Hi, here’s what I’d like to do but need a better way:
This is a common issue I’ve run into, cutting very smooth (by smooth I mean no small waver in the curve), long curves with my jigsaw (I know it’s not the “right” tool. I’m cutting 1x5x40″ board, one side straight, the opposite side has a slight curve (bow) in it. (see the attached drawing)
First I must explain that I live in Manhattan, and have limited work space + tools, when I’m working in a room, that room becomes a temporary shop, and you would be amazed at how many tools and material you can fit into a towel closet (aka: the Toolshed).
I tend to cut these subtle curves with jig saw, but have found the blade is so small its hard to track a very smooth, long curve. My 7-1/4″ circular saw is a monster and too big (I used to frame houses and I have a soft spot for that brute), something in between would feel just right……..like a 3.5″ saw of some type. A band saw would be the tool but that is not a possibility for me.
Any suggestions would be appreiciated.
Thanks
Peter
Replies
If you rough it out with the jigsaw, you could clean it up with a router following a template.
Alan, thanks. I'dGood suggestion but I'd like to explore other possibilities first, without having to cut a hard template (that I could use as a router guide/template). In fact thats the problem if I could cut a hard template without any "wiggle" that a thin blade like a jigsaw allows, I could cut the wood the same way.ThanksPeter
Not only is the thin template material easier to work, but if you mess it up, all you need to do is to redraw your curve and take off a bit more material (by sanding, or whatever) until it looks right. Then you follow the template to cut your workpieces all the same.In NYC, the noise of a router is another potential difficulty. A spokeshave is a possibility that would be a lot quieter. A more expensive option would be a compass plane. If you are interested in hand tools in NYC, Joel at http://www.toolsforworkingwood.com is supposed to be a good person to talk to and buy from.
" if I could cut a hard template without any "wiggle" that a thin blade like a jigsaw allows, I could cut the wood the same way."
Actually, the template dosent have to be so perfect. Since it is only 1/4" thich it is easy to sand the roughness out of it. In fact what most of us do is cut the template just shy of the curved line and sand up to the line. I generally use a spindle sander so it may seem easier to me, but if you cut on the line and just smooth out the saw marks it is not much sanding at all. Actually if you use a large diamater flush trim bit (I use a 1/2") its larger bearing will even out most small cut marks left by the saw even if you didn't sand.
Mike
I had a sugestion passed to me on this issue a while ago - the problem was templates for car frame components but whatever..
Template can be cut just shy of the finished size, them use a fairly stiff edge binding material for kitchen cabinets on the template. This will both even out any residual uneveness and reduce wear from the bearing if it is to be used several times.
Dave
I second the suggestion that you would be better off using a template and a router to get the final shape.
It is much easier to get a fair curve in a thin piece of grainless template material than it is in a thicker piece of solid wood. You also don't have to make both halves of the curve, make a half template first and then use it to make the full template by flipping it over.
John White, Shop Manager, Fine Woodworking Magazine
I also, make a 1/4" template for curves. It's far easier to clean up a 1/4" thick material than something approaching 1". A jigsaw will cut better and truer in 1/4" than 3/4" material. If you do it with the template, you can always make another piece later.
When I clicked on your image it froze my browser. :(
OK, I'll use a 1/4" template & router to finish the curve.Thanks for the advice.Peter
Peter,
Try cleaning up the roughness, etc with a curved bottom spokeshave...quick, quiet, clean, small, and easy....
James
http://www.lie-nielsen.com/catalog.php?sku=Boggs
http://www.lie-nielsen.com/catalog.php?sku=SBS
http://www.leevalley.com/wood/page.aspx?c=&cat=1&p=50230
http://www.thebestthings.com/newtools/spokeshaves.htm
http://www.jonzimmersantiquetools.com/tools/shaves.htm
http://www.craftsmanstudio.com/html_p/C004005.htm
I second the motion on the spokeshave. Even after I bandsaw a curve, I clean it with the spokeshave. Best of all worlds.The older I get, the better I was....
I hope this does not sound ludicrous but I would use a western made pullsaw in these circumstances. The speed of cut allows for accuracy and the time it takes is remarkably short. the surface finish is worth the effort.
If the curve is an arc (i.e. part of the circumference of a circle) you could rough cut the workpiece and then use a router on the end of a board as a compass. That is, bolt/nail/screw one end of the board at one end of the bench, and attach the router (with an extra base plate or with the straight guide) to the other end of the board. Use a framing square to get the workpiece perpendicular to the compass. Turn on the router and swing it.
Boy, that strikes me as an opaque description of a simple technique - it must be past my bedtime. I've used this technique with great success on arcs with up to a 6 foot radius.
Just as the above post mentioned mounting a router on the end of a board and using it to arc the cut (does that sound right?), you could also mount your jigsaw on the end of a board and make your curve. If you've got a good stiff blade and go slow, I suspect you will get a very good curve. You can not push hard, go slow and easy and I think it will work well.
Rusty
I was thinking of replying with this the other day and it's the method I probably would have used as well. But then I realized that for the radius he has, he needs a trammel arm roughly 200" long (assuming about a 1" peak in the curve - it's hard to guess from his sketch). I figure if he's as cramped for working room as he says, there's no way he's got enough space to set up a jig that long and swing it through the curve. Otherwise, it's a good method.If you build it he will come.
doug,
I think what he is cutting is an ellipse not a circle. If you're faced with a similar problem log on to http://www.josephfusco.org. He has every imaginable math formula, written for us laymen, you can imagine.
Don
Thanks for all the suggestions.I usually have a few non-rectangular parts in my projects, many of which are in NY, NY.
Due to the size/space constraints you can almost never lay any large curve out using the center of a circle. I'm an architect & former house framer so I know how tough it can be like to lay out a curved anything, especially complex curves.For example enclosed is an apartment renovation I recently completed. The main wall of the apartment is a curve (which has another curve of different radius coming off it.) There are also some curved shelves which again are difficult to lay out.For the wall (clad in vertical grain Douglas Fir) I plotted a full sized template 3' x 30' long for the carpenters, and for the shelves (Mahogany) I gave the cabinetmaker full sized templates.Russian contractor & workers, fantastic.........if they ever hinted that anything is difficult I'd say "come on you guys put Sputnik in space". ThanksPeter
Quit your whining, Pete. If you can't cut that simple shape with only a bit of sanding afterwards we'll have to take that jig saw away from you. Just joking. More than likely you are using a lousy blade. Many makers have fine cutting blades (smooth scrolling, super smooth scrolling) that look a little like handsaw teeth, they are more expensive than those coarse black type blades you get in a variety pack. I have a PC bayonet saw. I have to use PC type blades. The 10pt Swiss made blades give very nice results. They also make a 20pt but they are a little too fine for 3/4" stock. In the old days all I had was a green plastic Black and Decker jig saw. It took some skill to keep that going straight. Using a good blade really helped. Bosch also makes similar blades as I'm sure, many others do. Another aid in making nice cuts is to firmly support the work and clamp it, so it doesn't move. I don't think you'll need much more than a little sanding after using a good blade.
Beat it to fit / Paint it to match
Well it's me not the equipment, my jigsaw is a Bosch w/a fairly new wood blade. I slowed down my cut, kept still, and got a much cleaner line. I showed it to "the boss" my older daughter (9), who is very particular, she thought it looked fine.Thanks for the suggestions.Peter
My closest experience is finish carpentry and framing...I love my 77 bosch worm drive and skilsaw 77 but for what you want to do I think you should buy the DeWalt battery powered saw. More than one guy on our jobs, mostly finish carpentry, use these small battery powered circular saws . It's blade is about 4 1/2 to 5 inches in diameter and easily cuts slight curves without binding. Second, make a template of the curve you're attmpting to cut and finish it to a smooth curve with sandpaper. Make the curved template with some good quality 3/8 thick material and when it's finished shape is what your attempting to make, screw and glue some 1/4 inch hardy board or pressed board to the bottom that extends out about 4 inches from the curved edge. Clamp this two piece template arrangment to some flat surface with room below for the saw blade to cut all the way through the 1/4 inch material. Using your new Dewalt saw place the foot of the saw, with the edge farthest from the blade, against the curved edge of the template and cut the resultant gentle curve out of the lower portion of the template. You now have a template that makes perfect repeated cuts of the same curve and quick too. The edge of the template supports the majority of the sole plate for the saw and more importantly, the cut edge of the template exactly marks where the new cut is going to be. These Dewalt saws hold a charge for quite a few cuts, they're light to carry and no cord is needed. I think you'll be more than pleased with the result
Oh yea, when you wish to make the cut "for real" place the template into position and clamp the template to the work piece with a couple of wood clamps or "C" clamps and cut away. You could use the template with your jigsaw too but you need to decide which saw your most pleased with and use that one only. Once the template's 1/4 inch material has been cut with either the dewalt saw or jigsaw, the remaining space on the template is set and you can't go back to a different tool. Well, in most cases but I'm sure you'll crasp the meaning here. If you have no idea of how to do this...you don't need any more suggestions just more practice. May the luck of the Irish be with you.
May the luck of the Irish be with you.
May the wind at your back never be yours.My goal is for my work to outlast me. Expect my joinery to get simpler as time goes by.
The routah with a template idea is good, but even to get a smooth template gets you back to the same problem, only somewhat easier to deal with.
If you cut your curve as accurately as possible, not forcing the jig saw (which will almost certainly cause the blade to wander), them auto-body magicians (and of what I remember of driving in NYC, there's got to be a million of em there) have this wonderful autobody rasp which is conformable to curves just like the stanley and record curved planes (another option), and they are sharp and can rasp down yer curve so that it is real smooth and "fair". The work real well with MDF, and I have used them with real lumber too, although they are slower. Regardless they are effective at achieving fairness of curve.
Any tool marks are quickly and easily taken out with a pneumatic sanding drum look for 4 to 5 inchish diameter drums to use in a drill press. Rigid ones just re-indroduce tool marks. Or if yer tool challenged, just take one of yer offcuts and turn it into a sanding block. Takes a bit more elbow grease though.
If you don't already know, closing your eyes and running your hand along the curve will let you know how close you are to a smooth curve.
Hope that helps.
Eric
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