27 January 2010

Product Review: Gemstones Etc. Koil Kutter


I’ll start this by saying, I’ve been cutting rings by hand with a jewellers’ saw for about 8 months. This does the job perfectly, but slowly. I’ve wanted a powered cutting setup for quite some time. I’ve looked into several options including buying a stand alone slotting saw arbor and rigging an old drill. While it works, it really requires a solid rig to secure your coil. Something I haven’t made the time to do, and I figured I only really needed it to cut stainless, since the hand method was working.

Well, time became a factor, I wasn’t getting even copper rings cut fast enough for my liking.

Enter, the Koil Kutter.

A grooved aluminium box with a slotted lid of sorts to secure a pre-cut coil, a saw arbor and safety guide to fit a Dremel, also available in Proxxon and Foredom compatible models.

Starting with the coil holder. It’s well machined, with attention paid to rounding off corners, not to perfect symmetry, but the look of a tool is beneath secondary to it’s function. Not getting jabbed by right angles is very nice. The box will secure up to a 1” coil easily. I haven’t tested it for a minimum size yet, but if you’re working with a coil smaller than this can handle, your cuts need a microscope to examine. The slotted top secures with a pair of hex driven machine screws, hex key included in your kit. Nice touch there. If I have to be picky about anything, it’s the lack of a baseplate that can be secured to your bench; but it does fit nicely in a vise. Overall finish is a utility brushed look. Again, function over form is perfect with me.

The safety collar screws on in place of the Dremel’s collar. It’s made of durable PVC and notched to fit over the coil holder and guide the blade directly into the cutting slot. While I have to say the notching on the PVC isn’t a precision job, the cuts and corners are a bit rough but it still accomplishes the intended effect perfectly, and to accommodate any variations between your particular rotary tool and the next one a pair of thumb screws allow for some adjustment. All told it’s a simple; yet strong solution.

The blade arbor on the Dremel model doesn’t suffer from any flaws that aren’t inherent in anything else made for a Dremel. Namely the need for that stupid little wrench everyone loses, but you’ll only need it for about a quarter turn after hand tightening. The included blade is .010” thick, with 3/8” keyed hole. Secured with the same hex-head machine screw. It’s well balanced, doesn’t seem to induce any of it’s own wobble. Most importantly, it does the job, and incredibly fast.

So far, I’ve cut 1.2mm copper, .8mm bright aluminium, and .8mm nickel silver without a single snag, and only one ring marred. But how does it cut? Fast, a 4” long coil is slit open in about two seconds. Faster if I could turn the Dremel up to 11…

I’m not going to assign an X out of 10 rating or anything, not my style, but what I will say is this: If you want an inexpensive and effective, powered ring cutting setup, the Koil Kutter is a prime choice and I’m perfectly happy with it. Not spending multiple hundreds of dollars on an alternative option now feels like a good decision.

Have fun

Dave Arens of Gemstones Etc. may be contacted directly for orders and inquiries by email gemstonesetc@gainbroadband.com