OldTools Archive
Recent | Bios | FAQ |
270997 | James DuPrie <jbn.duprie@g...> | 2020‑05‑25 | gravity well project update |
well, the glue up of the 6" and 3" thick 20" diameter blanks was a lot easier than I thought. Building a solid cylinder instead of trying to do fancier segmented bowl style glue-ups is the way to go. Error #1: I was planning to use a coping saw to round the blanks. I forgot that you can't use a coping saw on something 6" thick, and even a 3" thick hunk is tough - there isn;t enough room in the frame to get a good stroke,and the blade clogs up. So, I ended up a slew of cutting tools instead. Draw knife, spokeshaves, and a couple of plains where the grain was being difficult. Took a couple hours, but got both blanks round enough to toss on the lathe. Smart thing #1: using a brace and hex adapter to drive the 1 1/2" screws to hold the blank onto the faceplate. I love it when I can use a brace to drive screws. So easy..... I manged to get the exponential curve turned today, and it works pretty well. This was out of the 6" thick blank, so the grain ran across the face (flat surface) of the blank. That means that it wasn't as smooth as I would have liked - using cheapo dimension 2 by X stock makes it hard to smooth the surface without getting SOME grain ripples. Confirmed my idea to set it up for end grain when I make the real one (still thinking Beech...). In any case, a pool ball does a nice round orbit that decays with a very satisfying wub wub wub wubwubwubwubwus as it moves down the throat of the funnel. I was surprised how much noise it made just rolling across the higher parts of the curve, but overall still completely satisfied (also assuming it will be a bit quieter without the grain ripples). A marble (about 3/4") does OK, but doesn't have the mass or size to deal with the surface defects, so it decays a LOT faster, and doesn't exhibit a round orbit. Still makes a nice wub wub as it goes down though. I'm supposed to get a batch of 1" stainless steel ball bearing in a couple of weeks. I expected the proof of concept to take longer, and I didn't want to take anything from the client until I was more certain it would work. Sometime in the next few days I'll turn the 3" thick blank, and see if I can get a curve in that that works. I'm guessing no - I had to use most of the 6" in the current one to get a decent orbit and decay, but we'll see. the 3" disc is also set up with end grain on the face, so, assuming the tear out isn't too horrible (I don;t really like turning softwood) I can see how much difference it makes to the sound.... -James |
|||
270998 | don schwartz <dks@t...> | 2020‑05‑25 | Re: gravity well project update |
Great stuff! Pictures, pictures Please! Don On 2020-05-25 3:38 p.m., James DuPrie wrote: > well, the glue up of the 6" and 3" thick 20" diameter blanks was a lot > easier than I thought. Building a solid cylinder instead of trying to do > fancier segmented bowl style glue-ups is the way to go. > > Error #1: > I was planning to use a coping saw to round the blanks. I forgot that you > can't use a coping saw on something 6" thick, and even a 3" thick hunk is > tough - there isn;t enough room in the frame to get a good stroke,and the > blade clogs up. So, I ended up a slew of cutting tools instead. Draw knife, > spokeshaves, and a couple of plains where the grain was being difficult. > Took a couple hours, but got both blanks round enough to toss on the lathe. > > Smart thing #1: > using a brace and hex adapter to drive the 1 1/2" screws to hold the blank > onto the faceplate. I love it when I can use a brace to drive screws. So > easy..... > > I manged to get the exponential curve turned today, and it works pretty > well. This was out of the 6" thick blank, so the grain ran across the face > (flat surface) of the blank. That means that it wasn't as smooth as I would > have liked - using cheapo dimension 2 by X stock makes it hard to smooth > the surface without getting SOME grain ripples. Confirmed my idea to set it > up for end grain when I make the real one (still thinking Beech...). > In any case, a pool ball does a nice round orbit that decays with a very > satisfying wub wub wub wubwubwubwubwus as it moves down the throat of the > funnel. I was surprised how much noise it made just rolling across the > higher parts of the curve, but overall still completely satisfied (also > assuming it will be a bit quieter without the grain ripples). > A marble (about 3/4") does OK, but doesn't have the mass or size to deal > with the surface defects, so it decays a LOT faster, and doesn't exhibit a > round orbit. Still makes a nice wub wub as it goes down though. > > I'm supposed to get a batch of 1" stainless steel ball bearing in a couple > of weeks. I expected the proof of concept to take longer, and I didn't want > to take anything from the client until I was more certain it would work. > Sometime in the next few days I'll turn the 3" thick blank, and see if I > can get a curve in that that works. I'm guessing no - I had to use most of > the 6" in the current one to get a decent orbit and decay, but we'll see. > the 3" disc is also set up with end grain on the face, so, assuming the > tear out isn't too horrible (I don;t really like turning softwood) I can > see how much difference it makes to the sound.... > > -James > ------------------------------------------------------------------------ > OldTools is a mailing list catering to the interests of hand tool > aficionados, both collectors and users, to discuss the history, usage, > value, location, availability, collectibility, and restoration of > traditional handtools, especially woodworking tools. > > To change your subscription options: > https://oldtools.swingleydev.com/mailman/listinfo/oldtools > > To read the FAQ: > https://swingleydev.com/archive/faq.html > > OldTools archive: https://swingleydev.com/ot/ > > OldTools@s... -- "So it goes." Kurt Vonnegut “Worry less, concentrate more, and above all relax.” James Krenov “If you’re always hitting the target, it’s too close.” Wendell Castle |
|||
270999 | Claudio DeLorenzi <claudio@d...> | 2020‑05‑25 | Re: gravity well project update |
yup, old tools rules, pictures or it didn’t happen. C |
|||
271000 | Erik Levin | 2020‑05‑25 | Re: gravity well project update |
Good to hear hat it is going well. When you mentioned marbles, my thought was steel balls as I have a bunch on hand (I go through a respectable number of them for various purposes, the rare old tool purpose being in there), then I read further and saw that you have them coming. *** This message was sent from a convenience email service, and the reply address(es) may not match the originating address |
|||
271007 | James DuPrie <jbn.duprie@g...> | 2020‑05‑26 | Re: gravity well project update |
Once I get to the point where I'm making the real one I'll do some pics. I'll put them on the oldtools facebook page. I hadn't really thought about doing a magazine write up. Not sure where I'd send it. I AM intrigued enough by this to start contemplating doing a rolling ball sculpture in wood though. Lots of potential for a good time wasting project.... -J On Mon, May 25, 2020 at 5:46 PM Claudio DeLorenzi |
|||
271008 | Dan Beck <drumsandbacon@g...> | 2020‑05‑26 | Re: gravity well project update |
I have nothing of real value to add to this conversation, but I wanted to say: (1) this seems like a really cool project and I look forward to seeing how it progresses, (2) I would also love to see process photos, and (c) I work at a science museum and we have one of the big 5' fiberglass gravity wells, and people - of all ages - love to see their coins "circle the drain". |
|||
Recent | Bios | FAQ |