Newbie cutting baffles

[michaelp]

Never cut a baffle before, and I have a couple questions. (For me this is the most intimidating part about DIY speakers.)

First, I have engineering background and I have taken some shop classes in high school and college (a long, long time ago). However, I have very limited experience with power tools (lived in apartments most of my adult life).

I inherited from my father:
power drill
circular saw
jigsaw
simple router (not plunge) and a handful of bits
(I'll have a table saw someday, when I drag it back from my mother's house)

I've been reading here in Tech Talk about circle jigs and plunge routers, and I don't have either. Since I am just getting started, and since I don't know how many speaker builds I may or may not do in the future, I'm reluctant to spend much money on tools at this point.

Is it possible for me to make some decently round holes with what I have? (I'd certainly consider buying a circle jig, but I'd like to avoid buying a new router)

Can I cut holes with a non-plunge router (for example, drilling a hole first to get the router started)?

Can I use a circle jig with a non-plunge router?

Is it possible to flush-mount a driver with the tools I have (possibly buying a circle jig)?

I guess that's all I can think of for now. Thanks in advance for any advice.

[danklugherz]

Re: Newbie cutting baffles

Welcome Micheal to an addicting hobby. You can build speakers with the tools you have but I would really reconsider the router. A plunge router is really a requirement for flush mounting woofers and tweeters IMO. You could purchase a used one on Ebay or buy new. You don't need a top of the line router, Ryobi would be a good choice. A circle jig would also be required. I think you'll find after your first build you'll want to build another so a new router would get alot of use. As far as router bits I use 1/4" up-cut spiral bits on bare MDF and down-cut on prepainted baffles. I also use 3/4" straight cut bits for flush cutting drivers and 1/2" round-over for baffle edges. Some clamps are also something you'll find are very helpful. Your skilsaw will work for cutting pieces as long as you use a cutting guide for straight cuts.

Buy a plunge router and a circle jig you'll be on your way.

Later
Dan

[Ludo]

Re: Newbie cutting baffles

Michael,

Yes, it is possible to cut recesses and holes without a plunge router but it is more prone to errors as you need to guide the router down onto the baffle very slowly and evenly. I don't have a plunge router either and have been getting by for about 5 years. Until I joined this forum last fall I didn't even know there was such a thing as a plunge router. :o Now for the circle jig, I don't think you can get by without that.

Louis

[philiparcario]

Re: Newbie cutting baffles

Never cut a baffle before, and I have a couple questions. (For me this is the most intimidating part about DIY speakers.)

First, I have engineering background and I have taken some shop classes in high school and college (a long, long time ago). However, I have very limited experience with power tools (lived in apartments most of my adult life).

I inherited from my father:
power drill
circular saw
jigsaw
simple router (not plunge) and a handful of bits
(I'll have a table saw someday, when I drag it back from my mother's house)

I've been reading here in Tech Talk about circle jigs and plunge routers, and I don't have either. Since I am just getting started, and since I don't know how many speaker builds I may or may not do in the future, I'm reluctant to spend much money on tools at this point.

Is it possible for me to make some decently round holes with what I have? (I'd certainly consider buying a circle jig, but I'd like to avoid buying a new router)

Can I cut holes with a non-plunge router (for example, drilling a hole first to get the router started)?

Can I use a circle jig with a non-plunge router?

Is it possible to flush-mount a driver with the tools I have (possibly buying a circle jig)?

I guess that's all I can think of for now. Thanks in advance for any advice.

nikbrewer a member on site cuts baffles at a good price. send him a pm and ask.

[jonpike]

Re: Newbie cutting baffles

You could get by by slowly dialing the fixed router down into the work, making a pass, dialing down again, etc... and cut the hole 1/8"-1/16" at a time. You do want to do it in steps even with the plunge router, it's generally not a good idea to mow thru the whole 3/4" in one pass...

Basic steps, if you're flush mounting:

Determine diameter of driver.
Determine depth to flush mount the driver.
Determine thickness of baffle.
Carefully zero your router depth, then drill down and make the OD cut. (plunge you would set fixed depth, then drop it down)
Reset on the circle gauge to the thru hole diameter, start cutting layers.
Make sure you stop about 1/16" before cutting all the way thru, this prevents a divot when the center section comes loose.

The other way is to get rabbet bits, which will let you cut a fixed wider "shelf" in a preexisting hole. Then you determine what size thru hole plus what standard rabbet size will equal the driver OD.

I'd agree a plunge router is MUCH more convienent, but hope this shows you can do it. I'd also reccommend buying a circle jig, but you can make one as well.

For your circular saw, Google "sawboard" for a very easy to make cutting jig, easy cheap and slick. :D

Get some cheap plywood and practice making cuts...

Hope that helps..

[johnastockman]

Re: Newbie cutting baffles

As jonpike said, I've been doing that with my non-plunge Ryobi 160 for over 12 years now. I do it just like he described...get the diameter set for the recess, then dial the 1/4" spiral bit down 1/8", make a full circle cut, dial down another 1/8" (or 1/16" depending on the recess depth), etc. Then I reduce the diameter of the cut and cut the width of the "shelf" or recess for the drivers flange width. Then you can cut the through-hole. Of course, you will need some form of circle-cutting jig, whether home made or a Jasper or Router Buddy. I use the Jasper. Get some scrap pieces of either plywood or MDF and practice. Always measure your drivers when you get them, don't go by the published dimensions...they can be off a little. Here's a pic. The little hole in the center is for the 1/8" pivot pin that the Jasper uses. I reduce the diameter about 1/4" at a time until the recess is the width I need.



Cut the through-hole the same way, lowering the bit 1/8" at a time for each pass. You can get a perfect fit like this, but as you can see, using a non-plunge router takes more time and work.



But a circle-cutting jig of some kind is a must for flush-mounting drivers. There's no way I could get a nice, round recess doing it freehand. I tried in the beginning, following the line I drew with a compass. Too inaccurate.

John A.

[michaelp]

Re: Newbie cutting baffles

Thanks all for the good advice. I'm thinking about buying a circle jig and playing around with some scrap pieces, and see what I can do with the router I have. I already own it, so I might as well give it a try before I buy a new one.

If I find I'm doing a lot of this (or if I don't like using the one I have), then I might consider a plunge router in the future (and I see the cheaper ones aren't all that expensive).

In the meantime, my current router is a Craftsman, so I'm thinking about trying one of those Craftsman router guides. A number of people seem to like them, and I understand Zaph was talking them up a while ago in his blog.

[michaelp]

Re: Newbie cutting baffles

Oh, and jonpike, thanks for that sawboard tip. I just downloaded a pdf document that explains it well. You are right: it looks easy, simple, and very useful.

Mike

[john trials]

Re: Newbie cutting baffles

I just borrowed my dad's non-plunge Sears router, and he already had that Sears circle-cutting jig (it's about 25 years old, and he's never used it).

I've been practicing using the circle jig, and it works great. Infinitely adjustable radius is nice, but you do have to make careful measurements of the radius when setting it up (unlike a Jasper, which has marked radius holes). You have to insert the center pin into the wood just slightly, and then lower the pin and the router bit into the wood at the same time with the router on. It's not as simple as a plunge router, but it still works.

[tomzarbo]

Re: Newbie cutting baffles

I've been reading here in Tech Talk about circle jigs and plunge routers, and I don't have either. Since I am just getting started, and since I don't know how many speaker builds I may or may not do in the future, I'm reluctant to spend much money on tools at this point.

Mike,

If you don't want to outlay any more cash, there is an alternative.
My local Home Depot sells 1/4" and 1/8" MDF and hardboard handy panels (precut 2' x 4' pannels)

You could always just cut the holes with a jig saw to mount the drivers in your baffle with the thin board clamped or screwed temporarily on top but not glued on.

Then place the drivers in the thin board and with a sharp pencil, trace out the outside of the drivers. Then, cut out the "recess" holes in the thin stock and with some light sanding, you can glue that to your baffle and get a pretty nice "recess" on your speakers.

If you decide to build more speakers, which you most likely will... then I echo other's comments:
A good plunge router with a 1/4" bit is INVALUABLE!
I made my own circle cutting jig for big drivers, and use the smaller Jasper jig for smaller drivers. Between the two of them, I'm covered for any size driver.

Welcome, and have fun!
TomZ

[[email protected]]

Re: Newbie cutting baffles

ditto above. suggest spiral bits. you can buy a 3 pack at harbour frieght real cheap. may not be real great quality but for mdf they work fine.

arlis