How do I cut this - angle/bevel/chamfer?

[zeeprogrammer]

What did you grind the bit from? Only red bits I have are those carbide tipped ones that I could do without.

I've used enough of the 'ranting smiley' recently...but could use one more here. You're right Bob. I didn't think I had any carbide tools. Thinking it was HSS, I just grabbed a red bit that came with the lathe and had a go.

It was 'pointy' and I used the 'straight edge' method to center the bit.

... salt cucumber. ...the tool bit just does not look like HSS to me,...

Anchovies for me but the salt cucumber will be tried.

Why do you say 'does not look like HSS'? The color of the metal on what is supposed to be a rake? I found my first attempt to grind a tool bit...it is certainly HSS...and it doesn't have that coloration.

Thanks all. There's several positives here. 1) Knowing that I made fundamental blunder means the confidence hit I took last night is restored to 'maybe I can'. 2) In investigating my blunder I found a bag of HSS bits I had purchased some time ago. So I have the right material to practice on.

 

[Lew Hartswick]

There have been times when I was so deep in the sequence that I literally forgot what the final objective was. It's sort of like programming deeply nested loops.

I had to really laugh at that one. I've done it myself a time or two.
...lew...

 

[radfordc]

I also once tried regrinding the red carbide tools that came with the lathe. Can't be done! At least not with the grinders I have.

Get some HSS blanks for a couple of bucks and see how much better everything will work. It's fun now to grab a blank and grind out a special tool for each new cutting task. Last night I was turning a small flywheel from brass and needed to make a plunge cut in the side of the wheel. A 1/8" HSS blank, five minutes on the grinder and the job when easy as pie.

Charlie

 

[Maryak]

Why do you say 'does not look like HSS'? The color of the metal on what is supposed to be a rake? I found my first attempt to grind a tool bit...it is certainly HSS...and it doesn't have that coloration.

Zee,

Difficult to explain but it looks more like carbon tool steel such as a chisel would be made from. The way the grinder has marked it, (that's why I asked about the grit of your wheel); and the way the tip of the tool has rolled up. It's more usual for HSS to groove away and down from the cutting edge or to fracture on the edge than to roll back up on top of the tip when cutting tough steel.

Sorry I can't add more than that. :-\

Best Regards
Bob

 

[mklotz]

A 15:1 martini is 15 parts gin to 1 part vermouth. You don't make proper martinis with vodka. Vodka is useful for disinfecting wounds, fueling small boilers and removing certain types of stubborn stains but you don't make martinis with it.

It certainly looks like you ground a brazed carbide bit by accident. The only good thing about that episode is that any possible metallic loading in your grinder wheel is now gone so the wheel is probably well-dressed to grind HSS.

Try grinding the same shape into HSS. Don't attempt yet to radius the point - leave it sharp as it comes off the grinder. Stone the top of the tool to remove any burrs. Now you've got a chamfering tool. Set it up on center and try using it to chamfer the edge of a piece of faced scrap (using the edge, not the tip of the tool). It should cut cleanly without chatter. This will prove that you've ground the relief angles correctly and set the tool on center.

If this works, try using a Dremel with a flat stone to radius the tip slightly following the angle of the relief you've already ground in. Set the tool up in the lathe. Check that the tip contacts the stock only in a line contact at center height. Take a trial cut in some scrap. The tool should cut cleanly and leave a nice finish. If it doesn't, you've still got a chamfering tool.

 

[cobra428]

Zee
Don't listen Marv on the Martini's. Vodka is the only way! James Bond drinks the vodka martini "shaken not stirred". No onion......olives!
Tony

 

[itowbig]

i think maybe you guys should give up those martini's and have beer instead. its better for you. the best part is you dont need ice or any other thing to mix with them you just grab one from the fridge and drink.

 

[mklotz]

Sid,

I'll give up martinis when I'm the same temperature as the (perfectly chilled) martini glass.

Just remember...the three best things in the world: a martini before and a cigarette after.

 

[zeeprogrammer]

Rof}

Well that certainly started a little activity.

I'd hate to see the topic of 'what to drink' fall into the same company of 'topics to avoid in social situations'. ;D So keep it clean and nice. ;D

My wife uses gin...I use vodka.
If she runs out, or I run out, we can't blame the other. We never attempt to discuss the benefits of either but are known to laugh at the other when they're out. :big:

When we're together...it's wine. Never ever be out of wine. Ever.

But I digress...as I mentioned before...I found some HSS bits...I'm off to try again.

 

[zeeprogrammer]

Progress. Not good yet. But a whole lot better than the last one!!!

Thanks for the help everyone.

 

[Foozer]

Progress. Not good yet. But a whole lot better than the last one!!!

Thanks for the help everyone.

Lot quieter on the cutting was it? Looks like your drawing part now. It'll clean up nice with the sand and polish. How did it do when you flipped it end for end, you pick up the center diameter OK. It'll only get harder as you challenge yourself, but that is the hobby.

 

[bearcar1]

There now, that looks a whole lot better now doesn't it? And grinding that cutter did not hurt (me) a bit? Rof}

BC1
Jim

 

[zeeprogrammer]

Bunch of funny guys on this forum, ain't there? :big:
Good thing too.

Bob...the part with the new cutting tool was the first part. It was goofed in that the two ends were supposed to be symmetrical. They aren't. I went too far the first time so there wasn't as much on the other end.

This pic shows the 2nd part. Better...and I'm happier. Although it doesn't show very well, I did manage to meet up in the middle pretty good. As you know...a little sand and elbow grease will make it nice.

Jim...yes much better (but the fingers got a bit warm ). Much more improvement needed but that will come with practice. I'll make sure it doesn't hurt (you). :big:

Thanks for all the support everyone.

I haven't cleaned up the sides yet...I'll do that after I bore the piston hole and drill/tap the holes for the cap and the posts. So who knows...we may get to see a 3rd attempt.

 

[bearcar1]

A decent looking piece Z', as you said, a little elbow grease will have it cleaned up in a jif. Also, it is a common practice to keep a small vessel of water nearby when you are grinding cutters. It does two things, as the tool reaches the point of being too warm to handle, you quench it in the water to assist it cooling down. And the second is if you become thirsty during the process and Vodka isn't available............ :


BC1
Jim

 

[Foozer]

Bunch of funny guys on this forum, ain't there? :big:
Good thing too.

Now if you use a stone to "round over" the bit end a tad, you'll get a fairly shiny finish. This is a 6" dia piece, largest that i can fit into machine. Started with a pointed HSS ground bit like yours and eased the tip slightly rounded with a stone. Ol Duke agrees that the finish passes muster.

Little practice and some scrap stock, couple shots of Tequila and you'll be there. . .

Bob

 

[zeeprogrammer]

Jim. The first time I heard it go 'pssst' when I quenched, I started going back and forth more frequently.

Bob. Thanks for the tip. Another tool on the shopping list.

Vodka, tequila....tequila, vodka...
What? No bourbon drinkers out there?
Or should I have said whiskey?

 

[bearcar1]

I always preferred the Rye products myself. Tastes vary, but a good single blend and a fine cigar is quite the ticket on rare occasions. :

BC1
Jim

 

[Dhow Nunda wallah]

Carl, glad to see you got it sorted. Nothing like a drop of C2H5OH to steady the hands

And gin is just vodka contaminated with juniper berries!

edit to add; if you want to grind carbide, you need a silicon carbide wheel. Usually green, but check the label.

Rgds,
Lin