The wheel is the heart of the instrument. We turn it on the metal lathe because we can get much better accuracy (specifically in repeatability of putting it on the lathe several times) than on a wood lathe. Even with that said there is always some hand scraping to be done. Any step that involves taking the wheel from rough-cut to smoother and finally to running true is going to stress and test the shaft, the wheel, whatever connects the two together, the collet or chuck that's holding the shaft, the lathe live center and tailpiece, and the tool and toolholder. A big industrial lathe shouldn't really introduce any variation from the collet and other machine parts, but most of us mere mortals don't own a big industrial lathe, nor do we want our precious HG wheel in proximity to such a greasy monster. Our 1930's South Bend 9" lathe is up to the task, but one has to be careful not to push the machine too hard or some significant errors start to creep in. Forgetting to snug up the tailpiece is disastrous, but snugging it too much will bog down the lathe. Probably more than you wanted to know... but just a reminder that this is a factor in your design, specifically how the shaft is constructed, and how the wheel is connected to it, and what keeps them stable together. This plays into the question of wheel edge width and whether to make the wheel flat or discus-shaped. We favor discus-shaped because it adds to the stability of the wheel on the shaft: greater thickness at the center means less flexing side to side, while the discus-shape is defined by needing the edge of the wheel to be narrower - 13-14mm is about right. Alden F.M. Hackmann [email protected] "Beati illi qui in circulum circumeunt, fient enim magnae rotae." On Mon, 7 Nov 2011, Stan Leake wrote:
Would you make the wheel on a metal lathe? I would think you could use a metal lathe for some of the smaller-diameter parts and make the wheel on a wood lathe. In the absense of a wood lathe, you could even cut the rough shape of the wheel on a band saw with some further shaping by mounting it on a drill press. The final truing, of course, would be in-place with a scraper. Stan On Mon, Nov 7, 2011 at 9:57 AM, Kazimierz Verkmastare <[email protected]> wrote: Since the most common hobby metal lathe is an Altas 6 inch or one of the clones, there is compelling reason to consider parts that can be made on this lathe, if there is no acoustic or performance reason not to. Remember, this is not a thread to see what kind of a compromise gurdy we can build, it is to see if a truly reasonable instrument can be built, at or below the cost of a professionally built instrument, but an average craftsman. I have no specific knowledge of anything that would make a 6 inch wheel better or worse than a 7, so I will ask the builders and players if they can give a reason to stay with 7 inch or can agree on the 6 inch (152 mm) instead. Chris > Just a thought , 7" is pretty much standard for lute backed > instruments but it's worth considering a smaller wheel - say 6" > which is more the norm for Guitar bodied gurdies. The smaller wheel > makes no difference to articulation of trompette ( imho ) . The > slower rim speed helps to minimise the unpleasant resonances that > can occur and the overall volume is slightly less. A 6" wheel may > also be a more practical size for those with only access to a small > lathe. I use an average of 16mm for rim width and 18mm rim to > bridge.Regards > Neil > On 7 Nov 2011, at 07:24, [email protected] wrote: > >> >> Today's Topic Summary >> >> >> Group: http://groups.google.com/group/hurdygurdy/topics >> > - ***Builder HG*** Current 'Builder HG' specifications [7 Updates] - > Brocker translation is now available online [2 Updates] - *** > Builder HG*** specification responses [1 Update] >> >> >> ***Builder HG*** Current 'Builder HG' specifications >> >> >> Kazimierz Verkmastare <[email protected]> Nov 06 09:21AM -0600 >> >> > So I am going to start this new thread, called 'current builder HG > specifications. Please do not respond to this thread - responses > should be to the thread 'specification responses' previously >> ...more > >> >> Arle Lommel <[email protected]> Nov 06 12:45PM -0900 >> >> > I would suggest making all measurements in metric, and setting the > default wheel size at 178 mm, for the reasons listed below: > > Alden's size (7" = 177.8 mm) is normal for western instruments, > which > >> ...more > >> >> Alden and Cali <[email protected]> Nov 06 02:20PM -0800 >> >> > I agree - specs should be metric whenever possible. > > We end up using metric, fractional inches, and decimal inches in > the shop, because our various tooling demands different things. > I'd be > >> ...more > >> >> Scott Gayman <[email protected]> Nov 06 04:32PM -0800 >> >> > Hello Chris, > > If you are basing it around a non-trompette sinphone then it could > have a smaller wheel. The standard concensus regarding wheel > diameter is that larger wheels make for better control >> ...more > >> >> Kazimierz Verkmastare <[email protected]> Nov 06 06:59PM -0600 >> >> > I thought we were going for an instrument with 2 chanterelle, a > petit bourdon, a gros bourdon, and a chein. This would give the > opportunity to design around and learn how to set up pretty much > every >> ...more > >> >> Kazimierz Verkmastare <[email protected]> Nov 06 07:02PM -0600 >> >> > I agree, metric (I will convert to US as necessary to use my tools) > should be the standard. > > Now I need to go out and get a couple decent metric straightedges > (and metric pencil lead - 0.7mm for my >> ...more > >> >> Kazimierz Verkmastare <[email protected]> Nov 06 07:07PM -0600 >> >> > OK, to go with the wheel diameter (enough for coup control, not so > much as to eliminate the possibility of some of the faster central > European based music) what about rim width. Is a perimeter >> ...more >> >> >> Brocker translation is now available online >> >> >> timw <[email protected]> Nov 06 06:01AM -0800 >> >> > Thank you both! > > This is really appreciated, and I know it took a lot of work for > everyone involved. Thanks for adding this information to the group. > Tim > >> ...more > >> >> Ulrich Joosten <[email protected]> Nov 06 08:01PM +0100 >> >> > Dear all involved people, > > thank you for this great treat. It was long overdue that this > standard work is now available in English language. Really big > kudos for this big effort to all involved > >> ...more >> >> >> ***Builder HG*** specification responses >> >> >> Kazimierz Verkmastare <[email protected]> Nov 06 09:21AM -0600 >> >> > In order to keep track of everything we are discussing, I propose > we keep 3 threads alive on the builder topic. > > The first set of threads should have ***Builder HG*** > Specifications for proposed > >> ...more >> >> > You received this message because you are subscribed to the Google > Group hurdygurdy. You can post via email. > To unsubscribe from this group, send an empty message. For more > options, visit this group. > > >> -- > You received this message because you are subscribed to the Google > Groups "hurdygurdy" group. > To post to this group, send email to [email protected] To > unsubscribe from this group, send email to > [email protected] For more options, visit > this group at http://groups.google.com/group/hurdygurdy The rules > of posting, courtesy, and other list information may be found at > http://hurdygurdy.com/mailinglist/index.htm. To reduce spam, posts > from new subscribers are held pending approval by the webmaster. >> >> > Best regards > > > Neil Brook > > > [email protected] -- You received this message because you are subscribed to the Google Groups "hurdygurdy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hurdygurdy The rules of posting, courtesy, and other list information may be found at http://hurdygurdy.com/mailinglist/index.htm. To reduce spam, posts from new subscribers are held pending approval by the webmaster. -- You received this message because you are subscribed to the Google Groups "hurdygurdy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hurdygurdy The rules of posting, courtesy, and other list information may be found at http://hurdygurdy.com/mailinglist/index.htm. To reduce spam, posts from new subscribers are held pending approval by the webmaster.
-- You received this message because you are subscribed to the Google Groups "hurdygurdy" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/hurdygurdy The rules of posting, courtesy, and other list information may be found at http://hurdygurdy.com/mailinglist/index.htm. To reduce spam, posts from new subscribers are held pending approval by the webmaster.
