What's new
What's new

New Design 26" Prism/Straight Edge/Parallel/ Level is ready to go!

dgfoster

Diamond
Joined
Jun 14, 2008
Location
Bellingham, WA
About two months ago I started talking about making a new straight edge/prism of about 24" length. One of many good suggestions I got here was to make it just a little longer---26" That seemed like a very good idea. So that is what was done. This straight edge is very similar to my 18 (which has been very popular) except it is a little taller and wider as well as 8" longer. It will accommodate a precision level vial in either of the center two "bays" just like the 18 does.

As cast it weighs right at 20 pounds (and about 15 pounds or less machined). It is 26 3/8" long. The sole is 3" wide and it is 2 1/2" tall. It can be shipped for about 40 dollars anywhere in the US and PR. the faces intersect at about 45 degrees, but can easily be machined to much steeper angles if needed.

Here are a few pics.

Just coming out of the sand
26 Casting3.jpg

Seams ground and gates trimmed off
26 Casting.jpg


I am pleasantly surprised at how straight it is right out of the mold. A straight edge laid on the faces shows no more than a 1/16th gap. The faces are cast at about 45 degress included angle. But there is plenty of meat to machine the faces fully to 55 degrees. And, if an even steeper angle is needed for some reason, the faces could be milled to an even steeper angle with the top face being about 2 to 2.5 inches (should be a great plenty for almost all applications) wide.
26 Casting4.jpg


A couple more views.
26 Casting1.jpg26 Casting2.jpg

I will be properly thermally stress relieveing every one. I sell none with any rail or prism face defects larger than normal casting pock marks which could be as large as 1/16" or so and would be expected to machine out as at least 1/8" is intended to be machined off each face. Incidentally machining it should bring its weight to 15 pounds or so. In the 18 this design has proven to be very rigid and stable.

I have now cast this pattern 3 times all with good results so I think I can say the bugs in casting (actually it worked from the first casting which I never expect!) are worked out. I will be pricing it at 275 plus shipping. A few folks signed up early on when I suggested the price would be "about 250" and I intend to honor that price for them. Their encouragement helped me push this through to completion.

Denis
 
Here is a video of the first 26 pour. I left it long on the end so you could watch the coal gas that evolves from the mold catch fire and slowly char the flasks. Subsequent to this pour I applied aluminum flashing to the flasks using the char areas as clear-cut maps as to where flashing was needed. The flashing doesn’t completely prevent charring, but it does help. I dare not just hose down the flasks with water as that could chill the iron causing it to become hard. In the larger steel flask is a mold for a 36 camelback.


Denis
 
That’s pretty cool. How long does it take to cool to ambient?


Sent from my iPhone using Tapatalk Pro
 
That’s pretty cool. How long does it take to cool to ambient?

I don’t always let them cool completely to room temp. Letting them get down to 250 is well past cool enough. They will be in that range 4 or 5 hours after pouring. If I leave them for 12 or 15 hours, they still will be a little warm—-maybe 20 or 30 above ambient.

Pouring always makes for good drama video, but in reality, the real skill and “touch” is in the pattern making, green sand molding, and mold prep. It takes an hour and 45 minutes of very careful work to pack mulled sand into a mold and have it ready for pouring. There are many hand steps in the cutting of gates, pouring basin, runners and risers and blowing out every last remnant of loose sand. Even so, there is probably a 25 to 40 per cent failure rate where a bit of sand fails, or a piece of slag slips by the filter and lands in the wrong spot. Opening cooling molds is like Christmas—-you have high hopes even though you are unsure what the package contains. And getting the sand mulled right so it is damp enough to pack well, but not so wet it emits too much steam also takes judgement. In other words, there is a lot of guesswork. In a huge factory like GM where they are making motors etc, they have everything instrumented, computer simulated, and lab analyzed to remove practically all the guesswork. But in the small or even medium sized foundry that is simply not feasible.

I think that is what makes it fun.

Denis
 
Looks like you're getting some good help from Joe Magarac. Nice to know he didn't just disappear with the advent of computers and such.

No, that guy in the video was me! I can see why you might have mistaken me for him. ;-) ;-) ;-)

Truth be told I did not know who Joe was. Google came to my rescue.

"Joe Magarac was an imaginary folk hero, like Paul Bunyan, whose story came from eastern European immigrants working in Pittsburgh area steel mills. His physical power and his brave, generous, and hard-working character made Joe Magarac (whose name "Magarac" means "donkey" in Croatian) the greatest steelworker who ever lived.

Physical traits

Joe Magarac, the story goes, was a man made of steel. He was born in an iron ore mine and raised in a furnace. Some versions of the story said Magarac was seven feet tall. Others claimed he was as tall as a smokestack! His shoulders were as big as the steel-mill door and his hands like the huge buckets (ladles) used to pour molten steel. He ate that hot steel like soup and cold steel ingots like meat. He could drink a gallon of liquid in one swallow.


Actions

The mighty Magarac could do the work of 29 men, because he never slept, working 24 hours a day, 365 days a year. He stirred vats of hot steel with his bare hands and twisted horseshoes and pretzels out of iron ingots. He made railroad rails by squeezing molten steel between his fingers. As the steel cooled, he made it into cannon balls as easily as kids make snowballs.


Character

Besides being physically strong, Joe Magarac was generous,
self-sacrificing, and brave. Once, for example, he won a weight-lifting contest and the prize was marrying the mill boss' daughter Mary. But Mary was in love with Pete Pussick. Instead of claiming his prize, Joe stepped aside so she could marry her true love (after all, if Joe had a wife, she would be very lonely while he worked 24 hours a day, seven days a week!).


Joe could appear just about anywhere in the mill in seconds by walking from one hot furnace rim to another. He used this ability to appear out of nowhere to save steelworkers from danger. When a crane holding a ladle with 50 tons of molten steel broke right above his crew, he caught it with his bare hands. Not a drop of hot "soup" splashed on anybody.

A whole train of loaded ingot-buggies broke loose and headed full steam downhill toward a group of employees. Just in the nick of time, Joe caught the last buggy and pulled the train back up hill, saving everyone!

No one is sure what happened to Joe. In one version of his story, he jumped into a Bessemer converter to save a load of steel and lives on in the girders of a new building or bridge. Another version claims that he is still alive, waiting in a abandoned mill for the day that the furnace burns again


 
I'm quite impressed, Denis. Obviously casting iron at home is a labor of love. I hope you make a bucket full of money.

metalmagpie
 
I'm quite impressed, Denis. Obviously casting iron at home is a labor of love. I hope you make a bucket full of money.

metalmagpie

Let's see, "labor of love" and "bucket full of money" don't usually go together. I make a little more than my expenses for fabrication and maintanence of the equipment (particularly the furnace) you see and don't see in the video, fuel costs, driving to and from the heat treater and metal supplier, cutting tools,and general barn maintenence. I'm afraid what's left over won't cover the grocery bill. But, that certainly was not the primary goal. It is a hoot trying to figure out how to come up with a useful tool of a new design and then make a pattern that actually pulls from the sand and then figure out how to fill the mold without shrink defects, pouring short, sand wash, chill defects etc. This is about as intiguing a game as I've ever played.

There may be a half dozen to dozen or so folks in North America who melt iron on a small scale using fuel-fired furnaces. Almost all the other iron is cast by full-on foundries using induction furnaces and having 20 to 30 people on the payroll as a minimum. I am fortunate to have a commercial foundry an hour's drive away that mentors me and helps me source otherwise-difficult-to-find raw materials. I think it is interesting that when they are allowed to turn on their furnace certain hours of the day, they can draw down the regional power supply if they are not very careful. Thus the time restrictions on the hours of melting.

Denis
 
that is really cool. I'm particularly impressed with how seamless the process was - the booms/ cranes were in the perfect place to deliver the material exactly where it needed to go. I'm guessing that the lack of drama or excitement is truly the mark of a smooth and well practiced operation!
 
that is really cool. I'm particularly impressed with how seamless the process was - the booms/ cranes were in the perfect place to deliver the material exactly where it needed to go. I'm guessing that the lack of drama or excitement is truly the mark of a smooth and well practiced operation!

Thank you! Yes it helps to have done it many many times. Each time I notice something that can be improved with a tweak here or and adjustment there. What you are seeing is the result of a lot of tweaks. I keep trying make it work more smoothly and therefore predictably. Then something breaks down. That is when it gets interesting, like when my pyrometer gave out on a night time pour. Guessing on melt temp is no fun. Guessing in low ambient light is much harder. It worked out, but a lot of molding work and setup time goes down the drain if things go sideways. In iron casting it is very hard to have it go right without the occasional glitch. That is true for the small-timer like me and for my mentor too. He has some pretty good stories to tell.

Denis
 
No, that guy in the video was me! I can see why you might have mistaken me for him. ;-) ;-) ;-)

Truth be told I did not know who Joe was. Google came to my rescue.

"Joe Magarac was an imaginary folk hero, like Paul Bunyan, whose story came from eastern European immigrants working in Pittsburgh area steel mills. His physical power and his brave, generous, and hard-working character made Joe Magarac (whose name "Magarac" means "donkey" in Croatian) the greatest steelworker who ever lived.

Physical traits

Joe Magarac, the story goes, was a man made of steel. He was born in an iron ore mine and raised in a furnace. Some versions of the story said Magarac was seven feet tall. Others claimed he was as tall as a smokestack! His shoulders were as big as the steel-mill door and his hands like the huge buckets (ladles) used to pour molten steel. He ate that hot steel like soup and cold steel ingots like meat. He could drink a gallon of liquid in one swallow.


Actions

The mighty Magarac could do the work of 29 men, because he never slept, working 24 hours a day, 365 days a year. He stirred vats of hot steel with his bare hands and twisted horseshoes and pretzels out of iron ingots. He made railroad rails by squeezing molten steel between his fingers. As the steel cooled, he made it into cannon balls as easily as kids make snowballs.


Character

Besides being physically strong, Joe Magarac was generous,
self-sacrificing, and brave. Once, for example, he won a weight-lifting contest and the prize was marrying the mill boss' daughter Mary. But Mary was in love with Pete Pussick. Instead of claiming his prize, Joe stepped aside so she could marry her true love (after all, if Joe had a wife, she would be very lonely while he worked 24 hours a day, seven days a week!).


Joe could appear just about anywhere in the mill in seconds by walking from one hot furnace rim to another. He used this ability to appear out of nowhere to save steelworkers from danger. When a crane holding a ladle with 50 tons of molten steel broke right above his crew, he caught it with his bare hands. Not a drop of hot "soup" splashed on anybody.

A whole train of loaded ingot-buggies broke loose and headed full steam downhill toward a group of employees. Just in the nick of time, Joe caught the last buggy and pulled the train back up hill, saving everyone!

No one is sure what happened to Joe. In one version of his story, he jumped into a Bessemer converter to save a load of steel and lives on in the girders of a new building or bridge. Another version claims that he is still alive, waiting in a abandoned mill for the day that the furnace burns again



That much research, we can make you an honorary Iron City citizen!

Fair warning.. Steelworkers ARE legendary EATERS!
It had never been exactly "light work".

Max's Allegheny Tavern, Northside, (my birthplace is nearby), and "my shout", ever we happen to be in the area same time. Check out the menu. Some of it should be familar enough?


(412) 231-1899 - Home

Not the same cuisine as at "Paris, 1930" at the old Ritz, Taipei, but there you have it..

The Landis Taipei Hotel

honest enough food at either. Main difference is the COST!

Northside is not the most attractive of environments. Nor Pittsburgh, in general. Guess that's part of the reason so many of us "from Pittsburgh" are FAR "from..".

But the mix of people, a true "melting pot" are its grandest, and most attractive strength. Much as the set of attributes they respected in "Joe Magarac" tells as much about the story spinners telling it as it does about the hero the've spun to speak of.

Mind.. I may be a poor commentator, given I find that "people thing" true much the world-over?

But there yah have it. What keeps life interesting.., humans, their many and curious endeavors... and how they handle it all.

:D
 
In iron casting it is very hard to have it go right without the occasional glitch. That is true for the small-timer like me and for my mentor too. He has some pretty good stories to tell.

I realise that they are not "your" stories. Even so, it would be nice to hear some of the better ones here :D.
 
I just received a 26" prism casting as well as an 8" prism casting. Both castings are clean and as advertised. Denis did a great job packing these for shipment in a custom made wooden crate and went out of his way to keep me up to date on the shipping status. I could not be more satisfied. It'll be a while before I can get to getting these machined and scraped but it'll be great fun once i can finally get to it.

Mark
 
I just received a 26" prism casting as well as an 8" prism casting. Both castings are clean and as advertised. Denis did a great job packing these for shipment in a custom made wooden crate and went out of his way to keep me up to date on the shipping status. I could not be more satisfied. It'll be a while before I can get to getting these machined and scraped but it'll be great fun once i can finally get to it.

Mark

LOL! If Denis ever runs out of new things to chase?

He could take up fine cabinetry as an extension to his shipping-case techniques!

I cheated. Ordered my one and its predecessors fully-machined. And told him to take all the time he needs! Results have been "impressive" to say the least!

Taking MY sweet old time with "Mother Nature's thermal cycling" since I could NOT get them into my bottom-drawer freezers after all.

"Lookin' good" so far. Very!

He may yet win a side-bet we have on when they go off for precision grinding.
 
Watching that, I was initially "interested" at the wet-looking ground, and apparent lack of any meaningful PPE.

Once I saw the setup, and realized how far you actually are from the metal at all times, it became clear to me. Very slick and smooth!
 
Watching that, I was initially "interested" at the wet-looking ground, and apparent lack of any meaningful PPE.

Once I saw the setup, and realized how far you actually are from the metal at all times, it became clear to me. Very slick and smooth!

Yes, I spent quite a bit of time trying to come up with a foundry setup that would allow me to safely work solo.I actually love working with folks but hate relying on them.

Wet ground is not the issue that damp concrete presents. I’ve spilled onto the very damp ground which, in the summer time, is wet due to me hosing it down to prevent potential fire. All that happens is the ground sizzles a bit and some steam rises, but no spattering and certainly no explosions. Now, damp concrete is known to erupt with steam and scatter molten iron over a wide radius. I am able to stay 6 to 8 feet away from the crucible as it is transported and poured. The only time I get within arms’ reach is to lightly skim the standing crucible as a final step prior to pouring.

The hoisting tongs are something I sketched out on a napkin and luckily they have worked without ever even a hint of poor grip. I don’t think I’ve posted info about my foot-controlled wireless hoist/trolley setup that allows painless handling of the molds some of which weight just south of 500 pounds. It would be considered too “home shop” for this forum. But it sure is a big improvement over the chain hoist I was using. And then there is the straddle wagon made from a modified garden cart that lifts and transports the molds from inside to the pouring area. Truly fun stuff to figure out and tweak until they do their jobs just right.

Denis
 
Last edited:








 
Back
Top