Author Topic: Q: How to make a hollow *tapered* pole?  (Read 1623 times)

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mmagliaro

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Q: How to make a hollow *tapered* pole?
« on: March 10, 2019, 10:11:39 PM »
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I want to put a light pole out in the middle of the storage and parking area near a factory on my layout.
An 8" diameter pole would be .050" and although 8" is a little oversized, I'm going with that to make my life easier with wiring.

The question.
Is there a way to make a TAPERED, HOLLOW pole like this?   Getting the brass or stainless thinwall tubing is easy.  But making it tapered?

If there's no straightforward way to do this, I'll live with it being non-tapered.  I just thought it would be a nice touch if there was some technique for doing this that I'm not aware of.

Thanks!

draskouasshat

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Re: Q: How to make a hollow *tapered* pole?
« Reply #1 on: March 10, 2019, 10:33:31 PM »
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I would go with a thick wall tubing that's longer than what you need. Chuck it in a lathe and get the desired tape, then cut to length.

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mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #2 on: March 10, 2019, 10:43:39 PM »
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I would go with a thick wall tubing that's longer than what you need. Chuck it in a lathe and get the desired tape, then cut to length.

Drasko

I thought about that, but even if I had a lathe (which I don't), the problem is that the tubing would have to be pretty huge to allow for a thick enough wall to machine down for the taper, while still allowing some hollow space in the center for wiring.
If it's .050" at the bottom, and, say, .032" at the top, we will be machining off .009" by the top.  So the starting wall thickness has to be, say, .020".  (I'm just guessing that cutting .009" off a .020" thick wall would survive, but might not if the wall were much thinner than that).  With .020" walls, a .050" tube would only have a space in the center about .010" wide, which is barely enough for one magnet wire.

C855B

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Re: Q: How to make a hollow *tapered* pole?
« Reply #3 on: March 10, 2019, 10:54:16 PM »
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Don't try to do it with a single piece of tubing. Take advantage of the K&S telescoping sizes, and build a step taper of soldered pieces. Lathe not necessary, I'd chuck it in a drill and go at it with a file and then emery paper. Should work.
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peteski

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Re: Q: How to make a hollow *tapered* pole?
« Reply #4 on: March 10, 2019, 11:50:49 PM »
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Don't try to do it with a single piece of tubing. Take advantage of the K&S telescoping sizes, and build a step taper of soldered pieces. Lathe not necessary, I'd chuck it in a drill and go at it with a file and then emery paper. Should work.

That is an excellent idea.  And use the thin-wall tubing from Special Shapes Co. (division of K&S) to make the filing/sanding even easier.
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mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #5 on: March 11, 2019, 12:10:10 AM »
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Hmmmmm... .yes, several pieces of telescoping tubing might be the ticket.  The more individual steps I use, the easier it will be to create a reasonably smooth tapered look on the outside with files or sandpaper.

And besides K&S., there is Albion.  They make amazingly small, super-thin-wall brass tubing.

Looking at some light pole company products, something about 25' tall (2" in N Scale), in a tapered aluminum pole typically has a base diameter of 8 to 9" and a top diameter of 4.5".  That would be .056" at the base and .028" at the top in N Scale.
So I can go with .062" at the base - (about 10" in scale), and I'm betting nobody will quibble over .006" and that lets me use a the common 1/16" size tubing.  At the top, .032" (also very slightly larger at 5.1", but .032" is a common size).

Okay... I'll do some experimenting and let you know how it goes.



narrowminded

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Re: Q: How to make a hollow *tapered* pole?
« Reply #6 on: March 13, 2019, 01:11:53 AM »
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Hmmmmm... .yes, several pieces of telescoping tubing might be the ticket.  The more individual steps I use, the easier it will be to create a reasonably smooth tapered look on the outside with files or sandpaper.

And besides K&S., there is Albion.  They make amazingly small, super-thin-wall brass tubing.

Looking at some light pole company products, something about 25' tall (2" in N Scale), in a tapered aluminum pole typically has a base diameter of 8 to 9" and a top diameter of 4.5".  That would be .056" at the base and .028" at the top in N Scale.
So I can go with .062" at the base - (about 10" in scale), and I'm betting nobody will quibble over .006" and that lets me use a the common 1/16" size tubing.  At the top, .032" (also very slightly larger at 5.1", but .032" is a common size).

Okay... I'll do some experimenting and let you know how it goes.

If you get stuck I know a guy. :)
« Last Edit: March 13, 2019, 01:18:13 AM by narrowminded »
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mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #7 on: March 13, 2019, 10:17:48 PM »
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If you get stuck I know a guy. :)

I have no doubt that you could figure out how to machine something like this, oh "Master of the Lathe"!  Thank you.
I'll take some cracks at it first.  If I get stuck, this thread will be the first place to know.

mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #8 on: March 15, 2019, 06:16:09 PM »
+3
A quick update.
I telescoped 3 pieces of thinwall stainless tubing (from NGineering).

.050" over .042" over .032".  They fit snugly and beautifully.  I just put some red Loctite 680 (retaining compound) on them, slid them together, getting plenty of overlap for strength, and boy oh boy.. those sure aren't coming apart.

I set them at equal sections of 2/3 of an inch each, giving me a 2" pole (about 26.5 feet in N Scale).  I'm not sure how tall parking lot poles are, but it looks good proportionally when I stand it in the yard I want to light up.

Since it's stainless, there's little hope of machining or filing it to smooth out the transition points where the tubing size changes, so I coated it with JB Weld very thinly, let it get hard, and then I chucked that up in the mill, spun it, and held sandpaper against it (backed by a wood block to keep it straight).  I took off most of the epoxy.  I just wanted it to ease the transitions and give me a smooth taper.  Then I hit the transition points with another epoxy coat, and repeated the process (just like iteratively getting a smooth patch/transition on a drywall seam, now that I think about it).

I think it looks really nice. 

There will be photos... I just haven't taken any yet.

Then I coated it with some JB We

paultccrn

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Re: Q: How to make a hollow *tapered* pole?
« Reply #9 on: March 18, 2019, 08:31:37 PM »
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I'm thinking the same technique would work for 19th century factory chimneys...maybe use styrene rods instead with Green Squadron filler...

mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #10 on: March 18, 2019, 10:16:21 PM »
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I'm thinking the same technique would work for 19th century factory chimneys...maybe use styrene rods instead with Green Squadron filler...

Except that those tended to be brick.  Also, there are some really nice ready-case stacks and chimneys like that.
Not so much for a slim, reasonably-in-scale N Scale light pole.

There has been progress.  I have 2 lights in place in the 4-light setup at the top.  And I took some photos.  I just haven't gotten around to posting them.  I will.

SandyEggoJake

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Re: Q: How to make a hollow *tapered* pole?
« Reply #11 on: March 20, 2019, 05:46:34 PM »
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Max, are you trying thread just one wire (as you mentioned) .... using the tube itself to complete the circuit (the trick used by many others including the N-gineering folks)?

Did your lights work?

If using the method you suggest, you may wish check the resistance of your tube before you invest more time into her.  If short, I'd blame the Loctite 680 (Red is an insulator).  If a redo, try an adhesive that is also a conductor (ex. Loctite 3888 or silver containing glue) - but you might be able to salvage - perhaps by adding some solder at the junctions? (I'll leave it to others to suggest how to solder ss - I've heard some suggest it is possible but I have doubts more a brazing thing in my hands.)   

Given your time investment in this project, I hope this suggestion is superfluous.  Looking forward to the pictures. 
« Last Edit: March 20, 2019, 05:50:23 PM by SandyEggoJake »

mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #12 on: March 20, 2019, 07:07:01 PM »
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Max, are you trying thread just one wire (as you mentioned) .... using the tube itself to complete the circuit (the trick used by many others including the N-gineering folks)?

Did your lights work?

If using the method you suggest, you may wish check the resistance of your tube before you invest more time into her.  If short, I'd blame the Loctite 680 (Red is an insulator).  If a redo, try an adhesive that is also a conductor (ex. Loctite 3888 or silver containing glue) - but you might be able to salvage - perhaps by adding some solder at the junctions? (I'll leave it to others to suggest how to solder ss - I've heard some suggest it is possible but I have doubts more a brazing thing in my hands.)   

Given your time investment in this project, I hope this suggestion is superfluous.  Looking forward to the pictures.

Yes, I will use the pole as one conductor, and no I have not had a problem with the Loctite insulating the joints between the sections.  It conducts, and I have the 4 lights wires in place.  I did worry about that, but I didn't "lay on" the loctite, so there was always part of the sliding surfaces uncoated.  It would be pretty hard to get a perfectly insulated joint between the two sections.  They fit together pretty snugly.

mmagliaro

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Re: Q: How to make a hollow *tapered* pole?
« Reply #13 on: March 25, 2019, 03:49:49 PM »
+3
Just to the close the loop on this, here's how the 4-lamp pole fixture turned out.

I have since gotten a little domed cap over the cluster of wires at the very top of the pole.  I will post a final shot when it's on the layout and the lights are on.

It was a lot of work for something like this.  I am happy with how it looks, but I don't think I'd try to hand-make these if I needed 10 of them!








peteski

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Re: Q: How to make a hollow *tapered* pole?
« Reply #14 on: March 25, 2019, 04:00:03 PM »
+1
Wow Max, you amaze me again!  Soldering those 4 arms to  the center section while keeping the inner ends open for wire threading is impressive by itself! How about a photo of the LED side of the shades? 
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