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C.LeQuanViolins

Drill for bow maker

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They are indeed hand made. Contact one of the bow makers trained in the French tradition, like  Noel Burke. They probably know who makes them and how much they cost. I think they are made in batches by someone who does it as a sideline. 

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Hi ! I'm new on this forum, my name is Clement and I'm a student at the Newark Violin Making school 

I want to do bow making and I'm looking for this drill for drilling the faceplate, those ones http://www.altmanbows.com/bow_drill.jpg

 

Do you know where can I get one ? Or are they handmade ?

 

Thank you !

 

The unit in the link photo was made by my friend Micheal Hattala & myself.  Here's the short story:

 

While working at Tomachot's in Paris in the '90s, Mike took measurements & photos of Stephane's foret à archet, and suggested we make a few for ourselves & our teachers, which we did.  I did the drawings, the split pattern for the castings and made the drive line parts.  Mike knew a foundryman (who was a violinist!), had the castings made, machined them and assembled the forets.  In answer to demand, we produced a couple batches of them over the years for colleagues.  The foundryman (now over 80) finally decided to retire and chucked all the patterns in his shop, so that's the end of it.

 

BTW, the bow that supplies the horsepower for these things was traditionally a leftover fencing foil.  Universities & fencing clubs usually discard them after their useful life as a foil.  Just break off the extra length and heat up the end and bend it into a squiggle to hold the cord.  I use a discarded gut bass string for the cord.  If you can't find one of those, I'm told weed-whacker cord works okay.

 

Cheers,

~B~

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Hi Clement,

 

you could also decide to make one yourself. The one in your picture is indeed very nice but it is also quite heavy, and one of the nice things regarding bowmaking is the ability to travel light...

I finished mine today, it is based on the one that I saw in Oberlin this year, made by Eric Lane.

It is quite simple:

a U-frame holding two bearings in recesses that are locked into place by the screws on top, a 10mm axle that fits the inside of the bearings (outside is 22mm), and a drum made of aluminium locked onto the axle by a set screw.

You could also use an old wooden thread drum, they got exactly the same outside shape and you simply drill the bore larger, according to your axle diameter.

On the left side the axle sticks out of the frame and there is a adapter that will connect the axle to a key chuck that's got a 10mm axle sticking out of the back (offered by Proxxon as a accessory to their mill).

Driven by a fencing coil that I will have to nick from the garbage can of my fencing club next monday...

 

Making wasn't too much fun, as I hate that sort of rough metal working, but it only took a day and costs were about 50 euros (including the chuck at 35...)

 

Greetings, Florian 

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Another ready-made frame & axle for a foret can be a headstock & quill from a watchmaker's lathe.  They are not worth much by themselves, and can sometimes be procured from a dealer in old tools & machinery, or of course from a purveyor of old watchmaker's tools.  It already has a bottom attachment for a base of your own making, usually of wood; add a spool, adapt a chuck and you're in business.  Just be sure to adjust the bearings properly and oil them now & again.

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advantages: -light and small (easy to travel with)

                    -quick setup for all tasks

                    - very versatile ( I can use the foret for drilling starter holes for mortices, screw holes, pearl eyes, parisian eyes, anything not done                                     manually, whereas I need a mill as well as a lathe if I don't use the foret)

disadvantages: -needs some practice to do precise work

                         -for some tasks I would prefer a higher cutting speed, than I can produce with a foret

                         -can't do rings on the button

                         - most bowmakers have a lathe anyway to be able to make tools

 

Florian

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Can anyone suggest the advantages and disadvantages of using a foret instead of a lathe?

 

Ed

 

The traditional bow drill, or foret, is technically a bow-driven lathe.  In bowmaking, it is fitted with a chuck and normally used as a temporarily bench-mounted drill for performing operations on a hand-held workpiece.  These include drilling holes to initiate the chiseling of mortises in the frog, head and stick; drilling the hole and pilot hole for the adjuster screw, drilling holes for pinning & riveting metal linings & button rings, and creating the hole & groove for a Paris eye.

 

Its advantages include exact control of drill or cutter speed, direct feedback of "feel" of the workpiece during the operation, instant correction of directly observable variables, minimal setup time, instant adaptability to variations or changes in design or technique, minimal cost and maintenance, minimal shop space, hand-driven (no electricity), portability.  The utter simplicity of the foret can be appealing to a profession that traditionally requires a minimum of tools.

 

Effective use of the foret demands eye/hand coordination (not unlike playing an instrument), and requires acuity and judgment – skills that are already vital to the art of bowmaking.  It is not effective for artless, high-volume, high-repeatability tasks like eyelet or screw production, which might better be outsourced to a specialty shop.

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Thank you Florian / Bill.  I've seen a foret in use but never tried it myself.  I can imagine using it for many of the processes you mention, except for drilling the hole for the screw.  To get the hole right in the middle of the stick and lined up perfectly looks very difficult to me!  But, I know that it can be done.

 

Ed

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Thank you Florian / Bill.  I've seen a foret in use but never tried it myself.  I can imagine using it for many of the processes you mention, except for drilling the hole for the screw.  To get the hole right in the middle of the stick and lined up perfectly looks very difficult to me!  But, I know that it can be done.

 

Ed

 

Ed, in the traditional method I follow, the stick is roughed out large in diameter at the butt, frog is fitted up with a screw adjuster, then the stick is planed down to size.  That's how the hole ends up in the center.

 

I apparently cannot send you a PM due to my probationary newbie status here on MN, so I'll breach normal forum protocol and mention a commercial enterprise:  If you are still in the Syracuse area, you could visit Hosmer Violins and ask for Michael.  He can tell you all about the foret we produced, and how they're used.

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Bill:  Thanks for the description.  I get how the hole ends up in the middle when you make a new bow but it seems to me to be very difficult to get it right if you are bushing the hole and can't plane the stick any more!  Actually I have seen it done - I watched Constatin Popescu do it once at a summer class and he got a perfect result. 

 

I do know Michael - he told me about your joint production of the forets a few years ago, but I've not seen him working with one.  He makes very nice bows. 

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Bill:  Thanks for the description.  I get how the hole ends up in the middle when you make a new bow but it seems to me to be very difficult to get it right if you are bushing the hole and can't plane the stick any more!  Actually I have seen it done - I watched Constatin Popescu do it once at a summer class and he got a perfect result. 

 

Did it appear very difficult for Popescu to obtain a perfect result?

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No it didn't seem to hard for him.  But he was obviously not doing it for the first time.

 

I've thought of getting a foret for my own work, but I started with a small lathe and find that it works fine.  Maybe one day!

 

Ed

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Sorry for the lapse here, been some busy.

 

An easy and inherently accurate way of locating the adjuster hole exactly where it needs to be in the end of the stick, for smooth operation:

 

Find (better to make) a pilot drill that exactly fits the minor thread diameter of the eyelet, and chuck it in the foret.  Hold the frog tightly on its stick facets, but at the rear of the stick with its eyelet butted up against the stick end to act as a drill guide.  Line up the bow with the drill and pilot drill the end of the stick.  Proceed drilling with graduated drill sizes, thru to the mortise.

 

If the pilot hole has also been bushed, hold the frog as before, but now with the frog in its normal position, eyelet tight against the front of the stick mortise.  Use the same pilot drill and technique to locate the pilot hole for the adjuster screw, finishing with the proper size drill to accommodate the pilot diameter and length of the screw.

 

If the adjuster screw has a smooth, well-finished end that is quite concentric with the screw (i.e., not hand-filed), it is usually good to adjust the depth of the pilot hole so that it will act as a thrust bearing by leaving just a whisker of space between the stick and the collar of the adjuster button.

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Yes, very useful.  How do you make sure the drill bits follow the pilot hole exactly?  It seems to me that when I try to enlarge an existing hole (with a hand drill, not with a lathe or foret and not in bows necessarily) the larger bit does not go down the exact center of the existing hole but wanders off quite a lot. 

 

Ed

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Yes, very useful.  How do you make sure the drill bits follow the pilot hole exactly?  It seems to me that when I try to enlarge an existing hole (with a hand drill, not with a lathe or foret and not in bows necessarily) the larger bit does not go down the exact center of the existing hole but wanders off quite a lot. 

 

Ed

 

"Exactly" is the rub here, and often we might not wish to exactly follow the pilot hole if it requires correction.  The lathe seems to be a popular tool for drilling the adjuster hole, but does not offer a means for instant correction if the grain forces the drill out of concentricity with the stick.  Much of this drilling business can seem counter-intuitive at first blush, and it gets worse with uneven grain, particularly in end-grain drilling for an adjuster screw.  Where there is grain runout, the drill tends to wander opposite the grain direction (into the side-grain), as the end-grain is harder to cut.  A flatter angle on the nose of the drill can help to minimize runout caused by grain runout, and it is easier to steer along its path.  Also, consider making your own drill from smaller rod.  Heat & flatten the end and grind to a somewhat obtuse two-fluted point.  This is easiest to steer, as the point is not being guided by its smaller diameter shank.

 

When drilling for a bow screw with a foret, now & again poke a similar size drill or rod into the hole and take a gun-barrel sighting to indicate corrections along the way.  When using twist drills, I keep an extra of each on hand for this purpose, and usually drill in at least three size steps.  Evacuate the bench of tools in the background that can be distracting, perhaps lay down a sheet of plain paper to sight against, and rotate the stick often to its various quadrants to average your error.  Also, one can lay a straightedge on the bench, aligned with the drill, to sight against with the bow stick.  Not too difficult, as the hole is only a couple of cm deep.  If possible, use high-quality ground twist drills, as cheap ones are often out of straight.

 

Also, the smaller holes can be corrected with a round file if necessary, before the final size diameter is drilled.

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A spade bit like the one in the link below is very usefull to correct directions in initial drilling:

 

 

 http://www.mscdirect.com/product/01150077

 

 

a round needle file is a great tool as well...

 

Florian

 

 

edit: the link given was the wrong one, this is what I meant to link to, looks the same as the homemade bit in the next post!

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Florian, that spade bit is interesting, I've never tried it for this application.  I use one in the drill press for spot-drilling graduations in instrument making, as it has no "web" at the business end.  It cuts very cleanly and does not crush the wood fibers (esp. spruce) at the point.  Mine is slightly crooked, probably not stress-relieved.  Perhaps if I got a better one...

 

fiddlecollector, very interesting link, good drawings.

 

I presume both these bits are used in the lathe for in-line drilling.  My old lathe is not so good, and a bit shaky.  Again, perhaps if I got a better one...

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