I was given a Metal Lathe., Help me choose projects. Options

[Darren C]

Good information. Thank you.

I think I understand angle of attack, but I need more on rake. While I understand the rake plane, what is an example of zero rake vs high rake?

Does the tool always intersect the piece at the 270 degree point in the rotation? (270 being the point that represents west if you look at the chuck end-on).


Also, when you say Right-hand and Left-hand, is that a reference to the direction the tool is moving against the piece or the direction the piece is spinning in the lathe?

I'm under the assumption that almost everything is turned in a CCW direction at the chuck.

Rake angle is adjustable dependent on the metal, most metal can be cut like wood does with a plane. The shavings curl off the wood if a sharp plane is used in long continuous shaving pieces to leave a smooth finish. With a soft metal a larger rake angle tool tends to do the same. Harder metals can be too hard to cut with "shavings" without immense speeds and pressure, so the rake angle is less and they cut with "small chips" not shavings...This is the best way I can think to explain it to you at the moment.
RH & LH is the direction the tool takes not the rotation of the lathe. Normal turning is RH where the tool travels towards the chuck. LH is where the tool starts near the chuck and moves away from it.
99% of stuff is turned with the CCW direction, but for access reasons or some awkward shape piece there is the ability to reverse the rotation. This is also very common when thread turning.

I'm still concerned for you....

Operating a lathe is a little like flying an airplane.....you can ask 1000's of questions, watch multiple films and read 1000's of books.....but when you start you really need someone by your side to stop you making dangerous mistakes, watching over your shoulder to guide you and prevent things going wrong before they do.

Why don't you contact your local school or college and see if you can enroll in some basic class for turning...you seem like a switched on guy and I think a few hours with a tutor would be great for you.

[Series9]

RH & LH is the direction the tool takes not the rotation of the lathe. Normal turning is RH where the tool travels towards the chuck. LH is where the tool starts near the chuck and moves away from it.

That is backwards to me. If the tool is traveling toward the chuck, it's moving to the left. Why would that be RH?

I'm happy that came up, because the directions you put on the tool picture I posted seemed backwards.

And again, please give me a simple explanation of "high rake". I assume zero rake would be directly perpendicular to the piece. Is high rake tip up?

I would love to go take a class, but I've spent hours trying to find one in Central FL and have come up empty. All the tech schools have shifted to IT and no longer offer machine classes of any sort.


As for the flying comment, I'm an 8000-hour jet captain and firmly believe flying a 172 only on book knowledge would be easier and safer than trying to learn this lathe without previous experience.

.....but I will.

[Darren C]

LH & RH tools and examples of where they are used.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456081775.1.jpg)

Rake angles (side and back rake)

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456081775.2.gif)

[Series9]

LH & RH tools and examples of where they are used.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456081775.1.jpg)

That is the single, most useful piece of information I have been given.

From basic observation, I still think LH and RH are reversed, but if that's how it is, then that's how it's is.

LH tools move right and RH tools move left. Okay.


The rake angle diagram, however, actually made things worse.

Simply show me an example of a high rake tool and a zero rake tool, please.


I appreciate the contributions to this thread very much, but you guys are seriously mixing PhD-level lathe processes with middle-school, with high-school, with 2nd grade....

Right now, I'm in lathe Kindergarten. Let's keep it on that level for the moment. I've always been a quick study, but I didn't start my flying career by sitting down in a jet.

(IMG:style_emoticons/default/smile.gif)

[Series9]

More questions:

How do you run a finishing pass with this tool if you need to complete the pass at a 90* angle on the right side of the pass?

A good example of the need to do this would exist on crankshaft main journals.

[Series9]

The direction of travel on this makes no sense to me.

Do you have to set it up so the cutting surface is precisely parallel to the intended finish?

How do you begin the cut? Do you move the tool in to full depth and then move it to the face to start cutting? That scenario would require a lot of tool surface cutting all at once.

It seems like you would move the tool from the outside toward the center.

[veekry9]

Scope,
the overall scope of the task at hand is knowing the the machine will hurt you if not operated correctly,as I've pointed out.
Evidently,a new career in shafting is not in the plan,but obviously if the standards of reference are unknown to you,the links have all the info available.
And yes,everyone who has taken the curriculum has asked the why of the LH/RH question,it's good that you asked.
I believe it came about a few hundred years ago at the very beginning of the 'industrial revolution',while turning bronze cannons,by hand.
The tools were used in a way similar to wood spindle makers,the tool levered to the right hand to turn left,the iron tool shank offset right.
The right hand thread derived it's name from the same roots,the lathe CCW rotating.

Take note that some of the drawings,from 1914 as above,are greatly exaggerated for visual clarity.
The difference between the lh and rh is annoted,for those falling off the turnip wagon.
(A stunt was to draw a face on the back of his head,stumping some beginners!)

http://www.nist.gov/
http://www.nspe.org/
http://www.astm.org/
http://www.sae.org/
https://www.ansi.org/
https://en.wikipedia.org/wiki/BSI_Group
http://www.iso.org/iso/home.html
https://en.wikipedia.org/wiki/Metric_(mathematics)
https://www.google.ca/webhp?sourceid=chrome...-8#q=metallurgy
https://www.google.ca/search?q=involute+spl...fuID7UQ_AUIBigB
https://www.google.ca/search?q=involute+spl...h&q=splines
http://bbs.homeshopmachinist.net/threads/6...nvolute-splines
https://www.google.ca/search?q=thread+turni...1URScmeD2ycM%3A
https://www.google.ca/search?q=lathe+tool+r...zPDxLma0rFDM%3A
http://www.amazon.com/Eshbachs-Handbook-En...r/dp/0470085789
http://www.sandvik.coromant.com/en-gb/pages/default.aspx


Here is a demo of the spline or involute gear forms possible on your lathe.
And how he did it,a most useful idea,though an additional heavy disc brake would ensure the stability of the chuck.
https://www.youtube.com/watch?v=lqreWsmXG4k
https://www.youtube.com/watch?v=BgGXQUeYNKw
Yes,I used this technique recently a few years ago on a heavy 12' X 8' 20T platen.Broaching or shaping by cnc,a keyway or spline into a stationary bore.

I also like the RC heavy equipment he built.
https://www.youtube.com/watch?v=rt8VfgfWa54

The answers to the most basic questions are on page 2 of the manual. (IMG:style_emoticons/default/idea.gif)
https://www.youtube.com/watch?v=Hjsfs49SRbc

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[veekry9]

Dedicated tooling and machinery,expressly for the manufacture of crankshafts.
A manual lathe can be used,however,it is a long laborious and expensive process of many steps.
The tools are designed for their single purpose,hence the designation of their names.
The toolpost on the lathe must be indicated to index true,the tooltip must be at the vertical centerline of the shaft.
While threading shafts,the compound slide must be set at the correct angle and zeroed.
The stops must be set to avoid crashes,the speeds and feeds calculated beforehand.
The correct operation of the lathe's feedscrew and halfnut phase dial must be known.
The use of the headstock gearbox also must be understood.
Boring tubes and holes is a primary task,broaching or scraping rifling grooves another.
Drilling deep holes,undercutting and relieving bores is more.
Heavy grooving tools are the methods traditionally used to ruf out crank billet bars.
Offset and steadyrest turning and grinding of cranks is a whole science and skillset by itself.
A 4340 forged 16' X 5' stroke marine crank was done a decade ago in the shop,from scratch to ground finish.
Many tons of chips made,without error,a thing of beauty,by one guy,who had survived a bad accident in '04.

https://www.google.ca/webhp?sourceid=chrome...fts&tbm=vid
https://www.google.ca/webhp?sourceid=chrome...rge+crankshafts

Some useful drops of info,the iso tooling from Walter is just what you might need.
Other vendors sell competing tools too,so buy the lowest price possible.
As mentioned earlier,the hss and brazed carbide tooling is cheap,but requires expert grinding to achieve good results.
These tools,with the quickchange holders,will have you up and running in a jiffy,painlessly.
Jurassic,some retro tools for the small hobbyist user,making the choice easy.

https://www.google.ca/webhp?sourceid=chrome...%20and%20speeds
http://www.walter-tools.com/en-us/tools/st...es/default.aspx
http://www.jurassictools.com/store/tools-engineering-etc

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Walter:external::screw type:
http://waltertools.blaetterkatalog.de/gc2012/en/#page_A80

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https://www.youtube.com/watch?v=7cXBXewS4IM
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[veekry9]

A trip to the wreckers,an old rusty crank brought to new life by dirty '30s tech.
A little pickle to remove the rust,then a shoestring polish.
All of this came from before,the T Fords and babbit bearings.
This low level flying,or retrotech can be applied to your VW crank if you are looking to stroke for a larger displacement.
A few passes of weld,turning and grinding,and presto,a piece of work.For the all hands on deck type of machiner.

https://www.youtube.com/watch?v=j7DZxqPUQto
http://175.103.60.140/globalindo/carbon-st...cst60aisi-1045/
An entire industry was built out of this,this enterprising approach to the make it better cheaper and faster equation.
(IMG:style_emoticons/default/biggrin.gif)
http://www.hotvws.com/catalogs-2013/2/
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https://www.youtube.com/watch?v=6lfpip4u-pA

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[Darren C]

I appreciate the contributions to this thread very much, but you guys are seriously mixing PhD-level lathe processes with middle-school, with high-school, with 2nd grade....

Right now, I'm in lathe Kindergarten. Let's keep it on that level for the moment. I've always been a quick study, but I didn't start my flying career by sitting down in a jet.

(IMG:style_emoticons/default/smile.gif)

You're most welcome,
When I get home from Work this evening I'll take some pictures of some of my lathe tools to explain "rake angle" and post them.

In the meantime, my worry is that a loaded gun left in Kindergarten is just as likely to harm as one left in high school in naive or untrained hands.

[veekry9]

http://www.914world.com/bbs2/index.php?sho...73101&st=52

The details of the'Hopping Herbert'is entertaining to some degree.
Must have been late'70s,an aquaintance of the shop owner,looking for work,I suppose the music biz not panning out.
A simple collet chuck turret lathe series of operations.
https://en.wikipedia.org/wiki/Oxygen-free_copper
Copper alloy bar 1-1/2"dia X 20'length.
Well,neglecting to clamp the barfeeder clamps,the bar,unencumbered,began flapping around the back end of the heavy lathe.
From the other side of the shop,I saw the heavy'wire'create a giant spiral whipping about at high rpm.
Crossing the plane of the whirling,hopping mass,I stopped the spindle,again.
The unbalance of the unique creation had been lifting the Herbert almost a foot,noisily.
When I released the collet,the Danish bun looking thing came out without breaking,the plasticity of the material saving us.
Had it broken,the spinning wheel would have raced around the shop wreaking havoc at 1200 rpm.
Needless to say,that ginger was frozen in fear,the ashen pale look on his face said incomprehension.
A common household 12ga wire might show the same results if spun up in a hand drill.
/
Safety:
Brings to mind the'starting plane',that,which is directly in line with the chuck and work.
Always stand clear of the projectile plane,when starting the spindle,ensure no tools can fall off into the spinning chuck or work.
A place for tools is in safe areas only,secured.
Make a box for them as required.
/

[Darren C]

Ok……home from work now.....

Lets get down to basics….

There are 6 important angles to understand on a simple HSS lathe tool. The best illustration I can find is this.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456173478.1.gif)

Looking down on the tool you have front and side cutting angle. This relates to cutting in line with the lathe or across it (turning down or facing off).
These angles can be set or fixed by grinding the tool or by clamping the tool post at differing angles.

Back rake and side rake are in the horizontal plane and I think were the ones perplexing you? These refer to the top surface of the tool. It can angle downwards to left or right (side rake) in LH or RH tools and angle back towards the lathe operator (hence back rake angle)

Side relief and front relief are in the vertical plane, and hopefully self explanatory in the picture above.

I have been making lathe tools for over 40 years and I’m a qualified toolmaker for my sins, yet I'm still learning stuff. Here’s a few home made basic samples in “proper” High Speed Tool Steel.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456173478.2.jpg)

This is what good old fashioned HSS lathe tools should be like.

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456173478.3.jpg)

The tool steel is purchased as a bar (far right in photo) and you precision grind it by hand, sometimes to within + or – 1 thousandth of an inch where the rake angles are hand ground to minutes of degrees.

Today however these skills are lost and most lathe users are NOT tool makers, just tool sharpeners and the majority are blissfully unaware of what a true tool maker can do. Most HSS lathe tools today are like this….

(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456173479.4.jpg)

Only a small amount of quality HSS is brazed or welded into a poor quality steel holder. The tip is only HSS. These come in all shapes and sizes. But fundamentally they’re pre made so you don’t need to grind any angles or profiles, just dress them on a stone to keep them sharp.

I’m not sure what you have with your lathe, but this is just a real basic guide/help for you to understand simple tool shape. The possibilities of shape and angles are limitless. Understanding what the correct angle on all 6 planes takes years to master and is variable on material, speed and feed.

Hopefully that’s helpful to you for now.

Ceramic or tipped tools are another thing altogether with usually zero apparent back and side rake. Here’s one I set in my lathe tonight to show zero rake.
(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456173479.5.jpg)

My advice is start with some basic HSS tools, learn and understand how they work before going on to tipped tools. Plus get yourself on a basic lathe class!

[Series9]

That is incredibly helpful.

The amount of time you spent on that for me is greatly appreciated.

Thank you.

[Series9]

I purchased this today.

(IMG:style_emoticons/default/smile.gif)

[Series9]

This is the tooling that came with the lathe.

I've been operating on the assumption that you "get what you pay for" with this stuff.

I have successfully turned some pieces and I've also destroyed some tools.

I'm not afraid to spend some money on high quality bits. I'm looking at carbide and ceramic.

[Darren C]

Ok, you got a fair mix there..
(IMG:http://www.914world.com/bbs2/uploads_offsite/i265.photobucket.com-18255-1456222810.1.jpg)
Some are no good, others need work and just a few are useful to you as a beginner. I’ve numbered them so you know which tool I’m referring to.
1. Parting tool HSS and Holder. (very good, keeper. Get it sharp, grind the correct front relief, very tiny side relief and no side rake. A medium back rake will see you through most materials) A very good basic and useful parting tool. As it wears you re-grind and move the HSS steel forwards. ALWAYS set the tip contact with the job at dead centre height or ever so slightly low. NEVER go above centre height.
2. Plain Parting HSS (looks to be too wide for holder 1, you may need another holder for this)
3. Resolution on photo poor, but looks like a badly ground/messed up HSS parting. Cut off re-grind and start again with a suitable holder. (may fit same holder as 2)
4. Including 9, 16 & 30. HSS tool holders for smaller maybe what looks like ¼ or 3/8 HSS. You buy the HSS as in my first photo of the early rake descriptions and grind whatever tool you need. Very good old tool holders worth their weight in gold but too advanced for you for learning without good HSS ground tools to fit them. (keepers. Put them in your tool drawer for the future and get a new locking screw for 30 it looks a little chewed up)
5. Including 6 are RH knife tools profile for bevel turning steel Side & Front cutting angle too steep for straight turning and facing off steel, but ok with brass & aluminium.
7.Including 24 & 20 LH knife tool uses as for 5 & 6 above.
8. Including 10, 14, 22 & 23 Ream tools. I doubt you’ll ever need these.
11. Including 17 from the poor resolution photo look like unground tool steel. (put them in a draw for the future)
12. Including 18, 25 & 26 RH Knife tools. These have better side and front cutting angles for steel but they look well used and poorly re-ground. This is the sort of shape tool you need as a beginner but unfortunately these four look in a poor condition and need grinding work to restore them.
13. Including 27 are LH knife tools but old 13 looks useable as 27 needs a re-grind like your RH knifes.
15. Knurl tool. Good basic tool. Check the wheel spindle pins aren’t worn and the wheels are firm and don’t wobble or side in the shaft as any movement will make for a "double" inprint knurl. Plus also check the knurl profile is sharp. They do get worn down over the years and then they’ll be no good.
19. RH facing tool, looks badly ground on top surface back and side rake. Profile looks ok for facing off, but rakes need re-grind.
21. Including 28 & 29 are HSS thread cutting tools. Again these are not for you at this learning stage, stick them in the drawer for the future.

Overall you have a reasonable selection of tools but none are really up to scratch for using successfully.
Try and find a good machine shop or college nearby, take them in and get someone who knows what they’re doing to re-grind them for you. This shouldn’t cost too much money (may be just a crate of beer) and will be far cheaper than buying carbide/ceramic tipped tools and holders that you’re not ready for just yet.
You only need 1, 18 & 19 to learn with at an early stage.
Good choice on new tool post, very handy for setting tool height easy without shims under tools.

[Series9]

Fantastic information. Some of the tools have a wax-like protective coating on the tips. That's probably what you're seeing as "poor resolution".

[mbseto]

This is turning into a pretty cool thread!



(see what I did there?)

[nathansnathan]

I haven't tried using carbide on my lathe so take it for what it's worth, but there are a number of disadvantages to carbide.

I'm not sure how fast your machine will turn or if it's got the horsepower to sustain recommended feed rates at higher speeds, but I can say that mine doesn't come even close.

Carbide doesn't like sudden changes in temperature, which means running full coolant is preferable. If you stall out your spindle which carbide, you are going chip your tool. In my experience running production lathes with indexable carbide tooling, it's just a different word as far as rigidity. HSS is going to be much more forgiving of chatter, any flexation. Also the nature of using turn screws to manually feed vs even a jog wheel much less cnc control makes hss seem more at home on a toolroom style manual lathe.

HSS can be sharpened easily in whatever grinder, carbide is going to be more difficult to sharpen. At lower spindle speeds of a manual lathe, you're going to chip and dull carbide bits a lot more than if you could go 3x faster, which is where carbide shines. There may be a sweet spot for heavy cutting if you are turning large material (high surface feet per minute) where a carbide insert tool would be handy, but it will probably come down to if your lathe has the heft to maintain that. Like I said, stall the spindle and you'd be flipping the insert.

We never ground carbide when I did production. With indexable turret style tooling, you flip the insert when it gets dull. Each insert has like 2 -4 sides, and they are expensive, like $20 for each insert - and you don't buy just 1.
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.sixstarhardmetal.com-11782-1456237590.1.jpg)

So problems with carbide are need to run flood coolant ideally, not enough spindle speed, not enough spindle power at higher sfm, difficult/not possible to sharpen depending on what style you get, and more expensive.

Like I said, I don't have any carbide tooling for my little lathe. Based on my reading/research, it wouldn't be worth it.

[Series9]

This is turning into a pretty cool thread!



(see what I did there?)

(IMG:style_emoticons/default/sunglasses.gif)