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Forum topic by John Steffen posted 08-18-2010 12:38 PM 2643 views 0 times favorited 18 replies Add to Favorites Watch
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John Steffen

218 posts in 1809 days


08-18-2010 12:38 PM

Topic tags/keywords: question circle tool

I’ve been charged with making several (10 for now and possibly more in the future) of these things for our living room and dining room. I’m just going to use 1 3/8” Birch dowels for the cylindrical parts, and use a hole saw to cut away the intersection. That seems to work very well as the cutaway part will be covered by the actual curtain rod.

The problem comes when I try to use a 2 3/4” hole saw to cut the base (part that attaches to wall). Even in my drill press at 220 RPM (the slowest my press goes) it still chews and mangles the wood. It looks terrible, and it’s far beyond what sanding will fix. I’ve tried it on 3/4 birch and some old scrap 1/4 oak so far. I have some new 1/4 oak coming in the mail that I’m hoping will have better results. But after cutting the scrap, I’m doubtful it will. I think I need to find a better way to cut the base circles. Short of buying a scroll saw or a band saw, what do you all suggest?

-- Big John's Woodshed - Farmington, IL


18 replies so far

View Camper's profile

Camper

232 posts in 1609 days


#1 posted 08-18-2010 01:43 PM

never tried it myself but maybe one of these may give you a cleaner cut.

-- Tampa-FL

View dbol's profile

dbol

135 posts in 1751 days


#2 posted 08-18-2010 02:12 PM

Are you sure your hole-saw is sharp? Is it tearing out when you finish your cut? If it is only cut half way thru then turn over and cut the other half way thru.

View John Steffen's profile

John Steffen

218 posts in 1809 days


#3 posted 08-18-2010 03:04 PM

dbol, it may not be sharp… I used it right out of the pack. I will check tonight for sharpness, though I’m not really sure how to sharpen it.

-- Big John's Woodshed - Farmington, IL

View David Craig's profile

David Craig

2135 posts in 1862 days


#4 posted 08-18-2010 03:39 PM

I believe hole saws are designed to preserve the area from which the wood was removed at the expense of the wood removed. So the edges on the board are cleaner than the edges of the circle removed. The circle cutter that Camper posted a link to is usually the tool of choice if one wants to preserve the edges of the circle. One thing you can try is mounting the circles on a 1/4 inch steel rod and having the rod turn on the drill press like a lathe. Take a 1/4 ID 1/2 OD bearing and a scrap board. Drill a hole for the bearing and raise the table of the press so that the steel rod spins on the bearing. Take high grit sanding paper and let the circles spin against it to clean up the edges.

David

-- There is little that is simple when it comes to making a simple box.

View CaptainSkully's profile

CaptainSkully

1195 posts in 2312 days


#5 posted 08-18-2010 04:27 PM

I’ve seen a nice circle-maker made with a sanding disk in the table saw. You rough cut the circle on the band saw, and sneak up on the true circle by using a jig that mounts into the miter slot. You can gradually slide the moving part of the jig into the disk, clamp/screw it down to the right radius and turn the work 360°. This will give you a perfect circle every time, that’s already sanded.

-- You can't control the wind, but you can trim your sails

View Billinmich's profile

Billinmich

237 posts in 2485 days


#6 posted 08-18-2010 05:13 PM

could you drill a1 3/8” hole in square stock and put your dowel in hole and drill with your hole saw.

-- Bill in Mich

View Triman's profile

Triman

50 posts in 2336 days


#7 posted 08-18-2010 05:29 PM

If you (or a friend) has a lathe, you could turn some stock down to 2 3/4”, then use a band saw to cut the disks.

-- Bruce, San Jose, Ca www.spotofwood.com

View PurpLev's profile

PurpLev

8476 posts in 2402 days


#8 posted 08-18-2010 05:34 PM

have you tried sandwiching the part you are trying to cut between 2×1/4” or 1/2” plywood to act as backer-boards to prevent tearout?

I’d try that one first, since you already have the hole saw.

another option is to rough cut the blanks, and use a jig on the router table to finish up the circle cut.

what other tools do you have in your arsenal? that might help people suggest other options

-- ㊍ When in doubt - There is no doubt - Go the safer route.

View Gregn's profile

Gregn

1642 posts in 1737 days


#9 posted 08-18-2010 05:38 PM

Hole saws weren’t designed to give a smooth cut. So you may want to do as camper suggested and purchase a circle cutter,or do as I do when making wheels. I will make the circles over sized and clean them up on the router table. To do this you will need to make a V jig to mount to the router table to safely do this. Another alternative would be to use a lathe and turn a cylinder and then cut to desired thickness. You can see the wheels I made in my projects, Hobby horses and the TV tray these are 2 1/2” wheels. These were made with a hole saw and the router table method.

-- I don't make mistakes, I have great learning lessons, Greg

View John Steffen's profile

John Steffen

218 posts in 1809 days


#10 posted 08-18-2010 06:56 PM

Thanks for all of the suggestions guys. My wheels are turning a bit.

PurpLev: I think the pertinent tools I have for this job are my Drill Press and Router (I can table it in my Table Saw extension if I need, but I would need to build a fence). I also sort of have access to a lathe, but it’s an hour away, and I have to talk my dad into letting me use it… So, I would rather avoid that if possible.

I think I’ve got an idea of using the drill press as a lathe in an attempt to clean up the edges with sand paper. (I’ll try it with my scrap piece to see how it goes tonight).

-- Big John's Woodshed - Farmington, IL

View Ger21's profile

Ger21

680 posts in 1884 days


#11 posted 08-19-2010 04:03 AM

Get a circle cutter like Camper linked to. They’ll give you the best circles with glass smooth edges. Just don’t run them faster than 250rpm, or the chuck on your drill press may come off.

A standard hole saw will never give you a good disc. Maybe one with a carbide tooth, but I’ve never used one. Go with the circle cutter.

-- Gerry, http://g-forcecnc.com/jointcam.html

View Rick's profile

Rick

7341 posts in 1786 days


#12 posted 08-21-2010 10:10 AM

I recently bought a Circle Cutter as shown below at Canadian Tire for $35.00. Not sure why the Pic shows 2 Holes, or why it shows a “Smooth Cut” on both sides of the Blade. Maybe the Pic is From Lee Valley’s Site.

H Cutter Med 319x285

The one I bought appears to be the same one that Lee Valley sells at $31.50CND. The recomended MAX RPM is 500. If you want to use the “Inside Circle” as you do i.e. a “Wheel” you slide off the end cutter piece and set it so the smooth cut is inside. If you want to cut a Large Hole in something you turn the Blade the other way.

It has a habit of “Burning” The wood on the Slanted edge (the part you don’t want) and also Grabs the wood and stops the cutting action. I handled that simply by backing off the cut until it got back to speed, then down again, but I don’t think it should do that.

Maybe it’s a cheap imitation or I should try as mentioned above and slow down the RPM’s. It also “Burns” the actual cutting bit, which didn’t appear to be all that sharp to start with.

OOPS! I think I answered my own question in the first paragraph. I THINK this IS a Pic from Lee Valley’s site. Probably a Better Cutter Blade that cuts Square on BOTH Sides.

I’ll see if I can Grab The Link to Lee Valley’s Page.

Think I got it okay. http://www.leevalley.com/en/wood/page.aspx?p=32275&cat=1,180,42316&ap=1

Now! Do I still have the Receipt for the Crappy One I got at CTC? ...LOL…

-- How long is a Minute? That depends on which side of the Bathroom Door You're On!

View John Steffen's profile

John Steffen

218 posts in 1809 days


#13 posted 08-23-2010 10:14 PM

I did end up just cutting them rough with the hole saw and cleaning them up with some sandpaper using my drill press as a lathe. The results are good enough for my purposes. I will post some pics of the project in the next couple days.

-- Big John's Woodshed - Farmington, IL

View aurora's profile

aurora

206 posts in 2005 days


#14 posted 08-23-2010 11:25 PM

you might approach it from a different process. instead of coping one piece to fit the other, i would machine a flat on each of the two mating cylindrical surfaces. router bit in a drill press and a manual feed table. or just plunge the router bit into the dowel and reposition, the replunge to the same depth using a depth setting on the drill.

if you are set in just cutting a circle in one piece, use a 1 and 3/8 drum sander and feed it into the dowel. it removes less material and will raise less tear out.

good luck

View emtwoodworker's profile

emtwoodworker

51 posts in 2248 days


#15 posted 08-24-2010 02:14 AM

I’m sure most people will tell you that this a bad idea and I don’t recommend it myself if you have options, but I cut 60 circles (diameter 2 1/4”) using a table saw. http://www.youtube.com/watch?v=Wxbzrf4z_cg . Again it’s not the safest method but it does work. I too tried a similar circle cutter like the lee valley one and it didn’t work.

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