There have been a number of questions concerning the design considerations particularly the grade calculation and I can see why. Most internet discussions avoid the details completely, making it difficult to see just how they are making their grade calculations, and only a few offer explicit details. The NMRA website offers no details only generalities. www.staging.nmra.org/clearance-and-grade Some seem to disagree on the calculations. For example some seem to calculate grade based just on the distance between the roadbeds whereas others seem to include the roadbed thickness in the grade calculation. For a really good discussion of this I suggest visiting the websites linked below (and I hope UA-cam will not delete this address but if they do I will put it in the description). The first one has a complete helix calculator and seems to include the roadbed thickness in their grade calculation. www.modelbuildings.org/helix-design-calculator/ The second website has a grade calculator. They too include the roadbed thickness in the grade calculation as I have done. When I input my parameters the result is the same as in my original design video-1.86%. www.trainweb.org/s-trains/helix/percent_grade.htm In my next video I will try to provide some clarity on these questions in the feedback segment, so stay tuned.
I am very new to railroading but watching your videos and exploring all your different ideas gives me great hope that I can accomplish just a part of what you have shown would be awesome. Thank you so much for EXPLAINING how to do things, and not just go through the motions. I look forward to all your videos.
I have been looking forward to this project. Not that I am going to build one; I really don't have room or need, but because it is you who is doing it and I knew it would be done right. I cannot wait to see the finished project. I have questions that will probably be answered in the next segment. Great project!
Larry The Helix is coming along lots of great tips. I am expanding my Helix to a third level now lots of prep work to be done. Looking forward to see the other levels added
Great Video, workmanship, I see from some the Comments from other Contributors care is needed when calculating the overall Clearance between Rail Tops on each Level. Looking for to watching the next Episode that see you’ve already posted on UA-cam. Mind those Fingers when using the Cutoff Saw to create the square ends to each Segment.
Yes, the calculations are critical for getting the desired slope. Most saws made today, including mine, have a shield between the blade and any fingers that might get into the path, but I remember my great-uncle had a short index finger as the result of mishap with a saw many years ago.
Very good video. If I'd seen one like this in 2007 I'd have a double decker layout. I can't now because of lumber expense + track and roadbed. I also have a 36" wide layout. So that would make my lower level wider then my upper level making both in reachable. Oh well , that's life.🥴
The sub-roadbed pieces look pretty good Larry especially for being cut freehand with a jig saw. And good emphasis on the critical requirements of getting the first turn grade correct and consistent. One thing that does worry me though is that front corner sitting out there, it will almost certainly become a real shin and knee "killer"! The ends of those frame members aren't supporting the helix so I recommend cutting the front and side pieces back about 10" and close the open gap with a piece that fits in at 45 degrees to them making for a much safer frame corner.
I could have angled it but it really isn’t a problem. That corner will be recessed 6” under the edge of the main deck immediately above it plus there will be a 6” shelf on the edge of that so it really will be recessed 12”. Consequently I didn’t think ithe extra work to build in those angles would be worth it a d it is probably stronger without them.
Dear Larry, absolutely agree on the importance of getting the first part of the grade of the helix as accurate as possible. Nevertheless, for people who aren’t as apt with making the calculations, there’s also a trick to overcome inconsistencies of the first grade percentage. When the tangent towards the helix is adequately stiff, then people could also choose to make the first two loops, either with the 3” risers mounted on the first loop and clamped on the second loop. Or, by clamping the two loops all the way. That will temporarily stiffen the two loops, so when people are uncertain about their calculations they can cross reference their risers from the actual measurements they will then be able to make. I find this also a good method to check back on the base of the helix. The 1”x4” struts are of course sturdy enough, however going in and out the frame can sometimes dislocate a member, if only leading to just a fraction of an inch difference, this will seriously compromise the work done. As soon as the first to loops are fully connected, then it will sturdy up the under frame. And yeah, clamp the second loop, because one wants to put the track in first, before permanently mounting the second one and each consecutive loop. To further strengthen the helix, I humbly think 70° elements create a more sturdy structure. That will prevent the different splices all ‘cornering’ up above each other. Further, love your calculations and explanations. Great to see the build. Thanks 🙏 for sharing.
Also, subsequent loops of the helix should use stock laid sideways. No measuring necessary as long as there is a stock width that works. For N scale, a 1x3, which is 2.5" finished dimension, is good for this.
I agree with the other poster who thought showing the layout of your template on the plywood would be a good idea. Describe it all you want, but you know what they say about a picture. Not too late to show a scale drawing.
So very easy to cut a perfectly straight line with a jig saw. Simply clamp a straight edge (piece of wood or anything else) I usually use a level, to the piece of wood you want to cut and let the base of the jig saw follow the straight edge of whatever you clamped to the wood. So very simple...
This is looking good Larry. I'm interested to see you do not intend to use the threaded rod approach to fine height setting on the upper levels. The builders of other Helixes (e.g. the one that Charlie Bishop had made for Chadwick) seem to make great use of that technique. Your use of blocks does seem like a solid plan, my only worry woudl be how much they might obscure access to derailed stuff on the helix, but at this stage I can't really visualise how much of an impediment they might be. I shall watch with interest! As a by-comment..... Whew! Watching this it occurs to me that all these different calculations and relationships between points on the helix would be so much easier to do in metric, but I guess it's what you're used to. As you may know, in the UK we seldom used to use metric - but in the last couple of decades it has taken over for a lot of things and yes, I was initially resistant to this "foreign" system - but after I get into "Maker" hobbies and got used to using it I came to see that it makes a lot of things just SO much simpler to work out. I look at my old tool sets like drills with their fractional inch sizes (like 5/64" or similar) and I thank goodness I made that switch. Anyway, great work and I love how well you do your lighting for videos - makes them so much more watchable than when people just expect the camera to "make it right" when they don't bother.
I know many modelers that have one or two Helixes on their roads and the blocks do not come close to getting in the way of the maintainance of the road in any way. Charlie Bishop's helix is good but the block way is less cost.
Yes, and threaded rods require adjust a pant load of nits to just the right height. I think it is easier to simply set up a jig on my chop saw and cut a bunch of 3” riser blocks.
I have a question... Would establishing the grade of the first turn not be easier if you used a product such as Woodland Scenics foam inclines on a plywood baseboard ? This would eliminate all those elevation calculations and ensure a constant grade.
A point of clarification: you figured your helix for 3"/turn rise, but you said you cut your spacer blocks at 3", which would make your rise 3 1/2" (assuming you used 1/2" plywood). Did I miss something?
Ron-in the first video the slope was calculated based on the total 3.5” rise per revolution. The riser blocks only account for the space BETWEEN each section of roadbed, and the 1/2” thickness of the roadbed is baked in. Since the riser blocks are 3” and the roadbed is 1/2” there is your 3.5”.
Yes, but the individual blocks are only cut to 3” on the loops above the first one. On the first loop you have to install your risers to different heights to create that initial slope. My head spins every time I go down this path.
Larry Hi, another interesting and informative video, but I'm wondering if I have spotted a flaw in your plan ? If you are going to continue to use 1/2" pieces to join or splice the helix lengths together then that will reduce your height or clearance to only 2.5" at each joint and if you intend to use a sub road bed of cork or foam then it will be only about 2.25" clearance and I'm jut wondering if that is going to be enough ? Also you won't be able to use 3" risers at the helix joints as there is that extra 1/2" already there so you will need 2.5" risers for the joints unless you don't go full width with the helix length joiners ? This is the problem I am currently facing and I don't have a solution so I'm looking forward to how you've solved it :). I would also like to know how you got your 13 pieces out of one sheet ?
The splice plates fitted underneath the sub-roadbed are only used on the first turn. Once the sub-roadbed is stacked over itself the joints are aligned and strengthened by the riser blocks bridging each joint. You can also use biscuits to establish the initial vertical alignment until the risers are in place although granted biscuit cutters are not in everyone's tool set. Using 1/4" roadbed would yield a clearance of 2.75" which is fine for equipment in Larry's era. For modelers running modern equipment such as autoracks and double stacks then this is too tight and a risers of 3.25" to 3.5" would be a better choice
Good answer and that is what I will be doing since the risers will support the roadbed at the joint a splice plate there isn’t really necessary. If a joint falls somewhere other than where you want risers then you can add a couple of 1/2” plywood strips. If you use cork or other roadbed then yes you will need to 9n creases your riser height accordingly to compensate. In my case the track will be laid directly on the roadbed. It will be noisier but in a helix I think that will be a good think as folks get a bit antsy if they can’t hear their train moving in a hidden helix or long stretches. Down the road I’ll also be installing detectors and an LED display to show where the train is in the helix as it ascends. More on that next week. As for the 13 pieces, I just laid them out one right after the other stair step fashion and 13 fit. I was surprised too, and I think that using the 1/4 turn configuration made that possible. More splices but cheaper.
@@68Jaguar420G Actually, you are overlooking the height of the actual rail when you say the clearance will be 2.75", I was allowing 1/4" for the track and another 1/4" for underlay or roadbed when I suggested the clearance would only be 2.5". It appears to be a common mistake people make that thanks to videos like Larry's I now hope to avoid.
I see one problem you didn't cover. Adding each layer or circle then no splices can be used between each quarter board. That would take up a half inch giving you only 2 and a half inches in clearance, and with added roadbed with track that cuts down on your 3 inch clearance. But I will wait until next week to see how you have corrected it. Another good video.
You might use the riser blocks, one on each side to reinforce the splice and then you wouldn't need any correction in the math. We'll see what he does next...
Too late, I already cut them all out. However I just put the template along the bottom edge of the 4’ side, marked the outline with a pencil, then moved it up clearing the first outline by about 1/8” and marked that outline, etc.
I have looked at various comments about the height of the roadbed but surely if you put a 3" block on the top of one roadbed and fix it to the underside of the roadbed above you have got a 3" rise and not a 31/2" rise. I may be wrong and stupid but it would work for me.
Do an experiment. (1) Lay out a sheet of 1/2” plywood. (2) Place a pair of 3” tall wood blocks next to each other on the plywood. (3) Place another piece of 1/2” plywood on the blocks. (4) Measure the height from the top of the first piece of plywood to the top of the second-that is your total rise and it happens each time you go around the helix. As I calculate it the track is rising 3.5” per loop. I am not a mathematician so maybe I am wrong, but if I am then my slope is actually closer to 1.6% instead of 1.85%.
@@TheDCCGuy I think the confussion comes about because you constantly refer in the video to a rise of 3 inches. Now in most of our heads the rise is the height increase from the TOP of one trackbed to the TOP of the next, not the gap between the top of the lower and the bottom of the upper. Maybe if you had refered to "a rise of 3 1/2 inches" throughout the video then there would not be all this confussion ;-) All in all though, a great series of videos that will surely help many modellers. Keep up the excellent work.
It would only be necessary where a much steeper grade is required as Charlie Bishop did. In my case with a grade under 2% and multiple locos on each train I figure I can pull 14-15 cars.
That one is about 40 years old and probably isn’t available. However there is a similar device called a Curve Runner. Just do a search for it and others will also pop up.
Two comments, which I imagine you’ve taken into account. First, The height of the spacer block should be 3 inches minus the thickness of the plywood. Second, since you did not start the slope exactly at a 90 degree segment line, each of the initial risers will not be an exact multiple of 3/4”.
I agree with your first comment (the blocks should not be 3" for a 3" rise in trackbed). The 3/4" multiples are added to the initial rise for the first 90° segment line. So if you cross the 90° point at 1/4" then you add 1/4" to the exact multiples of 3/4" (first point is 1/4", 2nd is 1", 3rd is 1 3/4", etc)
@@hughjardon5101 In the helix design video Larry accounted for the 1/2" sub-roadbed thickness. Total rise per turn was 3" for clearance PLUS 1/2" for the sub-roadbed thickness for a total delta per turn of 3 1/2". If one wants to be really pedantic then you might add the height of the roadbed, ties and rail to the total rise per turn to maintain 3" clearance above the railhead but that is rarely taken into account in helix design. Larry has this one sorted!
@@68Jaguar420G Mea culpa, I did not go back to the other video before I commented. It would have been useful for Larry to mention that calculation here. All in all, this is a good video.
There have been a number of questions concerning the design considerations particularly the grade calculation and I can see why. Most internet discussions avoid the details completely, making it difficult to see just how they are making their grade calculations, and only a few offer explicit details. The NMRA website offers no details only generalities.
www.staging.nmra.org/clearance-and-grade
Some seem to disagree on the calculations. For example some seem to calculate grade based just on the distance between the roadbeds whereas others seem to include the roadbed thickness in the grade calculation. For a really good discussion of this I suggest visiting the websites linked below (and I hope UA-cam will not delete this address but if they do I will put it in the description). The first one has a complete helix calculator and seems to include the roadbed thickness in their grade calculation.
www.modelbuildings.org/helix-design-calculator/
The second website has a grade calculator. They too include the roadbed thickness in the grade calculation as I have done. When I input my parameters the result is the same as in my original design video-1.86%.
www.trainweb.org/s-trains/helix/percent_grade.htm
In my next video I will try to provide some clarity on these questions in the feedback segment, so stay tuned.
I don't need a helix but your attention to detail, and how your building it is: to quote Darth Vader " impressive most impressive". Thanks.
I am very new to railroading but watching your videos and exploring all your different ideas gives me great hope that I can accomplish just a part of what you have shown would be awesome. Thank you so much for EXPLAINING how to do things, and not just go through the motions. I look forward to all your videos.
You’re why I keep making these videos.
Well Larry, I am thinking to myself, hmmm, maybe I CAN build a helix for my layout. Very good level of detail in the series, thank you.
Thank you for sharing. Enjoyed.
I've been waiting all week for this video, Mr. Puckett.
I have been looking forward to this project. Not that I am going to build one; I really don't have room or need, but because it is you who is doing it and I knew it would be done right. I cannot wait to see the finished project. I have questions that will probably be answered in the next segment. Great project!
Larry The Helix is coming along lots of great tips. I am expanding my Helix to a third level now lots of prep work to be done. Looking forward to see the other levels added
Great video, waithing for the rest
Larry looking great, I am considering doing this for my new layout, next week
Great Video, workmanship, I see from some the Comments from other Contributors care is needed when calculating the overall Clearance between Rail Tops on each Level. Looking for to watching the next Episode that see you’ve already posted on UA-cam. Mind those Fingers when using the Cutoff Saw to create the square ends to each Segment.
Yes, the calculations are critical for getting the desired slope. Most saws made today, including mine, have a shield between the blade and any fingers that might get into the path, but I remember my great-uncle had a short index finger as the result of mishap with a saw many years ago.
Very good video. If I'd seen one like this in 2007 I'd have a double decker layout. I can't now because of lumber expense + track and roadbed. I also have a 36" wide layout. So that would make my lower level wider then my upper level making both in reachable. Oh well , that's life.🥴
The sub-roadbed pieces look pretty good Larry especially for being cut freehand with a jig saw. And good emphasis on the critical requirements of getting the first turn grade correct and consistent. One thing that does worry me though is that front corner sitting out there, it will almost certainly become a real shin and knee "killer"! The ends of those frame members aren't supporting the helix so I recommend cutting the front and side pieces back about 10" and close the open gap with a piece that fits in at 45 degrees to them making for a much safer frame corner.
I could have angled it but it really isn’t a problem. That corner will be recessed 6” under the edge of the main deck immediately above it plus there will be a 6” shelf on the edge of that so it really will be recessed 12”. Consequently I didn’t think ithe extra work to build in those angles would be worth it a d it is probably stronger without them.
Dear Larry, absolutely agree on the importance of getting the first part of the grade of the helix as accurate as possible. Nevertheless, for people who aren’t as apt with making the calculations, there’s also a trick to overcome inconsistencies of the first grade percentage.
When the tangent towards the helix is adequately stiff, then people could also choose to make the first two loops, either with the 3” risers mounted on the first loop and clamped on the second loop. Or, by clamping the two loops all the way. That will temporarily stiffen the two loops, so when people are uncertain about their calculations they can cross reference their risers from the actual measurements they will then be able to make. I find this also a good method to check back on the base of the helix. The 1”x4” struts are of course sturdy enough, however going in and out the frame can sometimes dislocate a member, if only leading to just a fraction of an inch difference, this will seriously compromise the work done. As soon as the first to loops are fully connected, then it will sturdy up the under frame. And yeah, clamp the second loop, because one wants to put the track in first, before permanently mounting the second one and each consecutive loop. To further strengthen the helix, I humbly think 70° elements create a more sturdy structure. That will prevent the different splices all ‘cornering’ up above each other.
Further, love your calculations and explanations. Great to see the build.
Thanks 🙏 for sharing.
Sounds good to me.
Also, subsequent loops of the helix should use stock laid sideways. No measuring necessary as long as there is a stock width that works. For N scale, a 1x3, which is 2.5" finished dimension, is good for this.
Yes, that would be good if someone made a real 3” wide 1x3.
A 1x4 is 3.5" finished. For HO I'd be going with that anyway.
thank you for detailed video
Thank you, this well help me doing my N Scale.
I agree with the other poster who thought showing the layout of your template on the plywood would be a good idea. Describe it all you want, but you know what they say about a picture. Not too late to show a scale drawing.
I do have the sheet of insulation foam board that I did a test on, would that do?
Great idea! Thanks.
So very easy to cut a perfectly straight line with a jig saw. Simply clamp a straight edge (piece of wood or anything else) I usually use a level, to the piece of wood you want to cut and let the base of the jig saw follow the straight edge of whatever you clamped to the wood. So very simple...
First I’d have to cut a straight edge for those curves.
@@TheDCCGuy Not really. I have free handed curves and still have cut the ends straight with the straight edge that I mentioned.
This is looking good Larry. I'm interested to see you do not intend to use the threaded rod approach to fine height setting on the upper levels. The builders of other Helixes (e.g. the one that Charlie Bishop had made for Chadwick) seem to make great use of that technique. Your use of blocks does seem like a solid plan, my only worry woudl be how much they might obscure access to derailed stuff on the helix, but at this stage I can't really visualise how much of an impediment they might be. I shall watch with interest!
As a by-comment..... Whew! Watching this it occurs to me that all these different calculations and relationships between points on the helix would be so much easier to do in metric, but I guess it's what you're used to. As you may know, in the UK we seldom used to use metric - but in the last couple of decades it has taken over for a lot of things and yes, I was initially resistant to this "foreign" system - but after I get into "Maker" hobbies and got used to using it I came to see that it makes a lot of things just SO much simpler to work out. I look at my old tool sets like drills with their fractional inch sizes (like 5/64" or similar) and I thank goodness I made that switch.
Anyway, great work and I love how well you do your lighting for videos - makes them so much more watchable than when people just expect the camera to "make it right" when they don't bother.
I know many modelers that have one or two Helixes on their roads and the blocks do not come close to getting in the way of the maintainance of the road in any way. Charlie Bishop's helix is good but the block way is less cost.
Yes, and threaded rods require adjust a pant load of nits to just the right height. I think it is easier to simply set up a jig on my chop saw and cut a bunch of 3” riser blocks.
I have a question... Would establishing the grade of the first turn not be easier if you used a product such as Woodland Scenics foam inclines on a plywood baseboard ? This would eliminate all those elevation calculations and ensure a constant grade.
Yes, that would make it easier I suppose if they have the incline you need.
A point of clarification: you figured your helix for 3"/turn rise, but you said you cut your spacer blocks at 3", which would make your rise 3 1/2" (assuming you used 1/2" plywood). Did I miss something?
Ron-in the first video the slope was calculated based on the total 3.5” rise per revolution. The riser blocks only account for the space BETWEEN each section of roadbed, and the 1/2” thickness of the roadbed is baked in. Since the riser blocks are 3” and the roadbed is 1/2” there is your 3.5”.
@@TheDCCGuy Ok, that makes perfect sense then. Thanks for clarifying for me. 👍🏼👍🏼
@@TheDCCGuy if the gain per loop is 3.5”, then the gain per quadrant is 7/8”, not 3/4”.
Yes, but the individual blocks are only cut to 3” on the loops above the first one. On the first loop you have to install your risers to different heights to create that initial slope. My head spins every time I go down this path.
Larry Hi, another interesting and informative video, but I'm wondering if I have spotted a flaw in your plan ? If you are going to continue to use 1/2" pieces to join or splice the helix lengths together then that will reduce your height or clearance to only 2.5" at each joint and if you intend to use a sub road bed of cork or foam then it will be only about 2.25" clearance and I'm jut wondering if that is going to be enough ? Also you won't be able to use 3" risers at the helix joints as there is that extra 1/2" already there so you will need 2.5" risers for the joints unless you don't go full width with the helix length joiners ? This is the problem I am currently facing and I don't have a solution so I'm looking forward to how you've solved it :). I would also like to know how you got your 13 pieces out of one sheet ?
The splice plates fitted underneath the sub-roadbed are only used on the first turn. Once the sub-roadbed is stacked over itself the joints are aligned and strengthened by the riser blocks bridging each joint. You can also use biscuits to establish the initial vertical alignment until the risers are in place although granted biscuit cutters are not in everyone's tool set. Using 1/4" roadbed would yield a clearance of 2.75" which is fine for equipment in Larry's era. For modelers running modern equipment such as autoracks and double stacks then this is too tight and a risers of 3.25" to 3.5" would be a better choice
Good answer and that is what I will be doing since the risers will support the roadbed at the joint a splice plate there isn’t really necessary. If a joint falls somewhere other than where you want risers then you can add a couple of 1/2” plywood strips. If you use cork or other roadbed then yes you will need to 9n creases your riser height accordingly to compensate. In my case the track will be laid directly on the roadbed. It will be noisier but in a helix I think that will be a good think as folks get a bit antsy if they can’t hear their train moving in a hidden helix or long stretches. Down the road I’ll also be installing detectors and an LED display to show where the train is in the helix as it ascends. More on that next week. As for the 13 pieces, I just laid them out one right after the other stair step fashion and 13 fit. I was surprised too, and I think that using the 1/4 turn configuration made that possible. More splices but cheaper.
@@68Jaguar420G Actually, you are overlooking the height of the actual rail when you say the clearance will be 2.75", I was allowing 1/4" for the track and another 1/4" for underlay or roadbed when I suggested the clearance would only be 2.5". It appears to be a common mistake people make that thanks to videos like Larry's I now hope to avoid.
I see one problem you didn't cover. Adding each layer or circle then no splices can be used between each quarter board. That would take up a half inch giving you only 2 and a half inches in clearance, and with added roadbed with track that cuts down on your 3 inch clearance. But I will wait until next week to see how you have corrected it. Another good video.
You might use the riser blocks, one on each side to reinforce the splice and then you wouldn't need any correction in the math. We'll see what he does next...
What he said!
Hi Ron. Can you mention that if you have long cars they can tip in to the center of the helix. And why that would happen.
Was that question meant for Ron or for me?
Can you please show the layout on the sheet of ply? Thanks
Too late, I already cut them all out. However I just put the template along the bottom edge of the 4’ side, marked the outline with a pencil, then moved it up clearing the first outline by about 1/8” and marked that outline, etc.
I have looked at various comments about the height of the roadbed but surely if you put a 3" block on the top of one roadbed and fix it to the underside of the roadbed above you have got a 3" rise and not a 31/2" rise. I may be wrong and stupid but it would work for me.
Do an experiment. (1) Lay out a sheet of 1/2” plywood. (2) Place a pair of 3” tall wood blocks next to each other on the plywood. (3) Place another piece of 1/2” plywood on the blocks. (4) Measure the height from the top of the first piece of plywood to the top of the second-that is your total rise and it happens each time you go around the helix. As I calculate it the track is rising 3.5” per loop. I am not a mathematician so maybe I am wrong, but if I am then my slope is actually closer to 1.6% instead of 1.85%.
@@TheDCCGuy I think the confussion comes about because you constantly refer in the video to a rise of 3 inches. Now in most of our heads the rise is the height increase from the TOP of one trackbed to the TOP of the next, not the gap between the top of the lower and the bottom of the upper.
Maybe if you had refered to "a rise of 3 1/2 inches" throughout the video then there would not be all this confussion ;-)
All in all though, a great series of videos that will surely help many modellers. Keep up the excellent work.
Have you considered installing DCC Concepts powerbase. It's relatively cheap but may help certain locos.
It would only be necessary where a much steeper grade is required as Charlie Bishop did. In my case with a grade under 2% and multiple locos on each train I figure I can pull 14-15 cars.
@@TheDCCGuy That's fair enough. I didn't appreciate it was only 2%.
What is the tool you used to measure along the centerline and where did you get it? Good video.
That one is about 40 years old and probably isn’t available. However there is a similar device called a Curve Runner. Just do a search for it and others will also pop up.
what would be the formula if I wanted 4 in for the helix
See my pinned post and visit the website provided.
Two comments, which I imagine you’ve taken into account. First, The height of the spacer block should be 3 inches minus the thickness of the plywood. Second, since you did not start the slope exactly at a 90 degree segment line, each of the initial risers will not be an exact multiple of 3/4”.
I agree with your first comment (the blocks should not be 3" for a 3" rise in trackbed).
The 3/4" multiples are added to the initial rise for the first 90° segment line. So if you cross the 90° point at 1/4" then you add 1/4" to the exact multiples of 3/4" (first point is 1/4", 2nd is 1", 3rd is 1 3/4", etc)
@@hughjardon5101 In the helix design video Larry accounted for the 1/2" sub-roadbed thickness. Total rise per turn was 3" for clearance PLUS 1/2" for the sub-roadbed thickness for a total delta per turn of 3 1/2". If one wants to be really pedantic then you might add the height of the roadbed, ties and rail to the total rise per turn to maintain 3" clearance above the railhead but that is rarely taken into account in helix design. Larry has this one sorted!
@@68Jaguar420G Mea culpa, I did not go back to the other video before I commented. It would have been useful for Larry to mention that calculation here. All in all, this is a good video.
If the gain per loop is to be 3.5”, then the gain per quadrant should be 7/8”, not 3/4”.
HELLO LARRY ITS IS RANDY AND I LIKE U VIDEO IS COOL LARRY THE BIG HELIX IS COOL LARRY THANKS FRIENDS RANDY
My club has two helices and according to the other members they're in each other's spot.
I'm confused. In the planning you went with a slope of 1.86. Now at 9:03 it's 1.059.
Probably just a slip of the tongue. It is about 1.9% all the way. When I get time I’ll check at your time stamp.
😊
I don't need a helix but after this series I at least feel competent to build one, and I'm the worst carpenter in the world.