Author Topic: Tehachapi, BC  (Read 266322 times)

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peteski

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Re: Tehachapi, BC
« Reply #1950 on: October 06, 2020, 08:04:35 PM »
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Thin-wall brass tubing might be easier to work with than stainless steel hypodermic tubing.  I used to get mine from Special Shapes Co. It was taken over by K & S Metals, but they might still carry the thin-wall tubing.

I used to get my stainless steel hypodermic tubing from Small Parts Inc. but they were swallowed by Amazon, and while they still exist, there is no good way to search their stock. However I recently found a company that seems to be just like the old Small Parts Inc. - even their stock numbers look dimilar.  It is http://www.componentsupplycompany.com/  I have ordered from them and can recommend them.

Albion Alloys (in UK) should also be a good source of SS and brass thin wall tubing.
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GaryHinshaw

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Re: Tehachapi, BC
« Reply #1951 on: October 06, 2020, 09:05:37 PM »
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Thanks @peteski. I just put in an order for .032" thin wall SS from Ngineering (along with a bunch of other stuff), so I'll see how that works out first.  I'm sure it's harder to work with than brass, but each 2-head mast only requires 1 cut to length and one filed opening for the lower head leads.  It can't be too bad.

A pair of pliers for a good grip on the brass mast and it pulls out fairly easily.

Indeed, it was easier than I expected:



I think the path ahead is clear: keep building one-head masts until the SS arrives, then finish up with the two-head builds.  (Thankfully, there is only 1 three-head mast to deal with.)  Then, maybe someday, we can actually operate the railroad again and put these signals to work...  It's been more than a year since the last session. :|

peteski

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Re: Tehachapi, BC
« Reply #1952 on: October 06, 2020, 10:17:58 PM »
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Thanks @peteski. I just put in an order for .032" thin wall SS from Ngineering (along with a bunch of other stuff), so I'll see how that works out first.  I'm sure it's harder to work with than brass, but each 2-head mast only requires 1 cut to length and one filed opening for the lower head leads.  It can't be too bad.

I was thinking more about ease of soldering than machining.  Unless you are planning to use adhesives.

For larger quantities of SS tubing Component Supply Co. will likely have much better prices than Nginnering.  That can also cut the tubing for you (but that of course costs extra).
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C855B

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Re: Tehachapi, BC
« Reply #1953 on: October 06, 2020, 11:35:08 PM »
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Dremel with a cutoff disk works fine for me. The mid-mast hole(s) I start by nicking enough with the disk to get a drill to bite, and then ream it with the drill, gradually reaming a down-angle to accept the wire bundle for the head(s). You just have to avoid "working" the wires too much, which can scrape the insulation off. You might recall I had one on the 3-head which shorted to the mast but it didn't impair operation. That wouldn't be the case if two were damaged that way.
...mike

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peteski

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Re: Tehachapi, BC
« Reply #1954 on: October 07, 2020, 12:35:08 AM »
+1
Dremel with a cutoff disk works fine for me. The mid-mast hole(s) I start by nicking enough with the disk to get a drill to bite, and then ream it with the drill, gradually reaming a down-angle to accept the wire bundle for the head(s). You just have to avoid "working" the wires too much, which can scrape the insulation off. You might recall I had one on the 3-head which shorted to the mast but it didn't impair operation. That wouldn't be the case if two were damaged that way.

So you are not using the metal mast as the common connection for all the heads?  That leaves more room for other wires inside the mast. That's why I was mentioning ease of solder to brass tubing.  I have done that on a test signal I did years ago.

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C855B

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Re: Tehachapi, BC
« Reply #1955 on: October 07, 2020, 12:48:34 AM »
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So you are not using the metal mast as the common connection for all the heads? ...

Nope. Like I said, 12 #36 wires are doable in the SS thin wall.
...mike

http://www.gibboncozadandwestern.com

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babbo_enzo

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Re: Tehachapi, BC
« Reply #1956 on: October 07, 2020, 05:35:07 AM »
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So, please, can you summarize wich 3 color LED you're using? I understand that are not the Showcase "originals"?
I've some Showcase kit to mount and I'm searching a proper RYG 3 color led to fit in.... at ceaper price if possible!
Thanks in advance for any shop link and LED model.
Stay safe and cheers
Enzo Fortuna
Modeling the Espee in ... Italy

Wolf N Works

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Re: Tehachapi, BC
« Reply #1957 on: October 07, 2020, 07:06:17 AM »
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I believe he is using the SS-RGY-24 from https://www.rr-cirkits.com/description/index.html (last item at the bottom of the page).

babbo_enzo

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Re: Tehachapi, BC
« Reply #1958 on: October 07, 2020, 08:14:39 AM »
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I believe he is using the SS-RGY-24 from https://www.rr-cirkits.com/description/index.html (last item at the bottom of the page).
OK thanks so much Wolf ... also a good Prince!
I’ll check if it can be useable on the Showcase head...
Cheers
Enzo


Oh oh ... 3 mm ... HO scale ... probaby not good but I ‘ll verify anyway!
I’m in N.ormai scale! :)
« Last Edit: October 07, 2020, 09:45:13 AM by babbo_enzo »

GaryHinshaw

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Re: Tehachapi, BC
« Reply #1959 on: October 07, 2020, 11:52:44 AM »
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Hi Enzo.  Yes, I confirm that I'm using the RR-CirKits LEDs that Wolf linked to.  They are pre-wired with four 36 gauge leads and - using my callipers - I measure them to be ~1.25 mm wide and 1.65 mm tall.  (They are not 3 mm wide - not sure where you saw that...)  The leads are wired to come straight off the bottom, but they are flexible enough to be bent straight back, and stiff enough to hold that shape.  They will fit into the Showcase head castings, but it takes a bit of effort because the inside width is a little too narrow to hold them as is.  They will fit at a slight angle with very little work, but the illumination is not ideal.  They fit into Mike's printed heads with almost no effort, so that is what I have been doing (thanks again, to Mike's generosity).  I'll try to post some build photos later, to illustrate this better.

RE the masts, my preference is to avoid using them electrically, unless I have to.  It now sounds like I don't have to. :)
« Last Edit: October 08, 2020, 08:56:40 PM by GaryHinshaw »

babbo_enzo

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Re: Tehachapi, BC
« Reply #1960 on: October 08, 2020, 02:06:02 PM »
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Hi Enzo.  ... - using my callipers - I measure them to be ~1.25 mm wide and 1.65 mm tall.  (They are not 3 mm wide - not sure where you saw that...) 
...
They will fit into the Showcase head castings, but it takes a bit of effort because the inside width is a little too narrow to hold them as is.
...I'll try to post some build photos later, to illustrate this better.
. :)
Ho Gary and thanks for the details.
I've read on the https://www.rr-cirkits.com/Notebook/Searchlight-led.html the description and he states:
disadvantage for us as a manufacturer is the difficulty and time required in soldering four very small (#36AWG) wires onto a 3mm diameter circuit board that has the LED mounted on it.
I'll try to order some ... if you find time for a picture you're welcome ...
Cheers
Enzo

DKS

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Re: Tehachapi, BC
« Reply #1961 on: October 08, 2020, 02:23:11 PM »
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disadvantage for us as a manufacturer is the difficulty and time required in soldering four very small (#36AWG) wires onto a 3mm diameter circuit board that has the LED mounted on it.

What's the purpose of the printed circuit board? Why not just solder the leads directly to the LEDs?

peteski

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Re: Tehachapi, BC
« Reply #1962 on: October 08, 2020, 04:57:24 PM »
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RE the masts, my reference is to avoid using them electrically, unless I have to.  It now sounds like I don't have to. :)

Gary, what is the reason for avoiding using the mast as electrical common for the signal heads?  It could eliminate up to 3 wires from being stuffed inside the small-diameter mast.  Sorry if you already explained this earlier - I did not go looking thought the older posts.
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GaryHinshaw

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Re: Tehachapi, BC
« Reply #1963 on: October 08, 2020, 08:50:39 PM »
+1
Hmm, that notebook page that Enzo linked to seems to be outdated.  The leads are soldered directly to the chip, which again is ~1.25 mm wide × 1.65 mm tall.  I did manage to get some halfway reasonable photos of the LEDs and heads, so here you go.  (Captions below each photo.)



[Left to right: Showcase head casting, RR-CirKits LED, @C855B 's printed head with LED installed.]



[Same as above with the LED semi-inserted in the Showcase head.  It is a very tight fit, but it will insert further with some work.]



[Side view of the heads.  The quality of the printed head is superior in every way.  Note the slit opening in the Showcase head where the top corner of the cavity is breaking through.  Not all of the castings have this problem, but many do.  The tape strip is 1/2" wide, for scale.]

Gary, what is the reason for avoiding using the mast as electrical common for the signal heads?

A couple of reasons: 1) I prefer to solder the leads to the solder pads on @Wutter 's base board since I lack the skill to consistently make a clean joint to the mast, especially with stainless.  (And it's more prototypical to have the leads go in the mast.)  If the thin wall tubing can really accommodate 12 leads, as Mike notes, then I'll have no trouble getting 8 down (all but one of my masts are 1 or 2 heads only).  2) Having the mast be neutral minimizes the risk of shorting due to scarred insulation in the coloured leads.  So for my application, assuming the thin-wall pans out as expected, there really is no advantage to making it a common.

C855B

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Re: Tehachapi, BC
« Reply #1964 on: October 08, 2020, 09:01:33 PM »
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Gary, what is the reason for avoiding using the mast as electrical common for the signal heads?  It could eliminate up to 3 wires from being stuffed inside the small-diameter mast.  Sorry if you already explained this earlier - I did not go looking thought the older posts.

I concur with Gary's points, plus (for myself) my preference is to avoid commons when there is the possibility that separate controlled components - in this case, each head - may be fed by unrelated circuits which may or may not be subject to revision at a later date. I've had enough experience with ground loops in similar situations to know that if I don't have to use a common ground (or positive rail), I'd rather not set the stage for difficult-to-diagnose gremlins.

Similar reason I gap both rails for detection even though one side may be tied together back at the terminal block. There's the non-zero chance that a given block may see a reverser in the far-distant future.
...mike

http://www.gibboncozadandwestern.com

Wake me when it's over.