hi Bill !
as you asked me to do, "when [I am] ready to do this , please post " .....
Thanks , I am ready to absorb / see [hopefully!] this information !
[I will be out at "Hicksy''s on [our] friday....[your] thursday , I believe ].
I will shoot you an answer this evening. I gotta get home now and catch the season opener of LOST!
i hope you had a good christmas. i have been reading and rereading the
thread you did on your method of cutting rail bands. one thing i have
not been able to get my head around has to do with the cutting of the
bands and how it relates to the desired foil of the board.
if i have understood correctly, you state that your rail bands are
wider where you want the thickest part of the foil to be. what is
confusing me is this, in order to make that area of the band wider, you
must open up the shoe of the planer which will create a deeper
(therefore wider) cut into the foam. by doing this, dont you remove
more foam and thus make that area of the foil thinner as opposed to
thank you in advance for your time bill.
I understand your confusion.
Trying to put these concepts and actions into understandable language is difficult. I will try to explain better. Lets say we have two blanks the same thickness but are making too different boards. On thicker and one thinner. As you noted, the thinner board will require deeper cut bands. This will cause them to also be wider.
On the other hand, if you have two different blanks, one thicker and one thinner, then the thicker board from the thicker blank will require wider bands because a thicker rail (larger diameter or radius) will require wider bands to to span the greater diameter.
As you can see in the drawing below.
The RED band is wider because we are making a thin board out of a thick blank
The BLUE band is narrower because we are making a thick board out of a thick blank
The PUPRLE band is narrower because we are making a thin board out of a thin blank
BUT..... the thicker board, regardless of blank thickness, will still require a wider band to span the thickness.
Does this make sense? Finding reasonably simple language to cover all possibilities is a challenge.
Once you have absorbed this, then feel free to ask more questions to ensure you understand it all and help me to get the descriptions more clear. Hope the Drawing makes sense.
[img_assist|nid=1048117|title=Rail Band Widths and Blanks|desc=|link=none|align=left|width=640|height=336]
thank you for the explanation and graphics. i think i understand whats going on up until this point. i see that in order to span the greater distance of a larger diameter rail, we use wider rail bands, this makes complete sense to me.
what i still find confusing is this.. a wider band requires a deeper cut. a deeper cut removes more foam. so how can i effectively use the wider cut to create my larger diameter rail and not make it the thinnest part of the rail at the same time? how does the natural foil of the uncut blank come into play here?
i'm sorry that i keep asking you to explain this over and over. i feel like i am on the cusp of getting it, but it's just out of reach and this is really frustrating me. thanks again for your time and patience.
brasco wrote: hi bill,SNIPwhat i still find confusing is this.. a wider band requires a deeper cut. a deeper cut removes more foam. so how can i effectively use the wider cut to create my larger diameter rail and not make it the thinnest part of the rail at the same time? how does the natural foil of the uncut blank come into play here? brasco
what i still find confusing is this.. a wider band requires a deeper cut. a deeper cut removes more foam. so how can i effectively use the wider cut to create my larger diameter rail and not make it the thinnest part of the rail at the same time? how does the natural foil of the uncut blank come into play here? brasco
Maybe some of your confusion is just a misunderstanding of my previous comments. Often time I over emphasize things to make a point or to insure that the concept gets traction in the readers mind. I do this because when you are trying to teach someone something new you usually have to dislodge previously existing beliefs, habits or old wife's tales, otherwise the new info not only won't stick but will not even be noticed as the reader will slip right past the new stuff like it was teflon coated. People tend to only hear what they like to hear. Absorb what they feel has value. And use what makes them feel better in the end using. And most of the time these will be things they are familiar and comfortable with even if it isn't overall the best thing.
In my previous comments in this thread I said early on......... "Use the width, depth and taper of your bands to regulate the volume and shape of your rails"
The thickness of the blank relative to the thickness of the board will regulate the width of the bands. As will also the thickness (diameter) or volume of the rails.
I also said........ "Since the rail band is normallly not being cut on a flat surface. Only 2 things will regulate the width of the rail band regardless of how wide or narrow the cutting width of the planer blades are.
1. is how deep you cut it into the curved surface. 2. is what the diameter of the curved surface is."
Hopefully you are beginning to see and the confusion is lessening. Here are some more......
"Assuming the same diameter of cylinder (see previous post) wider bands are simply the result of deeper cuts into the cylinder. Several of these next to each other at equally spaced tangents to the curve, will eventually create a smaller diameter cylinder.
Most blanks already have a foil or smaller cylinders at the ends. So much so, that when cutting rail bands we need to decrease the depth of our cuts and therefore the width, at the ends of the boards because the diameter of the cylinder is smaller and the same depth cut might take away too much material. But if the blank was a square block of foam, this wouldn't be the case and the nose and tail would get massively wided cuts to bring their thickness/diameter down to size."
You summarized previously
Quote: if i have understood correctly, you state that your rail bands are wider where you want the thickest part of the foil to be.
The thickest part of the foil can be two different things.
1. The thickest part of the overall board
2. The thickest part of the rail
You have to determine what your trying to achieve in your particular board and the blank you are shaping it from and then when you roll your bands around from the bottom each band will be cut as deep and wide as necessary to arrive at your particular design out of the blank you are using.
Remember that terms like deeper and wider are relative terms....... as in.... wider then what? Or deeper then which? Etc! Because of this, your summarized version of my comments should not be taken in a totally absolute way. Remember the relative nature of the terms. They only make sense when you know what they are being compared or gauged against.
If the blank is thin and your board is thick and boxy railed you won't be making very wide bands but they still might be wider then they would be if the board was thin and tapered rails from a very thin blank with a domed deck.
Hope this helps
thanks again for your time and patience. this thread has helped me out immensely. i think i've almost got my head around it (well, some of it at least)
Ok Ben, here ya go. Its a long one so tough up!
In my world, cutting rail bands have 3 purposes.
1. To transfer the bottom curve into the deck curve, harmonizing everything in between while controlling precision and symmetry.
2. To create the actual profile or shape of the rail.
3. To create the volume of the rail and ultimately the whole board.
Creating the actual rail shape is fairly obvious and while it is super important there is a way to do it that will blend all the various aspects of the boards design in the process.
I build my boards from the bottom up. But I visualize my boards as a wire frame floating in space were I can see each line and how it relates to the next line as the whole shape blossoms into full view.
If we take a templated, blank in its most primitive form it consists of the deck, bottom and rails, which are nothing more than the vertical surfaces that are the outline at this point. Lets imagine that this blank has the same 3” thickness throughout, in other words, no foil to it.
As a base starting point I use the rocker line down the bottom stringer line of the board. To keep it simple, lets start with a flat bottom rail to rail even though any bottom shape is possible. With a flat bottom, the rocker along the stringer is the same rocker as it is along the rail. If we cut a 45 degree rail band on the bottom and we make that band exactly the same width from nose to tail, then the bottom rocker will be evident in the upper edge of that rail band where it intersects the outlines vertical, just like it was evident in the bottom/template junction. Do you see the connection?
Now lets make it more realistic but more complicated. Imagine the board with a Vee Bottom. If the board has the same amount of Vee, say a 1/4” from stringer to rail and nose to tail, then in a sense, one half of the boards bottom is really a wide band cut on a very shallow angle. If we cut the same bottom edge rail band, then the upper edge of that rail band will still reflect the actual bottom curve at the stringer, twice removed.
If the Vee is not consistent throughout the bottom it will complicate things further. If the Vee is 1/4” only in front of the fins, then fading to zero at the tail and the nose, the stringer rocker won’t be exactly duplicated out at the template. The rocker line at the template will be altered relative to the Vee panel.
Of course, the rail band at the bottom edge of the template needs to be a tapered band to create the rail edge and thickness foil of the board. Since that tapered band is narrower at the nose and tail, it also transmits a slightly different rocker curve from its bottom side to its top side. But the top side though progressively changing is still a reflection of the original centerline rocker and that is the key.
The widest part of this lower rail band will be 1/2” to 3/4” depending on how big you want the radius or ball bearing of the rail to be. The secondary band you cut on the lower side of this band will regulate how far under the tucked edge will be.
Now when you flip the blank over, deck up, and look at it from an upper side view, the top side of the bottom rail band will give you an accurate idea of what the bottom rocker is like, even though you can’t really see that stringers rocker curve anymore.
Remember that our blank is 3” thick. So at the nose and tail we will be getting almost 3” measured from the top of the bottom rail band. But in what will be thickest point of the board, the measurement from the top of the rail band to the deck will be more like 2.5” or less.
To cut the initial top rail band, you have to be able to visualize that wire frame view I mentioned so you can see where this bands lower edge should be relative to the thickness of the finished boards rail. Between the lower side of the top band and the upper side of the lower band will be the remaining vertical surface of the Template. This is now also a band. And this vertical band also needs to be tapered. The way this taper happens is by how far you cut down the lower edge of the upper rail band and the secondary band that will be cut right on top of the junction of the template band and the upper bands lower edge. Don’t make the vertical band too narrow or the rail will be too thin. Remember you can’t add back foam and the only way to save it will be to make the template narrower to thicken the rail back up.
Imagine again that wire frame. Don’t cut the upper band too far down or the rail will be too thin or tapered. Remember that you will be cutting a secondary band and you have to leave enough material there to cut this band and round out the rail without making it too thin.
The taper of the template band is crucial to the thickness flow and foil of the rail. It takes experience to know how far to go and where to stop. Additionally, since you are matching the lower edge of the upper band to the top edge of the lower band with the template band caught in between, you can see that the lower edge of the upper band will collect the stringer lines rocker from the lower bands top edge and the top edge of the upper band should, as we have discussed, be a continuing progressive reflection of the bottoms stringer rocker as it has wrapped all around the board.
But at the deck, there is a problem with this and that is the regularity of the thickness of the deck of the blank and how that upper band’s edge interacts with it. Since the deck of blanks are rarely exactly what one might want, then the deck needs to be shaped down and the regulator in doing that is the primary deck rail band’s lower edge. Typically the upper edge of the band will warble all over the place depending on the thickness of the deck. Because of this you need to keep an eye on the lower edge of the deck band as you cut the deck down toward it, creating a nicely tapered band with clean arcs on both upper and lower sides.
Assuming all other bands have been cut and tapered properly this top edge will now reflect the bottom rocker and as such its arc can be matched up to the deck stringer line to create a deck arc that nicely matches the bottom curve.
While I have discussed mostly the primary bands, there are also secondary bands that go on the junctions of each of these primary bands. These bands are really no different accept that they are much narrower and taper out much finer at the ends. Keep adding bands on top of bands till the rail is smoothly blended into the deck and bottom.
Visualize well, the finished board you want to make.
Plot your rail bands to match your vision, use a wire frame view to isolate the lines.
Utilize the edges of the bands to transfer the bottom rocker around to the deck
Use the width, depth and taper of your bands to regulate the volume and shape of your rails
Maintain clean consistent arcs in the edges of your bands to eliminate bumps and dips and ensure symmetry
Have good lighting in your room to pop the shadows and highlights so that your bands are highly visible.
Hey Bill this is some good info..when you said you refrence the rail bands you begin shaping the bottom rail bands first meaning the under tuck? do we just make one even depth pass or does the bottom rail line need to taper from tail to nose? I seen the photos you posted but could you post another photo of the bottom side band..much appreciated thanks Bill
I don't have a bottom rail band picture handy. But to answer your question.....
Yes, the bottom primary band partially establishes the amount of under tuck and also the radius of the rail. The secondary band on the bottom side of the primary band will specifically define the tucked edge. Sometimes the primary band is all that is needed on the bottom side of the primary band.
When the primary bottom band is small (not wide) as on thinner boards, you probably don't need secondary bands on either side done with the planer. But on thicker boards with very full rails like on the Lifeguard Rescue Boards I make, you will need the secondary bands.
No you don't make one even depth pass.... though depth may not be the best way to describe it. The band will be wider at the point where you want the fullest point of the rails foil to be.
Then it will taper down in width from there toward the nose and tail. The amount the band width.... tapers, will depend on how much tuck and the size of the radius you want.
I will post more photos when I find some in my archives or shape another board with my camera handy.
Let me know if that answered your questions, or feel free to ask more.
Thanks for your quick reply and the info you have shared with us.Hope to see some pics of your rail bands shaping,maybe some info and techinques of shaping concaves and V with the planer.Hey Bill maybe someday you should produce your shaping 101 Videos?? also i like to know if your website is up and can we have the links, i like to see what modifications and tools you use to create fine boards..Thank you for your time Bill you have been very helpful