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[4]

Home made power scraper

January Project of the Month [3]
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Holescreek

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#1
I haven't done any scraping in a long time but though I'd share how I made my own power scraper.

scraper010.jpg

The whole project is based on a variable speed Harbor Freight sawzall where the saw blade is replaced by a carbide tipped insert. The only difficult part is modifying the reciprocating mechanism to make the stroke adjustable.

scraper001.jpg

After disassembling and cleaning I decided to remove the fixed post and milled a dovetail slot so I could add an adjustable bearing post in its place.

scraper006.jpg

scraper007.jpg

The inset is brazed onto a mild steel flat bar ad ground just as you would for hand scraping.

scraper008.jpg

- - - Updated - - -

scraper009.jpg

At first it was a little choppy until I settled on an 1/8" stroke and learned to cradle the sawzall on top of my forearm with the handle resting against the inside of my elbow. I use my free hand to help guide the blade while the hand underneath is supporting the weight. After a little experimenting it became natural and what took days by hand was done in a couple of hours.

Scraping002.jpg

There used to be a video of me using it online somewhere, not sure where it is now.
 

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bcall2043

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#3
The whole project is based on a variable speed Harbor Freight sawzall where the saw blade is replaced by a carbide tipped insert. The only difficult part is modifying the reciprocating mechanism to make the stroke adjustabl


There used to be a video of me using it online somewhere, not sure where it is now.
Thanks for the post. I just picked a reciprocating saw with a bad motor at the scrap yard a week or so ago. My thought was to try the same approach as you have. You have proved the concept and I now have the mechanism to play with (read "ruin") before I spend the money to ruin a good one.

Any other suggestions or thoughts about attempting to copy your project?

Benny
The Orphanage Never Closes
 

Holescreek

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#4
Thanks for the post. I just picked a reciprocating saw with a bad motor at the scrap yard a week or so ago. My thought was to try the same approach as you have. You have proved the concept and I now have the mechanism to play with (read "ruin") before I spend the money to ruin a good one.

Any other suggestions or thoughts about attempting to copy your project?

Benny
The Orphanage Never Closes
Just be prepared to hear "it will never work" a lot.
 

Dresden

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#5
That surface looks scratched not cut, a Biax scraper has ergonomics designed for the job the saw is designed for a different use, if you use both side to side you will see the difference.
 

Holescreek

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#6
To each their own. If I was scraping for a living I would show up with proffesional equipment. Since I'm not even a wana-be machine tool builder I used what made sense. I've scraped enough by hand to know the action is the same, its not been an issue for me. People sink a lot of money in specialty equipment just for bragging rights.
 

tertiaryjim

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#7
Have seen a post by another member who did the same. Perhaps that was you.
This is something I would like to do when I have the time.
Tool geometry and speed could perhaps be adjusted for a better job.
All the time saved could be used for making more tools. OH BOY!
 

Silverbullet

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#8
No two scrappings will ever look alike , unless done by a machine. Hand scrapping is just that each person who does scrapping will create there own lines or design pattern. Even tho it's straight line , the whole idea is to get the surface flat and leave tiny scratching for oil to lay in. I've seen real beautiful patterns and others where the lines cross and no lines straight hardly at all. Just remember they're for oil not appearance. At least that's what I've learned over the past forty years.
 

4gsr

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#9
That surface looks scratched not cut, a Biax scraper has ergonomics designed for the job the saw is designed for a different use, if you use both side to side you will see the difference.
Who cares if it is scratched. I've been doing this kind of stuff since I was 15 years old! And I still scratch! and I own a Biax, too!

Go easy on these guys. We can use some pointers to do better. We want to learn. Most of us here are not able to go out and buy the 'good tools of the trade' to do the job right. But we getting better and smarter!
 

Old junk

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#11
Making a tool to do a job is why we are here.i like it.few things feel as good as using a tool you made.
 

Keith Foor

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#13
I was just thinking that the little M12 sawzall that is battery powered would be a good candidate for this modification. It's smaller and light weight. Not sure on the battery idea though. Now sure how long it would run. But this has merit and is worth playing with. Pawn shops are full of old saws that are missing the front guide that can be had for next to nothing because they are missing parts
 

NEL957

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#14
Holescreek
I applaud you and your ingenuity and design to take a normal piece of equipment and make a very impressive tool for a whole lot less.
Very nice
Nelson
 

Kernbigo

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#16
when i used to scrape with the biax i used to spot finish using different patterns that i created myself. That is after the scraping is done for looks and oil pockets.
 

NEL957

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#18
Holescreek
Looking at the picture of the head stock removed from the bed with original scraping, it look so large until I say the size of the lathe. That is a beautiful job and I am sure that man had done it for years. It looks very nice, one day if my hands do not fall off I can get around to that. Thanks for sharing
Nelson
 

Kernbigo

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#19
most people that scrape use a spotting pattern of there own to finish the scraping job, this guy was a real artist
 

tertiaryjim

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#20
That was some pretty work. I think the pattern is called Butterfly Frosting.
Usually just a decorative pattern that was too shallow to hold oil.
If it was deep enough to hold oil it would be flaking.
There's a mention of it in the Connelly book and other information can be found online.
 

middle.road

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#21
Oh to have the time, patience, talent and the 'touch' to do scrapping.
I've watched the videos on the web and such and am amazed.
I remember watching the tool & die maker at my first place doing it, too bad I was too young & dumb to realize what I was witnessing.
 
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