Thread: scraper hone

I have been scraping my shaper and my scraper has finally dulled. Today I scavenged a 1440 rpm electric motor with the intention of building a hone. My question is how big should the face of the hone be and what grade on diamond paste should I buy ?

Hi

I was recently watching the 2011 scraping class video on U TUBE

Somebody was sharpening the carbide ? tipped scraper , on a green grinding wheel ? The student used a sideways grinding action across the wheel face , both sides , the instructor was on hand to guide the learner . Might be worth having a look at it , its easy to find if you do a search for 'scraping' .Mike

From memory Andre I think the size was around 6", and although I think it was much debated, a 4 to 6 micron paste was used.
Check some of the post Scrapefest threads as I was pretty sure that making up a hone was discussed there.

Where's Phil (the clean shaven one) when you need him?

Michael

Originally Posted by welder

I have been scraping my shaper and my scraper has finally dulled.

How many months since you have been down here? And you have only just dulled your blade. What happened to the scrapping practice? I hope you were doing your home work.

6" / 150mm would be about right. I think the cast iron end on mime is a little smaller, but that was just what was on hand.

Forrest says's green - 9 micron. And I'm too tired to agree with him.The Hong Kong paste I have. On Mondays, Wednesdays, & Fridays I use the 5 micron paste, on all other days I use 10 microns, so I average 7.5 microns. (Trusting you blokes get that humour). If your some where about that range 5 - 10 -15. Anything less than 5 is like watching grass grow.

Remember you can just lick it up, on a stationary diamond lap, like an Eze-lap. And there was any amount of scrapping done with green wheels pre 1980's

Phil.

Hmmm

I have totally lost the gist of this thread .. Paste ? Cast iron end ? 6" relates to what ?

I should have attended a class it seems ..Mike

Hi Mike,
Talking about hones, not grinding wheel.
Take a disc of cast iron or aluminium(6" dia in this case), embed(charge) it with grit(in this case 7.50 micro diamonds in a paste ) and off you go.


I haven't been 100% sold on honing though I think a lot of that might come down to the time it takes me to change my grinder from a grinder to a hone. I've just realised I should be able to fix that with a simple bush.

Stuart

Andre
I have done a number of hours scraping Surface Plates, since the Course back in April this year.
Together with a lot of trial & discovery in Scraping.
Mentioned previously I use a slow speed 10 " dia Aluminium Lap on the wood lathe spinning at 300 RPM
I have used 14 micron & 7 micron diamond paste with kero as a lube.
The slow speed seems to work well for me, & is in line with traditional lapping methods.
However, I recently discovered that if a flat stationary cast iron piece on the bench is used like an oilstone, with diamond paste & the scraper rocked back & forwards in the direction of the end radius & tilted at 10 degrees or so, then a good result is obtained.
This method is also quick between scraping sessions. Its the method Connely mentions in his scraping notes on machine rebuilding, used with Carbon steel scrapers.
With the stationary block method, the 14 micron seems to work well.
The initial grind is done with a flaring cup Diamond wheel.
My next trial to keep things simple & low cost to you is to try the "Green Silicon Carbide Grinding wheel", instead of a Diamond wheel.
I have one of these in 8" dia by 1" wide & will set it up on a bench grinder, true it, & let you know results this afternoon.
When you bring your restoration, shaper bits & pieces here next week we can cover all of this in more detail.
regards
Bruce

Originally Posted by Abratool

Andre
I have done a number of hours scraping Surface Plates, since the Course back in April this year.
Together with a lot of trial & discovery in Scraping.
Mentioned previously I use a slow speed 10 " dia Aluminium Lap on the wood lathe spinning at 300 RPM
I have used 14 micron & 7 micron diamond paste with kero as a lube.
The slow speed seems to work well for me, & is in line with traditional lapping methods.
However, I recently discovered that if a flat stationary cast iron piece on the bench is used like an oilstone, with diamond paste & the scraper rocked back & forwards in the direction of the end radius & tilted at 10 degrees or so, then a good result is obtained.
This method is also quick between scraping sessions. Its the method Connely mentions in his scraping notes on machine rebuilding, used with Carbon steel scrapers.
With the stationary block method, the 14 micron seems to work well.
The initial grind is done with a flaring cup Diamond wheel.
My next trial to keep things simple & low cost to you is to try the "Green Silicon Carbide Grinding wheel", instead of a Diamond wheel.
I have one of these in 8" dia by 1" wide & will set it up on a bench grinder, true it, & let you know results this afternoon.
When you bring your restoration, shaper bits & pieces here next week we can cover all of this in more detail.
regards
Bruce

Andre
OK since I wrote the above, the Green Sil Carb wheel was tested.
Its an 8" dia by 1" wide 37C grade 80 J bond spinning at 2850 RPM (About 5700 feet per min)
The results were great. Thanks to "Morrisman" Mike for his suggestion on this low priced sharpening alternative for carbide insert scrapers.
Sometimes the simplest methods are overlooked.
The grade 80 grinding wheel naturally leaves a fairly coarse finish on the carbide, but does grind rapidly.
However this is quickly honed out on the stationary cast iron bench lap charged with
14 micron diamond along one section of the lap &
7 micron diamond along another section of the lap for a finish. Both with a splash of Kero
The latter lapping operations should suffice for some time between regrinds.
We will do some more work on this idea during your forthcoming visit.
regards
Bruce
ps The Green wheel is avail from H & F @ $35 A true running wheel is needed use a Diamond dresser from H & F @$22
The Diamond paste I got from the USA. If you contact "Anorak Bob" BT, he will put you onto the source.
It was low price.
regards
Bruce

Originally Posted by Stustoys

Hi Mike,
Talking about hones, not grinding wheel.
Take a disc of cast iron or aluminium(6" dia in this case), embed(charge) it with grit(in this case 7.50 micro diamonds in a paste ) and off you go.


I haven't been 100% sold on honing though I think a lot of that might come down to the time it takes me to change my grinder from a grinder to a hone. I've just realised I should be able to fix that with a simple bush.

Stuart

Ok thanks for that Stuart . But, do you buy these honing wheels ready to use , or do you make them yourself and buy the diamond paste as a seperate item ? It's all news to me , sorry but I'm only a bushy living out in the wilderness

Is this the idea ?

http://www.inthewoodshop.com/Woodwor...mondpaste.html

Originally Posted by morrisman

Is this the idea ?

http://www.inthewoodshop.com/Woodwor...mondpaste.html

Mike
Thats the general idea, however the concept of detroying a traditional Cast Iron Plane sole would be totally beyond what I could accept, & its not needed.
Just grap a piece of cast iron, face or mill it flat & if required post it to me for a surface grind.
Get hold of the diamond paste & your up & away.
Simple as that.
regards
Bruce

Originally Posted by Stustoys

I haven't been 100% sold on honing though I think a lot of that might come down to the time it takes me to change my grinder from a grinder to a hone.

I was never sold on it. I'm pretty sure I've mentioned that I only knocked mine up to test the U.S / Forest method. I'd never seen that before in industry.

We all know that when you embed a hard substance like carborundum or diamond in to a softer material it makes a lap.
You were there. Christian bought a blade at the grinder thing a month or so back. I sharpened it up for him. And when I was in the shop by myself, and could tune the angle of the lap to the angle of the grinder. I thought that was the best edge I've ever put on.

If your too shallow on the lap, you are only polishing the bevel of the crown where the two negative angles meet. Tip the edge up to where it becomes a sharp edge and you just rip the material out of the face. Marko doe's that to me, he has that high negative angle, so he just rips that face out of the lap. Like you can see shards of aluminium, just as you would fine free hand hand turning.

Originally Posted by Abratool

The results were great. Thanks to "Morrisman" Mike for his suggestion on this low priced sharpening alternative for carbide insert scrapers.

The wheel closest to the wall when you were down here was exactly that, a green silicon carbide wheel. Its not new. If I have to shape a blade that's still what I use. Diamond is too expensive. That's all the guys had 50's - 60's - 80's had.

I can still remember the first diamond wheel I ever saw. Mid 80's my late apprenticeship. Came in a dovetailed box, clothe lined, same quality a set of pearls would be. Name like Noritake Diamond. More than a month's wage.

I'm sure I can remember that blurb. Some thing about "Microcraking" I would have said if I cant see it it doesn't exist. Green wheels were the only way to sharpen Carbide up until the 80's. Remember brazed shank tooling? That was all touched up on green wheels.

Regards Phil.

Originally Posted by Machtool

Diamond is too expensive.

Seen these? Results for Cutting Tools: Diamond Tools:Grinding Wheels

Originally Posted by Bryan

Seen these? Results for Cutting Tools: Diamond Tools:Grinding Wheels

I think that's a point I was trying to make. How many years since screaming deals like that where available? I'm guessing 3- 4 at most, Internet, Ebay and the boom in Chinese manufacturing. Back when Prince was singing were gonna party like it's 1999. Each and every one of those wheels would have been $400 - $500 hundred back then.

And whilst you can get them to work, there a little small, both in diameter and the width of the face. When I needed a direct bolt on replacement for that Waldown toolroom grinder with the angle rests. 7" dia, 1" thick, 1" wide face, recessed centre. The best price I could find was $480 from Specialised Diamond Products. I got quoted over $800 from Winterthur diamond.

Regards Phil.

Originally Posted by Machtool

I think that's a point I was trying to make. How many years since screaming deals like that where available? I'm guessing 3- 4 at most, Internet, Ebay and the boom in Chinese manufacturing. Back when Prince was singing were gonna party like it's 1999. Each and every one of those wheels would have been $400 - $500 hundred back then.

And whilst you can get them to work, there a little small, both in diameter and the width of the face. When I needed a direct bolt on replacement for that Waldown toolroom grinder with the angle rests. 7" dia, 1" thick, 1" wide face, recessed centre. The best price I could find was $480 from Specialised Diamond Products. I got quoted over $800 from Winterthur diamond.

Regards Phil.

Phil
Yes, thats how I remember Diamond wheels, very expensive.
I have got one in its original felt lined box.
Always thought it was too good to use.
A lot of these new cheapies are low diamond concentration, & generally a thin wall coating.
However the price is low so they are attractive.
The Green Sil Carb wheel has surprised me, in its performance, confirming what you previously mentioned.
regards
Bruce