# Any use for oscillating multi-tool in metal shop?



## AndySomogyi (Dec 7, 2019)

I bought one of these oscillating tools to try it out. My original idea was that I read that a die grinder with a cutoff wheel or a small belt sander can be used to “scrape” hardened ways, I’d try this out.

Produced very lousy results, the finish was horrible, at least with this diamonds grinding blade. I find the die grinder produces a MUCH better finish. 

Also tried this on scraping automotive undercoat. Didn’t work well, a standard angle grinder stripping blade works much better. 

So is there any use for these in a metal shop? 

I can’t seem to find any so I think I’ll take it back tomorrow. 
	

	
	
		
		

		
			






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## ScrapMetal (Dec 8, 2019)

AndySomogyi said:


> I bought one of these oscillating tools to try it out. My original idea was that I read that a die grinder with a cutoff wheel or a small belt sander can be used to “scrape” hardened ways, I’d try this out.
> 
> Produced very lousy results, the finish was horrible, at least with this diamonds grinding blade. I find the die grinder produces a MUCH better finish.
> 
> ...



I hope that I am reading this wrong.  Are you saying that you tried using this on hardened ways, the things we need to keep precise?  

Please don't do that.

JMHO

-Ron


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## AndySomogyi (Dec 8, 2019)

ScrapMetal said:


> I hope that I am reading this wrong. Are you saying that you tried using this on hardened ways, the things we need to keep precise?
> 
> Please don't do that.
> 
> ...



No I didn’t try it on real ways. I tried scraping a scrap piece of cast iron just to see how it compares to a die grinder (which is the accepted tool for hardened ways when the machine can’t be moved). 

It was just an experiment to see if this tool had any use in a metal shop. So far I can’t find any use for it and I’m going to take it back. 


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## ScrapMetal (Dec 10, 2019)

Good to hear.  As far as a use for the oscillating tool in the metal shop, maybe grinding/deburring edges or some other kind of finish work?  I'm sure there is a use but I can't come up with more than that.

Best regards,

-Ron


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## eeler1 (Dec 10, 2019)

What’s your source for using a die grinder on hardened ways?  First I’ve heard that.


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## RJSakowski (Dec 10, 2019)

I have Rockwell oscillating tool that I have used quite bit but not on metal.  The sanding function is useful because it can get into tight corners and it is fairly aggressive compared to palm sanders.  They make carbide saw blades to fit which again can get into tight spots.  They also have rigid and flexible scraper blades.


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## FOMOGO (Dec 10, 2019)

I have a HF unit that I bought because my son said it was very handy for multiple tasks, and he was right. I've used it to cut metal roofing and flashing in hard to reach spots, and was really impressed. Mike


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## MikeInOr (Dec 10, 2019)

I have owned my Harbor Freight *variable* speed oscillating tool for about 10 years now and have used it a LOT!  I have never found much use for it in the metal shop but darned it is handy for so many chores!  I didn't expect the HF tool to stand up very well but this is one of those that is actually a pretty decent tool.  A friend bought the fixed speed HF model and he has been through 3 of those without much use on them.


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## Cadillac STS (Dec 10, 2019)

Good idea to ask what it can be used for in the shop

If you don’t have a use for it then return it.  Can always just buy a new one when needed


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## Latinrascalrg1 (Dec 10, 2019)

Thats one of those tools thats you will hardly ever need but when you do they sure are nice to have.....with that said if you dont have a current  need for it and dont expect to have a need anytime soon you would probably be better off taking it back for a refund!


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## AndySomogyi (Dec 11, 2019)

eeler1 said:


> What’s your source for using a die grinder on hardened ways? First I’ve heard that.



There are a number of threads where Professionals talks about using an Grinder to scrape when you can’t move the lathe. The key is control.







						Using a grinder to 'scrape' a hardened part
					

Today i tried to scrape a parallel but found it was damn hard, would have taken ages. It was one of 4 at 15" long, ebay bought, all of them bannered a good  .0008 or so.   With need being the motivator i got the grinder out. Setting up well down wind from the plate I got stuck into the smallest...



					www.practicalmachinist.com
				










						Scraping with an angle grinder
					

Hi guys,  I found a video on youtube where a guy scrapes his lathe with an angle grinder. Surprisingly, he does it with the great success. The guy is not from U.S. and he speaks Russian in the video. I was so impressed, so I translated the video and added English subtitles. Sorry, if it's a...



					www.practicalmachinist.com
				





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## Bob Korves (Dec 11, 2019)

If you are going to "scrape" with a grinder, you first need to use a precision straightedge to mark up the high spots with a very thin and evenly spread coating of ink on the entire surface of the straightedge.  The straightedge must be stiff enough to stay straight while rubbing it a short distance back and forth, no flexing allowed.  After marking it with the ink, you will want to remove the high spots on the work that were marked by the ink on the straightedge.  The straight edge should be longer than the surface being marked for best results.  Material is typically removed at not more than .001" per cycle, and that is for roughing passes.  Finishing passes are measured in tenths or less metal removed per pass.  By repeating cycles of the same technique, you will have more complete coverage of the entire surface with each pass, if you are doing it correctly.  You can also work to change the angles of surfaces by working harder at one end, less in the middle, and zero at the other end.  You will need a gentle grinder with a fine abrasive to have something controllable.  Randomly deeply gouging the metal will only ruin the machine.  What I have posted is roughly how to do it, but the devil is in the details.  To do that kind of work correctly and get good results, you would need to be trained by someone who is an expert and can maybe teach you how to do it correctly.

Bottom line, hardened ways are ordinarlily ground into flat and parallel using surface grinders, and have been done that way for more than a century now.  It is a mature process conducted by experts at doing the work.  If the machine is worth fixing, it is worth fixing it right.  Yes, it does cost money.  That is my take on the subject, please don't try to reinvent the wheel, or do so knowingly at your own risk...


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## eeler1 (Dec 12, 2019)

Here’s how to grind ways;     




And there are lots of legitimate videos on scraping.


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## Janderso (Dec 12, 2019)

Saw that one Jon. I don't know where Kieth Rucker finds the time and/or money to do all that he does and work as a scientist for Bayer during the day.
Those multi-tools are handy as hell.


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