems undamaged according to the Boss. It really doesn't matter because the 100 year old bolts are so much worse!

Reply to
Matty F

Is the tailstock knackered and letting the end vibrate?

Reply to
dennis

You could try increasing it even more.

HSS or carbide? Carbide needs to be used more aggressively on mild steel than HSS to get a good finish. If you are not using HSS, try using it as a finishing tool.

As you are making bolts, another trick, which should not be used on any bearing surface (it may leave embedded abrasive bits), is to finish with strips of increasingly fine grades of emery cloth wetted with oil or cutting fluid and half wrapped around the work piece.

Colin Bignell

Reply to
Nightjar

No point in moving the tool up or down as it should be on the centre line or a fraction below.

It could be the tool geometry, maybe the radius on the tip is too large, or the size of cut is too small or too large, surface speed too slow or way too high , feed rate is wrong or despite it working earlier the cutting tool is not suitable for the material.

First action has to be lubricating all the ways and nipping up all the gibs. If using carbide check for chips on the cutting edge. Use a suitable cutting fluid, increase surface speed and use carbide inserts that 'just work out of the box' rather than think you can grind your own brazed carbide or HSS cutting tool.

Reply to
The Other Mike

end several times. I reckon there will always be a messy bit somewhere in the middle. However he does get a nice finish.

inch high tensile steel to make bolts. The finish is good at the start but at one inch it's not as smooth. I've tried shifting the tool up and down w ith no improvement

I'm using carbide inserts out of the box. When I have nearly reached the fi nal size I have to take small cuts. Yes maybe a big cut would be smoother b ut then the job will be undersize. I slowed the feed rate down. I used cut ting fluid. I reckon it's something wrong with the tool. It's very frustrat ing.

Reply to
Matty F

Not my skill Matty and others may care to comment... someone once suggested to me that it might be better to reverse the cut such that the

*force* is pulling the chuck to the lathe bed rather than lifting...
Reply to
Tim Lamb

I have measured the play all over the lathe. The main problem is that the tailstock bearing moves 0.18mm sideways. I think that would be enough to cause the problem.

Here's a finished bolt, to replace the 90 year old original that spent half its life in a farm paddock exposed to the weather. I think the new bolt will last more than 90 years.

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I may need to make more precise components one day, but I fear a cheap lathe is not quite good enough for that.

Reply to
Matty F

In article , Matty F writes

When I saw your earlier post and pic as an example of poor finishing I thought, "what's he on about", and this pic confirms it, there's nothing wrong there. The finish is a lot better than some factory made stainless bolts I've just paid good money form so well done.

Perhaps

Reply to
fred

alf its life in a

The problem is that the finish is near perfect here

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until I get down to nearly one inch diameter, when the surface is rough, as if something is loose or the tool is broken. I reckon the play in the tail stock may be the problem but an expert has denied that and claims that the tool was too high or the feed was too great, both of which I deny. I'm sick of arguing about it.

Reply to
Matty F

Maybe the expert would care to demonstrate how to do it? Either you will learn that he was right, or he will have to eat his words.

Reply to
Davey

I trust what he says about 99% of the time. He has made one which is a bit smoother than mine, and about 1.0002" wide. Goodness knows how he does the final cut, because a fine cut is not usually very smooth for me. I eventually made one about 1.0004" wide. He's a quali fied engineer with years of experience and I'm a Jack of all trades and mas ter of none. Who is likely to be right?

Reply to
Matty F

He is far more likely to be right, but OTOH surely somewhere along the line he can teach you the skill he has so you can do the same?..

Can you not ask him to demonstrate how he does the final cut and I presume its the same lathe your both using?..

I think if I was in his position I'd not mind someone asking me how or what's the best way to do something, it hardly seems your going to put him out of work does it?..

Reply to
tony sayer

Now I reckon it's the tool. The tool is too big to fit on the left of the tailstock, so I had to swivel it to the right, and it made a perfect cut. I had to swivel it back to do the square cut on the left hand side.

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I'll just get a magnifying glass next time to look at the tool.

Reply to
Matty F

Definitely not my area of expertise but here goes . . .

When I dipped a to in this many moons ago I was advised not to try to take off too little at a time as there would be a risk of the tool elastically deforming the workpiece rather than cutting properly leading to a poor finish. I think when you reach that point it makes any play in the system more apparent as you get (elastic) push - cut - push - cut moving the tool/workpiece around rather than having all the forces in one direction as you would get in a continuous cut.

Perhaps the 'expert' uses bold strokes right down to the end and that is what gives him the better finish?

IANAME

Reply to
fred

Going back to the videos that prompted this thread, there is an old one showing him remaking a prop shaft in stainless. Ignoring the rather nifty tracer attachment he has on his lathe, the finish he gets with a normal insert style tool seems to be "gleaming". He does seem you use fairly heavy cuts normally, and then a 5 thou cut as a finish cut (sometimes followed up by a repeat on exactly the same settings as a "Spring cut" using tool pressure alone.

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Reply to
John Rumm

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