A Bender for Arch Bars

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, cbrew

Brian Hilgert
Posts: 232
Joined: Mon Jan 21, 2013 8:35 am
Location: Pittsburgh, PA

Re: A Bender for Arch Bars

Postby Brian Hilgert » Tue Nov 21, 2017 10:29 am

That is a nice design! Sure beats the way I did the arch bars for my shay!

Thanks for sharing the drawings!

User avatar
Greg_Lewis
Posts: 1395
Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: A Bender for Arch Bars

Postby Greg_Lewis » Tue Nov 21, 2017 10:49 am

A slight cut into the bar at the bend point with a hacksaw will insure that the bend happens at the exact spot you want, and will give a nice sharp bend. Such a cut is unlikely to compromise the strength of the bar considering the forces applied to the truck, but you can fill it in with silver solder, which is what I've done.
Greg Lewis, Prop.
Eyeball Engineering — Home of non-interchangeable parts.
Our motto: "That looks about right."
Celebrating 30 years of turning perfectly good metal into bits of useless scrap.

Soot n' Cinders
Posts: 627
Joined: Wed Jun 27, 2012 5:24 pm
Location: Marietta, Georgia

Re: A Bender for Arch Bars

Postby Soot n' Cinders » Tue Nov 21, 2017 11:33 am

Brian Hilgert wrote:That is a nice design! Sure beats the way I did the arch bars for my shay!

Thanks for sharing the drawings!


I agree! The shop press bent the bars easily but some of mine got a little off so required some banging and prying to assemble. I’ll definitely give this idea a go when I start making rolling stock archbars.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

jeffsmith
Posts: 48
Joined: Fri Jul 06, 2012 11:33 pm
Location: Mead, Colorado
Contact:

Re: A Bender for Arch Bars

Postby jeffsmith » Tue Nov 21, 2017 12:12 pm

You might think about adding a set screw on the die block. I have found that no matter how tight the fit between the two blocks the force of bending the arch bar can make it slide from its original position giving inconsistent bends.
Just a thought.

Jeff Smith

BClemens
Posts: 301
Joined: Sat Oct 08, 2016 10:04 pm

Re: A Bender for Arch Bars

Postby BClemens » Tue Nov 21, 2017 1:07 pm

jeffsmith wrote:You might think about adding a set screw on the die block. I have found that no matter how tight the fit between the two blocks the force of bending the arch bar can make it slide from its original position giving inconsistent bends.
Just a thought.

Jeff Smith


Center the die block and bend two angles at the same time...

User avatar
Pipescs
Posts: 1796
Joined: Wed Feb 03, 2010 10:16 pm
Location: Lester Alabama

Re: A Bender for Arch Bars

Postby Pipescs » Tue Nov 21, 2017 10:51 pm

You might think about adding a set screw on the die block. I have found that no matter how tight the fit between the two blocks the force of bending the arch bar can make it slide from its original position giving inconsistent bends.
Just a thought


I discovered this too. As you say when trying to bend the 1/4" x 5/8" bars it tends to move no matter how tight the bolts.

My thought is to cut a rabbit about .0625 deep for the die block to sit down into the plate giving it a stop to go against.

I will try it this weekend.
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

User avatar
Pipescs
Posts: 1796
Joined: Wed Feb 03, 2010 10:16 pm
Location: Lester Alabama

Re: A Bender for Arch Bars

Postby Pipescs » Wed Nov 22, 2017 5:34 am

I am thinking along these lines

Base.JPG


Bender Assy.JPG
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

BClemens
Posts: 301
Joined: Sat Oct 08, 2016 10:04 pm

Re: A Bender for Arch Bars

Postby BClemens » Wed Nov 22, 2017 7:35 am

Charlie,
Since you have drilled the arch bar blank material for the bolster pedistals, use the holes on dowel pins or bolts through the clamp blocks to assure the bends are the same distance from each hole when you turn the blank over to do the other end. Add a hole through the anchor blocks and slide a dowel pin or bolt through them with the blank between them. You may need to relocate the outer bolt holding the bend block in its seat slot.
Down and dirty 'out of perspective' sketch:
Attachments
Arch Bar Bender.jpg

BClemens
Posts: 301
Joined: Sat Oct 08, 2016 10:04 pm

Re: A Bender for Arch Bars

Postby BClemens » Wed Nov 22, 2017 8:54 am

ArchBarBender.jpg

User avatar
Pipescs
Posts: 1796
Joined: Wed Feb 03, 2010 10:16 pm
Location: Lester Alabama

Re: A Bender for Arch Bars

Postby Pipescs » Wed Nov 22, 2017 9:37 pm

This is an interesting approach.

My drawings are a little misrepresenting as I am planning on using the fixtures to drill the holes after bending.

You method would definitely have merit.

I did this tonight before running off to church. it is a stop guide attempt. I also swung by the steel yard to get a piece heavy wall tubing to make a cheater bar for the bending arm.

DSC_5051.jpg


DSC_5052.jpg


DSC_5053.jpg


Out of curiosity. is your drawing in Solidworks?
Charlie Pipes
USMC Retired

Current Projects:

2.5 Baldwin 2-4-2/2-4-4/0-4-4 Conversion (What ever)
Little Engines American Restoration
Bobber Caboose

BClemens
Posts: 301
Joined: Sat Oct 08, 2016 10:04 pm

Re: A Bender for Arch Bars

Postby BClemens » Wed Nov 22, 2017 10:38 pm

Keycreator - it doesn't like being converted to a jpg. Stops are a good thing.

BClemens
Posts: 301
Joined: Sat Oct 08, 2016 10:04 pm

Re: A Bender for Arch Bars

Postby BClemens » Thu Nov 23, 2017 7:54 am



Return to “Live Steam”

Who is online

Users browsing this forum: 765nkp, rrnut-2 and 12 guests