Hi,
Just got a router for my 40th birthday 🙂 along with a new drill and other bits and bobs.
Now i have to cut a lot of 4" holes (64 to be precise). I have a hole saw of the correct diameter which tends to leave the holes i drill a bit uneven it's also very hard to hold steady when going through 1/2 inch wood I don't have a table drill or whatever theyre call so its very hit and miss getting the sides vertical. I drilled 12 holes with the hole saw for a prototype panel (open baffle line array) and found them to be very uneven.
Also whats the best way to setup for even centre to centre spacing. The driver diameter is 110mm ideally i want no spacing between them so whats the best way to mark for hole cutting or is it just measure twice cut once ?
Would I have more luck with the router and if so which bit would i use? btw i'm a bit of a woodworking noob If you hadn't already guessed.
p.s. if i'm building a 4" hole cutting guide for the router where do i measure from to get the correct size. I'm assuming a basic guide will be a piece of wood screwed to the base of the router with the correct cutouts and a single hole for pinning the wood in place the correct distance from the bit?
Just got a router for my 40th birthday 🙂 along with a new drill and other bits and bobs.
Now i have to cut a lot of 4" holes (64 to be precise). I have a hole saw of the correct diameter which tends to leave the holes i drill a bit uneven it's also very hard to hold steady when going through 1/2 inch wood I don't have a table drill or whatever theyre call so its very hit and miss getting the sides vertical. I drilled 12 holes with the hole saw for a prototype panel (open baffle line array) and found them to be very uneven.
Also whats the best way to setup for even centre to centre spacing. The driver diameter is 110mm ideally i want no spacing between them so whats the best way to mark for hole cutting or is it just measure twice cut once ?
Would I have more luck with the router and if so which bit would i use? btw i'm a bit of a woodworking noob If you hadn't already guessed.
p.s. if i'm building a 4" hole cutting guide for the router where do i measure from to get the correct size. I'm assuming a basic guide will be a piece of wood screwed to the base of the router with the correct cutouts and a single hole for pinning the wood in place the correct distance from the bit?
Hi Oublie I made my own circle jig for my router for cutting round holes. Just use a straight bit of sufficient length to make it through your thickness of wood. A small diameter will be much easier on the router.
I've attached a picture of my circle jig in the making. Note that I did use a drill press to make it but there is no reason you couldn't use a normal drill.
You need to take into account the diameter of the router bit and add the radius of it to the distance to the pin around which you spin the router. The reason it looks like there are two lots of holes in this jig is because the first one wasn't quite right and this is the picture of the second attempt. After the point where all the lines are radiating out from was drilled out and is where the router bit went through. I took the plate off the bottom of the router and replaced it with the jig. Obviously if you only need one diameter hole cut you can simply measure and drill one hole for the pin. 🙂
The holes this cut were quite good. second pic shows the result. Note my router bit wasn't long enough to make it through the 25mm MDF and I had to flip it over and finish from the reverse side. I also used a much larger diameter bit (due to the rebate).
Tony.
PS. I used a hole saw for the holes for the ducts in my bass reflex speakers, it was a 70mm hole saw and 70mm pvc but the resulting fit was very loose... not so accurate, and I'd use the router next time.
I've attached a picture of my circle jig in the making. Note that I did use a drill press to make it but there is no reason you couldn't use a normal drill.
You need to take into account the diameter of the router bit and add the radius of it to the distance to the pin around which you spin the router. The reason it looks like there are two lots of holes in this jig is because the first one wasn't quite right and this is the picture of the second attempt. After the point where all the lines are radiating out from was drilled out and is where the router bit went through. I took the plate off the bottom of the router and replaced it with the jig. Obviously if you only need one diameter hole cut you can simply measure and drill one hole for the pin. 🙂
The holes this cut were quite good. second pic shows the result. Note my router bit wasn't long enough to make it through the 25mm MDF and I had to flip it over and finish from the reverse side. I also used a much larger diameter bit (due to the rebate).
Tony.
PS. I used a hole saw for the holes for the ducts in my bass reflex speakers, it was a 70mm hole saw and 70mm pvc but the resulting fit was very loose... not so accurate, and I'd use the router next time.
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For routing small holes it can be difficult to pivot a router around a fixed point. If you have a circular base on your router, for small diameter holes you can rout a larger hole in a template and use this as a guide for your router. The size of the template hole = the distance from the edge of your router bit to the edge of the router base + the desired hole radius. If you are doing a lot of holes in a line, attach a strip of wood to the underside of the template, and use this as a guide. At least you get all the holes in a straight line, all you have to worry about them is the spacing.
follow up
Hi oublie,
Further to my previous post, I dug out some photos of a couple of router jigs that I have used.
The timber setup was for routing knob holes in 3mm thick alloy plates and the clear polycarbonate jig was for routing the recess shape for some Tang Band W3 full range speakers. A photo of the finished speakers is also shown.
Hi oublie,
Further to my previous post, I dug out some photos of a couple of router jigs that I have used.
The timber setup was for routing knob holes in 3mm thick alloy plates and the clear polycarbonate jig was for routing the recess shape for some Tang Band W3 full range speakers. A photo of the finished speakers is also shown.
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There's a router circle guide sold by Sears or maybe B&D... it has an offset pivot that makes it possible to cut smaller diameters (with a radius smaller than that of the router base).
For 64 holes, though, a drill press and a hole saw is attractive. "Imported" 8" or 10" drill presses can be cheaper than a good electric hand drill if you catch the right sale.
On the other hand, you have the router and bits already. Something like audi0's clear jig could work. Make a guide out of scrap material the length (or half the length, if you don't mind moving it down the baffle after doing half), mark out the intervals and drill. Put pins (dowels, cutdown nails, bolts with countersunk screws) in the jig which plug into the guide board. Then just clamp or otherwise attach each baffle alongside the guide, and shift the jig along the guide for each hole. This should save some time, since you only have to lay out the hole intervals once, rather than repeat it for each baffle.
For 64 holes, though, a drill press and a hole saw is attractive. "Imported" 8" or 10" drill presses can be cheaper than a good electric hand drill if you catch the right sale.
On the other hand, you have the router and bits already. Something like audi0's clear jig could work. Make a guide out of scrap material the length (or half the length, if you don't mind moving it down the baffle after doing half), mark out the intervals and drill. Put pins (dowels, cutdown nails, bolts with countersunk screws) in the jig which plug into the guide board. Then just clamp or otherwise attach each baffle alongside the guide, and shift the jig along the guide for each hole. This should save some time, since you only have to lay out the hole intervals once, rather than repeat it for each baffle.
I highly recommend the Jasper Jig- I bought the combo pack. I have used these many times with PERFECT results. Parts-Express.com ? Jasper ? Jasper Tools, Jasper Audio, Circle Jigs, Circular Template, Plunge Router Circle Guide, One-Pass Circle Guide
Hi,
for small holes <10cm I don't like the router since it's a pain to turn it over such a small space, and I'm too lazy to make a template. For larger holes, or for recessed edges, the router is king!
In my experience, using hole saws on a hand drill is outright dangerous! As soon as you tilt the hand drill a little bit, the hole saw 'bites' in the wood and the drill gives you a mighty kick in the hand you won't quickly forget (guess how I know 🙂 )
OTOH, I have very good experiences using hole saws in a (cheap) table drill press. Had perfect holes every time.
Just my experience.
Kenneth
for small holes <10cm I don't like the router since it's a pain to turn it over such a small space, and I'm too lazy to make a template. For larger holes, or for recessed edges, the router is king!
In my experience, using hole saws on a hand drill is outright dangerous! As soon as you tilt the hand drill a little bit, the hole saw 'bites' in the wood and the drill gives you a mighty kick in the hand you won't quickly forget (guess how I know 🙂 )
OTOH, I have very good experiences using hole saws in a (cheap) table drill press. Had perfect holes every time.
Just my experience.
Kenneth
When I built my line arrays I used a Jasper Jig to create a template/jig for my front baffles. After the template was ready I clamped it onto the blank front baffle and routed out the holes using a guide bushing 1-3/16" Brass Template Guides - Lee Valley Tools and 1/4" straight bit from Lee Valley. An elaborate and time consuming process but it did result in perfect front baffles. I also rabbetted the driver cutouts to mount the drivers flush.
Regards,
Dan
Regards,
Dan
This one is adjustable
http://www.diyaudio.com/forums/equipment-tools/166515-small-hole-circle-router-jig-pictures.html
I hope it will work ok
🙂
btw, I think some hole jig saws can be mounted with a centre steering, which at least makes it more accurate
This is what I used for smaller holes. It does require a drill press or drill stand.
Adjustable Circle Cutter
Adjustable Circle Cutter
For clean large(ish) holes I use and suggest a forestner bit.
Forstner Drill Bits ? Rockler ? Large Sawtooth Bits, Sets, Sharpening Kit, Coin Bits
(first link I found)
There are a few types, but these are how you get clean, flat-bottom holes at ANY angle in a piece of stock. So clean- no need to sand (if the speed is not too high to burn the sides)
I have done 3/4" holes at crazy angles for output jacks on the edges of guitar bodies, and also truss rod screw access ports (about 5/16-3/8 range) at ~10 degrees with NO tear-out, and the edge was like paper... Larger diameters I have done, but straight for other projects.
Also great for doing a recessed driver- drill the flange OD to the flange depth; use the smaller clearance drill and align it with the center mark from the flange recess. Hole bottoms are clean, flat and sharp cornered.
They come Metric and inch, so a nice collection gets you pretty much every size you might need. Home Depot sells singles that are decent quality (inch only).
As to getting good spacing:
Measure a continuous line from top to bottom and then make your cross lines. Place the point of the bit on the cross and let 'er rip! A center punch can help get the drill pint right on the mark.
Keep speeds slow- probably as slow as your drill can go with a Forestner bit.
Although they CAN be done by hand, it is always better to secure the piece for each hole and use a drill press. A bench-top one might work depending on the width of your baffle. Remember (if it's wide) that you may be able to drill one from the edge, and then re-assemble the small drill press THROUGH the first hole you drilled to allow drilling the second hole, and so on.
A ghetto hole saw CAN make clean holes. You need VERY high RPM's and light pressure to do it, so the wood is shaved more so than ripped apart. Drill press is the ONLY way to get anything half-decent this way, and this ONLY works for through holes, as it 'cores' the piece. The hole will be round, but probably larger than the drill indicates. Forestner is WAY better for clean holes.
Get creative! But BE SAFE!
Forstner Drill Bits ? Rockler ? Large Sawtooth Bits, Sets, Sharpening Kit, Coin Bits
(first link I found)
There are a few types, but these are how you get clean, flat-bottom holes at ANY angle in a piece of stock. So clean- no need to sand (if the speed is not too high to burn the sides)
I have done 3/4" holes at crazy angles for output jacks on the edges of guitar bodies, and also truss rod screw access ports (about 5/16-3/8 range) at ~10 degrees with NO tear-out, and the edge was like paper... Larger diameters I have done, but straight for other projects.
Also great for doing a recessed driver- drill the flange OD to the flange depth; use the smaller clearance drill and align it with the center mark from the flange recess. Hole bottoms are clean, flat and sharp cornered.
They come Metric and inch, so a nice collection gets you pretty much every size you might need. Home Depot sells singles that are decent quality (inch only).
As to getting good spacing:
Measure a continuous line from top to bottom and then make your cross lines. Place the point of the bit on the cross and let 'er rip! A center punch can help get the drill pint right on the mark.
Keep speeds slow- probably as slow as your drill can go with a Forestner bit.
Although they CAN be done by hand, it is always better to secure the piece for each hole and use a drill press. A bench-top one might work depending on the width of your baffle. Remember (if it's wide) that you may be able to drill one from the edge, and then re-assemble the small drill press THROUGH the first hole you drilled to allow drilling the second hole, and so on.
A ghetto hole saw CAN make clean holes. You need VERY high RPM's and light pressure to do it, so the wood is shaved more so than ripped apart. Drill press is the ONLY way to get anything half-decent this way, and this ONLY works for through holes, as it 'cores' the piece. The hole will be round, but probably larger than the drill indicates. Forestner is WAY better for clean holes.
Get creative! But BE SAFE!
I have never heard a fly cotter called a ghetto hole saw. I have also never seen an 8" Forestner bit.
8" Circle Cutter
I did say a drill press was required. I got excellent results with a fly cutter, although I never needed a large flat bottom hole when building speakers. Whatever is used to make holes, I recommend a few practice runs before you start on your project.
Where did 8 inches come from?
"i have to cut a lot of 4" holes (64 to be precise). " I read that as 4 inch diameter, not eight...
Anyway, that aside, I was referring to hole saws as being ghetto, not circle cutters as ghetto hole saws.
In order of accuracy/cleanliness of holes:
Hole saw (but they can be clean if cut carefully; size accuracy is the issue)
Circle cutter (generally more accurate but often less clean due to single (or two) cutters cutting that entire diameter)
Forestner bit (I like these for smaller holes!)
And no, I have never seen an 8" forestner bit either (sounds scary!). I would make a circular template (probably from clear lexan with alignment scribe marks on it) and use a router with a template bit (bit with bearing on it at the same diameter as the bit)
"i have to cut a lot of 4" holes (64 to be precise). " I read that as 4 inch diameter, not eight...
Anyway, that aside, I was referring to hole saws as being ghetto, not circle cutters as ghetto hole saws.
In order of accuracy/cleanliness of holes:
Hole saw (but they can be clean if cut carefully; size accuracy is the issue)
Circle cutter (generally more accurate but often less clean due to single (or two) cutters cutting that entire diameter)
Forestner bit (I like these for smaller holes!)
And no, I have never seen an 8" forestner bit either (sounds scary!). I would make a circular template (probably from clear lexan with alignment scribe marks on it) and use a router with a template bit (bit with bearing on it at the same diameter as the bit)
An externally hosted image should be here but it was not working when we last tested it.
I agree that forestner bits make nicer holes than a hole saw, but they create such a bunch of wood scraps! When I use the hole saw, I can keep the scrap piece for use as "clamp pressure plates" when gluing wood 🙂 or I use them as feet for practice guitar amps 🙂
I must say, I don't know how I ever lived without a drill press. I think it's the single most important tool I have ever bought. Even my plunge router and battery -powered drill only come second. Having a drill press gives you so much nicer results and allows you to utilize so many cutting tools in a safe manner, I can recommend it wholeheartedly to everybody!
BTW, mine is a cheapo (100 euros) but for hobby use I find it perfectly acceptable.
Kenneth
I must say, I don't know how I ever lived without a drill press. I think it's the single most important tool I have ever bought. Even my plunge router and battery -powered drill only come second. Having a drill press gives you so much nicer results and allows you to utilize so many cutting tools in a safe manner, I can recommend it wholeheartedly to everybody!
BTW, mine is a cheapo (100 euros) but for hobby use I find it perfectly acceptable.
Kenneth
Kenneth - a 100% agreement!
at aged 66, after a good 55 years of all sorts of hobby and DIY, my 5 year old, $100US Chinese made, belt driven press is a serious contender for best tool of the millennium.
I have now all kinds of holes in things which are really TRUE!!
at aged 66, after a good 55 years of all sorts of hobby and DIY, my 5 year old, $100US Chinese made, belt driven press is a serious contender for best tool of the millennium.
I have now all kinds of holes in things which are really TRUE!!
One is definitely on my list of tools to buy this summer...I have a cargo van, so picking up a used Delta floorstander from Craigslist shouldn't be too hard 😉 🙂
I don't worry about the scraps.
If I need pieces for something else, they are budgeted into that project.
Those shavings make nice fire starter too!
If I need pieces for something else, they are budgeted into that project.
Those shavings make nice fire starter too!
It simply referred to the maximum hole size of the circle cutter in the link I gave. I'm not sure I've ever seen a 4" Forestner bit, but they may make them.
So, we agree completely on the hole saw. As a machinist, I tend to call the circle cutter a fly cutter. Just a different terminology. I used to cut front baffles on my CNC mill. Any shape hole I wanted with accuracy to 1/1000th of an inch. Not bad for wood work.
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