Station mold bevels

[wapitiscat]

I'm considering beveling the molds for my next project and was curious if there was a "correct" way to determine the angles other than using a batten, sanding, using a batten, sanding, ... etc. I've done some messing around with the geometry and get a fair approximation by using the distance between stations and the difference in the offsets of the respective molds and letting Pythagoras do the heavy lifting to get the bevel angle. Of course I'm overthinking this but that's what I do.

Todd

 

[Rollin Thurlow]

Design wise, if you have or and can make the lines plans for the canoe, then you can pick up the angles directly off the Plan view or the waterlines. You would need to pick up at lest four or five different angles for each half of each station . Of course now with computer aided designs the computer can tell you all that information. But it is possible to do it all by hand, and with very precise and accurate measuring and drawing you can bevel each stateion ahead of installing the stations. However, for most canoes, its much easier, faster and maybe more accureate to just use the batten method.

 

[wapitiscat]

Thanks Rollin. This is a project I started (or at least thought about) in 2011! I'm attempting to make a 1/4 scale model of the Atkinson Traveler using as many of the full size construction techniques as possible. This as opposed to carving a solid plug to build on. The reason I'm hung up on beveling the station molds is that I was considering using thicker stock for the molds to give the ribbands more support. I've already had one false start with the original molds while navigating a steep part of the learning curve.

FWIW, my trigonometry method yielded the following ...

Station Angle (degrees)
2 2
3 8
4 10-12 (from WL 15 to WL 5)
5 12
6 13

I did the math at each WL and the angle changed a bit (~0.5 degrees) along the station but I don't think that will move the needle so I was going to use the most frequent value. I may look at doing the same for the butts to check the angle below WL 5 as you move from midship to bow/stern. It looks like there could be some sort of rolling bevel as you get to Stations 4-6.

Todd

 

[Rollin Thurlow]

Well for exact numbers, the angle at the rail at each station is:
Station 1 - 0 degrees
2 - 5 degrees
3 - 9 degrees
4 - 12 degrees
5 - 15 degrees
6 - 17 degrees
The very center of the station is 0 degrees and so there is a rolling bevel from the rail , up the side of the station to a point close to the center.
If your using my plans, note that the stations are placed on the side of the station line facing the cente of the canoe, so the battens would just hit the edge of the station. If your beveling the stations , the station would want to be placed on the side of the station line facing canoe stem.
Here's a bad drawing but I think you'll already know whats going on.