Home made power scraper

[Holescreek]

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



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.



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.





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



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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.



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

 

[astjp2]

Too bad you don't make the conversion parts for us who don't have time or the tools to make our own. Tim

 

[bcall2043]

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]

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]

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]

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]

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]

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]

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!

 

[Kernbigo]

try it by hand and you will see how hard it is, the surfaces is only oil pockets , to get a good looking job i always switched to the half mooner for looks, did it for 30 some years, don't knock the guy.