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Using Spline Roadbed in Helix - Part 3 - Progress Update Journals/Blogs
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Super User 753 posts jmt99atsf Super User 753 posts
jmt99atsf

The spline roadbed helix story continues.  I have other projects around the house so I have only been working on this project part of the time as well as learning and documenting the process as I go. New pictures and a movie were added on 4 and 9 August to this section.

I have added the second and third turns and am ready to add the fourth turn probably next week.  The roadbed and track have been added and cleaned.  The movie  shows an older Con-Cor F3 (from the 1980s with the Kato motor) in ATSF freight colors running on the helix.  I did test both tracks in DC mode only.  I have planned on running two power bus branches vertically on both of the curved ends of the oval helix.  I am in the process of adding feeders. 

 

 

I have discovered that once each of the turns is smoothed with the surform tool, that the roadbed (glued) can be pre-installed.  The next item is to move the entire turn and temporarily put it in place on the helix to ensure everything is aligned.  Once I am satisfied with the location, I mark the places where the screw eyes are to be inserted so that they are lined up with the ones on the lower levels/turns.  I also mark where the cut has to be made and the biscuit cut will be made.  Once that is completed, I double check the biscuit alignment before finalizing the locations of the screw eyes. Next, add the screw eyes and cut the biscuit hole.  Then assemble and add all of those nuts and washers (the threaded rod method uses lots of them).  I did not use glue in the biscuit holes as that connection was very tight plus the threaded rods hold the structure from moving.

One of the problems that I have encountered was that both the starting and ending ends tended to want to drift toward the inside causing them to have a kind of spring tension toward that direction.  I added some additional length on both ends and tried to do a better job of ensuring that they were straight and vertically above each other.  I'll find out how well I've done next week.

That's it for now.  More to follow.

John

4 August 2012 Update

Here are some still pictures that represent the spacing of some passenger cars on the tracks.

0spacing.JPG 

0spacing.JPG 

0spacing.JPG 

9 August 2012 Update

Here are some pictures of how the spline helix section is cut before it is connected to the rest of the helix.

y_to_cut.jpg 

The helix is outside and ready to be cut with a circular saw.

eup_view.jpg 

This is a close-up view of where the cut will be made.  You can see a little bit of the tendency of the spline to spring to the middle just beyond the clamps to the near and far sides.

_the_cut.jpg 

This is after the cuts are made with the circular saw.

eftovers.jpg 

These are the two spline pieces leftover after the cuts.  I used the steel tines from my tractor box blade to weigh down the helix section so it would not move during cutting.

cuit_cut.jpg 

One of the biscuit cuts has been made.  I am cutting for a #20 biscuit.

it_cut_2.jpg 

This is a close-up of the biscuit cut.

More to come.  Thanks for looking as it gives me encouragement to continue.

John
Blog index:  https://forum.mrhmag.com/post/jmt99atsf-blog-index-12219303
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kcsphil1 Prolific poster 1,234 posts
kcsphil1

wow!

That's some serious lamination you have going there sir. 

Philip H. Chief Everything Officer Baton Rouge Southern Railroad, Mount Rainier Div.

"You can't just "Field of Dreams" it... not matter how James Earl Jones your voice is..." ~ my wife

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George J Frequent poster 741 posts
George J

Ditto!

Quote:

That's some serious lamination you have going there sir.

My thought's precisely!

George

"And the sons of Pullman porters and the sons of engineers, ride their father's magic carpet made of steel..."

Milwaukee Road : Cascade Summit- Modeling the Milwaukee Road in the 1970s from Cle Elum WA to Snoqualmie Summit at Hyak WA.
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ChrisNH Super User 1,277 posts
ChrisNH

Helix

Just saw this thread. One of the layouts I operate on, although not so much in the summer, has a helix made from laminated wood lathe in a very similar fashion. I will see if I can get pics. It seems very strong and the layers are thin. I think he just built up the spiral continuously but I will check.

 

Chris

“If you carry your childhood with you, you never become older.”           My modest progress Blog
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jmt99atsf Super User 753 posts
jmt99atsf

Helix

Thank you for the comment. 

When I started this project, I considered doing it as one continuous spiral but decided against it.  The gluing and clamping process is quite messy.  By doing it in sections, I am able to keep them pretty well cleaned of the stalagmites and stalactites created by the assembly of the spline.  The dripping of the glue to the lower levels (with track and wiring installed) would have been a bigger chore than I have to do now. Also, I am pretty well satisfied with the biscuit joints to assemble the helix sections as I have done many of them in woodworking projects.  I would be interested to see the pictures that you mentioned.

 

Thanks,

 

John
Blog index:  https://forum.mrhmag.com/post/jmt99atsf-blog-index-12219303
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jmt99atsf Super User 753 posts
jmt99atsf

Lamination Process

Thank you for your comment.

Each double track section is about 3" wide.  It takes 48 sections of spline (~7/8" x ~96") to build up each section. I was able to get 50 strips out of each of the last two sheets of masonite/hardboard.  Each section is surprisingly light but very strong.

If I was really motivated, I believe that each section could be built in 3-4 days.  Since I am retired and this is a hobby and not a job, I take about 7-10 days building the next section, smoothing/cleaning it up, cutting the section to join with the previous section, cutting the biscuit joints, measuring and installing the screw eyes so they line up with the lower ones, and installing cork roadbed prior to joining it to the installed helix sections. Then I install the track and add track feeders.

Thanks again,

John
Blog index:  https://forum.mrhmag.com/post/jmt99atsf-blog-index-12219303
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KCC Rail New member 2 posts
KCC Rail

Connector??

Hello John - I've had a look through all of your entries concerning your helix and have a question I can't seem to figure out either through reading or looking at your pics - that is: what is the name of the double screw eye "fastener" you are using to support the helix - or is it just 2 separate screw eyes (one from each side) that are imbedded into the spline itself (instead of underneath it?).

btw - love the work and your precision - Chris
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jmt99atsf Super User 753 posts
jmt99atsf

Screw Eye Connectors

I use an Ace Hardware screw eye, sku # 5360094 (0.157 x 1 3/8), that comes in a package of 6.  They match up really well with the 1/4 inch threaded rod that I use.  There are 28 used per level with 5 levels so 140 total for the helix at a cost of about $60.

Lining up the screw eyes from level to level takes a bit of time, but the result is solid and I really like the ease of adjusting the bolts to ensure that the helix is level from side to side and that the bottom of each level is at the correct height.  My calculations are based on my using the bottom side of each level as measured up from the table that the helix is sitting on.  Overall, I believe that this type of helix will be as strong, if not stronger, than one made from 3/4 inch plywood but significantly lighter.

Just let me know if you would like some additional information about the building process for this type of helix.

Thank you for your interest.

John
Blog index:  https://forum.mrhmag.com/post/jmt99atsf-blog-index-12219303
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KCC Rail New member 2 posts
KCC Rail

Screw Eye Connectors

John - thanks for the insight - very appreciated! Although it will be some time away until I build my helix I look forward to any future updates you have as you build out.  

Chris
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