Author Topic: DiY rail bender.  (Read 1107 times)

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SandyEggoJake

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DiY rail bender.
« on: March 28, 2021, 01:40:58 PM »
+1
So, sure... not a huge need for N, but still useful for tight turns.  (I'm making ring rails for a turntable, hence my current need for a rail bender). If you've ever spent time on the Fast Track website, you've seen their spendy rail bender.  You may have also seem the one on eBay that still retails for about $50.  How would you like to make one for less than 1/5 that price? 

Both are essentially adjustable three pins with bearings.  Bearings are super cheap, but the handles would take some effort to manufacture.  But for those who ever dabbled in watch repair will recognize the basic frame as nothing more than a watch case opener.  These little gadgets can be had on eBay for as little as $8 with shipping and a bunch of extra parts.  That's where I ordered mine.  But I overpaid!  Just saw that micro tools is running an extreme clearance sale on them in a kit with a bunch of other tools... for just $2.99.  Once my bearings arrive, I will include more details with photos on how to finish building this simple tool.

https://www.micro-tools.com/collections/closeout-sale/products/jt6228
« Last Edit: March 28, 2021, 01:43:06 PM by SandyEggoJake »

mmagliaro

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Re: DiY rail bender.
« Reply #1 on: March 29, 2021, 07:22:02 AM »
0
Excellent idea!  Yes, as long as you can find bearings that will slip over the 3 posts and achieve a good range between the rollers
for bending rails, this should work. I'll be very interested to see how you make this, because I am sitting on a Fast Tracks
jig right now for making a curved turnout, and was pondering how to do the rail bends without spending $85 for the tool, or making
something myself (I was considering machining it all out of a block of aluminum, putting in posts, bearings, etc, but it will take a bit of time... I'd rather weasel out of it if I can just bolt some bearings onto that watch case opener!)

Lemosteam

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Re: DiY rail bender.
« Reply #2 on: March 29, 2021, 07:52:42 AM »
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@narrowminded already has one designed for C40 rail and i assume C55 might work in there too.

Issues I see is that the bearings would need to be ground to the rail profile so that the bearing could contact the web of the rail to keep the rail from twisting on its axis while bein formed into the desired curvature.

narrowminded

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Re: DiY rail bender.
« Reply #3 on: March 29, 2021, 10:16:36 AM »
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@narrowminded already has one designed for C40 rail and i assume C55 might work in there too.

Issues I see is that the bearings would need to be ground to the rail profile so that the bearing could contact the web of the rail to keep the rail from twisting on its axis while bein formed into the desired curvature.

Yes, I've got one worked out intended for use with code 40 and code 55 (could probably do larger but haven't tried) that is part of my whole track, tie bed, turnout, and related pieces project.  I've been quiet about a lot of this stuff, figuring I'd release these things when it's all done and pieces are in stock but the rail bender design is ready to go, just not a stock run made (as with a lot of things at this point).  I've ordered and received the bearings and hardened washers for the guides under the bearings and the rest is done in house.  The one in the video has aluminum shoulder washers under the bearings that work fine but for the final unit that might see some heavy duty work I've changed those to hardened steel washers.  Might be overkill but it's not really that much money when you're buying more than a few so what the heck, go for it! :D

I haven't final priced them yet but if anybody wanted one I could do them now for $45 and a few weeks delivery.  Otherwise, they'll be ready with the full track bed line.  And pretty soon, I hope. :facepalm:  This is a lot of work.

Here's a link to that video that shows the first use of the prototype, making my code 40 Nn3 test track with 2 1/2" and 3 1/2" radius curves. :o 

Mark G.

SandyEggoJake

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Re: DiY rail bender.
« Reply #4 on: March 30, 2021, 03:24:07 PM »
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This rail bender is clearly more robust than what I am attempting to make for under $10.  The first set of bearing I'm exploring to use are salvage from an old pair of roller blades!


Chris333

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Re: DiY rail bender.
« Reply #5 on: March 30, 2021, 03:30:30 PM »
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I made a rail bender out of stuff I found at work. The 3 bearing I used have a little chamfer on the edge that the base of the rail fits right into.

SandyEggoJake

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Re: DiY rail bender.
« Reply #6 on: March 31, 2021, 06:38:33 AM »
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Grooved bearings are certainly available too, but finding them to fit rail would be an issue.  Theoretically a custom lathe tool ground could be done - but I can't even find someone who will grind me an RP25 profile N scale wheel tool. (fohrmann.com makes tooling for RP25 HO, but declined my request to make same in N scale).

But I agree grooved bearings may not be required with such light rail.  I was thinking of using a "carrier" consisting of suitable guage wire placed in the web as support, but now may give Chris's suggestion a try.

When I started trying with this, I was considering making custom rollers for a Seig mini metal roller that I picked up used on ebay.  Basically 3 horizontal aluminum rollers press fit on steel rods. It's not pretty, but an experiment of using a section of actual rail as the tooling produces enough 1/2 rail relief carved in AL. Once my over & under metric reamer set gets out of the Suez, I might still finish that option too... but it won't not be nearly as cheap!

mmagliaro

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Re: DiY rail bender.
« Reply #7 on: April 12, 2021, 01:28:09 AM »
+3
Well, I went off and made one of these from one of the watch case openers.  I spent $6.99 on the opener, and $7 each on some nice grooved 12mm bearings.  It did take a bit of lathing to make pins to fit into the opener and the bearings, and I also had to make a longer handle bolt from a 10-32 bolt so I could screw the center bearing further upward.  But all in all, it is a SPLENDED tool!  Just slip code 55 rail in between the rollers, the base of the rail rides in the groove keeping it nice and straight.

I used it to bend the stock rails on my first ever FastTracks turnout - a curved 22/18 that has now replaced my nemesis Atlas c55 curved piece.  How satisfying it is to watch long wheelbase steam locomotives roll backwards through a curved turnout without a hiccup.  Ha ha ha.

THANK YOU for SandyEggoJake for this idea!






mighalpern

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Re: DiY rail bender.
« Reply #8 on: April 14, 2021, 08:32:58 PM »
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Ok
So i bit the bullet and spent the $2.99 for the repair kit that from the web link that SandyEggoJake sent.
I actually live 18 miles away and was able to pick it up.  rather than spent 9.40 cents on shipping a 3 dollar item.  So the kit is cool and the tool looks strong enough,   I measured the three pins and they are roughly  .350" to .352"   I will probably take the tool apart and throw the pins on a lathe and make sure they are round.
  Now where to get those bearing you guys are talking about.
take it easy
Miguel

mmagliaro

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Re: DiY rail bender.
« Reply #9 on: April 15, 2021, 01:25:53 AM »
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Bearings:

https://www.vxb.com/624VV-V-Groove-Guide-Miniature-V-Bearing-p/624vv.htm

But if I had it to do over again, I'd get larger diameter ones so they would get close enough without me having to make
a longer bolt for the handle, and cut the handle bearing slot closer up toward the other two bearings.

https://www.vxb.com/608VV-V-Groove-Guide-Miniature-V-Bearing-p/608vv.htm
This one is 22mm diameter, 8mm bore, instead of  the 13mm diameter one I used.  8mm is .314, so your .350" pins would
have to be slightly turned down to fit, but since you have a lathe - no big deal.


mighalpern

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Re: DiY rail bender.
« Reply #10 on: April 15, 2021, 11:37:27 AM »
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thanks for the web site references
I'm kicking the idea of this bearing which is 16 mm   

https://www.vxb.com/688VV-V-Groove-Guide-Miniature-V-Bearing-p/688vv.htm

I'll have to measure the tool and see how much space I have.   
yours looks wider than what i got.
Many thanks
Miguel