Re: The Bauhaus Helix
Posted by Keith Hayes on Nov 06, 2017; 12:09am
URL: http://c-sng-discussion-forum.254.s1.nabble.com/The-Helix-tp9915p9977.html
Ah Jim...so many questions!
First, to clarify for Doug I actually use flex track and build my turnouts in a Fast Tracks jig. One reason I started with Leadville is I wanted to tune up my skills before I built some turnouts that are essentially hidden. I may construct the staging loop and keep it open and operate it for a few months to assure dependable operation before I start on the helix itself. Also, as I type, I may fully hinge the points to allow for less stress on the soldered tie rod at the points. Details. (It is a truth that the least accessible turnout will be the problem child: locos tend to derail on the turnout for the outbound lead from the roundhouse--I don't know why, and have to get up there on a ladder to scrutinize the issue in detail).
Good to know the problems tend to be on the tangent sections. My plan is to solder the flex track rails to longer pieces to avoid kinks on the curves. Also, I have had a careful wiring plan with my bus using red and white wires, red is always the rear rail: on the helix it will be the outside rail, and on the lower level, this will be reversed. Unless I make the lower level a separate power district with a reverse section, which I may. In fact, the Helix may warrant being a separate power district, too. Another issue is a reliable routing of the bus to the track--I run leads to each section (and still have trouble with dirty rails!).
Don Meeker shared some of his helix secrets. If I used cookie-cutter methods, it would indeed eat up a pallet of plywood. Don (a former math teacher) figured out that for a 30" radius, you can cut 8" strips of plywood and cut them to length at a 12 degree angle (I think). You do this with two layers of wood, glue it up and use a saber saw to cut the decagon (or whatever) to shape: the result is far less waste. The plan is to use two layers of 1/4" plywood. This method will probably result in using only a half pallet of plywood--a great savings.
One benefit of my model is that it helped to illustrate opportunities for splices on each segment. The first circuit will have a bottom layer extend to support the next circuit, which will match the top layer. It will take some planning, and I bet I screw one up, but it should work.
Colorado is blissfully dry, and I have never had issues with shrinking and swelling that others report. Plywood always has an odd number of plys, and they are laid up in opposite directions (the faces are always in the same direction), so plywood is more dimensionally stable than other (solid) wood products. That is not to say it is perfect, and my Dad and I found 1/4 plywood to be especially crappy. I am hoping that that two layers glued up will be more stable. I guess I could varnish the works before I install it: I am more apt to want to run a router around the edges to take care of any splinters.
Yes, our prototype did favor us with extra tall appliances on the locos. I thought I measured them a while back, but had planned for something like 4" clear. The track will be laid on 1/4" homobed directly to the plywood substrate--that seemed to have among the best sound characteristics when MR published tests years ago. The 12" tangent section helps extend the length of each circuit and keep the grade to about 2%. Half the first circuit beyond Solitude will be at the ruling grade and not hidden, so any issues will get ironed out in the open. Also, even B-4-Fs are only good for 4-5 cars on the heavy grades, so two and three-engine trains will match the prototype.
I have been collecting information on helices for about ten years now. It is astounding how many problems there are to solve in the construction of one of these beasts!
URL: http://c-sng-discussion-forum.254.s1.nabble.com/The-Helix-tp9915p9977.html
Ah Jim...so many questions!
First, to clarify for Doug I actually use flex track and build my turnouts in a Fast Tracks jig. One reason I started with Leadville is I wanted to tune up my skills before I built some turnouts that are essentially hidden. I may construct the staging loop and keep it open and operate it for a few months to assure dependable operation before I start on the helix itself. Also, as I type, I may fully hinge the points to allow for less stress on the soldered tie rod at the points. Details. (It is a truth that the least accessible turnout will be the problem child: locos tend to derail on the turnout for the outbound lead from the roundhouse--I don't know why, and have to get up there on a ladder to scrutinize the issue in detail).
Good to know the problems tend to be on the tangent sections. My plan is to solder the flex track rails to longer pieces to avoid kinks on the curves. Also, I have had a careful wiring plan with my bus using red and white wires, red is always the rear rail: on the helix it will be the outside rail, and on the lower level, this will be reversed. Unless I make the lower level a separate power district with a reverse section, which I may. In fact, the Helix may warrant being a separate power district, too. Another issue is a reliable routing of the bus to the track--I run leads to each section (and still have trouble with dirty rails!).
Don Meeker shared some of his helix secrets. If I used cookie-cutter methods, it would indeed eat up a pallet of plywood. Don (a former math teacher) figured out that for a 30" radius, you can cut 8" strips of plywood and cut them to length at a 12 degree angle (I think). You do this with two layers of wood, glue it up and use a saber saw to cut the decagon (or whatever) to shape: the result is far less waste. The plan is to use two layers of 1/4" plywood. This method will probably result in using only a half pallet of plywood--a great savings.
One benefit of my model is that it helped to illustrate opportunities for splices on each segment. The first circuit will have a bottom layer extend to support the next circuit, which will match the top layer. It will take some planning, and I bet I screw one up, but it should work.
Colorado is blissfully dry, and I have never had issues with shrinking and swelling that others report. Plywood always has an odd number of plys, and they are laid up in opposite directions (the faces are always in the same direction), so plywood is more dimensionally stable than other (solid) wood products. That is not to say it is perfect, and my Dad and I found 1/4 plywood to be especially crappy. I am hoping that that two layers glued up will be more stable. I guess I could varnish the works before I install it: I am more apt to want to run a router around the edges to take care of any splinters.
Yes, our prototype did favor us with extra tall appliances on the locos. I thought I measured them a while back, but had planned for something like 4" clear. The track will be laid on 1/4" homobed directly to the plywood substrate--that seemed to have among the best sound characteristics when MR published tests years ago. The 12" tangent section helps extend the length of each circuit and keep the grade to about 2%. Half the first circuit beyond Solitude will be at the ruling grade and not hidden, so any issues will get ironed out in the open. Also, even B-4-Fs are only good for 4-5 cars on the heavy grades, so two and three-engine trains will match the prototype.
I have been collecting information on helices for about ten years now. It is astounding how many problems there are to solve in the construction of one of these beasts!
Keith Hayes
Leadville in Sn3
Leadville in Sn3
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