Dual track bender

DGE-Railroad

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Ah... You may have hit on something there Greg. I've only used it on a single long piece of track.
I don't think it would clear the joiners on joined track. I'll give it a try and see though :)
 

Greg Elmassian

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That is one of the big advantages of the commercial benders, that they can go through joiners. Bending a single piece of track leaves the very ends unbent.

As I have stated other places, after track is "assembled", running the bender across joints makes a big difference in the consistency of curvature, and of course fewer derailments.

I have 2 commercial benders, an Aristo and a Train-Li, both have thin flanges on the 2 "center" rollers.

Also these benders have contours on these 2 rollers to help avoid twist and keep the rails on the rollers.

The contouring of these rollers makes a big difference.

Greg
 
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Rhinochugger

Retired Oik
27 Oct 2009
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Yep - two things.

I had a single rail track bender which I didn't get on with, largely because of that issue, that all I did was painfully jam my fingers in the works while trying to curve the ends of the rails.

Which is why the belly bender is comparatively successful, as it provides similar success in curvature without inflicting pain on the fingertips :emo::emo:

Fortunately, I do not model a high speed mainline as Greg does - I model a typical narrow gauge, where track kinks add to the prototypical appearance and operation.

That is my excuse, and I'm sticking to it :punch::punch:
 
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trammayo

Interested in vintage commercial vehicle, trams, t
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In the "real" world, I found that using a Jimcrow wasn't good at bending the rail joints. Mind you, it was only BS20 rail and the bending implement would not bend much heavier rail!
 

Gizzy

A gentleman, a scholar, and a railway modeller....
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I brought a single rail bender for a tenner at a model railway exhibition in Bassingbourn a few years ago.

I think it was home made, and it has flanges on the rollers that fit into the slot on the side of the rail.

I've used it to make bespoke track panels in those 'awkward to join' places, to bend LGB flexi-track, and to re-radius curves as required.

I've also used it as a 'Straitener' on some curved ART track my late Father brought for me.

It's very simple to use and adjust to get the curve that you require.

I do however admire the work Darren has done on his double rail version....

20200906_164936.jpg
 
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DGE-Railroad

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I brought a single rail bender for a tenner at a model railway exhibition in Bassingbourn a few years ago.

I think it was home made, and it has flanges on the rollers that fit into the slot on the side of the rail.

I've used it to make bespoke track panels in those 'awkward to join' places, to bend LGB flexi-track, and to re-radius curves as required.

I've also used it as a 'Straitener' on some curved ART track my late Father brought for me.

It's very simple to use and adjust to get the curve that you require.

I do however admire the work Darren has done on his double rail version....

View attachment 275879
Thanks Gizzy. Love that picture!

I have to say, I had already bent pretty much all of my curves with a fan single track bender, kindly gifted to me by Rhinochugger. Although there's more work, with the single benders, I found it more rewarding and enjoyable :)
 

phils2um

Phil S
11 Sep 2015
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Nicely done! Just one more question - You're rollers appear to be splayed a bit. Is this real or camera lens distortion? If real, perhaps you can add some "beef" to the corners for better support of the roller axels and slightly modify the cross-members to add a bit more stiffness.

Agree with Father McD, if I didn't already have an Aristo dual rail bender I'd be tempted to buy a printer and beg for your files!
 
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DGE-Railroad

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Nicely done! Just one more question - You're rollers appear to be splayed a bit. Is this real or camera lens distortion? If real, perhaps you can add some "beef" to the corners for better support of the roller axels and slightly modify the cross-members to add a bit more stiffness.

Agree with Father McD, if I didn't already have an Aristo dual rail bender I'd be tempted to buy a printer and beg for your files!
Thanks for the kind words Phil!

I think the splaying is partly due to the lens on the phone and partly down to the fact that the moving bar warped during the print. I had huge difficulty in minimising the warping which occurred on the ends of some parts.

In the end I reduced it but couldn't eliminate it.

I may have another go at printing it once I put that filament back in the printer. I have since changed the material I use on the build plate and it's incredibly good. Its made a huge difference with the usual 'PLA' type filament so may well improve things with the PETG' stuff.

The bender itself certainly doesn't flex or bend noticeably :)
 

Greg Elmassian

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Here is the contour of the bending roller on an Aristo:


Not super sophisticated, but you see how it keeps from slipping,

Below is the Train-Li roller contour, more sophisticated:

 

Hutch

G Gauge, Raising Peaches, Apricots
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I have well used AristoCraft bender that has created easements into and out of curves and custom curves. The built in levels make it easier to keep me from twisting the track when forming it.

---Hutch
 

Greg Elmassian

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The twisting I was talking about is the individual rails being twisted during the bending process, the modified contours on the rollers are to control that.

From my experience, the Train-Li seems to control that better than the Aristo, although both work fine, and I have stainless steel rail, much tougher to bend than brass.

I gave away my old Llagas creek single rail bender, that was really a pain on SS rail... you had to bend each individual rail and then thread it back into the ties, once was enough.

Greg
 

Gtarling

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Newbie to both G scale railways and 3D printing here.:) Keen to use some of my stash of flex track in my under construction layout, I thought I'd have a go at making one of these rail benders. However, being an older git who's unfamiliar with Github, I'm a little confused as to how to download the .STL files that I need. I've clicked on just about everything I can, but still haven't managed to download the correct files. Would someone please be kind enough to point me to the correct link to click on? Many thanks in advance.

Gordon
 

DGE-Railroad

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Hey Gordon. Welcome aboard!

I'll do my best to describe. Just above the list of files on the page, there's a green button which says code. Click on that and it will open up a dropdown menu where you can select 'Download Zip'

That will let you save off Pierre's collection of files to your computer.
You'll then want to extract the contents of that zip file to somewhere convenient.
Pierre has helpfully included lots of other stuff which you can peruse but is un-necessary. Go into the folder called 'STL'
In here are the files you need. The one called 'Full Bed' contains everything which you can load onto your 3D printer. The other files will allow you to load individual parts rather than everything in one go.

You'll need to load them to the printer via something that can understand the .STL format and send the resultant 'GCode' (the relevant temperatures and postions) to your printer - typically the 'slicer' software that came with the printer.

A word of warning here.. The filament you use to print this is quite important since it needs to be as strong as possible. Your printer probably came with (or you bought) PLA filament. This is the most commonly used and friendly to work with. The filament used for this is a different type - PETG. You printer will be able to do it, you'll likely need to specifically buy a roll of this filament though. By all means print a copy in PLA first to see how it comes out and to do a 'dry run' but in order to withstand the forces of the bending, I suspect PETG will be needed.

PETG *is* a bit harder to print with. This was my first time trying it and I certainly had some bed adhesion issues which after Googling, seemed like a common theme.

Be guided by the filament specs if they're provided but for guidance, I made a new copy of my PLA printing profile and changed a few things to make it work for PETG;

I increased the extruder temperature to 245C
I increased the bed temperature to 80c
I used pritt stick on the bed
I dialed the cooling down to about 60%

Don't let that put you off. It's rewarding and totally doable. Keep us posted with how you get on!

I can post the list of hardware parts I used and links to them (all ebay) if it is helpful

Kind regards
Darren
 

Gtarling

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Grantham
Hey Gordon. Welcome aboard!

I'll do my best to describe. Just above the list of files on the page, there's a green button which says code. Click on that and it will open up a dropdown menu where you can select 'Download Zip'

That will let you save off Pierre's collection of files to your computer.
You'll then want to extract the contents of that zip file to somewhere convenient.
Pierre has helpfully included lots of other stuff which you can peruse but is un-necessary. Go into the folder called 'STL'
In here are the files you need. The one called 'Full Bed' contains everything which you can load onto your 3D printer. The other files will allow you to load individual parts rather than everything in one go.

You'll need to load them to the printer via something that can understand the .STL format and send the resultant 'GCode' (the relevant temperatures and postions) to your printer - typically the 'slicer' software that came with the printer.

A word of warning here.. The filament you use to print this is quite important since it needs to be as strong as possible. Your printer probably came with (or you bought) PLA filament. This is the most commonly used and friendly to work with. The filament used for this is a different type - PETG. You printer will be able to do it, you'll likely need to specifically buy a roll of this filament though. By all means print a copy in PLA first to see how it comes out and to do a 'dry run' but in order to withstand the forces of the bending, I suspect PETG will be needed.

PETG *is* a bit harder to print with. This was my first time trying it and I certainly had some bed adhesion issues which after Googling, seemed like a common theme.

Be guided by the filament specs if they're provided but for guidance, I made a new copy of my PLA printing profile and changed a few things to make it work for PETG;

I increased the extruder temperature to 245C
I increased the bed temperature to 80c
I used pritt stick on the bed
I dialed the cooling down to about 60%

Don't let that put you off. It's rewarding and totally doable. Keep us posted with how you get on!

I can post the list of hardware parts I used and links to them (all ebay) if it is helpful

Kind regards
Darren

Hi Darren,

Thanks so much for that - blindingly obvious when you know! So, I have it printing in PLA right now and then will have a crack at printing one in PETG. I have some PETG and have tried printing a part for a model boat with it previously - it printed fine (several times) but despite what I tried, it still warped itself off the bed and ended up too distorted to be usable. I'm using a glass bed which has a PEI sheet stuck to it and then given a coat of hairspray - tried Pritt stick also, with poorer results. When the PLA print is done, I'll have a crack with PETG, starting with your settings and take it from there. Your list of parts used would be most helpful if you don't mind posting it.
I do have to say that I'm a little puzzled by the PETG 'requirement' though, as all that I've seen and read on t'internet has led me to believe that PLA produces a stronger print than PETG, though it's a poorer choice in some cases.

regards

Gordon
 

DGE-Railroad

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No problem Gordon. It's hardly the most intuitive Is it? :D

Yes, the warping is the problem I had with PETG and seems to be the most common. I was able to reduce it substantially by turning down the fan cooling over the duration of the print and off entirely for 5 or so bottom layers. I didn't eliminate it though.
I plan to reload the PETG at some point in the coming weeks and will see if I can remove the warping completely. I printed before I switched to a PEI plate which may help me a little. Interesting to note it didn't eliminate it for you though.

Here are the list of parts I used for my bender. I was in a rush at the time so there is a mixture of stainless and non-stainless :blush:

4off F608ZZ 8mmx22mmx7mm flanged bearing @1.12 each - needed for corners
F608ZZ 8mm x 22mm x 7mm Flanged Shielded Deep Groove Ball Bearing | eBay

2off F688ZZ 8mmx16mm x 5mm flanged bearing @1.45 each - needed for bender arm
F688ZZ 8mm x 16mm x 5mm Flanged Shielded Deep Groove Ball Bearing | eBay


1off 5 pack of M4x50 button head screws hex socket flange bolts @ 2.00 - needed for bender arm bearings
M4 ( 4mm ) A2 STAINLESS STEEL FLANGED BUTTON HEAD SCREWS HEX SOCKET FLANGE BOLTS | eBay

1off M4 nut 10pack @ 2.18 - needed for bender arm through bolts and knob
M2 M3 M4 M5 M6 M8 M10 M12 Hex Full Nuts A2-70 STAINLESS STEEL - DIN 934 | eBay

1off M4x40mm bolt @1.00 for knob
Hexagon Head Bolt - Zinc Plated | eBay

2off M8x40mm bolt @0.98 for horizontal bearings
Hexagon Head Bolt - Zinc Plated | eBay

1off M8 nut 10 pack @ 3.61 for horizontal bearings
M2 M3 M4 M5 M6 M8 M10 M12 Hex Full Nuts A2-70 STAINLESS STEEL - DIN 934 | eBay

4off 608-2RS 8x22x7 bearings @ 0.92 each - needed for rail tops
608-2RS Bearing 8x22x7 Blue | eBay

1off 5 pack 10x1.1/2” (5.0 x 40mm) countersunk wood screws @ 1.35 for corner bearings
3.5mm to 6.0mm A2 STAINLESS STEEL POZI COUNTERSUNK CHIPBOARD WOOD SCREWS | eBay

It'd be well worth trying the bender in PLA I think. It seems a very well-designed object strength-wise, so would be worthwhile seeing whether it could work in PLA. That'd remove another hurdle to people making one. PETG seems to have a slightly higher density which I believe gives it an edge in the strength department. This density doesn't seem hugely bigger though - 1.27 g/cm3 v 1.24g/cm3 from what I could find.


All the best
Darren
 

Gtarling

Registered
26 Aug 2019
11
6
71
Grantham
No problem Gordon. It's hardly the most intuitive Is it? :D

Yes, the warping is the problem I had with PETG and seems to be the most common. I was able to reduce it substantially by turning down the fan cooling over the duration of the print and off entirely for 5 or so bottom layers. I didn't eliminate it though.
I plan to reload the PETG at some point in the coming weeks and will see if I can remove the warping completely. I printed before I switched to a PEI plate which may help me a little. Interesting to note it didn't eliminate it for you though.

Here are the list of parts I used for my bender. I was in a rush at the time so there is a mixture of stainless and non-stainless :blush:

4off F608ZZ 8mmx22mmx7mm flanged bearing @1.12 each - needed for corners
F608ZZ 8mm x 22mm x 7mm Flanged Shielded Deep Groove Ball Bearing | eBay

2off F688ZZ 8mmx16mm x 5mm flanged bearing @1.45 each - needed for bender arm
F688ZZ 8mm x 16mm x 5mm Flanged Shielded Deep Groove Ball Bearing | eBay


1off 5 pack of M4x50 button head screws hex socket flange bolts @ 2.00 - needed for bender arm bearings
M4 ( 4mm ) A2 STAINLESS STEEL FLANGED BUTTON HEAD SCREWS HEX SOCKET FLANGE BOLTS | eBay

1off M4 nut 10pack @ 2.18 - needed for bender arm through bolts and knob
M2 M3 M4 M5 M6 M8 M10 M12 Hex Full Nuts A2-70 STAINLESS STEEL - DIN 934 | eBay

1off M4x40mm bolt @1.00 for knob
Hexagon Head Bolt - Zinc Plated | eBay

2off M8x40mm bolt @0.98 for horizontal bearings
Hexagon Head Bolt - Zinc Plated | eBay

1off M8 nut 10 pack @ 3.61 for horizontal bearings
M2 M3 M4 M5 M6 M8 M10 M12 Hex Full Nuts A2-70 STAINLESS STEEL - DIN 934 | eBay

4off 608-2RS 8x22x7 bearings @ 0.92 each - needed for rail tops
608-2RS Bearing 8x22x7 Blue | eBay

1off 5 pack 10x1.1/2” (5.0 x 40mm) countersunk wood screws @ 1.35 for corner bearings
3.5mm to 6.0mm A2 STAINLESS STEEL POZI COUNTERSUNK CHIPBOARD WOOD SCREWS | eBay

It'd be well worth trying the bender in PLA I think. It seems a very well-designed object strength-wise, so would be worthwhile seeing whether it could work in PLA. That'd remove another hurdle to people making one. PETG seems to have a slightly higher density which I believe gives it an edge in the strength department. This density doesn't seem hugely bigger though - 1.27 g/cm3 v 1.24g/cm3 from what I could find.


All the best
Darren

Thanks for the list of parts, Darren. I've ordered what I didn't already have. I'll certainly give the PLA a try before I print one in PETG. Have you tried printing PETG onto what's termed as Painter's tape? I've not tried that yet, but planning to if I still have problems next time I try. I've also read that bed temp can be very important, so might be worth upping that a bit and giving it a try. I'll post here again when I have something worth reporting.

regards

Gordon
 

DGE-Railroad

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My pleasure Gordon. I look forward to seeing it. Yes, I tried painters tape too. It didn't seem to make a difference to me :) Pritt stick and 80c bed seemed about the best combination i could find
 

Gtarling

Registered
26 Aug 2019
11
6
71
Grantham
My pleasure Gordon. I look forward to seeing it. Yes, I tried painters tape too. It didn't seem to make a difference to me :) Pritt stick and 80c bed seemed about the best combination i could find

Hi Darren,

Well, my printer was busy all day yesterday, but I'm pleased to report that I now have a totally unwarped PETG print. I'm happy now!
Here's my setup for your info - Creality Ender 5 printer fitted with a Micro-Swiss direct drive extruder and all-metal hotend. Creality glass bed fitted and that has a self-adhesive PEI sheet from Banggood stuck on it. The PEI sheet is then given two coats of Tesco 'value' hairspray. Bed temp set to 85C, hot end to 240C, with first layer at 245C. Print speed is 50mm/sec and layer height of 0.2mm. Ensure your first layer is getting a good 'squish'. I tried Pritt stick on the PEI - didn't work for me. NO print cooling used and when print is finished, allow bed to cool to ambient before removing it. I've also just reprinted a part for another model with which I had three warped prints previously and have now got a perfect print of that part, too.

regards

Gordon
 
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