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moon47

Steel tube/bar bending and fabrication needed for prototype.

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Does any one know of any places that can bend small radius tube or bar?

 

I am designing a backpack and need a frame built out of 5-10 mm steel tube or rod.

 

Preferably a small shop because I just need one frame for now so that I can build and test the prototype.

 

 

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Better buy the bending tools yourself, they are cheap....those companies all can't spea inlit....

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I think you misunderstand this is not something that can be done with a hand tool from Home Pro.

 

This tool below would still be inadequate for what I need as there is no gauge for rotating the tube/bar while it is clamped in the die for calculating the next bend angle in regards to the last.

 

See the link below for US prices.

 

rdb10-manual-bender.jpg

 

These things are not cheap especially with steel die tooling.

 

http://www.trick-tools.com/HB1_Small_Diameter_Hand_Bender_Deluxe_Kit_DeluxeHB1_2294

 

They do not need to speak english just be able to do the job, I can speak Thai well enough to explain what I need.

 

Edited by moon47

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Dude there is nothing complicated about bending 5-10mm cold roll. There are calculations easily available online. I have several benders in the states, one of witch is a mandrel unit. It is all calculations and fitment. Radius of the die, angle of the bend, what plane, etc. 

 

For cold roll, literally any shop that makes gates can do what you need. And cold roll, you can take your drawing to any shop and they most likely don't need a bender at all. 

 

Do you have a diagram of what you are trying to fab? I can help. 

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I know it is not complicated however I do not have tools or a shop to work in.

 

I built one of these at school when I was back in the states and had access to a metal shop.

 

Below is a schematic with bends and two 3D models. One is half the frame that needs to be bent out of one piece of material. Then the two half are joined with couplings and held together by the tension of the pack itself.

 

The schematic linked here is for 3/8" aluminum as it was easier to bend for the prototype I made for my final project as it was just for demonstration and not actual use. The aluminum was way to soft for practical use and could have been easily bent out of shape.

 

The first frame is only a prototype so anyone could make it with the right tools. 

 

I will still need to find a shop that can do the work as I would like to make a small run of about 50-100 of these as well as a shop to do the sewing but those are all over the place and I can find that. Finding a shop to do the bending is not as easy as not everyone will have the tools to do this.

 

Schematic of the bends for 3/8" aluminum bar:

https://www.dropbox.com/s/t9n0lcnrsq4lz4u/Frame-02.png?dl=0

3D models:

Full frame couplings not shown:

https://skfb.ly/TFuL

Half frame:

https://skfb.ly/TFuF

Edited by moon47

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there are tons of metal shops at the  start of Chinatown , selling metal and making stuff

 

go to the start of Yaowarat Rd , where the traffic circle is ,  go on the left side of the circle and walk down some of those side streets,  dozens of shops on each street , plus nuts and bolts , bearings , pullys etc

 

Go to Google street view and have a look :)   Talat  Noi on Google map

 

good luck , let us know how it works out

 

 

Edited by BKKdreaming

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Ya, you can get these all over Bangkok. There are plenty of shops and companies that sell them but again I do not have a shop to set it up in and it is a waste of money as I will most likely only use it one or twice.

 

Once the prototype is built I do not plan to do my own manufacture and assembly. The prototype is only for testing and then demonstration to shops to get the manufacturing on a small scale started.

 

Thanks though... =]

 

I will probably take a stroll through China Town next week.

Edited by moon47

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On 9/26/2016 at 9:04 AM, moon47 said:

I know it is not complicated however I do not have tools or a shop to work in.

 

I built one of these at school when I was back in the states and had access to a metal shop.

 

Below is a schematic with bends and two 3D models. One is half the frame that needs to be bent out of one piece of material. Then the two half are joined with couplings and held together by the tension of the pack itself.

 

The schematic linked here is for 3/8" aluminum as it was easier to bend for the prototype I made for my final project as it was just for demonstration and not actual use. The aluminum was way to soft for practical use and could have been easily bent out of shape.

 

The first frame is only a prototype so anyone could make it with the right tools. 

 

I will still need to find a shop that can do the work as I would like to make a small run of about 50-100 of these as well as a shop to do the sewing but those are all over the place and I can find that. Finding a shop to do the bending is not as easy as not everyone will have the tools to do this.

 

Schematic of the bends for 3/8" aluminum bar:

https://www.dropbox.com/s/t9n0lcnrsq4lz4u/Frame-02.png?dl=0

3D models:

Full frame couplings not shown:

https://skfb.ly/TFuL

Half frame:

https://skfb.ly/TFuF

 

Ive been studying your sketches for a minute now, and the only variable that I do not see from your schematic is the Bend Allowance. I see what your end goal is, but you can achieve, for example, a 90 degree bend with any length of pipe. Im sure there are people that can deduce what your allowance will be, but the sketches should be clear in all variables. 

 

I will have a better look at it later, but its not that complicated if you want to use cold roll for the prototype. 

 

A simple Jig on a welders table and some hand made "dies" to form around should be enough. 

 

unspecified.png

Edited by Strange

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The bend radius is 1" on center for all bends (top) if that is what you are referring to.

 

Its at the top left view. 

 

Here is a better diagram in inches that describes just the right half from one bar as the other piece would be the same in reverse IE -90deg(270):

https://www.dropbox.com/s/8v1ec2uiz557lmr/Frame-02-inch.jpg?dl=0

 

And one in mm. Not scaled perfectly (by 25 not 25.4) to give better mm dimensions:

https://www.dropbox.com/s/zdzdzffr8osnhb1/Frame-02-mm.jpg?dl=0

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If you are referring to the length of the arc at the centerline I have not calculated those. These could easily be calculated with online tools from the radius, angle and material thickness.

 

When I made my prototype I just used a bar longer than needed and eyeballed the tangent lines then cut off the excess when I reached the end of the last segment.

 

That would be sufficient for the first prototype. It does not have to adhere to any tolerance it just needs to be close to the diagram and as close to mirrored as possible on both right and left pieces.

Edited by moon47

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I found plenty of shops that sell raw material in Chinatown (Yaowarat) but none with the tools to do bending, and that is what I expected but I thought it was worth the effort to look just incase.

 

I will be trying Samut Prakan later and I am sure there is a shop there that can do the work. However the area is so big and there are so many shops that specialize in different types of manufacture that it is a heavy task to find the correct one. Virtual needle in the haystack. And there is allot of hay down there... =]

 

If any one is familiar with the area some advice on where to start would be helpful.

 

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If you can hold out another few weeks, this is probably a good bet to find anything having to do with fabricating metal in Thailand.  METALEX

 

Several spring benders usually exhibit and their machines can make anything out of steel rod and tube.  

 

http://www.bitec.co.th/events/the-grand-metalex-2016.html

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I have already registered however I expect most of these companies will only take orders in quantity. I will be going to source production facilities. 

 

What at I need right now is a small shop with a tool like I posted above to do one or two of these. 

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