Hole saw redux (stupid human trix)

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Frankenspeakers · #1 Post by **Frankenspeakers** » Fri Jul 21, 2006 6:32 pm

One piece of experience gained at my expence: When I was beginning to build speakers, I thought a swing-arm cutter on a hand drill motor was a neat trick. (there's a reason the tool has "for use only in a drill press at low RPM's" printed on the box)

thats OK I'll be careful- nothing will happen

Yeah, right. My right knee has a small indentation where the swing arm swung when it grabbed the wood

Oh yeah, I was wearing shorts too

This was before they invented the RotoZip cutter... and I was too cheap to get a router. I think pain was invented to keep us from doing too many stupid things

mike butler · #2 Post by **mike butler** » Fri Aug 18, 2006 9:54 pm

One thing I have found, the regular hole saws (the ones that are a full circle) are a good thing. (Oh yes, and I do have a RotoZip, and a router, and a Dremel...

) I have two sets, one that goes from ridiculously small (like 5/8"... I don't know why you wouldn't just use a drill bit) up to 3" and another set that goes from 3" to 6".

Of course, using a drill press is better, but when you need to bring the tool to the work (like you need to make a hole in a house) you can chuck the holesaw into a nice hand drill motor (my little 3/8 De Walt VSR works fine). Just be patient and go easy, these things generate torque that will spin your @$$ around if it catches in the wood due to your leaning into it too hard.

One tip, drill from both sides. Once the pilot bit pokes all the way through but before the saw teeth do, take the tool out of the hole and start cutting from the other side. This will prevent grain tearout when the saw breaks through.

Fri Aug 18, 2006 10:09 pm

Heat build up with hole saws slows them and dulls them, and sawdust in the cut retains heat. First drill 1/16th of an inch deep, then drill a few 1/8" holes through the wood on the hole saw cut line to give the sawdust a place to fall through. This lets the blade stay cooler, cut faster and stay sharp longer.

Tom · #4 Post by **Tom** » Tue Oct 10, 2006 4:55 pm

One of my Band mates works in the hospital ER, and felt obliged to tell me that the new number one ER visit related power tool is.....drum roll please....

The RotoZip cutter.

Be careful out there.

Harley · #5 Post by **Harley** » Mon Oct 23, 2006 3:06 am

Tom wrote:One of my Band mates works in the hospital ER, and felt obliged to tell me that the new number one ER visit related power tool is.....drum roll please....

The RotoZip cutter.

Be careful out there.

True! I can imagine that.

I spent an absolute fortune importing one here, buying a 240V/110V 1kw transformer to power but after using it ( carefully ) several times find that it's quite a dangerous machine. Plus the circle cutter attachment is limited to 12" dia!!!!

Now it just gathers dust - all in all an outlay in $NZ of about $680.00

My $50.00 Ozita ( chineez ) router with large dia circle attachment is far safer and much more stable and reliable to use and is much more versatile.

Harley

#6 Post by **Bill Fitzmaurice** » Mon Oct 23, 2006 8:28 am

I like my RotoZip, and went to the trouble of making a large radius cutting jig for it. It's perfect for cutting arcs on DRs because the kerf removes just enough material, whereas even a 1/4" bit in a router takes off just a bit too much. But it is a very demanding tool that requires great care in its use. If in doubt over which to choose, or if you can only go one or the other, go with a router. Where routers are concerned the most versatile is a 2HP that can use both 1/4" and 1/2" shank bits. 1/2" shank bits are heavier, therefore cut smoother and last longer. But sometimes being able to use 1/4" bits is handy. Less than 2HP won't handle 1/2" shank bits, while 3HP models are too heavy.

Harley · #7 Post by **Harley** » Mon Oct 23, 2006 1:50 pm

Bill Fitzmaurice wrote:...went to the trouble of making a large radius cutting jig for it. .....

Do you have a pic of that radius cutting jig please Bill, - I have the Bosch Roto Zip. edit - DON'T BOTHER - I found the one you sent me in march!!!
One area I found it good was for the tops and bottoms of the DR, cutting the semi circles and with the 5/32" kerf the cut off piece at the back was a perfect match as the back filler piece ( I made the depth oversize so that it cut out in one piece, and trimmed it after gluing it into place )

I have two routers, one el cheapo 1300W that takes 1/2 and 1/4 bits but it is very light and easy to use - it will break eventually but it cost $NZ50 ( $US 32 ). The other one is a Makita Heavy Duty which is almost bulletproof but weighs a ton. I've stopped using it until the Chinese on breaks beacuse it is so heavy

hclague · #8 Post by **hclague** » Mon Oct 23, 2006 4:24 pm

Bill

I second Harley's request for a Picture of the Roto zip Radius Jig. I was using one I made for a cheap "Tool Shop" brand cutting tool but the attachment I was using that was specific to the tool wore out. Now I'm out of luck with the roto zip cause it won't work with my old jig.

Hal

fender3x · #9 Post by **fender3x** » Sat May 12, 2007 11:06 am

hclague wrote: I second Harley's request for a Picture of the Roto zip Radius Jig.
Hal

I'd like to see Bill's too. I am sure it will be prettier than mine!

My photos are not too good, but here's the one that I adapted (taken with my phone). I had a trammel arm of the "turnlock" variety for my router ($15 on sale at Sears). I made this really ugly adapter for my el-cheapo spiral cutter saw ($20 at Harbor Freight).

http://www.frappr.com/?a=viewphoto&id=1 ... myphotos=1

http://www.frappr.com/?a=viewphoto&id=1 ... myphotos=1

With practice it is working reasonably well, but it took practice to get it to work well. Starts and stops were hard to get it to cut to the right place...and not farther or to jump. I practice pretty much all my cuts at least once or twice on wood I don't care about before going in for the real thing. Two other things I have learned (as usual, the hard way).

One is to make sure that the jig is Always flat on the workpiece. If I take my hand off of it, it iwll jump. I have to always be applying a small amount of downward pressure on the tool/jig for it to remain steady. My heavy 3hp router doesn't need this, but this little lightweight tool jumps around without a hand on it.

2nd is to always cut the arc in the same direction that the tool spins. My tool spins clockwise, so my cuts have have to be clockwise too. Don't even try it the other way. At best it cuts like a drunken sailor. At worst it could jump up and really become dangerous.

If I were designing one of these, I'd put a "deadman switch" into it, so that if you release your grip it would cease to run. Mine doesn't have one of these, and it is so small and light that it is tempting to treat it as though it were not dangerous. The combination of smallness, lightness and great torque, however, means that it can jump surprisingly, so you really have to be careful.

Tim A · #10 Post by **Tim A** » Sat May 12, 2007 11:34 am

You guys do know you can get 1/8" straight bits for a 1/4" router, right?

I hate my zip saw, the circle cutter that came with it is a piece of crap. Bill, any photos of the one you made? I'd like it much better if it would stay where I wanted it too...

fender3x · #11 Post by **fender3x** » Sat May 12, 2007 10:20 pm

Tim Ard wrote:You guys do know you can get 1/8" straight bits for a 1/4" router, right?

I haven't found one of those for a 1/4" collette. Where did you find yours?

tallclyde · #12 Post by **tallclyde** » Sat May 12, 2007 10:33 pm

fender3x wrote:
I haven't found one of those for a 1/4" collette. Where did you find yours?

Try Lowe's I got one there or a local wood worker supply store. Like Woodworkers Source or Woodcrafters.

Harley · #13 Post by **Harley** » Sun May 13, 2007 1:35 am

Tim Ard wrote:You guys do know you can get 1/8" straight bits for a 1/4" router, right?

I hate my zip saw, the circle cutter that came with it is a piece of crap. Bill, any photos of the one you made? I'd like it much better if it would stay where I wanted it too...

I put a 1/4" router bit on mine and it worked a treat.

With the 5/32" Rotozip bit, it was like a wild pony ride and most my cuts ended way up the wop!

Harley

Tim A · #14 Post by **Tim A** » Sun May 13, 2007 7:07 am

fender3x wrote: I haven't found one of those for a 1/4" collette. Where did you find yours?

Any real woodworker's supply will carry them.

He're a link to a page of various sizes. The 5/32" is a good alternative, slightly larger diameter and longer cut.

http://www.woodcraft.com/family.aspx?familyid=8000

Tim A · #15 Post by **Tim A** » Sun May 13, 2007 7:19 am

Harley wrote: I put a 1/4" router bit on mine and it worked a treat.

With the 5/32" Rotozip bit, it was like a wild pony ride and most my cuts ended way up the wop!

Harley

I tried that too. The problem with mine (roto zip) is the base sucks. It wants to wobble back and forth when cutting. No matter how hard I try, keeping it plumb is a virtually impossible task that adds too much time to a cut. Regardless of what they say in their marketing lit., these things were designed for drywall and 1/4" plywood. Anything heavier is a challenge I don't need to deal with.

A 1/8", 5/32", or even 3/16" spiral bit in a router with a Jasper Jig is the fastest and most accurate method I've found, at least for me.