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Work holding a Featherweight 18" straight edge for machining

I was referring to the distance measured between the sole and the top rail. My mill is much, much, less than new. 😉 There is plenty of wear in the table. So I suppose that would make sense. When the table is at the extreme left or extreme right, it probably sags that much, raising each end of the SE just enough to cause the error? Hmmm. Now I need a 48" SE. 😂

I wonder if it's feasible then to put a .0015" shim under the center some how to account for it? Not for this project, just for the next one. 🙂 I'm going to leave it as is. It'll have to be scraped out, if I decide to take it that far. I'm not too concerned at this point, based on your opinion that it's not "bad." But if I my assumption is correct, at least it's something I can work around when I need to.
I think I’d sit down, put my feet up, and savor a job well done!

Denis
 
I still have a few more machining operations to do tomorrow when I get home from the rail yard. I am going to take an end mill down the front and rear of the top rail, then move some clamps around to get the sides nice and straight. Next will be the back of the sole. And I found a .500" ball end mill (likely shop ground) that I am hoping is sharp enough for the finger groove. All of that should go pretty quickly until I get to the finger groove, which I already know exactly how I am going to set that up, and as long as the end mill is sharp-ish, should come out nice.

Stay tuned.

Denis, in case I forget to tell you when I am done with it, I could not have done any of this without your help (or your casting! 😂). Please know that you and the others that have chimed in are very much appreciated.
 
Although somewhere along the way I made a mistake. When I measure the thickness, the right end is .0002" thicker than the left. But the center is .0014" thicker.

Those numbers put you in scraping territory. It doesn't make sense to spend more time with the mill. (If you have a surface grinder then you could improve the flatness before scraping.)

Either with a Biax or by hand this shouldn't take long. Just remember to "paint scrape" it flat first, before you start shooting for points and scraping for real.

Here's some inspiration, look about 14:30 in:
 
Those numbers put you in scraping territory. It doesn't make sense to spend more time with the mill. (If you have a surface grinder then you could improve the flatness before scraping.)

I don't have a surface grinder. There's one at the rail yard, but I have never seen it in use (it does run) and don't really know how to set one up properly. Plus, I doubt it's wide enough for this SE.

As for scraping, the reason I am working on this so fervently, but with some level of patience, is I am taking it with me to a scraping "class" a friend has set up at his home for me and one other person. We're going to spend a two days at his shop in Wisconsin starting on Tuesday and this will be my classroom project, or I hope it to be. I'm going to take a small angle plate with me as well, just in case. 🙂

We'll see how far I get in class and then finish it back here at home. I still have to procure the proper hand scrapers, and a means to sharpen the carbide, but I am waiting until after class so I know what I want to get. I have no immediate need for the SE, but will by this time next year, if all goes to plan. That'll give me time to practice and practice some more.
 
Some instruction is a good idea. But don't wait for that. Instead of spending your time trying to mill it flatter, I suggest that you do the following:
(1) buy or build a carbide scraper
(2) make a carbide scraper sharpener
(3) get a piece of cast iron, and
(4) start practicing.
In particular (2) will make it possible for you to scrape efficiently. I think you've already got a surface plate and you can get bluing or the stuff to make it at an art store. For (4) you can find decent tutorials on YouTube.

You can get everything on the cheap if you want. For (1) you buy a Sandvik 20 x 25 or 25 x 30mm carbide scraper insert and get some flat strip steel and turn piece of wood or get a sanding pad as a handle. For (2) you repurpose a cheap (Ebay/Craigslist) 4 or 5 or 6" grinder, with either a cast iron disk plus diamond lapping compound or a cheap (Ebay/Alibaba) diamond disks.

Here's my 18" (Richard King) straightedge as I was scraping it in.
 

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Some instruction is a good idea. But don't wait for that.
(1) buy or build a carbide scraper
(2) make a carbide scraper sharpener
(3) get a piece of cast iron, and
(4) start practicing.
In particular (2) will make it possible for you to scrape efficiently. I think you've already got a surface plate and you can get bluing or the stuff to make it at an art store. For (4) you can find decent tutorials on YouTube.

My class starts 4 days from now. Not sure I have time to do all that. 😂
 
Denis, in case I forget to tell you when I am done with it, I could not have done any of this without your help (or your casting! 😂). Please know that you and the others that have chimed in are very much appreciated.
I think you got a lot of help from a lot of folks on this. But, for my part, I truly enjoyed approaching this familiar-to-me casting in a way different from my routine. You opened my eyes to some options I had not considered.

I love it when people who have purchased my castings send me progress reports and "ta-da" pics of their finished straight edges. I do enjoy casting them and all that goes with it (spent the last full week redesigning and rebuilding my furnace lid and chimney, for example.) But, it is the contact with people and the beautiful finished results that completes the process.

Denis
 
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Been a very busy day, but I completed the machining on the SE!

But first I spent about 6 hours at the rail yard finishing the machining on some pins that are used for part of the suspension on a steam locomotive. Fun stuff.

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Once I got home, I finished the machining of the top rail, front and back, then machined the sides.
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Then I had the extra long (and extra dull) end mill I was able to use on the back of the sole.

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If I had an HBM, I'd have machined those webs, too. 😂

The last op was for the finger groove. I finally put my K&T to use for a "real" job!

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I still need to debur everything, and give it a good cleaning with some degreaser. I'm thinking of putting a little color in the back where the remainder of the unfinished surfaces are. As Denis predicted, it lost about 2 pounds.

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I could not be happier with the result, and you are all are why it came out as good as it did. Could not have done it without your help and advice.

I think I'll build a nice box for it. But, in the meantime, I will be headed up to Milwaukee, WI from Cleveland, OH for a couple of days to begin my education on machine scraping it!
 
I did discover one issue yesterday afternoon, and it's too late for me to do anything about it now, as far as remachining it. When I placed the SE on it's bottom on the three brass domes, it looks like those domes might be bronze instead of brass. It left little dimples in the sole. 😢

I am sure they are small enough and shallow enough that it won't affect the ultimate use of the tool, but a little disappointing that it's not "perfect." I can be a bit of a perfectionist, and a bit OCD, so it bugs me. Especially since I spent a good chunk of change (for me) on the casting and even more in time machining it.

If I had to guess, I probably have 10 hours into this. I have almost 5 hours of video footage that I will have to whittle down to around 30 minutes for the yootoobs. That should be fun! 😵‍💫
 
I did discover one issue yesterday afternoon, and it's too late for me to do anything about it now, as far as remachining it. When I placed the SE on it's bottom on the three brass domes, it looks like those domes might be bronze instead of brass. It left little dimples in the sole. 😢

I am sure they are small enough and shallow enough that it won't affect the ultimate use of the tool, but a little disappointing that it's not "perfect." I can be a bit of a perfectionist, and a bit OCD, so it bugs me. Especially since I spent a good chunk of change (for me) on the casting and even more in time machining it.

If I had to guess, I probably have 10 hours into this. I have almost 5 hours of video footage that I will have to whittle down to around 30 minutes for the yootoobs. That should be fun! 😵‍💫
There's an old trick I learned, you take a wet towel and a hot clothes iron and...

But seriously, you haven't scraped it yet, they look worse now than they will when you are done, if they are visible at all.

Edit: Or use the half rounds to dimple the entire surface in an aesthetically pleasing, semi-random pattern, embrace them as a form of flaking.
 
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I did discover one issue yesterday afternoon, and it's too late for me to do anything about it now, as far as remachining it. When I placed the SE on it's bottom on the three brass domes, it looks like those domes might be bronze instead of brass. It left little dimples in the sole. 😢

I am sure they are small enough and shallow enough that it won't affect the ultimate use of the tool, but a little disappointing that it's not "perfect." I can be a bit of a perfectionist, and a bit OCD, so it bugs me. Especially since I spent a good chunk of change (for me) on the casting and even more in time machining it.

If I had to guess, I probably have 10 hours into this. I have almost 5 hours of video footage that I will have to whittle down to around 30 minutes for the yootoobs. That should be fun! 😵‍💫
Just for fun, measure the depth of those "dimples." I would think they really are just a bit of crushing of the raised texture left by the cutting tool. If you managed to press brass into cast iron, you will have a scientific paper to present to ASM.:D

Easiest way to measure them would be to put a DTI on your mill head and traverse over the spot in question. I think you might see a decrease in the nervouse vibration of the DTI needle, but probably a few tenths, at most, deflection.

They will scrape out on the first pass.

Denis

Added later: The short version of this note is "It'll buff out." ;-)
 
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Progress. Took some pictures throughout the day. I'm probably 7 or 8 passes in. It was high in the middle at the start, but as I continued to scrap the blue areas, the edges are starting to find spots. Tomorrow, I will keep scraping over the whole thing until I see blue spots from edge to edge. Part of this looks like I am going backwards, but I am assured that I am actually making progress. I am hoping by the end of the day, I am at least close to getting the sole scraped in. But I am pretty sure that was easy part.

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Try this: before rubbing the straightedge on the blued surface plate, first put a contrasting colour onto the straightedge. I like red and yellow. Put a dab of colour and spread it with a paper towel, then use a spritz of brake cleaner or carb cleaner followed by another paper towel to thin it. THEN rub your part on the blue surface plate. The contrast makes it much easier to see and read the pattern. (See the picture in post 65 above.)

Also, from the looks of the patterns you are showing us, you shouldn't be going for points yet, you still need to scrub away the high areas to get the surface roughly planar first.
 
Thanks for the tips. I had been receiving similar instructions from my teacher.

Here it is after the end of day 2. This was 100% hand scraped by yours truly. The old schools guys that are showing us the ropes said to leave it as is and send it. This is just the sole. Could it be better? Probably. Will it make much of a difference? Some would say yes, some would say no. For now, I am going to move on to the prism, but I'll be doing that on my own, back in Ohio. I was given a nice hand scraper that has a HSS cutting edge on it and a handle made from one of his kid's baseball bats. I also received a Sandvik blade to make my own carbide scraper. I tried his Biax, but I wonder if it would take more practice to learn to use it than the hand scraper! LOL! That thing can get away from you in a hurry.

End of Day 2.JPG


Ron can still make the nice hook pattern even after all these years. I am impressed with how easy he makes it look. Took him about a year as a full time scraper to get that good. Which might mean I'll never be even a tenth that good. But I will keep pressing on to learn new things.

 
So, does Ron regularly teach scraping or is this a sort of special class he set up for you and the other guy? A student teacher ratio of 2:1 is pretty nice!

Denis
 
So, does Ron regularly teach scraping or is this a sort of special class he set up for you and the other guy? A student teacher ratio of 2:1 is pretty nice!

Denis
It ended up being 3:1.5 😉
Kyle from Vanover Customs joined us, and one of Ron's longtime friends and machinists/rebuilders, Roger, came up for part of the second day.

Ron says he is retired from all this after our class. He wants to sell all of his K&T parts, etc. and maybe even sell the property his shop sits on. The only project he has left is a K&T 1H that he is restoring and is donating to the West Allis Historical Society that is taking over the old K&T building and turning it into a museum. I think it might even be considered a national landmark or something.

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Of course, we kept kidding him and telling him he can't retire, or at least not until we all come back for the advance class! 😂
 
It ended up being 3:1.5 😉
Kyle from Vanover Customs joined us, and one of Ron's longtime friends and machinists/rebuilders, Roger, came up for part of the second day.

Ron says he is retired from all this after our class. He wants to sell all of his K&T parts, etc. and maybe even sell the property his shop sits on. The only project he has left is a K&T 1H that he is restoring and is donating to the West Allis Historical Society that is taking over the old K&T building and turning it into a museum. I think it might even be considered a national landmark or something.

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Of course, we kept kidding him and telling him he can't retire, or at least not until we all come back for the advance class! 😂
Sounds like a guy with a huge knowledge base. Too bad to lose him to retirement! Would he be at all interested in contributing some of his knowledge to PM?

This question can go into the dumb question file, I suppose. But does he pronounce it Kerny or Carny? The reason I ask is that Nebraskans pronounce “Kearney” as “Carney.”

But then S Dakotans pronounce Pierre as pier…

Denis
 
I honestly couldn't say, but he doesn't strike me as someone that likes to sit in front of a computer. He and I text occasionally, but I get the impression he'd rather talk on the phone. He thinks we have to be nuts to hand scrape for "fun." 😂 He does enjoy telling people about it and sharing what he knows. I did record some video and plan to edit it into a short YT presentation at some point.

IIRC, he pronounced it like "kur-nee" - and he knew both Kearney and Trecker personally, so I would take it for what it is. Maybe he also mispronounced it and Kearney was too nice a guy to correct him? 🤷🏼‍♂️😂
 
Mule,

I know it really does not mattter. But, did you get any sense as to how flat you got the faces using the milling methods you showed us? And were the "dimples" really just very superficial or were they more than just blemishes on the milled surface? Just curious.

Denis
 








 
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