HP inset bar

Ian

Notorious member
Exactly. The engenuity of some our south of the border friends is not to be underestimated.
 

Pistolero

Well-Known Member
Nope, that was no slam, actually a comment of the ability to do stuff with
what you have at hand.

Just to clarify the mental image.....rubbing the cinder blocks on the heads, or just
to flatten the floor, and rubbing the heads, parting face down, on the floor. I am
guessing the second.

Bill
 
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Ian

Notorious member
There's a technique to flatten a surface by rubbing two different flat-ish surfaces on it, eventually the average wear pattern becomes perfectly flat. I'm not sure exactly how it is done but it has been known for millennia. Once the concrete slab had been dressed perfectly using cinder blocks, it was wetted down and the head moved around on it in a figure-8 pattern.
 

KeithB

Resident Half Fast Machinist
A shirttail relation from my wife's side of the family used to mess with motorcycles, usually Brit stuff like Nortons and BMWs. I saw him use a piece of plate glass and some type of grinding paste to flatten the heads out to a very flat finish. He also used a figure 8 pattern to even out the wear.
 

KeithB

Resident Half Fast Machinist
Brad, if you can make the base of the pin into a .001 interference fit into the bar I bet that would be all you would need to hold it in place while machining. Do you have a 3/16" reamer? You mentioned turning the base of the pin to .2", why not just a snidge smaller at .189"-.190" for a light press fit into a .188" reamed hole?
 

Pistolero

Well-Known Member
Friction is the most reliable force on the planet.

And a different pattern will give you a spherical hollow, and then even a finally,
slightly different pattern will approach a pure parabola within an 1/8th wavelength
of visible light. I made a telescope mirror this way. One pattern for roughing to
a spherical shape, coarse, fine, finer, finest. Then 'figureing' to take off a few millionths
extra in the right places to go from spherical to parabolic. Simple tools can do some
truly amazing things, read Ian's signature line one more time.

Bill
 
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Brad

Benevolent Overlord and site owner
Staff member
No 3/16” reamer. Not going to be a round hole but I could easily drill a hole and turn a stub for a press fit. Had not considered that.
I don’t own an arbor press but the mill vise should work fine.
Tooling costs are rapidly adding up. Got in 3 orders last week. One from Shars and a couple from EBay for end mills and a couple dial test indicators. Just got ina couple taps and a die along with the drill rod from MSC today.
 

Brad

Benevolent Overlord and site owner
Staff member
You have an entire brand new tool chest that "needs" filling up, long ways to go yet.
Care to make a donation?
I am fortunate to have a wife who doesn’t question much. I try to keep purchases in line and under control.
 

Pistolero

Well-Known Member
Thank goodness I have built up my stuff over the years a good bit, spreading the
expenses out. Lots of money there in the fun department. Wouldn't change a thing.

Bill
 
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freebullet

Guest
I'm pretty well convinced a man can't possess enough tools, just like guns, lead, primers, & powder...no such thing exists in my mind.
 

Brad

Benevolent Overlord and site owner
Staff member
I got an HP roughed put today before work. I need to make the other one as close to the same as possible, that will be a test for me.
 

Brad

Benevolent Overlord and site owner
Staff member
This thing is kicking my ass. I spent 4+ hours on it today’s so far.

I got the mould drilled, the pins made, and am now in the final fitting stage. I don’t feel binding but the mould doesn’t close fully at the bottom. After I get lunch I will look at that more and get it done.

There isn’t a snowballs chance in hell I would do this for anyone else. I don’t know that I would do it again for me.

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freebullet

Guest
Pretty impressive if you wined up with something usable for a first try with this type of project, especially at the hobby level. Nice work, Brad.

I reckon a second retrofit might go easier/faster. Anything you would do different if you tried another?
 

KeithB

Resident Half Fast Machinist
There isn’t a snowballs chance in hell I would do this for anyone else. I don’t know that I would do it again for me.

Had that thought before and totally understand! It does look pretty good, ought to make one bad-A hollowpoint.