View Full Version : Top plate edge thickness
newmando7
Dec-10-2005, 7:07pm
Hello everyone,
Well I am still carving my first F-style top but have some questions for you builders out there.In my prints it shows the edge thickness at .187 how important is it for me to be at that thickness when finished and what effects will it have if I go to less than that say .160 or so on the very edge of the plate???
Dave Cohen
Dec-10-2005, 7:50pm
If the thickness at the edge of the plate is not consistent, the binding height will not be consistent. It will look crude, but will probably be all right structurally. When you are done carving the recurve, consider trying to adjust the outer edge thickness to a constant 0.160" all around the plate (except at the scroll, of course). That will insure that your binding will be uniform around the top plate.
newmando7
Dec-10-2005, 8:03pm
I do understand that the edge needs to be uniform and the same around everywhere except the scroll.The reason that I am asking is I have two areas as of now that are about .164 at the rear point and the top rear quarter.This happened as I was using my contour B template.Thank you for adding some insight.
Dale Ludewig
Dec-10-2005, 9:35pm
Dave is right- your edge thickness (except around the scroll area) needs to be uniform to look right. I'm even using CNC for roughing out and leave my outside a little thick and then use a Wagner Safe-T-Planer (sp?) to bring the edge down to .25". I know that's a little thicker than most people do, but it's purely for looks. Sometimes I take it thinner. I wouldn't likely go thinner than what Dave said, 'cause it would look odd. The actual edge thickness, IMHO, has no importance in sound as long as the recurve is right in thickness.
mandolinplucker
Dec-11-2005, 9:41am
I don't have a safety planer so I have to go with what I got. The only way I could figure out to get the outside a consistent thickness was to use my router table with a 3-wing slot cutter. I set the height of the underside of the cutter just short of the width of the binding. I made a fence by drilling a hole slightly larger than the bit and close to the edge of the fence. Then clamp one edge of the fence to the table and turn the router on and let the bit cut out the depth that you want to cut the edge of your plate. Clamp the other side of the fence. This gives me a thickness edger with a depth stop.
Dale Ludewig
Dec-11-2005, 11:17am
Eeek! Be careful with that 3-wing cutter. I'd have guards all over the place to protect my fingers. Even after 30, maybe especially after 30 plus years of woodworking, I'd be scared to death of trying to use one of those cutters with it either in the router and held by my hands (keeping them away from the cutter)or using a power feeder (not an option in this case). IMHO.
Dave Cohen
Dec-11-2005, 11:30am
What's wrong with a caliper and a block plane? I think that you could do the job with those in not much more time than it would take for set-up with any of the other stuff you mentiioned.
mandolinplucker
Dec-11-2005, 7:56pm
Dale, It ain't that scarey. It's hard to explain but the whole bit is inside of the hole that I drilled with a forsner bit in the fence. The only cutting edge is the portion that is exposed when I cut the bit through the front side of the fence. If I made the fence taller I could glue a piece of 1/4 ply to the top of the fence and the only part of the bit seen would be the 1/4" or so that is exposed. I don't have a safety planer yet but just looking at that thing scares me. It looks like it could shoot stuff across the room or take big chunks of meat off your hands if you ain't careful. Everything in the shop is dangerous if we aren't careful and alert.
sunburst
Dec-11-2005, 8:07pm
Everything in the shop is dangerous if we aren't careful and alert.
And don't ever forget it!
So far, I have ten complete fingers, but I have, in fact, cut myself with a block plane.
BTW, I do a "rough cut" to thickness the edge of the plate oversize with the safeTplaner, then finish it later with hand tools, like Dave suggested.
Without some sort of feather board or hold down device, it's easy to get thin spots around the edge of the plate with a power cutter. Also there always seems to be a little bit of tear-out.
Michael Lewis
Dec-11-2005, 11:10pm
Use the depth stop on the drill press. Set the depth of the thickness you want and drill away, then hog it down with a shrp hand plane or finger plane. Pretty easy and mindless method, as you don't have to contimuously pick up a cliper and measure with it. Just remove material as long as there are holes visible. When the holes are gone STOP! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif
The safety planer does a good job but if you don't have one this is a shop made tool that should do the trick. You have to make it so that it sands at the correct depth. Put some sticky sandpaper on it and have fun.
oldwave maker
Dec-12-2005, 10:28am
Another way to reference the edge- borrowed from the old fiddlemaker I once apprenticed with, available wherever dremel bits are sold...
PaulD
Dec-13-2005, 10:18am
I like Dr. Dave's idea, but using a marking gauge instead of a caliper. You would mark the thickness with a marking gauge around the edges and then scrape or plane to that line. It wouldn't take long and the worst injury you could cause yourself is the nick with the plane or scratch with the gauge.
The Saf-T-Planer is designed so that if you stick your hand in it you can't take too big a chunk all at once, unlike a shaper cutter or 3 wing router bit. Still, they make me nervous so I don't own one.
I think I can picture what Tony is describing for his "guard/fence" for the 3 wing cutter, and I've done similar setups on the router table that I'm comfortable with. The entire cutter could be contained within the fence except the little bit that is needed to trim the plate. You could easily build a hold-down and Plexiglass guard over the exposed cutter to make it impossible to give yourself an accidental manicure.
Tope, I like your simple, quiet, and safe solution as well.
pd