I consider myself pretty solid when it comes to wood working and cabinet building but I come into problems from time to time. My biggest issue is with a wave guide for a compression driver because of the shape and angles of it. Basically after the recess you have to cut a hole where it kind of twists in place and also have angle routed into the hole as well so it is a procedure and a half. Also some of the drivers I have used I can't get the exact OD of for the recess - the Lab 12 for example doesn't have that info. my questions are:
1) If I already recess the mounting area and cut the circle for the driver and find out that the recess needs to be an additional 1/16th or 1/8in wider, what is an easy way to do this? since the inside of the circle has been cut and the bits with the guide wheel aren't long enough, I am drawing a blank on how to do it. Also if I cut the circle too small for the driver I use a file to open it up more however this is time consuming and I am sure someone figured out a better way to do it...
2) What has been a good way to make jigs and templates for router work to make tolerances tighter? Sometimes I will make an error and have to use wood fill or bondo to fill in areas the bit traveled and removed material that I do not want removed. I want to make a tower with constrained layers and mahogany for the outside of the cabinet. Where bondo and wood fill worked before and can possible work, i imagine i would see a difference when the stain and poly is used. Any tips at all for routing recesses to super tight tolerances and best practices for making jigs and templates?
1) If I already recess the mounting area and cut the circle for the driver and find out that the recess needs to be an additional 1/16th or 1/8in wider, what is an easy way to do this? since the inside of the circle has been cut and the bits with the guide wheel aren't long enough, I am drawing a blank on how to do it. Also if I cut the circle too small for the driver I use a file to open it up more however this is time consuming and I am sure someone figured out a better way to do it...
2) What has been a good way to make jigs and templates for router work to make tolerances tighter? Sometimes I will make an error and have to use wood fill or bondo to fill in areas the bit traveled and removed material that I do not want removed. I want to make a tower with constrained layers and mahogany for the outside of the cabinet. Where bondo and wood fill worked before and can possible work, i imagine i would see a difference when the stain and poly is used. Any tips at all for routing recesses to super tight tolerances and best practices for making jigs and templates?
For #1 I would make an MDF template of the proper (larger) diameter and carefully center it over the existing hole attaching with double sided tape. Then use a pattern routing bit with bearing to enlarge the hole to the template.
#2 will be following good basic woodworking techniques which can take many years to develop. In general the most critical factors are having good tools, good quality router bits (Whiteside or Bosch for me), the means to hold the workpiece (clamps, bench, vise, etc.), accurate measuring scales, etc.
As an example, when using a circle jig to cut a circular opening in a panel I place the panel on a larger sheet of MDF, clamp the two together, drill (preferable on a drill press or with a guide) an accurately positioned and perpendicular 1/8" center hole through the workpiece and into the MDF. This way when the router bit breaks through the workpiece the 1/8" center pin will hold the offcut circle in position rather than have the bit grab it and jam up the cut.
Always in woodworking it is useful to setup a process or glueup, get all of the clamps, etc. positioned, mentally go through the steps you will follow, identify any problems and resolve them BEFORE you switch on the tool or spread any glue. Like anything else discipline and planning are your friend!
#2 will be following good basic woodworking techniques which can take many years to develop. In general the most critical factors are having good tools, good quality router bits (Whiteside or Bosch for me), the means to hold the workpiece (clamps, bench, vise, etc.), accurate measuring scales, etc.
As an example, when using a circle jig to cut a circular opening in a panel I place the panel on a larger sheet of MDF, clamp the two together, drill (preferable on a drill press or with a guide) an accurately positioned and perpendicular 1/8" center hole through the workpiece and into the MDF. This way when the router bit breaks through the workpiece the 1/8" center pin will hold the offcut circle in position rather than have the bit grab it and jam up the cut.
Always in woodworking it is useful to setup a process or glueup, get all of the clamps, etc. positioned, mentally go through the steps you will follow, identify any problems and resolve them BEFORE you switch on the tool or spread any glue. Like anything else discipline and planning are your friend!
I am not following you on part one...basically you are making a template of the recessed cut which is the larger diameter - placing it over the circle that has already been cut...How are you centering it perfectly? Also how does double face tape hold it tight enough when you put pressure on it from using a rolling bit? What is the largest size rolling bit they make for side cutting the recesses? I have a few but they were all on the small side. Also how would you increase the OD of the hole itself? If i am off I use a file but this is time consuming and tedious sometimes.
If you want it centered "perfectly" use a router circle guide to cut out two circles, the OD of the first one is the ID of the circle you cut wrong; the OD of the second one is the ID of the circle you want to recut. Both will have a 1/8" hole in the middle from the template pivot pin. Stack the two circles with a pin to center small one down and place into the too small hole. Lower the template for the correct size hole over the large one and it is "perfectly" (not really an applicable term in woodworking) centered. As to the bit you'll use it would have a bearing on the router side the same OD as the bit and the length will depend on the thickness of your template and workpiece.
OTOH the human eye is really good at judging parallelism and I would expect that as long as the error were small (1/8" in radius or less) you could visually place the template with an error in the centering of 1/64" or less.
Oh and double stick tape is widely used to position router templates...this isn't the stuff used to mount photos in an album but really grippy stuff that takes some effort to get back apart after use. Some use carpet tape although that can be really hard to get apart...woodworking supply stores carry tape that is made for this purpose.
OTOH the human eye is really good at judging parallelism and I would expect that as long as the error were small (1/8" in radius or less) you could visually place the template with an error in the centering of 1/64" or less.
Oh and double stick tape is widely used to position router templates...this isn't the stuff used to mount photos in an album but really grippy stuff that takes some effort to get back apart after use. Some use carpet tape although that can be really hard to get apart...woodworking supply stores carry tape that is made for this purpose.
You can always cut a circle from scrap MDF which will snugly fit into the existing hole, glue in place and re-route to the correct diameter with your circle cutting jig.
Thanks so much. I guess there really is no fast easy tricks. If I have scraps large enough I can certainly do what was suggested. For the rebate cuts I can use a roller bearing bit to open it a little more I need to take a look at the drivers but I wouldn't be surprised if a 25mm one or so with interchangeable roller will hit most if not all of the recess cuts.
Jack, I believe that I read something about you somewhere. Didn't you do a LFET design a few years ago?
Jack, I believe that I read something about you somewhere. Didn't you do a LFET design a few years ago?
I wrote an article for AX on using the LM4702 to drive L-MOSFETs.
There is a very active audio society in NJ, fwiw.
I was able to make some jigs for the binding post plates with a router bushing set. Some of my drivers don't have a simple circular outside so rebating them now requires some patchwork. I don't have a band saw to cut the shapes out and obvs because of the back of the drivers are there a bushing set won't work. Thinking of mounting the drivers on something close in size and using a flush trim bit to get an exact copy of the shape. I guess I would then have to use a busing kit then to make the jig unless someone has a better and faster idea?
I got one of these rabbeting router bit kits that works "most" of the time. Occasionally, I can't find the exact combination that I need to clean things up.
There are times when I need a step in size that's just in between the bushings that I have. A few wraps of tape around the smaller bushing can provide the cutting depth that is needed. Just have to watch so that the tape doesn't come off. 😀
You can use the rabbeting bit to enlarge a through hole also. Cut most of the way through the piece. Then change to a flush trim bit (for example 1/2" cutter with 1/2" bearing) and put the bearing against the surface you just cut with the rabbeting bit.
Making a template with the correct size works very well also. Your eye is actually quite good at centering. And double backed tape can be a good friend.
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Metal washers work nicely.
I use 3 - 4 washers (all the same size), and use them as centering spacers.
Bit suggestion, very nice for speaker work.
https://www.amazon.com/Amana-45481-...&qid=1493039922&sr=8-5&keywords=amana+pattern
Not a bad idea to double up the bearings for extra long life and less problems.
I use 3 - 4 washers (all the same size), and use them as centering spacers.
Bit suggestion, very nice for speaker work.
https://www.amazon.com/Amana-45481-...&qid=1493039922&sr=8-5&keywords=amana+pattern
Not a bad idea to double up the bearings for extra long life and less problems.
Actually just picked up a few more router bits and some are similar to this one. What is the best way to make a jig for a non circular recess to flush mount drivers? I end up having to use wood fill and bondo to fix my messed up ends and I would like to use mahogany ply for a build where fill will be noticeable. Lets assume the hole is a 3.5in circle however the drivers shape is a square with rounded edges .25in deep. I know to set the depth gauge to my desired depth but I am trying to figure out the best way to make a jig for my drivers that aren't basically circles inside of circles - others have a slight flare where the mounting screws are...another one I am picking up is almost like an octagon. If I screw the driver into MDF or some other material to make my jig, I guess I can make something cut to the identical size using a flush trim bit with a bearing or it will be slightly oversized possibly because of the bearing. Doing this I also run the risk of hitting my drivers with the router and I am not interested in doing that at all. I imagine it would need to be undersized to account for the bit thickness and cut the pattern/jig out to be smaller by 1/4in if using a 1/4in bit...Anyone have any good pointers or tips to make an accurate jig/pattern so I don't always have to backfill messed up ends?
If the two recesses (square and circle) are at different depths it will take two templates. Rout the outer circle with a circle jig and the bit set to the appropriate depth. Devise a method of registration so the square template can then be placed over the workpiece centered on the circle then clamp in this position. Set the depth and rout the square recess...the corners may need chisel cleanup if the bit radius is larger than the corner of the square. Then return to the circle template to cut the smaller diameter through hole for the driver basket.
i am looking to make a jig to do the rectangular areas with decent speed but very with precision. MDF, I don't mind filling in with bonds the whoops areas but I would like to use mahogany ply a design and filling in isn't an option for the best aesthetics. What is the best way to make a pattern jig so that I can route the external areas fast and then remove the rest with hand or conversely mount a pattern to the ply with double face tape and sent the depth gauge and go to town?
The details of order of attack and registration of templates depend to a degree on the size of the work piece and specific jigs/tools you are using. Since the circle jig registers to a 1/8" pivot pin I would be inclined to start with the 1/8" hole in the work piece. Make a matched square template from MDF and a square fitting tight to the template center drilled 1/8". Pin through square into work piece, template over square and clamped or 2-side taped to work piece, remove the registration square and rout the square recess to proper depth, then move to the circle jig for the circular recesses.
thanks, i got the order of operations under control - making the matched square template is what i am having an issue with - can you please advise me on how to make the template itself?
It depends entirely on the tools you have available. Let's say you need a 4" x 4" square template. One easy way if you have a tablesaw would be to rip a 4" wide piece of plywood and cut it into 3 pieces, one 4" long and two longer. Then rip two outer parts of the template to a size that matches your work piece. Glue (this is why I switched to plywood) the two longer 4" pieces between the outer pieces with a 4" gap at the middle...that's your square recess template. The remaining 4" x 4" piece should fit tightly into the gap. No tablesaw, then a sabersaw (some call it a jigsaw but that is a stationary tool) will make a square recess after cleaning up with a fine file and the cutout can be wrapped on edge with masking tape until it fills the gap left by the saw kerf.
Gotcha - I guess a plunge router could be used to make a jig as well - just tack guides like a track saw in place before going to work on it. If I don't have a tool, I have access to it quickly. I figured there would be some kind of tip or trick to making super accurate tight tolerance jigs quickly without the need of cleaning and trimming them up with files and sandpaper. I have access to a nice bandsaw as well and I like using it because I can get very accurate with it - I can't cut holes into something with it obviously and making a jig from 2 pieces seems like it would leave a margin of error. I guess the best thing would be to remove as much stock as possible as fast as possible, then use my table router to bring the jig to as close to size as possible - then sanding and filing to get the fit perfect. It make take a little while to get a nice tight tolerance but once it is done all recess cuts for those drivers and things like binding plates will be so much faster and cleaner. Thank you for all your help.
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