Re: [Emc-users] Excedrin headache, somewhere in 6 digit space

[Gene Heskett]

On Thursday 10 August 2017 14:40:35 andy pugh wrote:

> On 10 August 2017 at 04:41, Gene Heskett  wrote:
> > Anybody else have a better idea short of making yet another new
> > cathead out of a considerably thicker walled pipe?
>
> Use a much shorter cathead and poke the barrel down the spindle so
> that you don't need a steady.

Then I'd have to fight with this tap to zero chuck after loosening the 
mounting bolts. What I did was run the lead of the reamer in till the 
end of the neck cutter was just touching. Then, because any damage there 
will be cut away by the reamer, I ran a dead center into it with 20 lbs 
or so push after slathering the center with some very old, black but 
says lithium on the gun tube, chassis grease.  Moved the steady out of 
the way and made an inch of it round again.

Worked a treat and I shaved around 9 thou off a section where the steady 
shoe were going to ride, leaving a near mirror finish but with the dull 
cutter evidence in the subsurface scratches, which did a nice job of 
keeping the grease in place. Steady heating less than 10F. Sweet turning 
now with maybe 5 lbs of pressure. Then of course linuxcnc quit working 
(it only good for 2, sometimes 3 days uptime on the pi, where the pi is 
at 15 days uptime right now), so I had to tear the whole setup down in 
order to rehome it after a restart, not of the pi, but LCNC.  Once that 
was done, and the touchoffs were done again, the rest of it was a matter 
of adjusting this and that, smoking it and test fitting to see where I 
needed to cut another thou.  So thats done and the threads filled with 
this same black grease to forestall any tendencies to have the stainless 
gall and freeze it into the action forever.  Next is the feed cone in 
the back face, which has to be very well polished.  Thats tommorrow, I'm 
beat. It's a 45 degree cone, max o.d. 1.000".

Progress, I think. :)

Thanks Andy.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

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Re: [Emc-users] Excedrin headache, somewhere in 6 digit space

[andy pugh]

On 10 August 2017 at 04:41, Gene Heskett  wrote:

> Anybody else have a better idea short of making yet another new cathead
> out of a considerably thicker walled pipe?

Use a much shorter cathead and poke the barrel down the spindle so
that you don't need a steady.


-- 
atp
"A motorcycle is a bicycle with a pandemonium attachment and is
designed for the especial use of mechanical geniuses, daredevils and
lunatics."
— George Fitch, Atlanta Constitution Newspaper, 1916

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[Emc-users] Excedrin headache, somewhere in 6 digit space

[Gene Heskett]

Evening All;

This supposedly one ragged hole at 300 meters barrel is a P.O.S., but the 
final judgement will be the target of course.

So far I've made 2 catheads, and I've spent the last two days hunting for 
the center of the bore on the butt end of the barrel, and I just now 
came to the conclusion that I'd be dumb and happy if the carthead had 
thick enough walls that the centering bolts couldn't distort it from the 
tension from the 4, 8mm brass bolts used as centering bolts.

I very carefully machined a track where the steady shoes would ride, and 
mine is like all the other steady's, 3 shoes. I put that track about an 
inch back from the centering bolts. I started to make a cut to clean it 
back to round with the bolts tight, as in about 1/4 turn from stripped.

But after watching it bounce from shoe to shoe because its now 4 cornered 
about 5 thou, and the shoes are riding it hard enough to heat pretty 
good despite a coat of lithium based chassis grease, I came to the 
conclusion I should stick a bullet into it far enough I had a smooth 
surface to put the dial finger on. So I ran the reamer in to the end of 
the cartridge neck, letting it guide itself. Insert bullet, probe it, 
needle going 8 to 10 thou crazy at 75 rpms. Several times a revolution. 
Its the 3 shoes bouncing off the high points created by the 4 bolts bolt 
tension.

So tommorrow, I'll put a live center in it, any damage that does will be 
removed by the reamer anyway, and loosen the steady & move it out of the 
way, and see if I can then "fix" the steady track on the cathead with 
the barrel still in it. This ought to be fun.  Not...

Anybody else have a better idea short of making yet another new cathead 
out of a considerably thicker walled pipe?

Thanks guys.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

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