Building a Flat Top Bender

[astroracer]

I purchased a HD bender from SWAG a couple of years ago. It works in my hydraulic press. SWAG also sells what they call a flat top bender that just sits on top of the big bender or it can be used by itself. It's a piece of 5/8" X 6" X 19 1/2" steel plate with a couple of 3/8" x 3" x 19 1/2" plate that bolt to it. The thinner plates are slotted so they can be adjusted in and out. This will allow for much sharper bends in thinner stock then the big bender does. SWAG wants 120 dollars for their bender. I figured I could make one similar for a lot less.
I called my local steel supplier for a quote on a piece of 5/8 plate to make the base for my bender. Uncommon size, didn't have any in stock. Would cost 70 bucks to order it... Hmmm, not very cost effective. I asked about 3/4" and they had plenty of that! A 6" inch wide piece that was plasma cut on one side was 20 bucks! Perfect! I had a 6" wide hunk of 3/8th's in the rack so I took that with me. They sheared the 3 /8ths to length and split it down the middle for me and I walked out of the shop with everything for 30 bucks...
Here is the piece of 3/4" set up in the drill press.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-45.jpg
After drilling the four corner holes to 27/64th's I clamped the plate up on the fab table for tapping the holes for 1/2-13.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-46.jpg
Tapping the holes. I use Tap Magic cutting fluid for all of my drilling and tapping. Makes a HUGE difference. Took about a half hour to tap all four.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-47.jpg
All tapped and cleaned up. I ran a chamfering bit into the holes after tapping and cleaned up the plate with a flap disc on the 4" grinder.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-48.jpg
Tomorrow I'll work on the two "bend" plates. Getting them set up in the mill and cutting the slots.
Mark

[andrewb70]

Nicely done.

Andrew

[astroracer]

Thanks Andrew! The upper plates didn't turn out "quite" the way I was planning but it will work fine. My little lathe/mill combo wasn't up to the task of milling the slots... I just couldn't keep the plates stable enough to keep the end mill from wandering.
This is my initial attempt at milling the slots. This got ugly real fast... You can see how the mill was trailing off and wandering.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-49.jpg
Not good. I gave up and trimmed off the holes. I cut them down and will use them as "washers" to clamp the plate to the base.
After getting everything trimmed and cleaned up.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-50.jpg
The washers will work alright for now.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-50.jpg

https://static1.pt-content.com/images/pt/2014/03/ry3D400-51.jpg
I laid a centerline on the base. It's not really necessary but I'll use it to align the two benders. I can set the width of the plates using a piece of tubing or any thickness stock for that matter.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-52.jpg
I'll have to experiment with the gap to determine what works for specific bend angles.
Mocking the benders up. This is the SWAG bender.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-53.jpg
With the flat top bender loaded.
https://static1.pt-content.com/images/pt/2014/03/ry3D400-54.jpg

https://static1.pt-content.com/images/pt/2014/03/ry3D400-55.jpg

This will work okay for now. I have a few ideas to try if I make another one. I have plans to pick up a "real" mill. a co-worker has a "frankenmill" he wants to sell. I have looked at it and committed to buy it. THAT would let me do some of this machining I am unable to do now.
Mark