[Coco] [coco] CNC coco

[George Ramsower]

 I learned a long time ago that cutting steel with an abrasive wheel is okay 
if the steel isn't very thick. On thick pieces, it is important to keep 
moving the part and get a cool spot. As the steel heats, it liquifies and 
causes the cutting wheel to literaly float over the surface..generating more 
heat and wasting time. If you were to work a square piece as if you 
drilling, ie: hit, get off, hit again, get off.... etc. it would work a 
little better. It's called "Pecking".

 Last year, I had to cut a four inch round stock with an abrasive wheel. It 
didn't take long to SEE what was happening. So I started rotating the stock 
as I was grinding through it and suddenly it was finished.
 Use a mill to finish the part after it's rough cut. Don't count on a saw to 
make a good part. Even a machine shop will cut off a piece large enough to 
finish it with a machine to make a good part. It is a lot faster and more 
precise.

 I don't think my coco cnc machine can do this, unless it's about 1/4 inch 
thick... and our energy resources will last long enough or the sun doesn't 
burn out first.

George
----- Original Message ----- 
From: "Gene Heskett"

> On Friday 08 February 2008, George Ramsower wrote:
>>WOO:HOO!
>
> Join the club George.  I have a similar project under way.  Lacking a 
> power
> hacksaw, I'm crazy enough to use a WhizCut abrasive wheel to cut off the
> amount of a 2" sq steel bar that I need to make the clamp block for a 
> boring
> bar, spinning it with that puny little motor on my micromill.  I blew so 
> many
> fuses I hit the shack for a meter & enough stuffs to make an amperage draw
> meter so I could see how hard the motor was working, and in about 10 hours
> run time over the last 2 days, I'm about .85" deep with the cutting line
> right now.  But its going faster since I found it cut better if I swept it
> back and forth with emc, only cutting 50 thou at a time, which narrows the
> cutting surface and speeds the overall cut.  A straight plunge cut soon 
> has
> so much surface in contact with the wheels edge that I can only advance
> about .002/minute.  But I should have pretty close to an optical flat on 
> the
> cut surface, which will be the bottom, sitting on the lathes cross slide 
> when
> I'm done, which is not the ideal as I'll have to make another pass and 
> dish
> it in the center about 3 thou so it will crush into 100% contact when
> tightened down.  I had to do the same with that Phase II quick change tool
> post, otherwise it was just so much rubber sitting there.
>
> This is truly lights out manufacturing as once a cut pass is underway, I 
> can
> leave and warm up my feet & get a fresh cuppa.  Sometimes one measures
> progress with a micrometer?  :-)
>
>> When I started this project, it  was mostly an experiment. Now it's
>>becoming a reality.
>>
>>I'm about to crash and burn... kuz I wus up all night, working out the
>>software on this coco to make this machine work.
>>
>> I suppose it's the approximation of success that does that.
>>
>> Anyway... it's so cool to see the thing actually move around  the table 
>> as
>>planned.
>>
>> After some sleep time, I'm going to actually make an automated machining
>>process to finish the construction of the X axis.
>>
>> I'm tired. I'm turning it off and landing... It might not be a smooth
>>landing but, if I can walk away, it's a good landing.
>>
>>
>> Piper Cubs forever!!!
>>
>>
>>Buenos Noches, amigos! Even if it IS almost luch time.
>>
>>George
>>
>>
>>--
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>>Coco at maltedmedia.com
>>http://five.pairlist.net/mailman/listinfo/coco
>
>
>
> -- 
> Cheers, Gene
> "There are four boxes to be used in defense of liberty:
> soap, ballot, jury, and ammo. Please use in that order."
> -Ed Howdershelt (Author)
> Neurotics build castles in the sky,
> Psychotics live in them,
> And psychiatrists collect the rent.
>
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