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View Full Version : An interesting machining problem



Rustybolt
06-25-2007, 08:26 PM
Planing irons, or planing forms. When making a split bamboo(cane for our british friends) fly rod the piece of bamboo(culm) is split into small strips each strip is then planed to a 60 deg profile on the planing forms. A small block plane is normally used.
The planing forms are usually made from .750 square CR, 60 inches long. A tapered 60 deg groove is milled along the length of the material. To do this the two pieces are are joined together with dowel pins and screws.
The taper usuall goes from @.025 to@ .080 and then the two pieces are flipped and a wider taper, from @.080 to@ .125 on the other side.
How would you accomplish making the tapered grove having only a BP? Assuming the material is straight and flat.

darryl
06-26-2007, 01:59 AM
Hmm. I can see using a dovetail cutter in the mill. Between the flat bottom and the angled side of the cutter, you could get 60 degrees. It seems like it's more of a problem to clamp the piece to the table such that the groove produced is deeper at one end than the other. Getting the dovetail cutter to make a groove with both sides at the proper angle with respect to the workpiece would be another orienting and clamping problem, but shouldn't be too hard to do.

Maybe more details on the project would help us give better ideas.

Swarf&Sparks
06-26-2007, 02:04 AM
Seems to me you could do it with a sine vice/table, rotated on the mill table to give a compound angle, just using an end/side mill.
Caveat emptor, I haven't sat down and worked out the trig tho!

oldtiffie
06-26-2007, 06:58 AM
Deleted/edited-out

Swarf&Sparks
06-26-2007, 07:49 AM
My apologies, I didn't notice the 60" length.
In that case, I'd go along with tiffie.

I'm a lazy bastard, so I'd start with the 9" angle grinder followed by 5" with flap disc, then draw file.

John Stevenson
06-26-2007, 07:58 AM
All that to drown a worm ????

.

Swarf&Sparks
06-26-2007, 08:03 AM
make a compleat fool of yourself :p

ptjw7uk
06-26-2007, 08:07 AM
I thought split cane rods were made using hand tools and planning boards.
Once they are set up the angles and tapers are easy just produce dozens and pick the best which I think is why thet cost so much to buy!!
Peter

PTSideshow
06-26-2007, 08:18 AM
Go to How's it made from the discovery channel and look for the program they just had it on in the last couple of weeks. How some fancy rod company builds them and they went over that.Sorry I'm of the
John Stevenson All that to drown a worm ????
school of thought I didn't pay attention when they were showing putting the 60'angle on the pieces and how they ran it thru the machine. But I think it was a router type set up.:D

Evan
06-26-2007, 08:34 AM
All that to drown a worm ????

It's fly fishing, no worms. Regardless, while I like to eat fish catching them is best left to professionals with nets. I think of recreational fishing as in the same category as watching paint dry. Long periods of boredom followed by more long periods of boredom...

oldtiffie
06-26-2007, 08:40 AM
Deleted/edited-out

Swarf&Sparks
06-26-2007, 09:24 AM
Fish (n): white flesh which comes shrouded in deep-fried golden, crispy batter;
Usu accompanied by chips and the heavenly aroma of salt and vinegar.
To be eaten directly from the paper.

Goes well with Emu Bitter or Strongbow original.
:D

chrisfournier
06-26-2007, 10:58 AM
To keep the block plane blade from digging into the metal planing form many rod builders mill a shallow groove down the centre of the planes sole. This allows the blade to engage the cane but not the metal form.

John, only a worm would suggest that flyfishers use - well - worms! Now we're not beyond using fluff to imitate a worm...

We flyfishers are a duplicitous lot.

Forrest Addy
06-26-2007, 11:28 AM
You could cut this groove on a BP but only 20" at a time depending on the available table travel. You have to set up for it. First make a long tapered fixture keyed to the table with a shoulder to stop the work against. then start cutting with a ground to form end mill. Cut and slide. pick up and cut again then slide again. PITA but it can be done. There will have to be some handwork but it's not a difficult problem.

As it happens I've made a few of these on a planer where I clamped the work to the proper slope and using the side head cut the groove detail.

BillB
06-26-2007, 11:34 AM
The chief advantage of flyfishing is that there's more to do when you're not catching fish. For the record, everyone I've ever fished with put their waders on one leg at a time, and had days when they got skunked. Real life lacks all the editing done on those TV shows.

Back to the planing forms: it's been a few years since I've seen any, and that was before I discovered the machinist approach to metalworking, but I do remember enough to be helpful.

The forms I've seen were considerably wider than .75", probably 1.5" - 2" on average. The length of the form depends on the desired length of the rod sections. 5' long sections would probably be used only for 2-handed spey rods or salmon rods. Most forms are therefore shorter.

I think the V-groove had little or _no_ built-in taper in any of the forms I've seen. The ideal rod taper is a subject of disagreement on a par with religion & politics combined, and varies with rod length and intended use. I know of one repairer/restorer who uses a roll of adding machine tape to record tapers full size, miking the rod every inch or so.

The taper is accomplished by setting the differential screws which join the 2 pieces of the form. This is the part I'm fuzzy on, since I haven't handled a planing form since long before I first cut a screw thread. IIRC differential screws have 2 different threads along the length of the screw (i.e. a different one toward each end) allowing precise fine adjustment of the taper. As far as diameter, tpi, thread class, etc. goes, I don't have a clue.

To build a cane rod, 6 precisely tapered identical pieces are planed for each rod section (generally 2 or 3), after pressing out the joints in the bamboo. The bamboo in question, Tonkin Cane, comes only from an area of about 40 square miles in China. The 6 pieces are then glued together, sometimes heat-treated, varnished, and grip, reel seat, and guides are added. Think of the last fishing rod of any sort you saw, and imagine planing and gluing 6 pieces that end up as small as that rod tip. The amount of hand labor involved pretty much precludes getting rich on rod-building, even given 4 figure prices for the finished product.

One rod builder I met said that even with religious obsession with the tapers, he was never sure how the rod would feel until he put a line on the finished product and cast it. This probably shouldn't be a surprise when one combines precise machining methods with an organic raw material.

A good cane rod has a wonderfully "sweet" feel when casting, but they are delicate, expensive, and _heavy_, which is why the vast majority of fly rods (including all of mine) are made of graphite (carbon fiber).

BillB

lynnl
06-26-2007, 03:44 PM
Here's a link to a site that discusses making the bamboo strip planing forms, along with a lot of other flyrod making info. (I think this was posted here before)

http://www.thomaspenrose.com/bamboo.htm

aostling
06-27-2007, 02:35 AM
Here's a link to a site that discusses making the bamboo strip planing forms, along with a lot of other flyrod making info. (I think this was posted here before)

http://www.thomaspenrose.com/bamboo.htm

I was wondering how the bamboo strips were planed initially to a non-tapering equilateral 60˚triangular cross-section. Your link shows that this is done in a triangular groove of 84˚. I don't see the connection between 84˚ and 60˚. I'll probably feel dumb when you tell me.

Rustybolt
06-27-2007, 07:28 AM
One rod builder I met said that even with religious obsession with the tapers, he was never sure how the rod would feel until he put a line on the finished product and cast it. This probably shouldn't be a surprise when one combines precise machining methods with an organic raw material.


That is one reason commercial bamboo rod builders impregnated their rods with bakelite, etc.. in an attempt to get a consistant action.

Evan
06-27-2007, 08:24 AM
Dynamite is much quicker and much less boring.

wendtmk
06-27-2007, 09:28 AM
Rusty,

Having made my forms by hand many moons ago, the one problem you might run into doing it on a mill with travel less than 60" is having a slight "step" in the groove where you have to re-jig the bars on the table. It may be durn near impossible to avoid that, since it will be a real pain to ensure that you get your depth in the cut set correctly. I used a set of tools designed by a good friend of mine, Don Schneider pictured on the Bamboo Rod Making Tips site, run by another good buddy of mine, Todd Talsma. Here's the page with the pics of the form tools: http://www.bamboorodmaking.com/html/jigs__tool_building.html. The rest of the site has a lot of really good tips, as wells as tons of pictures of other things cane rod making related. Also, if you're not a member of the Rod Making Listserv, I'd suggest joining that too: http://smtp.goldrush.com/mailman/listinfo/rodmakers

Mark

HTRN
06-27-2007, 09:44 AM
Dynamite is much quicker and much less boring.

It will also get you a $25K fine if they catch you.

This is why you use a generator, some heavy duty wire and some ground rods. Much quieter.:D


HTRN

BillB
06-27-2007, 07:03 PM
"Dynamite is much quicker and much less boring."

Around here we call that the DuPont fly, always fished on a cordite leader.

I once converted a good-ole-boy friend from such methods to fly fishing. He sold his MAC-10 to finance the purchase of an antique cane rod and suitable antique reel, and became quite the dry-fly purist. Ya never know.

BillB

platypus2020
06-27-2007, 10:03 PM
My first ex-father in law (yeah, yeah, I know) made custom bamboo fly rods for years, learned the art in Utica, NY in the 1930's for HI, it is a true art form, and he was a true craftsman. He had the bamboo spliting saws, the ferrel (?) cutting and mounting tools. and all the jigs. The rod was all hand made, the only parts bought were the eyes and the reel mounting hardware. In his 60's he didn't really want to make them anymore, but the calls kept coming, so the price kept going up, at the time of his death at 77, he was still making 5-6 a year.

Jack

mochinist
06-27-2007, 10:14 PM
It will also get you a $25K fine if they catch you.

This is why you use a generator, some heavy duty wire and some ground rods. Much quieter.:D


HTRNAn Uncle of mine once told me you could also do the same thing with some sort of crank phone that the military used to use? I guess you could buy them at military surplus stores awhile back, I have never seen one so never got to try it.






Not that I would:rolleyes:

Evan
06-28-2007, 01:27 AM
Many fish are extremely sensitive to electrical fields, even very weak ones. Fish have a special organ called the "lateral line" which in many species is adapted to detect electrical fields and possibly even magnetic fields. It is sensitive enough in some species such as sharks to detect the nerve impulses of nearby animals in the water.

Because of this they can be easily herded or stunned and even killed by relatively weak electrical fields. Fish and wildlife biologists use a simple electrical herding system to help count fish in streams.