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



## zeeprogrammer (Jun 8, 2009)

This is a picture of two parts I need to cut. I've done tapers but I can't get my head around this. The first is a cylinder. The second is a cross-section of a flywheel. Both have similar cuts but from two different directions (the first as a turning operation and the other like a facing operation).

The instruction booklet (for those of you following the thread on the open column launch engine) is silent about this.

The 1st part requires angles of 45 deg and the 2nd part is 30 deg.

I'm thinking it should be 'simple', and maybe it is to the knowledgeable ones here, but if it's more than two types of operation...it ain't simple to me.

Help would be greatly appreciated.







I tried doing an attachment...but when I hit post...my browser went blank and didn't come back. I'm hoping I'm not asking the same question twice.

Thank you.


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## bearcar1 (Jun 8, 2009)

Hi Zee', If those cuts are relatively shallow, <.250" (and I suspect that they are) you could grind a cutter bit to the required angle and with it mounted in your cross slide at 90* to the part, merely perform a plunge cut to depth and then machine out to the required diameter. There are other methods but this is along the lines of the KISS actions. Good luck, and it appears you are progressing well on your OC engine.

Cheers

BC1
Jim


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## zeeprogrammer (Jun 8, 2009)

Hi Jim,

Thanks for the quick response and the compliment on the OC engine. Good progress for now...going to slow down a bit while I wait for more tools...already itching to start another engine. The recent posts on the Stuart V10s and some beam engines have me drooling pretty bad. Those are the engines I remember as a kid that helped put me where I am now.

Yes you're right. The cylinder is 0.125. The flywheel has 0.13 and 0.25 (due to a boss). So I'm back to grinding a tool eh? Guess I can't/shouldn't avoid it.

'merely' huh? :big: :big: :big: Someday yes.

Thanks Jim.


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## mklotz (Jun 8, 2009)

With all due respect to Jim, I wouldn't recommend a form tool due to the high probability of chatter on a small lathe.

The angles on the topmost piece can be cut by angling the compound which minimizes the chance of chatter. Rough out the center cylindrical section first with a parting tool, then cut the half cone sections and, finally, trim the cylindrical part to size.

For the flywheel cut, there aren't really too many options. Plunge in and take very small cuts.
The trick here is to grind relief on the tool so the underside doesn't rub and cause chatter.


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## Tin Falcon (Jun 8, 2009)

the other option for short tapers with relatively large angles is to use the compound on the lathe.
Tin


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## zeeprogrammer (Jun 8, 2009)

Thanks Marv and Tin.
This seems to confirm my suspicions.
Guess I'll take the plunge :big:
Thanks again. You'll see the results in the OC engine thread...eventually.


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## bearcar1 (Jun 8, 2009)

It is as I said, "there are other methods" ........ however, smaller machine or not, the careful and judicious use of a cutter with the desired angles ground on it will yield good results for a novice. Start at the midpoint of the work piece and proceed to either side, then return to the mid-point, increase the cutter depth and machine from the center to the end points once again. Continue until the desired depth is reached. No fooling round with the top slide etc.

BC1
Jim


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## Foozer (Jun 9, 2009)

zeeprogrammer  said:
			
		

> Thanks Marv and Tin.
> This seems to confirm my suspicions.
> Guess I'll take the plunge :big:
> Thanks again. You'll see the results in the OC engine thread...eventually.





Grinding a bit and sneaking up on the finish will work, it is the chatter that might bite you. But then sandpaper is your friend  On your example, the first one, I can get away with the sneak up to about a 0.150 +/- depth without chatter, slow and easy. the full width side to side and each pass I just creep the bit to just meet the previous angle cut. For the times I want to be spot on , in the infield at least, the overall width of cut is slightly undersized and then use of the compound to finish up the angles. For me at least, it is important not to remove the part from the chuck at all. The part never goes back exactly on axis. So its a trial to ensure that there is room to accomplish the steps without having to move the part itself.

I like the form tool approach, my little lathe however, has its own view on that subject, sandpaper and files are your friend.

Clear as mud I know. . .


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## scoop (Jun 9, 2009)

Don't forget that if you get a chattered finish using a form or parting type tool it can be a saviour to just put on a small cut with the chuck stationary and then just turn the chuck by hand to get under the chatter to finish the last couple of thousands.
 saved me a few times now as removing chatter with abrasive paper is normally a pain.

  good luck Steve C.


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## zeeprogrammer (Jun 9, 2009)

Hi Jim. Thanks very much. Would you clarify what you mean by 'No fooling round with the top slide etc.'?

Foozer and Jim. Yes. I'm getting very acquainted very sandpaper. 

Thanks all. Very helpful.


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## bearcar1 (Jun 9, 2009)

Zee, I do not know what lathe it is that you are working with but the top slide (also referred to as a compound slide) sits atop the cross slide, the section of machine that moves the tool front to back. The top slide's angle of attack can be adjusted as needed, thus allowing the operator to move the cutter into and out of the work piece at an angle without having to use the normal crossfeed which only moves parallel to the chuck. I hope that this is an adequate expaination and that it makes sense to you. By using a cutter ground to the desired angle, you would not have to mess around with setting the top slide in opposite directions to achieve your goal. Tool chatter can develop but using very light cuts and proper spindle speed will usually overcome this problem. (usually)


BC1
Jim


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## Dhow Nunda wallah (Jun 11, 2009)

Zee, I guess by your moniker, you are a programmer.

Bite the bullet, just like your first steps in writing code. (BASIC FORTRAN,COBOL, Pascal, C.........?)

Get yourself some HSS (high speed steel) of a convenient size for your toolpost.
If you don't already have one, get a cheap 6" bench grinder.

When you've got the above, throw away the "fine" wheel on your grinder and purchase a quality white wheel.
(Norton springs to mind, but I'm not going out in the rain to get the number)

With a good wheel, a solid toolrest and some nice fresh HSS, tool grinding becomes a joy!

Don't worry about "spoiling temper" or other rubbish!

You can produce a custom tool in literally minutes.

Remember the vacu-video method, suck it and see!
What do you have to lose, apart from your time? (and that is time well spent)

For the most part, my paid work is in 316 SS, I use nothing but HSS tooling, no top rake and flood suds.
All of this on a little Jet 9x20 lathe.

Go forth and grind 

Regards,
Lin


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## zeeprogrammer (Jun 11, 2009)

Thanks Jim. Yeah I've played with the angle of attack and experimented with doing tapers. But this was a steep angle and worse...kind of close to the chuck. I played with some setups last night. I think I'm going to try grinding a tool with the desired angles and take light cuts as you suggest.

Which leads me to...

Thanks Lin. Yep. What you said. Thanks for the encouragement. BTW...nowadays it's 90% 'C' and an insignificant amount of assembly. I'm an embedded engineer. The other 10% is C++ for writing PC tools. Others long long ago.



			
				Dhow Nunda wallah  said:
			
		

> ...just like your first steps in writing code...



Yes...but my knuckles do not tremble at a keyboard. :big:


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## zeeprogrammer (Jun 11, 2009)

Well that was pretty much a disaster.
Ground a tool.
Ugly.

The sound was horrible. Not a chatter so much as it sounded like the metal was screaming in pain. Enough to make me wonder...'can metal feel?' (of course not).

Post mortem...

Not sure why the cranking the top slide handle didn't do anything...but noticed I was at the end of travel (to the left).

The tool...to put it politely...was "*&%#$%^@". The tip looked all messed up. Like brass was welded to it. (Should I patent that?)

Using the carriage hand wheel to make cuts has so far always been a bad idea except for the roughest of cuts.

Switched to a carbide insert (and reset the travels). What a difference!!! That's what told me it was my tool.

So I'm lousy at grinding tools. Real lousy. No doubt as lousy, if not worse, as anyone who first starts grinding their own cutters.

Unfortunately I can't say I'm real excited about getting better at it despite what others like. I want to make something...not so much to make something to make something.

 :rant: :rant: :rant:

But don't get the wrong idea...I will no doubt try again...and again...and again. I :rant: may :rant: be :rant: upset :rant:...but it's not stopping me. (I'm sitting here with a ;D on my face.)

I'm probably more upset that the purpose of the thread showing my project (the Open Column Launch Engine) won't be the thread I had hoped it would be.

All right. Apologies. Everyone has their day (or days). I love this hobby...and this forum is great.

Now I'll go away and think about how to proceed.


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## mklotz (Jun 11, 2009)

Turn the machines off and mix yourself a 15:1 martini. While you're sipping it, take a few photos of the tool tip. I know that nobody likes to show their mistakes but it's impossible to establish the problem without seeing the offending item.

You'll just have to get used to the make a tool to make a jig to make a tool to use to make just one cut on the part. It's inevitable and we all do it. 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.

Two other things bother me. Grinding should not be producing so much noise. Were you using the tool rests or holding the tool free hand? How about a picture of the grinder?

You should be able to turn by advancing the carriage with the handwheel. If the lathe cuts satisfactorily with the power feed, using the handwheel should work as well. Perhaps the cut might not be as smooth as under power, but by going slowly you should get at least reasonable results. Maybe you're trying to go too fast.


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## bearcar1 (Jun 11, 2009)

Hi Z'. I am sorry to hear that your first attempt to grind a cutter was unsuccessful. And yes, metal does have 'feelings', I mean c'mon, how would you feel if someone was applying tremendous amounts of force on you to separate yourself from a comfortable existence? :big:
Anyway, from the sounds of it (no funnies intended Rof}) the clearances were not ground properly on your cutter and the metal was not being cut from the stock but was being eroded away by friction, not a very good thing unless you were a sander or grinding wheel. ;D AFA the grinding of cutters, there is only one solution to becoming proficient at it and it as with anything else, practice. Sorry old boy but sooner or later, you are going to have to do it and it is best to get it over with in your early stages. In machine shop class at the UofI, we spent an entire week of classes doing nothing but grinding cutters for different applications. I never got so sick of doing something in my life, but when it was all over, I could grind a cutter for any material and any application imaginable. It is an art form and should be practiced to become good at and also to continue to be good. Were you finally able to get your piece finished to your satisfaction is the important thing here. If not, you know there is always knitting to fall back on as a hobby. It is said to be relaxing and isn't nearly as messy as machine work. Just something else to ponder over while you pass the hours away grinding cutters. Rof} Rof}


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## zeeprogrammer (Jun 11, 2009)

mklotz  said:
			
		

> Turn the machines off and mix yourself a 15:1 martini. While you're sipping it, take a few photos of the tool tip. I know that nobody likes to show their mistakes but it's impossible to establish the problem without seeing the offending item.
> 
> You'll just have to get used to the make a tool to make a jig to make a tool to use to make just one cut on the part. It's inevitable and we all do it. 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.
> 
> ...



The joy in showing your success is that someone will learn how to do it.
The joy in showing your failure is that someone will learn not to do it.

I have no problem talking about my boo-boos, whether stupid or not. Happily, this forum does not mind either.

Unfortunately..I'm on my second (third?) 15:1 martini (kinda missing the wife a little). What's the :1? The onion? Maybe the glass? What do you mean 'mix'? It's vodka and ice for me...and I'm unhappy taking the time to get the ice.

Here's a pic of the tool...hopefully it shows enough...






The noise wasn't from the grinding (a $50 Ryobi from Home Depot). Other than doing a lousy job of it...no problems. The noise was from using the tool. (Remember...I'm on martinis right now - not responsible for what you read into that sentence.)

But you're absolutely right. Probably the biggest mistake anyone makes is going too fast...and I'm the biggest offender.

As far as the carriage...you're right...that's what I meant. Cutting under power gives better results.

Lastly, "sort of like programming deeply nested loops"...unfair ;D...that's poor design...I don't do that and question the engineer if I see it in a design/code review.

Thanks Marv. A lot.


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## zeeprogrammer (Jun 11, 2009)

bearcar1  said:
			
		

> Hi Z'. I am sorry to hear that your first attempt to grind a cutter was unsuccessful. And yes, metal does have 'feelings', I mean c'mon, how would you feel if someone was applying tremendous amounts of force on you to separate yourself from a comfortable existence? :big:


Are talking about my family? Or the metal? :big:
The thing about any attempt is that I know it's never completely unsuccessful. It's just :rant: :rant: :rant: frustrating. Rof}
Yep...try try again.
Funny you mention knitting. It was on my list of 'is this a hobby for me' several months ago. Don't laugh...I could've been another needlepointer...what was his name?...the football guy?...Rosey! Luckily...I found machining. Whew.


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## Foozer (Jun 12, 2009)

zeeprogrammer  said:
			
		

> Unfortunately..I'm on my second (third?) 15:1 martini (kinda missing the wife a little). What's the :1? The onion? Maybe the glass? What do you mean 'mix'? It's vodka and ice for me...and I'm unhappy taking the time to get the ice.
> 
> Here's a pic of the tool...hopefully it shows enough...



Replace Vodka with Tequila, no ice 

What did you grind the bit from? Only red bits I have are those carbide tipped ones that I could do without. Light cut and they squeal like a scene from "Deliverance." I take it the bit had a point until it "burned off". 

Like its said, it takes practice to grind a bit. Did you try and round the point over and inadvertently lose the angle to it, I've done it, so instead of having a cutting edge the bit presented a flat surface? Bit above center? Hard to see from the photo, catch one from the business end, side view.

Bob


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## Maryak (Jun 12, 2009)

Zee,

Stick with the &#1042;&#1086;&#1076;&#1082;&#1072;. No ice but put the bottle in the freezer for at least 6 hrs. Shot glass full, (if it's at the correct temperature it's slightly creamy), down the hatch and followed immediately by salt cucumber. 3 or 4 of those and you can grind anything to any shape. ;D ;D ;D

On a serious note the tool bit just does not look like HSS to me, what is the grit of your wheel? The music and very soft edge also make me think the same thing.

Best Regards
Bob


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## zeeprogrammer (Jun 12, 2009)

Foozer  said:
			
		

> 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.



			
				Maryak  said:
			
		

> ... 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.


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## Lew Hartswick (Jun 12, 2009)

mklotz  said:
			
		

> 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...


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## radfordc (Jun 12, 2009)

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


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## Maryak (Jun 12, 2009)

zeeprogrammer  said:
			
		

> 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


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## mklotz (Jun 12, 2009)

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.


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## cobra428 (Jun 12, 2009)

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


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## itowbig (Jun 12, 2009)

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.


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## mklotz (Jun 12, 2009)

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.


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## zeeprogrammer (Jun 12, 2009)

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.


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## zeeprogrammer (Jun 12, 2009)

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







Thanks for the help everyone.


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## Foozer (Jun 12, 2009)

zeeprogrammer  said:
			
		

> 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.


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## bearcar1 (Jun 12, 2009)

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


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## zeeprogrammer (Jun 12, 2009)

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.


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## bearcar1 (Jun 12, 2009)

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


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## Foozer (Jun 12, 2009)

zeeprogrammer  said:
			
		

> 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


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## zeeprogrammer (Jun 13, 2009)

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?


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## bearcar1 (Jun 14, 2009)

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


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## Dhow Nunda wallah (Jul 8, 2009)

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


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