Scraping a King-Way Straight-edge and the Scraping Classes

Hi I was going to add something to Paolo's Dennis Foster Feather Weight SE tread. I tried to delete the whole thing, but it wouldn't work.
These were done by my students during a class or after a class I taught them.
Steve Watkins in Texas Planing 2 SE's

Working on some straight edges... - YouTube

Warrens friend planing a KingWay SE

Planing of Straightedge - YouTube

Stefan G in Denmark Class
6 minute mark and 17 is interesting about SE Bending. Scraping class 217 in Denmark - YouTube

Keith Rucker after a class

Scraping a Camelback Straight Edge Flat - YouTube

also a couple of good ones from John Sanders of NYC CNC

What is Metal Scraping? - YouTube

Fast Forward to minute 16

Richard King Metal Scraping Class! - YouTube

You can also see several others about my classes, scraping and machine rebuilding by searching on You Tube "Richard King Scraping"

Thank you for posting these.

I'm getting prepared for the scraping class in a few weeks. One of the things I am bringing is a now ready-to-scrape 24" KingWay straightedge.

First step was sandblasting and 2K epoxy:



Next step was to cut a reference surface on the ribs:



Then I trued the top. I did this because my mill (Deckel FP2) only does 500mm = 20" in X, and the scale is 600mm=24". So I needed a reference surface so I could reclamp the scale after shifting it 100mm = 6".



Now I could do the bottom (two clampings)



Then I did the vertical face (not shown). Then clamped in V-blocks





and "plane" the 45-degree edge with a spiral shell mill. Again, two clampings were needed.


Final result is ready to scrape. My surface grinder is only 450mm=18", but if the class has easy access to a longer surface grinder, I will run it through there first to clean up the "blends" between clampings

Richard, I'm going to make a storage box for the scale. If you don't advise me otherwise, it will rest on the Airy or Bessel points. Alternatively I can "suspend" it from the circular holes closest to those (probably holes #2 and #5) so that the bottom face is not touching anything. What do you recommend? As always, photos are appreciated .

Rich- thanks for posting, the youtube video with the planer made me jealous that I never got my planer going, but I know it now has a new home with somebody who will make some money with it.

My comment would be if people have the the opportunity- after they machine a straight edge from a raw casting- get it back in for another stress relieve. 4 hrs at 1250 is ideal but even if they can get 1000 deg it all helps. Remember slow cool.

We do this when we grind precision surface plates, after rough machine/ grind we toss back in the furnace for a stress. They finish grind much easier/no movement.

Note- these parts all had a stress at the foundry. Bur once we take the "crust" off it does change.

I had been recommending for years to have it stressed a 2nd time but after going to a new stress relief company that said 1 time after casting was good enough. He does it a different way. He gradually heats his 10' x 10 x 10 furnace up to 1170 and cooks the casting for 24 hours at that temp then shuts off the gas. He said it take approx. 8 to 10 hours for it to lower to appox 150 degrees and he opens and then lets them lower to room temp outside the furnace. He showed me the furnace and the walls were 12" of insulation.


I haven't had anyone complain with the new method. But have noticed that if you don't machine off at least 1/8" after clean up some of the intercepting tips where the angle and flat meet get hard.


Ballen if I were you I would mill the angle until the cut hits the ribs as that will lighten and increase the width of the angle. although that will narrow the flat.. I have been thinking a test in a few of mine by drilling 1/2" holes apporx 1 1/2" apart on the back side flat to lighten the casting a bit.


This straight-edge design was made by my Dad over 60 years ago. He felt the parallel design was more stable then the arch design like Brown & Sharpe and Challenge used. I also make and sell plane camelbacks with-out the angle that cuts down on the weight by a 1/3. I just made a new 12" camelback with a 45 and a 50 degree angle on them as it is handy sometimes especially when working on Monarch lathe compounds. We also used to make the non angle prism SE's but now that one can buy sawed Dura-bar I stopped making them.

I also make 12", 18", 24", 36", 60" and 72" Camel backs with angle like Ballens and the ones being planed (HKA model) and with-out (HK model) the angles. If anyone would like more info PM me your email address and I will email you the spec's. The 36" Plain HK-36 Camel back that we make is 33 pounds before machining. It is pretty light too. It seems many now-a-days buys the camelback with the angle so they can do a mill and a lathe. As a pro who scrapes both I would use the lighter non angle camelback as say for an example the HKA-36 (camelback with angle) weights 55 pounds. If your curious my dads name was Herman King. That is where the HK model description came from.
Pic's L to R: New HKAS-12 S= special, HKA-18 casting, HKA 18 getting scraped and HK-36

Richard King said:

Ballen if I were you I would mill the angle until the cut hits the ribs as that will lighten and increase the width of the angle. although that will narrow the flat.

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Richard, OK, will do. Shouldn't I leave a bit of a gap to the ribs, to make it easier to print the angle? Otherwise the surface plate will bump against the ribs and prevent good contact. Should I do the same thing to the vertical flat, meaning trim it back until it gets close to the ribs? Or better to keep some more meat there?

Would appreciate any wisdom regarding a wooden box. Perhaps I am overthinking it and having a (soft) support along the entire bottom edge would be best, this would spread the load.

Cash, my shop furnace is about 200mm = 8" inside, way too small. But for what it's worth, the cast iron had no skin, inclusions, hard spots, bubbles, sand, etc. It cuts beautifully, should be fun to scrape.

With our product line I have up to 72" long vacuum furnace available. So I can send items thru " for the ride" when needed.

It may be more of being anal, but every little bit helps.

Ballen- thanks for the pics and have fun! Your shop is so clean.

cash said:

Your shop is so clean.

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Cash, in all the time that I have corresponded with you here, this is the first dumb thing you have said. All my photos are carefully cropped to remove the chaos in the background.

[EDIT] Or perhaps you are just teasing. Looking at my pictures again, I can see a bunch of this chaos poking through in the background.

ballen said:

Richard, OK, will do. Shouldn't I leave a bit of a gap to the ribs, to make it easier to print the angle? Otherwise the surface plate will bump against the ribs and prevent good contact. Should I do the same thing to the vertical flat, meaning trim it back until it gets close to the ribs? Or better to keep some more meat there?

Would appreciate any wisdom regarding a wooden box. Perhaps I am overthinking it and having a (soft) support along the entire bottom edge would be best, this would spread the load.

Cash, my shop furnace is about 200mm = 8" inside, way too small. But for what it's worth, the cast iron had no skin, inclusions, hard spots, bubbles, sand, etc. It cuts beautifully, should be fun to scrape.

Click to expand...

Yes a Gap is good so you don't bump into a ledge. The back is fine. Some drill out some holes along the back to lighten it up. I have never done it myself. We will be ringing the straight-edge while you are scraping it. Hang from a rope and whack it with a soft blow hammer to do some in-person vibration stress relief. Like a tuning fork :-) As far a box I would make it a look like a Starrett Level box and have 2 1" felt strips at 30% from each end and felt or rubber cushions on the lid to hold it in place. Your pictures look GREAT and Cash is not dumb....lol Must be a error in translation...lol

Richard King said:

Yes a Gap is good so you don't bump into a ledge.

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OK, I trimmed back the angle edge, took off a few pounds/kg of mass. Also spent some time rounding over edges so it handles nicely no matter where you grab it.

A forum member bought a HKA-36 (45 deg. camelback 36") Just like Ballens but 12" longer today and I refunded his shipping cost.
I will do that for all state side orders for 2 more days the 5 TH on Straightedges 36 or less. Thanks