[delraydella]

I'm looking for some opinions on how to resolve a slight manufacturing problem. It's not really a welding problem, but i value the opinions of the many forum members here.

As some may know, I sometimes make hardware and fixtures for the entertainment industry and my latest project is called a Bailin Bracket. These are used by movie lighting grips to hold 2x wood stock for hanging lights, scenic backdrops, etc in places where they couldn't normally hang these things. It's nothing more than a chopped off 2 x 6 rectangle tube with a fixture pin welded on to it. About $5.00 in steel, 5 minutes on the lathe , 2 cuts on a band saw and a weld...... and they retail for over $57.00 each! Nice markup!

My problem comes when i cut the top off of the 2 x 6 piece of rectangle tube. i get a slight curl on both edges. The 2nd picture below shows the amount of curl. I want to straighten it purely for cosmetic reasons.

What would be the best way to straighten these?

[WerkSpace]

Manufacture two tools from metal bar stock. Each bar will have two roller bearings (spaced apart).
Use both tools simultaneously, by placing a bearing on either side of the metal to be bent.
Hold the metal part in a vise and apply just enough force to bend the metal to the desired shape.

To avoid warping metal, try using coolant when cutting it.
Lower temperatures save both the cutter and the metal.

[Alexa]

Delraydella.

Carbon steel with a slight distortion.
If both 'edges' are distorted, you might simply slide bar (approximately 2" x 2" x 6") into the center of the piece, and clamp down both sides to remove the deflection.
You should be able to remove the distortion without difficulty.

Also Werkspace's suggestion would probably work just fine.

How many of these do you need to fabricate?
If many, then perhaps you could prepare a jig to speed things up.

Alexa

[weldin mike 27]

Hey,

All I would do is to get a bit of round bar that fits snuggly in through the cut section, weld it to an vertical surface so that it was just high enough off the bench to clear the thickness of your part, the slide the part in and give each high corner a crack with a soft headed hammer. The round bar will hold the centre solid whilst allowing the corners to move.Maybe..

Mick

[Otto Nobedder]

So, is this 3/16" wall rect. tube, with a desired inside dimension of 1 5/8" for 2"X dimensional lumber?

Are you looking at making enough of these to build a reliable, repeatable fixture that can perform quickly? I'm developing an idea (my mind is a bit like MS Windows... Stuff like this runs in the background ) that would work well for this format, so let me know if that's the goal, and I'll share the details.

Steve S

[delraydella]

Steve,

The wall thickness is 1/8th inch, so there is plenty of slop for 2x lumber. I wouldn't have a problem going with a thicker wall, but I'd be concerned about the weight of the piece.

I'd start with an initial run of about 30,see how they sell, and then go from there. I doubt i would ever make more than a few hundred but you never know. This doesn't seem like very many, but I'd like to hear your fixture idea. The bracket I bought and modeled this off of has the same amount of curl, so i'm not the only one having this problem.

Other Steve

[Otto Nobedder]

Y' know what I said about MS Windows, and running in the background?

I've come up with a good reason to leave them as they are.

The slight curl causes these "Bailin Brackets" to "bite" into the wood at each edge, providing a strong friction grip, resisting twist. To flatten them completely is to present smooth surfaces to each other, possibly increasing the chance of "slippage".

Ignoring that, as it's speculation, I'd cut a block of hardwood (white oak?)to the 1 5/8" of dimensional lumber to fit the block, and radius out with a grinder a curve on each side (estimating 7/16") to center in the bracket. Each bracket would have this block inserted, then mashed in a press (with a broad head and foot block) to press out the curve.

I'm sure I can explain this more clearly, if needed... The program's still running in the background.

Steve S

[delraydella]

I never thought of the curl being used for a friction type grip and that does make sense to do it that way, but there is quite a bit of slop in these, even in the sample i'm working off of. If you look at the very top picture, there are three holes drilled in either side of the bracket for screws to hold the board in.

I think i'm going to try Werkspace's idea first. I'll probably adjust it a little by making the inner bearing slideable to change the amount of torque if need be. But if it gets to be where i'm making a lot of these things, a press would work very well here.

[Otto Nobedder]

I can't argue at all with WerkSpace's idea for a small run.

If the fit is as sloppy as you say, though, consider the 3/16 wall tube I mentioned... With a 2" outer dimension, this gives you a 1 5/8" inside dimension, just snug for finish-grade dimensional lumber. The up-cost won't be much, since you seem to be a perfectionist.

Steve S

[delraydella]

And if anybody is wondering why it's called a " Bailin Bracket"............I have no idea why! Probably the first guy to think of it was named Bailin?....For some reason lost to time, movie grip equipment is named like that. None of the names of the multitude of pieces are very descriptive of what the thing actually does.

[Alexa]

Delraydella.

Out of the many definitions of the word "bail", the two that seemed plausible were the following, which invites 'Old English' and/or Scandinavian origins.
See link:
http://www.thefreedictionary.com/bail

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bail 3 (bl)
n.
1. The arched hooplike handle of a container, such as a pail.
2. An arch or hoop, such as one of those used to support the top of a covered wagon.
3. A hinged bar on a typewriter that holds the paper against the platen.
4. The pivoting U-shaped part of a fishing reel that guides the line onto the spool during rewinding.
[Middle English beil, perhaps from Old English *bgel or of Scandinavian origin; see bheug- in Indo-European roots.]

=====

bail4, bale [beɪl]
n
1. the semicircular handle of a kettle, bucket, etc
2. (Engineering / General Engineering) a semicircular support for a canopy
3. (Engineering / Mechanical Engineering) a movable bar on a typewriter that holds the paper against the platen
[probably of Scandinavian origin; compare Old Norse beygja to bend]

Tanks.
Alexa

[dkennett]

You could make the device fail-safe by cutting out one side of the tube leaving a flange on both the top and bottom wide enough to insert the 2X6 and allow it to slide down and lock itself in. Screw/bolt holes would be provided for additional safety and to prevent lateral and up and down movement. This assumes that the load is not too heavy for the tube weakened in this manner.

Also, fabricating the device in this manner would facilitate setup easily accomplished by one person in overhead bracket situations-the brackets could be positioned in the truss before inserting the 2X6 beam into the bracket. This could be easily done by one worker and would avoid alignment to truss difficulties with pre-positioned brackets. ie, hang the brackets, insert the beams and retain to bracket with a single wood screw.

[delraydella]

That does sound like a pretty good way to make them. The way they are used now, there are two of them on either end of the length of the 2x 6. The pin fits into a holder on a height adjustable stand so everything is loaded at waist high and raised to whatever height is needed.

There's another piece called a Crowder Hanger that does have an adjustable bolt to tighten the lumber into the bracket. See picture below.