Template for "strange" driver mount?

Discussion in 'Archived Threads 2001-2004' started by Brian J Dupuis, Mar 5, 2002.

  1. Brian J Dupuis

    Brian J Dupuis Second Unit

    Joined:
    Jul 8, 2001
    Messages:
    341
    Likes Received:
    0
    Trophy Points:
    0
    Hey guys,
    Well, received my ACI Sapphire III kit on Monday. I'm really pleased with the package so far. Everything was very well packed, nothing missing, and just felt "professional", if you know what I mean. I ordered the non-assembled version of the cross-over, but received it assembled. Oh well, it's probably for the best anyway... less for me to screw up for my first attempt at a full-range, I guess, eh?
    So anyhow, man what a weird driver this Focal 7K4211DB in terms of the outline that I have to create to flush mount it. I'm trying to figure out the best tool to use to make the flush mounted flange. I'm thinking one of the following:
    1) top-bearing trim bit with a self-made MDF template. Seems to me coming up with the MDF template is only marginally less difficult than doing the actual flange. Am I missing something?
    2) some of those brass template guides with a self-made lexan or other thinner material template. This might be a bit easier than the previous, since it's a thinner material to work with. But I've never worked with template guides (and can't quite figure out how they would work) nor do I own any. I see these template guides, but do I need a whole set or just a few? Bear in mind I have the Bosch 1613EVS plunge router.
    3) trace and hand route close, then chisel and pray. Have no clue how this would go.
    Any insight, guys? Thanks in advance.
     
  2. Patrick Sun

    Patrick Sun Studio Mogul

    Joined:
    Jun 30, 1999
    Messages:
    38,777
    Likes Received:
    492
    Trophy Points:
    9,110
    Have you considered NOT flush-mounting the midwoofers? You might help in aligning the acoustic centers if you don't flush mount them.
     
  3. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Hi Brian,

    When I built my Saphire III's, I made a custom jig to recess those drivers. I think I still have it if you want. I'm just not sure if the Focal's are the same as the ones in my Saphire III's that were built about 2-3 years ago. The router I made the jig for had an edge to center of the bit distance of 2 7/8" I believe. I think I first cut the center hole and then clamped the jig in place and plowed out the recess with a 1/4" bit. If you just want a picture of the jig, let me know.

    Jeff
     
  4. Brian J Dupuis

    Brian J Dupuis Second Unit

    Joined:
    Jul 8, 2001
    Messages:
    341
    Likes Received:
    0
    Trophy Points:
    0
     
  5. Brian J Dupuis

    Brian J Dupuis Second Unit

    Joined:
    Jul 8, 2001
    Messages:
    341
    Likes Received:
    0
    Trophy Points:
    0
     
  6. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Wow Brian,

    You answered pretty quickly. If you could wait about a half an hour, I'll try to find the jig, get my digicam, take a pick and put it on my web site.

    Talk to you soon,

    Jeff
     
  7. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Brian,
    I found the jig. I was serious that you can have it if you want it. I'd be glad to send it to you for the cost of postage. Here's the pic I took. Sorry for the image quality.
    [​IMG]
    I think I previously posted a picture of the cutout that this jig acheived. In case I didn't, I've included the following image.
    [​IMG]
    Let me know if you need any additional help.
    Jeff
     
  8. Brian J Dupuis

    Brian J Dupuis Second Unit

    Joined:
    Jul 8, 2001
    Messages:
    341
    Likes Received:
    0
    Trophy Points:
    0
     
  9. Jeffrey_S

    Jeffrey_S Stunt Coordinator

    Joined:
    Jan 17, 2002
    Messages:
    206
    Likes Received:
    0
    Trophy Points:
    0
    Brian,

    I've only been woodworking for about 3 years and consider myself a novice. I have only made a few router jigs. I think you are right, however, that the base size and router bit size would be critical in using my jig.

    So let me see if I can remember how I made the jig. Hopefully you will find this helpful in making your own. I think I started by determining the diameter of the curved areas on the Focal driver. I added to this one half the diameter of my router base (which is a perfect circle) and one half of my router bit's width. Then I cut a circle out of a piece of plywood such that the opening in the wood had a diameter equal to my calculated diameter. Now that I had the jig component that would enable me to cut the curves for the Focal driver, I needed to interupt the circle I cut with straight wooden beams to allow for the straight parts of the driver flange. Of course I allowed for one half the diameter of my router base and one half the diameter of my router bit in positioning these straight beams. I ended up with the jig shown in the picture in my previous post. There was some trial and error involved. I didn't get the jig right the first few times I made it. Trial cuts in scrap wood allowed me to refine the jig. It was a pain to make but all in all the experience was very enjoyeable.

    Now keep in mind that I'm still pretty new to woodworking myself, so I'm sure there are better ways to make this jig. Maybe some more experienced woodworkers could chime in with some suggestions. And since you are new to woodworking, I just want to remind you of what Norm Abrams always says: Be sure to follow all safety rules, wear safety glasses, protect your hearing, and read the manuals that come with your power tools, and follow the safety instructions found there.

    Good luck. If I could be of additional help, let me know.

    Jeff
     
  10. Brian J Dupuis

    Brian J Dupuis Second Unit

    Joined:
    Jul 8, 2001
    Messages:
    341
    Likes Received:
    0
    Trophy Points:
    0
    Many thanks for the great description, Jeffrey. I figure working out a jig for this might be instructive in and of itself, and your insight into how you made yours is invaluable. I'll let you know how it goes!
     

Share This Page