I am currently working on a router jig for precise loudspeaker cutouts. Initially, I considered buying a Jasper jig but they`re only available in the US and are intended for a 1/4" router cutter head but have a few problems.
- with a 1/4" bit you need to make a few passes when routing to sink a chassis, especially on larger drivers.
- these bits are easier to brake and I have never found any difference in cutting speed between a thin and a large diameter bit
- the large bit can be sharpened by a professional service (costs much less than the bit)
- large diameter bits can plunge deeper
- the Jasper jig comes in inches only
I`m also unsure if the Jasper jig will fit pro routers as the ones that usually use small diameter shank bits like 6mm or 8mm (above I speak about cutting head diameter, not shank) are hobby (although the Jasper jig has the triangular holes very native to the DW625/Elu MOF177/Trend T11 router family).
Until now I used a home made jig with great results but I decided it is time for something more precise based on it and what I learned might be essential.
The new one is in progress and for now is made to accept the DW625 only. I can adapt it to accept other routers as well but will need your help here - a precise drawing of the table mount screws on its base.
All that being said, I set to work. The new jig is made for loudspeaker cuts. So far I have incorporated about any frame (outer diameter) and baffle hole (cutout diameter) for the following brands:
Scanspeak; SB Acoustics; Seas; Vifa; Peerless; Monacor; Visaton; Silver Flute; Mark Audio; Fostex; Eminence - the 15" family only; Beyma - the 15" family only; Eton - Orchestra line only;
Others may fit too as frames may be similar in diameter. All holes have been made for a 16mm cutter head diameter where the hole itself accepts a 5mm bolt. The ones that go under the router base, mostly for tweeter cutouts, will have their heads chamfered so a philips bolt`s conical head would sink in it and not cause any bump between the router plate and the jig (my own home made jig was done this way and did great). To stabilise it even further, they will be threaded. The ones outside of the router base won`t have a thread, its not neccessary. The radius is done exact with an extra +0.25mm or so (+/-0.03mm) so the cutout will be slightly larger than the frame dimension. I did this, because my current jig was made exact and when you make an exact cut, the speaker won`t fit easily and needs to be pushed in, which makes it troublesome to take it out, should you need to and you will, sometimes several times. Also, once a coating is applied it tends to flow over the edge of the cut and you`ll need to sand it away, which with some coatings may produce a white line (easy to fix but why cause it when it can be avoided). So, I decided to add this extra buffer of around 0.5mm to total diameter. On drivers up to 7", even a 1mm gap (so 2mm extra in diameter) is not visible to be of concern.
The jig is slightly longer than the one I have now and allows cuts for up to 15" drivers. At the end it it designed to have a handle or counterweight attached for better balance. And a wall hanger of course 🙂 It is oval and will have slight sanding on the underneath edges as if they`re straight, it will not run as smooth and when you are routing sunk waveguides for closer midwoofer mount, it may scratch them (don`t ask me how I found this out).
I plan to have this made out of either stainless steel or standard carbon steel, 4mm thick. Aluminium is also an option but is weaker and will need deep anodization which will make to more expensive. Also, with steel the center of gravity will be lower and if its carbon steel, jig will be cheaper to produce. Best will be stainless but 4mm sheets are really pricey so will figure it out.
The current work in progress model is attached, this is a PDF export of the CAD drawing. I would welcome any input on how to make it better and adding new speaker units to make it as versatile as possible.
Once finalised, I can produce more and post them to those interested in Europe at no profit or upload the CAD model here so you can make your own at a local laser cut facility. First option would drop the manufacturing cost per unit as here they charge a setup cost for the laser which is fixed in value, but if its made out of steel, I suspect its postage cost to be around EUR9 which may negate the benefit so local procurrement may be a better option.
Let me know what you think 🙂
- with a 1/4" bit you need to make a few passes when routing to sink a chassis, especially on larger drivers.
- these bits are easier to brake and I have never found any difference in cutting speed between a thin and a large diameter bit
- the large bit can be sharpened by a professional service (costs much less than the bit)
- large diameter bits can plunge deeper
- the Jasper jig comes in inches only
I`m also unsure if the Jasper jig will fit pro routers as the ones that usually use small diameter shank bits like 6mm or 8mm (above I speak about cutting head diameter, not shank) are hobby (although the Jasper jig has the triangular holes very native to the DW625/Elu MOF177/Trend T11 router family).
Until now I used a home made jig with great results but I decided it is time for something more precise based on it and what I learned might be essential.
The new one is in progress and for now is made to accept the DW625 only. I can adapt it to accept other routers as well but will need your help here - a precise drawing of the table mount screws on its base.
All that being said, I set to work. The new jig is made for loudspeaker cuts. So far I have incorporated about any frame (outer diameter) and baffle hole (cutout diameter) for the following brands:
Scanspeak; SB Acoustics; Seas; Vifa; Peerless; Monacor; Visaton; Silver Flute; Mark Audio; Fostex; Eminence - the 15" family only; Beyma - the 15" family only; Eton - Orchestra line only;
Others may fit too as frames may be similar in diameter. All holes have been made for a 16mm cutter head diameter where the hole itself accepts a 5mm bolt. The ones that go under the router base, mostly for tweeter cutouts, will have their heads chamfered so a philips bolt`s conical head would sink in it and not cause any bump between the router plate and the jig (my own home made jig was done this way and did great). To stabilise it even further, they will be threaded. The ones outside of the router base won`t have a thread, its not neccessary. The radius is done exact with an extra +0.25mm or so (+/-0.03mm) so the cutout will be slightly larger than the frame dimension. I did this, because my current jig was made exact and when you make an exact cut, the speaker won`t fit easily and needs to be pushed in, which makes it troublesome to take it out, should you need to and you will, sometimes several times. Also, once a coating is applied it tends to flow over the edge of the cut and you`ll need to sand it away, which with some coatings may produce a white line (easy to fix but why cause it when it can be avoided). So, I decided to add this extra buffer of around 0.5mm to total diameter. On drivers up to 7", even a 1mm gap (so 2mm extra in diameter) is not visible to be of concern.
The jig is slightly longer than the one I have now and allows cuts for up to 15" drivers. At the end it it designed to have a handle or counterweight attached for better balance. And a wall hanger of course 🙂 It is oval and will have slight sanding on the underneath edges as if they`re straight, it will not run as smooth and when you are routing sunk waveguides for closer midwoofer mount, it may scratch them (don`t ask me how I found this out).
I plan to have this made out of either stainless steel or standard carbon steel, 4mm thick. Aluminium is also an option but is weaker and will need deep anodization which will make to more expensive. Also, with steel the center of gravity will be lower and if its carbon steel, jig will be cheaper to produce. Best will be stainless but 4mm sheets are really pricey so will figure it out.
The current work in progress model is attached, this is a PDF export of the CAD drawing. I would welcome any input on how to make it better and adding new speaker units to make it as versatile as possible.
Once finalised, I can produce more and post them to those interested in Europe at no profit or upload the CAD model here so you can make your own at a local laser cut facility. First option would drop the manufacturing cost per unit as here they charge a setup cost for the laser which is fixed in value, but if its made out of steel, I suspect its postage cost to be around EUR9 which may negate the benefit so local procurrement may be a better option.
Let me know what you think 🙂
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I have the same router and the Jasper Jig 200 I think. It does suit the router ok. It also comes with a few formulas that you can use to calculate the right hole even if your bit is metric and whatever size.
At least in Germany it can be found
Jasper Circle Jig Model 240 | eBay
I'm sure your's will work as well. It might be a bit hard to find a hole needed though as they are spread pretty randomly. It might make sense to keep at least some waves like order in those so at least some of the consecutive diameters follow some arc and then when needed jump to a nect arc to fit them all.
At least in Germany it can be found
Jasper Circle Jig Model 240 | eBay
I'm sure your's will work as well. It might be a bit hard to find a hole needed though as they are spread pretty randomly. It might make sense to keep at least some waves like order in those so at least some of the consecutive diameters follow some arc and then when needed jump to a nect arc to fit them all.
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