What’s Under That Trap Door?


I thought I would show a tool I have made which is interesting to me, and probably to all other gear heads out there. 

It is a mechanical bender which is made into my main worktable. 

I came up with the idea after a friend showed me a power reducer attached to a tool he had made for his shop.

That got me started thinking of how I bend curves.  I use a jig that is simply two pieces of different size pipe welded to a piece of U channel.  It has served me well for a long time. Many a hard piece of steel has given way to the power of this tool. 

But now that I had seen a new device (new to me at least), I wanted to come up with a funner way to do the bending.

What better way than inventing and making a cool tool.

Some of you may wonder what is so cool about making a new tool.  Well what is so fun about going shopping?  What is so fun about playing basketball?  What is so fun about _________(fill in the blank with our thing).  It’s just fun to do.  We all stand around and talk about ideas and whats and wheres.

Then the hunt for the parts.  Most of us don’t have the cash to just go out and buy all the parts for a project so the scrounging and Ebaying is just part of the deal.

Finally the building starts!

The worktable I put it into was another self made project.  This one is designed after one made by Steve O. and with his help.  It has wheels and can be raised and lowered to contact the floor or be on the wheels.  Great design Steve!   I love the table and thought if I put another tool in it, it would have to be one that did not interrupt the useful design of the table.

3/4 hp/ 117-1 reducer

So the bender was going to completely concealed under the table.  I cut a 4 inch square in the center of the top for the power unit to come through.  The “trapdoor” was replaceable so the table stayed intact.

I had located a power reducer which changed 1750 RPMs into 11 RPMs.  So there was a lot of torque. It had face mount which made mounting

to the motor a breeze.  In no time I had one of those motors in my shop and it worked perfectly.  It was only ¾ hp but the reducer would give it a lot of power.  

All those pieces were bolted together and the power unit was ready to go.

I then made a pretty stiff bracket to hold the unit to the bottom of the table.  Most of it bolted on so I could take it off if needed. 

The real tough questions were 1) how is the unit going to connect with the bender dies?   2) how are the bender dies going to be made?

Another conversation with Steve O. landed the information needed for the attachment.  He suggested we take a piece of six sided stock (I am sure there is a real name for it but I don’t remember) weld it to the top of the reducer thus allowing a 1 ¼ inch deep well socket to drop down over it and hold the parts together.

Then I moved on to designing the dies for the top of the unit. 

I found some pipe of different diameters, cut them into pieces about 3 inches long and made mounts for each one. 

1 1/4 socket welded to each


the collection...so far


After about an hour of trying to wire the footswitch (so I could use both hands on the metal) I contacted another friend (who is a lot smarter than I when it comes to electricity) and he quickly adjusted the situation to make it work.  I then talked him into wiring the 2 way directional switch too.   

So now when I want to make a bend all I have to do is select the right size circle, place it on the unit, and step on the switch. 

It works great! 

And was a fun project to build. 

That’s what it’s all about.



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