So. . .
I’m in the process of converting a regular ol’ pointy vaulted ceiling into a barrel vault. My client – that is to say, my old man – would like to see a compound arch: a 120″ radius, with a short 14.5″ radius to finish ‘er off on either end.
Anyways, I made a template so I can cut out a whole bunch of OSB for this. I tried copying it ad nauseum with my top bearing flush bit, and the results sucked. I found the router wobbled way too much, throwing the tip of my bit in and out. An 1/8″ this way and that way makes for 1/4″; my pieces weren’t consistent at all when I stacked them. Then I managed to damage my template.
I ended up making a different template to follow with the base of my router; that is to say, the reflection (?) of my profile. This way, the entire router base is sitting on the work, nicely supported, and the larger radius of the router base evens out imperfections in my template. But I called it a day before I could give it a true test.
What would you do in this situation? I have a couple dozen of these to cut. Working with two trammel setups with two radii doesn’t appeal to me. That’s how I made my template in the first place, and it was tedious.
Replies
Maybe I should just use my jigsaw.
Rough out with th jiggy saw and leave an eighth to trim away with the router. The bits will chatter less and cut a lot smoother.Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
In my opinion the best way to do that is a nice template that is perfect, sand all the bumps out with somethign like a sureform, the templat bit your using is also fine. I'm not sure what kinda router your using but the simplest way to stop it from tipping back and forth is make and offset base for it outta some 1/4" lexan or plywood. http://www.hectorshardware.biz/shop/product.asp?dept_id=1811&sku=333286& ...Make something similar to that and it'll help alot. And my last recomendation is to rough it with the jig saw to within a 1/4" then rout it. P.S. use at least a 1/2" Pattern bit
I can't imagine not having the router ride on the good side of the rafter. Jigsaw all but 1/8 or so, route the rest with a template, use an offset base.
"Put your creed in your deed." Emerson
"When asked if you can do something, tell'em "Why certainly I can", then get busy and find a way to do it." T. Roosevelt
I think that's the way to go.
Routers behave themselves a lot better if your removing material from one side.
I've played this game too many times, seems like you end up sanding it smooth in the end no matter what.
Jigsaw or sawzall with thin blade. If it's possible to stay within 1/16" with either, I don't know that there's an advantage to using a router to cut OSB.
Beer was created so carpenters wouldn't rule the world.
Yeah. I'm feelin' the jigsaw route.
Hey, thanks for the advice. I tried using the jigsaw alone, but I wasn't completely happy with the result.I roughed-out all my pieces and finished off with my router with a scrap of plywood as a lame offset base. Worked awesome. It did take most of the day for my 24 pieces, but at least it's done.Next step is to sandwich 2x material between my OSB pieces. I think I'll have to do the same - cut it rough with the jigsaw, and then clean it off with my router.
Never underestimate a compass plane. Or a finger guide for your router.PAHS Designer/Builder- Bury it!
Pardon?Looks like I have some googling to do.
Generally a good plan, but which threw you?
A compass plane has an infinitely flexible sole. A finger guide encompasses your router bit, rides on your template. Makes for better cuts, eliminates your need to have the router positioned exactly with the template.
A pin router is an excellent template option, but you don't need it. Beyond that, there's CNC routing, which I could probably get you into in NW Ohio.PAHS Designer/Builder- Bury it!
Ha, I wasn't sure what either one was.
You call finger guide, I call a template guide bushing.
Now I get it.
Onsrud makes a sweet inverted pin router..always wanted one of them.Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
My same Ohio buddy has an Onsrud. He bought it to finger-joint. Which he no longer does, though it performed very well. Used to be incredible auction opportunities in Ohio. Maybe still are. Onsrud will work day in and day out without complaining.
New-to-me is an overarm pin router made from a metal surfacer (I think). Has a sweet X-Y table below the router. I took one look and decided it was really a mortiser, missing the clamp. Folks who built it had several pin spots tapped into the large aluminum table surface. Cost me a little less than the VS PC router alone was worth.PAHS Designer/Builder- Bury it!
I spent arm numbing hours on pin routers till we got the CNC..happy,happy day. Nothing like having the stock and template climb up a bit, or a sudden bit snap, or worse..the frigging pin lossen up an drop out under the table.Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
Pin routing is tedious at best. Nothing I want to do. Mortising on the other hand...
CNC probably isn't in my future. My buddy's machine takes up about 400 sq ft of floor, several concurrent heads. He thought he was going to be routing a lot of boat parts, but they haven't materialized. Really bad timing with the current economy. Last I saw, he was hogging fiberboard for some large DuPont crate parts.PAHS Designer/Builder- Bury it!
I've done this with the jigsaw and then router as others have specified.
Find where the jigsaw blade lands with the fence riding against your template. Clamp to and cut away.
Then if it needs to be perfect, reset the template for your router and clean up."Research is what I'm doing when I don't know what I'm doing..."
Huh, this is all really interesting. My cousin is into robotics as a hobby, and he wants to build a small CNC router, like benchtop size. I was very interested, but he didn't care at all - from his perspective, a CNC router is too simple and easy of a project. He only wants it to produce parts for robots!
Well, my top-bearing bit just snapped 1/2-way through trimming the 2x stock on the first piece. Sh.t. I think I should drive into town and get a new one. Of course, the top bearing on a 1/2" bit dictates a 1/4" shank, which I don't like at all.
My bottom-bearing bit has a 1/2" shank, but I don't think it has 1.5" of reach. . . and it is all the way out in the truck. That would work if I really shaved it close with the jigsaw.
Obi-wan has taught me much, but I am not a carpenter yet.
Ouch.
This is why you want a finger guide, or template bearing something-or-other that Sphere was talking about.
The sleeve is what rides against the template. You use an inexpensive straight router bit, no bearings. Well, upcut or downcut spiral bits are nice, but not necessary. Finger guides come in whatever size you need, both for your router and chosen bit. They don't break, allow use of cheap bits.
I'd be using a 3/4" bit (1/2" shank). Big difference in cut between that and a smaller bit. When you get to hogging out substantial wood, you get serious about your hardware.PAHS Designer/Builder- Bury it!
Hmm. Ok - so for the finger guide, I would just have to make a template that allows for the increased radius of the bushing.
I like the concept. One advantage I can see is that an 'oops' moment shouldn't have the bit digging into the template. There's a little room for real-world complications.
Exactly, you size your template accordingly. The one time that a bearing bit works better is tight inside corners, where the larger radius is a problem.
There's a little room for real-world complications
KISS is good.
My Makitas also came with a finger guide, which uses the substantial rails but puts a finger with rotating disc directly under the bit. Works pretty well, but you have to keep the router perpendicular to your template. Otherwise, you're routing differing distances from the template. Room for error, not KISS.
Speaking of which, with a finger guide, if it's not centered around the bit you have the possibility of wiggling the router (in relation to the template) and causing error. Shouldn't be any possibility of mounting the finger guide other than concentric to the bit, but that's dependent on the router base being correct.
Esoteric, but if you're looking for precision ...
Sphere's right about having backup bits. Beyond that, you have the opportunity of stocking up your most used ones when you find a good sale. Much cheaper for straight bits than bearing ones.
I've got 15-20 1/2" shank straight bits. Even if I lost the ones I was intending to use, I could always grab larger or smaller and keep working. Depending on application, might require a new template. No tool stores nearby here either.
I also use a finger guide with a dovetail template for zipper drawers, but that necessitates a 1/4" shank. So for larger dovetails, I use a 1/2" shank with a larger finger guide. There are dovetailed floor joists in my shop. No fasteners, drove the inspector nuts. 3 sizes of dovetail bits live here.
And I really don't enjoy using a router. Too noisy. But you sure can do a lot with them.PAHS Designer/Builder- Bury it!
Ha..DT floor joists.
Up in Pa I built an addition for some folks, they wanted 3x10 White Pine exposed second floor joists.
I had it all framed up and getting my insp. and the guy says " Hey, you need hangers on them joists"
I took him by the hand and we went up to the second floor and I pointed to the tops of the joists where you could see the taperd sliding DT exposed.
And I said "Hows that again?" " I have seen barns 200 years old done like this, and as a matter of fact, they are still standing"
He got google eyed and said " well sure enough, here ya go, I don't need to see anymore" and signed the framing insp permit.
Then he asked for a few cards..to hand out to anyone who needed a carp. that he may come across.
I'm trying to recall how I did that, I am pretty sure I didn't use a router..I think it was all chiselled..but maybe I routed the pockets. It was a fairly small addition about 14x24, and had a stair opening that gave me a headache.Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
In addition to what Tom said, when I get into a project like you are doing, I am sure to have at least 2 if not 3 of what ever bit I may destroy.
I don't live close to any decent supply place, and often have jobs on sites that are not in reasonable driving distance for a 20 dollar cutter.
When ever possible, I try to set myself up so that I am not dependant on one weak link in the chain of events..belt and suspenders approach is always best, have a back up cutter/plan/tool to finish without losing a day schlepping around looking for what you should have had with you.
I'm not preaching, and I have gotten caught my share of times.
Just another lesson in the school of hard knocks.
Spheramid Enterprises Architectural Woodworks
"Success is not spontaneous combustion, you have to set yourself on Fire"
Preach away, man. I am but small in the ways of the builder.
Ditch the router and use an Arcus "circular" saw blade.
http://www.arcusblade.com/
Solar & Super-Insulated Healthy Homes
I just bought one of those to cut some arches in 3/4 A C ply. I was skeptible (sp) , but dang if it didnt work just like advertised. Nice smooth radius'.
dug
I have been underestimating my jigsaw, as a tool. No router bit, btw, saw me through the rest of my day.
It's inexperience. I've not normally used a jigsaw for this kind of application. I had 12 units to cut. The first three, with the jigsaw, weren't awesome. But I kind of trained myself to the cut. #4 was OK. 5-12 were increasingly excellent. After I was done, I went back and fixed 1-3 so they were OK.
In retrospect, I probably could have saved myself a lot of time if I had combined persistence with the jigsaw in the first place. I think I have a lack of confidence in skills that require co-ordination, but I should trust myself more.
I will say that I only recently acquired a decent jigsaw. I forget the model - it's a DeWalt. The box says 'heavy-duty' right on it. ;-) It's nice.
Edited 2/13/2008 6:18 pm ET by Biff_Loman
Now that you are on the right track to fully utilizing the jigsaw, pay close attention to the blades you are using. Not only do the tooth material, size and shape differ, but also the set to the teeth. Two almost identical blades will cut entirely different with the set. Tight curves need a wide set and straight lines and smooth wider curves need a tight set.
A perfect example is the Bosch 244, a wide set coarse blade. It's perfect for a collins coping foot for coping trim. The wide set blade is also great for fine "rasping" of the edge of a cut by pulling the blade backwards along the cut in a way that is impossible with a shallow set blade. Just don't expect much on a straight cut and tearout is common.
It's also common sense to use a sharp blade, but not common practice--sort of a natural human instinct to run blades into the ground way past the point their performance suffers until the forward cut speed is shot. Just like with any saw, a sharp blade will make the straightest cuts.
If you want a step up in accuracy, the jigsaws with better blade stability, such as the new Bosch models, are tops and in practice the improvements do make a difference.
Instead of buying most blades from Home Depot or other outlet selling mostly general purpose blades, take a look at a tool outlet that stocks a wider variety. For carpentry I keep bosch coarse 6" blades that can slowly cut through a 4x4 if needed, the bosch 244 for coping or tight cuts, a coarse bosch 144 in a normal length for most straight cuts, a medium bosch for most finish cuts, fine bosch for finish projects that tear out easily, a down cutting blade for even more careful cutting of a finished surface that would tear out, and finally a few of any blade I can get my hands on.
A new quality sawzal can also take the place of many carpentry tasks usually done by the jigzaw, only much faster. I hate to admit it, but I used to hand sharpen even new sawzal blades so they would cut better. Again, going to a supplier with a wide variety of blades is the way to go to find the thinner wood blades better for finer cuts.
Good cutting!
Beer was created so carpenters wouldn't rule the world.