Hurdy gurdy construction questions.

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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

Since I got no suggestions on whether or not to inlay before bending, I decided to lower my sights a little and proceeded to install some banding on a piece of 1/16" thick maple and then try to bend it. It actually worked out fairly well with no obvious damage to the binding that I can see. Maybe at some point I will undertake another more ambitious cover, using two layers as I described earlier and see if that would work.
Incidently, I couldn't find a suitable piece of pipe to heat up and bend around so I used my trusty trouble light which I found worked very well for this 11" diameter bend. It took a little longer than bends that I have made with a 2" piece of copper pipe with a propane torch stuck in the end, but there was minimal chance of charring the wood either.
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hgcover1.JPG
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Charlie Schultz
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Re: Hurdy gurdy construction questions.

Post by Charlie Schultz »

Yet another bending tool!

Are you using anything like hinges or magnets to hold the keybox cover on?
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

I think I'll use hinges. I have some small brass ones kicking around. Not exactly authentic though. I think I will use a magnet to hold it shut. I also have a few 1/4" diameter real strong ones which should keep it closed. I also have to figure out some kind of decoration for it.
Barry
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Jon Whitney
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Re: Hurdy gurdy construction questions.

Post by Jon Whitney »

Barry, I hesitated to give my opinion on inlaying before or after bending, since I've never inlayed MOP on a curved surface before (not even a radiused fret board). But since no one else answered, I'll hazard a guess. I guess that if you inlayed before bending, you would have problems with the inlay glue releasing when you heated the piece to bend it. Also if you were inlaying something brittle like MOP it would crack. So, next time you probably want to inlay after bending.

A technique I've used that would work well - and you could still do this on your current wheel cover - is metal wire inlay like on this banjo rim:
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rim side river inlay.JPG
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

Hi Jon,
That's a nice idea and probably would work well for wood to be bent. Did you use round brass wire for this or something square in cross-section? I'd be interested also in the technique for cutting the grooves. Did you do it with dividers?

I did find that during the heating and spritzing some of my inlay did bubble slightly but when everything cooled down it was again flat and intact with no help from me. I had used plain old white carpenters glue, and wasn't aware that it would do that.
Barry
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Jon Whitney
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Re: Hurdy gurdy construction questions.

Post by Jon Whitney »

This was a few years ago so the details are just slightly fuzzy. I used strips of brass cut from sheet stock. I think the strips started out about 1/8" wide. This type of inlay, you do not cut a cavity by removing wood - you incise a path using double-beveled chisel-type tools that cut fibers but compress the wood. I made the chisels from some spade bits I got from the bargain bin - just ground them to the shape I wanted and sharpened them. I used mostly a point that was about 3/16" wide, and straight. After laying out the curves (I can't remember how but probably with CAD), I just went along them with the chisel, pounding it into the wood with a mallet. The brass is prepared by beveling the edges that will be inserted into the cut, and roughing the sides slightly with sandpaper. I put a coat of hot hide glue on the brass, or maybe in the cut, and then pounded the brass strip down into the cut. The hide glue was more for moisture to re-expand the wood fibers to lock in the brass. Some literature suggest that water could be used instead. I trusted the hide glue to make up for my deficiencies in preparing the brass strips and cutting the lines. The brass is left proud of the surface and then filed and sanded flat after it is inlayed. It's probably a good idea to give the wood a coat or two of shellac before starting, so that the metal filings don't go into the wood pores.
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

I'm at the stage of gluing the bits and pieces together now and have another question.
The distance between the nuts and bridge on the melody strings is 345mm. Will that length be the same for all of the other strings?
The problem is that unlike the melody strings which have movable nuts, the other four strings that are bowed by the wheel have the bridges and nuts glued in place (I think).
This is where my lack of musical knowledge is frustrating.
Barry
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

While I am trying to decide what to do about nut/bridge spacing (see above post) I decided to try to make a knob. I sold my lathe a couple of years ago since I really didn't enjoy turning wood so I decided to give it a try using my ancient Sears drill press. It actually didn't turn out too badly.
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Jon Whitney
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Re: Hurdy gurdy construction questions.

Post by Jon Whitney »

You've got to be careful with that kind of turning with a drill press. If the chuck-spindle attachment is a Morse taper fitting, they don't always withstand the lateral forces from turning or sanding and the chuck can loosen and come off with disasterous results. Or at least so I've read, fortunately I don't have that problem with my Shopsmith as the spindle for the drill press is also the spindle for the lathe.
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

Jon Whitney wrote:You've got to be careful with that kind of turning with a drill press. If the chuck-spindle attachment is a Morse taper fitting, they don't always withstand the lateral forces from turning or sanding and the chuck can loosen and come off with disasterous results. Or at least so I've read, fortunately I don't have that problem with my Shopsmith as the spindle for the drill press is also the spindle for the lathe.
Good point. I actually had the table a bit higher so there wasn't room for anything to fly out except at the end when I did the bottom part. Also I was wearing a face shield. It's funny but I used to have a General 260 lathe which in it's day was a Cadillac of lathes around here, but few things turned out as good for me as this knob!
Barry
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

I did a little research on this 30+ year old Sears 113 drill press and discovered that the chuck is held on by a screw on retaining collar which requires a spanner to remove. I love this drill press. It has an 8" quill which I find to be very useful as I rarely have to raise or lower the table.
Barry
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Barry Black
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Re: Hurdy gurdy construction questions.

Post by Barry Black »

Well, I have applied a couple of 'coats' of blonde shellac to my HG as per our discussion in Charlie's HG topic, and it's now ready for a light sanding and polishing. Meanwhile my house has sold and I must put it away again until we get settled in a new home which we have yet to find in the Comox Valley area of Vancouver Island, BC.
I am a little concerned that the move from an extremely dry climate to essentially ocean front may not be the best thing for it but hopefully the shellac has sealed the wood enough to lessen the effects.
My main concern now though is to dismantle my shop of 18 years and select the most important and valuable items to move over the Rockies to the Pacific ocean.
Barry
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Re: Hurdy gurdy construction questions.

Post by Michael Lewis »

Barry, Congratulations on your adventure. You will get through the move and eventually get your shop in order, and I think you will be glad you made the move.
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