Cabinet builder - How to create templates for irregular shaped drivers?

[Jim Holtz]

Creating a template for irregular shaped driver recesses has been one of many things in wood working I've struggled with over the years. I've searched online and found a couple tutorials but they seemed to be a bit complicated. Since there are so many exceptional cabinet builders on this forum, I thought perhaps you might have links or instructions that might help me get through this step of a build.

Thanks in advance for your help!

Jim

[dar47]

Jim,

Not much time right now but do some research on router bushing guide sets, you need to understand how they work and how to apply a template for this. Steve and Jon just put up some picks on the Horio's current Ardent build. I'm sure lots of guys can show how these work.

[5th element]

This is what I use...

https://www.trenddirectuk.com/inlay-kit-a

I used it to create these odd shape inlays.

[Steve Manning]

What shape are you looking at Jim? I spent a fair bit of time making jigs to make more jigs this week. The best route is CNC a template if you have that option otherwise, double stick carpet tape comes in handy?

Anyway, if you have a picture I'm sure we can come up with something.

[TEK]

This is what I use...

https://www.trenddirectuk.com/inlay-kit-a

I used it to create these odd shape inlays.

I don’t get it (never have).
To use this to make the cut-out you have to have the template that considers the difference between the router bit size and the guide bushing.

How do you make the template?:blink:

[BobEllis]

The loose bushing in the picture makes up the difference - one cut with, one without.

That said, I had better luck with a pattern like Jon used - a square frame sized to match the driver faceplate and a pattern bit of the same radius as the corner of the faceplate. It wouldn't work with the frames Matt shows, but worked fine for my Accuton C-79s. My router must have a lot of runout since the test cutouts were never consistent with the inlay set.

[TEK]

Could you describe the process?
I start having a speaker element with a odd shape.
What are the steps to follow?

[Jim Holtz]

What shape are you looking at Jim? I spent a fair bit of time making jigs to make more jigs this week. The best route is CNC a template if you have that option otherwise, double stick carpet tape comes in handy?

Anyway, if you have a picture I'm sure we can come up with something.

Hi Steve,

The driver shapes I have the most difficulty with are square like the Aurum Cantus AST2560 AMT's Curt and I used in the Bordeaux. I have a Dewalt 621 router and a full set of bushings but somewhere in my process, I'm not getting the precision I need to make the drivers fit snugly. So its the actual creation of the template and which bit to use to create the rounded square corners required for it to fit properly. The AST2560 is very picky about fit. Curt identified a response dip in the FR until he filled the gap I'd left around the driver frame, then it went away.

So, my question was a way to figure out how to upgrade my skills and to provide support for others that are building designs based on irregular shaped drivers.

Thank to you and everyone else that are offering suggestions! I really appreciate the skills and expertise all of you are willing to share.

Jim

[Steve Manning]

Hi Steve,

The driver shapes I have the most difficulty with are square like the Aurum Cantus AST2560 AMT's Curt and I used in the Bordeaux. I have a Dewalt 621 router and a full set of bushings but somewhere in my process, I'm not getting the precision I need to make the drivers fit snugly. So its the actual creation of the template and which bit to use to create the rounded square corners required for it to fit properly. The AST2560 is very picky about fit. Curt identified a response dip in the FR until he filled the gap I'd left around the driver frame, then it went away.

So, my question was a way to figure out how to upgrade my skills and to provide support for others that are building designs based on irregular shaped drivers.

Thank to you and everyone else that are offering suggestions! I really appreciate the skills and expertise all of you are willing to share.

Jim

Hey Jim,

If you have the option and know someone with a CNC router, go that route. The cost for something like that would pay for itself in a couple of uses. Otherwise .......

To make a template for that driver I think the way I would go is very much as Jon did here, http://www.htguide.com/forum/showthr...l=1#post627869. Lay the driver face down on the template board and shim the edges with what ever clearance you want, I typically add 1/32" all the way around, and then secure the guide boards down in what ever fashion you want, clamps, tape, etc. Then cut and trim the center with a flush cut router bit. The biggest pain is getting the corner radius's correct. If you can get flush trim bit the same radius your golden, if not drill the corners with a drill bit prior to cutting the bulk of the center out.

These are the shims I use, https://www.harborfreight.com/144-pi...ent-67585.html, you can go fancier, but they seem to work.

I'm sure the others have some good options as well.

[roadrune]

Sorry for posting to another forum, but post 27 here: http://www.avsforum.com/forum/155-di...ld-thread.html will show you how to make a perfect template.

[Steve Manning]

Sorry for posting to another forum, but post 27 here: http://www.avsforum.com/forum/155-di...ld-thread.html will show you how to make a perfect template.

Cool trick .... I guess you could add multiple layers of tape to increase your offset so you have room for finish. I'd be a little leery of trying that with a fragile driver though.

[TEK]

A fit as snug as the one he got does not leave any room for finish.
I guess you could use a larger differens in size between the bit in the first cut and the template.
Or, instead of tape use a thin strip with veneer (if you have paper backed veneer with glue it may be attached as glue).
But getting the right amount of space may be hard as the finish may add different amount of material.

But a nice method that seems to produce a very nice result.
But you do not really need the last template? You could just use the guide brush and go directly from the second template.
No way to check the result first - so a bit more risky.
But I do see that I should get a shorter template bit!

[5th element]

How do you make the template?:blink:

The device itself comes with a spacer, see the little ring in the picture, between the router bit and the plate/guide that attaches to the router? You push fit this onto the guide for the increased spacing to account for the router bit diameter.

But the critical question, how do you make the template? I use one of these...

https://www.banggood.com/681012mmFlush-Trim-Bit-14-Shank-Router-Bits-Carbide-Tipped-Bits-p-976987.html?cur_warehouse=USA

You have to clamp a piece of wood/MDF to the top of the drive unit that you wish to make the template for. Tape up the backside of the driver to protect it from the ingress of dust. I attach the MDF to the top of the driver using its mounting holes. Countersink in the bolt heads into the MDF so the router can slide freely across the top surface and use spacers between the MDF and driver front to prevent the surround from getting squished.

[dar47]

I have used the large spare wood trick before and it works great but you need the driver in hand as manufacturer tolerances can very. If your close to any any major center the easiest is go to a metal laser shop and have then cut a 1/4" thick metal template from plate, it's cheap and you have one forever or you can pass it on to other builders.

[TEK]

Hmm
Maybe I’m a bit stupid here, but...
If you have the option to create a template of the driver, is there any reason to not keep the «leftover» part instead and have a actual template right away?:unsure:

[Bill Schneider]

FWIW, I have a page showing how to create a router template for drivers that have truncated edges. The page is currently a mix of two different brands of drivers, but they share the "truncated' feature. Maybe this could spark some ideas.

http://www.afterness.com/audio/routing_truncated_recesses.html

[knifeinthesink]

As you are in Des Moines, you can go to this makerspace: https://area515.org/prototyping-inventors/

On their website they say they have cnc and a laser cutter.

CNC has a steep learning curve (one i haven't traversed), but laser cutters are pretty accessible. Depending on the software installed, a vector from illustrator, inkscape, or a cad program will produce a cutout that is accurate within extremely tight tolerances ( i think the cutter at the makerspace I'm part of is accurate to 1/1000 of an inch).

Depending on the shape you are dealing with, you could create a router template in 1/16 in ply (thicker with a better cutter or well maintained machine. not sure which they have), or you could laminate several pieces together. Using the laminate approach you can create a tight cutout for any shape, even it it has sharp corners.

[scottvalentin]

Jim,
On PE Tech Talk, look at Javad's threads, he goes in depth starting in Post #22 on page 2 here:

http://techtalk.parts-express.com/forum/tech-talk-forum/1357891-pretty-persuasions-indiy-coax-build-thread/page2

EDIT: very similar to Bill's method above.

I recently bought an Amana pattern bit as I'm planning a SEOS horn build at some point, but I haven't used it yet! I will be doing the method here that Javad shows.

[Jim Holtz]

Thanks to everyone that responded with the great ideas and template methods. I've been saving them all for when I do need to create a template and its a perfect time to pick up some new router bits that will allow me to hopefully create a perfect recess.

Thanks again!

Jim