Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: navdave on April 04, 2012, 04:55:50 pm
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I'm building a Plexi style headshell that's going to be all natural wood finish.
Anyone here ever build this type of headshell? If so what did you use to cut the
front baffle where the controls are a jigsaw or circular saw? I plan on cutting it out then routering and staining it but I want my cuts to be clean. I dont want to have to do too much sanding or have my routing messed up because my cuts weren't straight.
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I use a hole saw to make the radius then cut the radius... I can't remember off-hand what size I used. Then I use a circular saw to cut the straight lines.
I often use a battery-powered 5 1/2" circular saw, if you only have the 7 3/4" type then you may need to stop short of the holes and finish up the cut with a jig or hand saw.
j.
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Do you remember what size hole saw you used?
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Probably a 1" to give a 1/2" radius... if memory serves.
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Thank you sir I'll giver a try.
Probably a 1" to give a 1/2" radius... if memory serves.
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I'd use your router.
Clamp a metal ruler(fence) to a scrap board and make a pass with your router. Measure the distance between fence and cut(<-x->). Then clamp the fence that same distance from where you want the cut on your piece. Clamp some scrap wood with straight edges for sides. The size of the router bit=radius of corners. Let the fence be your guide. I've never been good at a straight line with jig or circular saw. I do it this way and get a perfectally straight cut every time(and you could practicaly do it blindfolded!).
P.S. It may be easier to rough cut first then use this method to get a nice straight line. Also may be easier to cut the hole first for extra clamping surface then cut to size. You can make one to use as a pattern then get a bit with a bearing to make more. That way you don't have to fence each time if you make one and can size it first.
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I'd use your router.
This is good advice.
Basically, make a full scale pattern out of some scrap plywood (ideally cabinet grade, it will be flatter) using a table saw or router/straight edges. Then on your actual work piece, use the pattern to mark the cut-out & remove waste to within an 1/8" of the line with a sabre saw. Next, clamp & carpet tape your pattern down & rout the finished cut-out with a top pattern bit in your router. Like this one:
(http://lh6.googleusercontent.com/public/lQvgw0buV-mVCkvPfoK50vZaOhq9w5rZf1N0A8K34hjPm2obbsm47f7msVL4ECEPyhKZCsPk4QLY_QGodmQ6Me2CyW2NlRGj_kcwxSoL36qEDjToglLevwWKn1ka4SvHgGoDPPztiU8m)
The bearing follows the guide & cuts below. As the bearing & the cutting section are the same diameter, the pattern is made to the actual size allowing for exact sizing & placement. It also gives you MUCH better visibility as to what you are doing. I use these nearly every day.
The finished cut will only require light sanding with a good pattern & sharp bit. Then use a roundover bit the break the edge to match the rest of the cabinet.
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That's what I use. I use the jig to draw the pattern, then use a jig saw to cut all the excess so the router has less to cut. Then use the router with the pattern to finish it off. Gives me perfect lines corners etc. I have a set of pattern jigs that I have made like that. Took me a few tries getting my jigs just right, but once I got a perfect one, I keep it hung up with the rest of them.
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Took me a few tries getting my jigs just right, but once I got a perfect one, I keep it hung up with the rest of them.
Yeah, that's the beauty of using the jigs. You can make as many (or screw-up) as you need to, to get it exactly how you want it.
Then there are no worries about ruining expensive lumber & you have done all the hard work should you want to make a second cabinet, third, etc......