Multifunction Divider/Compass

[CedarSlayer]

This is a simple enough tool. I grind the tip off the end of a Harbor Freight Divider. Done! But not entirely.
There are a lot more details on my blog, but the real advantage is that you can make your own points.



This is an interesting point. Ideally you want the curve to the inside of the circle being made. The curve makes the blade try to drift outward. This is good as the circle cut mostly ignores grain and remains full sized and clean.

You might want to draw a line, make a scratch or cut deeper. To cut deeper you might want a more normal blade, but it is easy enough with a long hex drive bit and a grinder to make all sorts of cutters.

Bob

[Hotz]

Bob nice job ..

[Altair]

Great idea Bob. I really dig the interchangeable tips.

Al

[CedarSlayer]

Great idea Bob. I really dig the interchangeable tips.

Al

Thanks,
The nice part of this is that a good tool bit like a screwdriver will typically be fine grained and hard enough to make a really nice blade.

Bob

[Captainleeward]

Good tool Slayer. :O)

[DIYer]

Those are nice mods. Not too costly to do too.

[kbalch]

Thanks Bob! I've added your Multifunction Divider and Compass to our Measuring and Marking and Grinding categories, as well as to your builder page: CedarSlayer's Homemade Tools. Your receipt:

edit

Multifunction Divider and Compass by CedarSlayer

tags: grinding, divider, compass

[Christophe Mineau]

Thanks, I'm late seeing this one.

I was questioning myself about what kind of easy found stuff could be hard enough and good enough steel quality for making cutting tools, it seems you are answering here.

And what about the hex keys for instance, do you think it can be reground and used as a cutting tool ?

[CedarSlayer]

Hex keys are brilliant for making blades out of. If you use 1/4" or larger, forgive me for being imperial, they are also fairly stable. Because of the bend you can make very low angle planes out of them for various contours. The next tool I post will show how I haveused them.

Roll pins can also be sharpened to make superb blades for cutting gauges and the like.

Another great source for hardened metal is cheap knives and scissors.

Fairly recently China developed a new method for mass producing stainless steel that is capable of producing amazingly good tool steel. Since the limiter for price is quantity often the make huge batches of top notch steel due to one request and then fill the rest of their requests with steel that is way over spec. If you find a deal on a good stainless knife, test it for edge retention, ease of sharpening, and it's ability to form a bur (work hardening) Use a cheap stone initially to test. Some stainless will gum up a sharpening stone and make it near useless.

Stainless is so complicated to heat treat, that you might as well obtain it tempered.

My trick to grinding hardened steel without ruining the temper is to use a plant fiber paint or oil brush. I wet the brush and put it on the tool as I grind. When the water starts to boil, I back off on the tool and wet the brush again. This way the tool angle and position are preserved and the tool never gets above boiling. It does eat brushes, but natural fiber brushes bought bulk are very inexpensive.

Bob

[Christophe Mineau]

Thanks Bob,
It's true that scissors are often used to make peg reamers for instance.
Whenever I can, I prefer to use carbon steel, but that more and more hard to find ... the demand is more turned on stainless nowadays ...
I like your remark on how sometimes, things purchased cheap and that are supposed to be on the lower end happen sometimes to be of superior quality.
Especially in the general purpose stores, not supposed to particularly sell fine tools, I have sometimes found good surprises.
I have in mind a set of nicely ground drill bits, purchased between bread and toilet paper , I think they keep being the best I have ...

thanks for the tip with the brush !
Christophe