Ozito multi sharpener

[mcchaddy]

Hi,

I was at the big green shed the othernight and saw an Ozito multi sharpener and drill sharpener. Has anyone seen, used or own one of these machines. They look like they work in a similar fashion to a drill doctor. You have to set the angle then insert it into the sharpening stone.

The multi sharpener will do scisssors, knives etc as well. They are well priced at under $100. I have been looking at a drill doctor for sometime now but cant justify the cost. Unless i buy from the states.

cheers

Michael.

[routermaniac]

I have not used either but the similarities if any to a drill doctor are just cosmetic. The ozito drill uses a crappy Al. oxide grinding stone, whereas the drill doctor a diamond disk. The jig to hold the drill in place in the drill doctor looks much better built/accurately machined than the ozito... need I go on?

[Batpig]

Dear Michael,

I think I've seen the unit you're probably talking about. Is it like this one from GMC?
http://www.gmcompany.com.au/index.cfm?module=products&pid=663

If yes, as far as sharpening Drill Bits is concerned, I'll add to Routermaniac's comments by saying that the sharpening principles employed by the two different types (ie. Ozito/GMC compared to Drill Doctor) are completely different. It's hard to explain, but Drill Doctor has got it far more down pat because their little in-built Jig leans the Drill Bit over further, via "Camming", as you twist it around, so that the "Point Angle" angle at the very end decreases as you twist the Bit. This means that the tip geometry at the end is somewhat maintained as originally machined, instead of just being ground away to a sharp point. In addition, it also allows a much more constant "Relief Angle" to be maintained relative to a travelling tangent as the Bit is rotated...

In contrast, the Ozito/GMC-style setup cannot reproduce these complex types of angle. They are in effect, just a motorised version of those little jigs that you set up beside your Bench Grinder. From my own experience of having such a Jig, I can tell you that you can easily end up ruining your good Drill Bits with them, especially if they don't prevent you from overgrinding one half of the Bit, so that your tip ends up off-centre. Suffice to say that since Drill Bits are not manufactured by a single-angle swipe-action past a Grinder (as the Grinder jigs and the unit you are interested in produce), they therefore cannot be properly sharpened by such. I will also say that the guys with the Magic Touch of being able to sharpen their Bits on a Grinder, are actually reproducing the kind of tilting/twisting action that a Drill Doctor automates...

So having said this, there's another unit that the BigB sometimes carries in the Tool Shop that in theory, will give you the types of "Cammed" grind that a Drill Doctor would. The unit is made by a crowd called "Multi-Sharp", and here is it's product page:
http://www.multi-sharp.com/index.php?products_id=38&option=com_oscommerce&osMod=product_info
The BigB ask about $50 for them from memory. I say "in theory" with regard to it's abilities, because:
1) They are a little flimsy in construction, and this might affect the accuracy of the grind (think of why Car Manufacturers are continuosly striving to make their monocoque chassis' stiffer - it's in order to allow the suspension geometry to function more closely to the theoretical arm and linkage angles assumed during the car's design)
2) They are Drill-powered - which is a whole different ballgame to grinding with a 20,000rpm Drill Doctor. If you have to push harder on the Bit as a result of only having 2,000rpm to play with, you might end up pushing the whole device out of true, and consequently end up with an inaccurate grind.

Have a think about it and see how you go. If you do end up getting the Multi-Sharp, please let us know what it's like...:-

Best Wishes,
Batpig.

[yjnb]

I have a multisharp, as noted above it does the cam grind thing. Works well for me.

Do yourself a favor if you get one and find an old singer sewing machine motor (eg at the dump) with the belt drive to power it. I just turned up a small wood pulley on the drill press and use a large O-ring for a drive belt. the foot operated speed control if handy as you can use 2 hands to do the sharpening.

The sewing machine motor removes some of the potential for flex introduced by the drill wiggling around.

Regards,

James

[rat52]

I've had the multisharp for a few years now and bought it for on site sharpening because of its portability and the fact it was the only grinder that would do spade and brad point bits

So long as you don't force it and follow the instructions it does a far better job than I have ever been able to do free hand on a grinder.

I have had to true up the wheel a couple of times with a diamond tool and today (because I'm on crutches. Compo) I touched up all of my drill bits (54 of them) in my assorted size box .

Thanks for the tip James. I've been wondering what to do with my wifes old sewing machine

[Stewey]

I'll just add my 2c worth (+ gst)

I held off getting a drill doctor for years, always doing a so-so job of resharpening bits by hand instead. I tried two cheaper jigs- a waste of time. When I needed a decent good hole, sometimes I'd buy a new drillbit, or one of those torpedo ones.

Finally I got the drill doctor with the ability to do split points also- GREAT!
As long as you line the angle up correctly befopre you start, they're a great invention- no more excuses for wonly holes or struggling.

I only wish I'd got the dearer one to hold bits bigger than 1/2" as well!

It may have been about $280 or $300 or $350 (I can't remember) but the relief, & lack of excuses, and general workshop efficiency was worth it.

Just have to teach the kids to use it properly, now...!