Stupid Question

Re: Stupid Question

David Walser

Jerry -- Your question isn't a stupid one. (I know it's not because I'm having difficulty coming up with a definitive answer.) You didn't say how you were mounting the 1/4" thick 12" square to the backer board. In addition to screws in the waste area, are you also going to be using double-sided tape or hot glue? If so, and assuming all the glue joints are sound, I'd suggest turning at your normal speed for a 12" object. If you're just relying on the screws, I'd turn the speed down to no more than 75% of your normal speed.

Allow me to suggest another approach to cutting the circles: use a scroll saw. Even a 1/16" parting tool leaves a much larger kerf than a bandsaw blade. A scrollsaw blade takes even less wood and, like the lathe, you don't have to cut the board in half.

Re: Stupid Question

John K Jordan

I agree with David's comment about the speed. If I'm imagining correctly what you are doing (I know nothing about such bowls), I think the speed should be about what you'd turn a platter or plate. Faster is generally cleaner, all else equal.

I suspect one issue will be trying to get smooth edges. Even a sharp fluted parting tool (I use two) will tear the end grain, but not as much as some other types of parting tools. One thing that might help is parting away from your line then sneak up on it, removing the tiniest bit of wood each time. I have had good luck with properly sharpened scrapers in cutting across end grain. I don't quite understand what you are doing and why the cut needs to be cleaned - I'm imagining these thin circles will be glued up then turned again, right. Maybe you could post some pictures or a diagram. (or get ideas from someone who knows what that kind of bowl is!)

One way people cut clean circles is with a router and circle jig. home made or otherwise. Or a router and templates.

JKJ

Re: Stupid Question

Jon Behnke

Speed isn't really that fussy for this, you don't need clean cuts because you will stack the rings and turn again anyway. Make your cuts at a 45 degree angle instead of straight in, largest diameter first. The angle will trap the ring and keep it from flying off.

Re: Stupid Question

Jerry Maske

I'm mounting using a wood screw and large washer on the side to hold things in place. Then I bring the tail stock up with a flat fitting on it and that seems to hold stuff in place.

I had some trouble on the last one I tried in that, for reasons that only a wood turner could understand, I'd NEVER sharpened the parting tool! Wasn't pretty. I sharpened the tool and tried an old piece from a vortex bowl I'd made before and it worked pretty well, but I ran it at 500 RPM.

I'm not worried about a little tear out because there will be a lot of sanding later; there always is. I don't like cutting the circles in half and glueing them back together. I've got a scroll saw and have tried that, even with the spiral bit. It works but takes a lot of time. That's not really an issue, but the bowls I've made where I cut the circles on the lathe seemed to come out so much better. Probably an aesthetic thing, but that's the way I'm going to do this.

I appreciate you guys jumping in on this and will, in fact, post pictures as it goes. I've come up with a way of turning Purple Heart a beautiful forest green. I know; why would you want to. Probably because I've never seen anyone else do it. Tomorrow I'll sand the big block and I'm going to do the "Greenerizing" process to see how it affects the other wood. I know it darkens Walnut but I don't know about the other pieces. Doesn't soak in so it's easy to get it off. I can post before and after pictures of all that too.

Gotta' love weird processes like this. But turning bowls gets boring after awhile, and I've given so many to all my relatives that I need to come up with something new or they will start returning the gifts, or use them for firewood.

Jerry

Re: Stupid Question

john lucas

Well I've done it. I used double stick tape and fastened the wood to a scrap blank. Speed is not critical as long as you don't go to fast. To slow is simply not an issue, you just have to cut slower. The parting tool kerf can be an issue when you get to the smaller rings. It can bind up although on a 1/4" thick piece that shouldn't be a problem. I had problems because I was parting 3/4" pieces.

I've also done it where I just fastened the middle and when I parted through the wood comes off. In that case it was nice not running the lathe so fast and I had to wear gloves because the wood was kind of sharp when it came off. That's why I went to the double stick tape so the wood stayed in place until I was done. Just a couple of strips work fine.

Re: Stupid Question

Jerry Maske

The small rings are a problem and will cause binding regardless of what tool you use or how slow you go. Fortunately, there aren't many of them that are small. I like to leave the bottom open and put a base of nice material there rather than a ring.

Several folks have suggested double sticky tape and I'll give that a try. I currently use screws with wide washers on each side and bring up the tail stock with a flat piece in the middle. Never had any problem with things moving around. And now that I've decided to sharpen my parting tool, I think I'll be just fine.

May be a couple of days before I get to ring cutting. Today the big blank should be glued and dried, so I'll be re sawing, and we all know how much fun that is. I've found that these bowls need to have the re saw process done BEFORE you do your design. I need to know how many pieces of re sawn wood I have to work with before I try to design something. So that's today's goal

Thanks for all the advice, and as this thing comes together, I'll post pictures.

Jerry

Here's a stupid answer

Ron Bauer

Why not use a small trim router with a 1/8" bit to cut the rings. A simple table and guide can be set up to do this and there is perfect control at very stage. No running of the lathe is involved. Since it sounds like you will be making more of these it might pay to make a set up. R.

Re: Here's a stupid answer

Jerry Maske

Ron,

That's actually an excellent idea. I've got a couple of routers that could be adapted to such a device, or a circle cutter put together to do it. I'll have to think that one through.

Thanks for the advice. Now I get to go buy more toys.

Jerry

Re: Here's a stupid answer

john lucas

You can't cut very deep with a 1/8" router bit without going painfully slow. It would be faster by far with a Scroll saw if you have the right blade. You should be able to cut 1/4" pieces pretty fast with the correct blade.

I was experimenting with using a metal working parting tool that is not a deep as woodworking parting tools. It would let you get into the tighter rings. That got put on the back burner when I moved and I just found it the other day. Don't know when I will have time to experiment with it some more.

Re: Stupid Question

Jerry Maske

It got worse. I was in the process of cutting the rings on a scroll saw, Dewalt 788, when IT QUIT! No reason I can find. Motor housing was cool, fuse is okay, it just won't run. Well, I've had this one for the better part of ten years and, frankly, found it awkward to run at best, so, I took the plunge.

Did my homework and found that the Jet, despite it's $$$ is as good as it gets. So there's a new scroll saw coming to live here. An interesting "thing" happened while I was looking around at various sites that had them; THEY LOWERED THEIR PRICES. Not kidding. I went back to a site and the price had dropped by $100. Another one threw in free shipping on my return visit. Never seen that happen before.

Anyway, I'm anxious to get it here. I'm stopped dead on cutting my rings. I could cut the board in half and use the bandsaw, but that requires glueing things back together and I'm not fond of that.

More as things progress as well as a review of the Jet.

Jerry