sheet metal benders

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

BD5builder

Well-Known Member
Joined
Jul 29, 2005
Messages
102
Location
Greenville, SC
I've been lookin at a few websites for a nice, yet fairly inexpensive sheet metal bender for my BD5 project. The problem is, all of the ones i've seen that are less than $300 have no provisions for bend radius's. How are you all bending your sheetmetal parts w/ the correct radius's? Are you members of a eaa chapter and that chapter has a bender and brake, or did you purchase a cheaper bender and make a piece of material w/ your own radius on it?
 

M51

Active Member
Joined
Apr 14, 2005
Messages
27
Location
MI
I find it a basic neccessity to have at least a "48 adjustable brake in my shop. Picked up a surprisingly decent brake from Northern Tool on sale for around $400 a while back. I'm scratch building a sheet metal plane though, so it really gets a lot of use. For a kit aircraft a local EAA source or machine shop could work out if you only have a few parts to bend. Depends on your situation, but I would highly reccommend just biting the bullet a buying one if you do have a lot of parts to fabricate. For me, it's been more than worth the initial price.
 

Captain_John

Well-Known Member
Joined
Feb 3, 2003
Messages
699
Location
KPYM
You could do it like we RV builders do it.

We make wooden brakes.

Two by sixes or eights on hinges with threaded rod to compress them works very well!

Put a 1/8" dowel inside the trailing edge to keep from creasing it. It forms a nice radii!

:D CJ
 

BD5builder

Well-Known Member
Joined
Jul 29, 2005
Messages
102
Location
Greenville, SC
M51, I would love to have on of the more expensive ones, but shop space doesn't allow it. I'm going to be building this thing in a 1 car garage that already has a good bit of shelve's and crap in it, and a 4'x16' table.



CJ. thats a pretty good idea. I was lookin thru the harbor freight freight catalog yesterday, and they have a 30" bender for less than $50 so i was thinking of getting that...

one question though, how do you keep the wooden dowel from moving up when you try to bend it... is there a notch in in the 2X6 that holds the dowel, or do you just clamp the dowel down with a C clamp?
 
Last edited:

Jman

Site Developer
Joined
Oct 22, 2002
Messages
1,881
Location
Pacific NW, USA!
CJ,

I too am interested in the brake you mentioned. Do you know where there might be some drawings for this? I've got a few small parts to bend and would like to keep it as cheap as possible but a bit more precise than pounding parts with a hammer. Thanks.

Jake
 

Captain_John

Well-Known Member
Joined
Feb 3, 2003
Messages
699
Location
KPYM
No plans guys. No real magic either.

This is how an RV skin looks before we bend it. It comes with the initial "crease" in it like this:



We install the stiffeners, prime and yada yada.

Then we stick it in the brake.



Here is a cross section of the brake:



Gravity holds the dowel in place. We start off with the clamps, but to deliver the needed pressure, 1/4" theaded rods are tightened as we compress the control surface.

Will that work for you?

:cool: CJ
 

BD5builder

Well-Known Member
Joined
Jul 29, 2005
Messages
102
Location
Greenville, SC
CJ,
that looks like it works really well.. but i've got a few pieces of .020, .032 and .125" material that i have to put bends in that range from 15 degreess all the way to past 90 degree's..
 

Captain_John

Well-Known Member
Joined
Feb 3, 2003
Messages
699
Location
KPYM
That is 0.032" material. I don't doubt that it could finish off a 0.040", but the .125" would be out od the scope of this tool.

George, the initial bend would have to be done in another type of bender, for sure. This tool is just for finishing off the last few degrees to get a nice straight trailing edge.

:whistle: CJ
 

BD5builder

Well-Known Member
Joined
Jul 29, 2005
Messages
102
Location
Greenville, SC
yea i figured that wouldn't work for .125 material..

but what about for making 90 degree bends of a correct radius using a dowel and not having to worry about the dowl moving and the bend occuring at the top clamp piece.. i guess a piece of 2x2 of so w/ an 1/8" radius routed on the edge is about the only thing that i can think of.
 

M51

Active Member
Joined
Apr 14, 2005
Messages
27
Location
MI
Originally posted by BD5builder
M51, I would love to have on of the more expensive ones, but shop space doesn't allow it. I'm going to be building this thing in a 1 car garage that already has a good bit of shelve's and crap in it, and a 4'x16' table.
Actually I think I bought my brake from Enco (sorry it was a few years ago). The link below shows some lower priced "48 adjustable finger brakes starting at about $300. These have stands available for them (look below the brake picture for the link to the stand that fits the lowest priced brake at the bottom). I have limited space as well, and used this stand with heavy duty locking casters on the legs. Can wheel it around out of the way very easily.

http://www.use-enco.com/CGI/INPDFF?PMPAGE=461
 
Last edited:

Captain_John

Well-Known Member
Joined
Feb 3, 2003
Messages
699
Location
KPYM
BD, you could make a similar brake for 90 degree bends.

I am thinking... get some good, straight wood. Form a right angle with the lumber and force a third piece into the wedge with threaded rod.

Kinda hard to explain, but if ya know whattamean...

:gig: CJ
 

BD5builder

Well-Known Member
Joined
Jul 29, 2005
Messages
102
Location
Greenville, SC
M51.. thanks for that link i might just go with one of those if i can't find anything else to fit my needs.


CJ,
are you talking about something like this?

 

BD5builder

Well-Known Member
Joined
Jul 29, 2005
Messages
102
Location
Greenville, SC
Jake,
I actually just drew that up on MS paint in about 5 minutes before i posted it LOL.

pretty much all it is, is 3 pieces of Nice flat 2x6's or 2x8's ( or possibly a few pieces of 3/4" MDF glued and screwed together). then with a pair of door hinges (1 at each end) and then 2 holes drilled drilled between 2 of the boards and a theaded rod and nuts on each side to clamp the bending piece between. Also the top part you could get a router and a 1/2 round routing bit of the correct radius (if they even make any close enough for aircraft bends) and do that on one corner of the top board to give you the correct bend radius. Then bolt one of the part of the "hinged" boards to your building table (w/ the mounting bolts countersunk into the bottom of the hing board. and then attach a 2x2 or similiar material as a handle.
 

iker

New Member
Joined
Sep 17, 2005
Messages
4
Location
North Dakota
I could tell you how most of the US Air Force sheet metal troops get the correct radii with a brake. Quite simply we have to make our own radius bar nearly every time. This is beacause no one ever really takes the time to order parts for the brake.

The way to accopmlish this is to start with a regular brake that has sharp feet. Then take strips of aluminum that are 2" wide by what ever lenght your part that needs to be bent is, and clamp them in the brake. Then bend until it is maxed out. Now you have a radius bar and adding additionial pieces of aluminum will increase the bend radius. All you have to do is to move the feet back to accomidate the aluminum strips. Also it helps to tape the strips to the feet to make it easier to insert the workpiece.
 
2
Top