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Tent Prototype

January 3rd, 2019, 3:54 am

mcpbowman
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Hello everyone,
I am looking to create a prototype of a tent like product and was wondering if anyone on here had experience in creating one?

I have the frame made up from existing tent poles and have butchered an existing tent to fit the frame but I would really like to get working on a more refined prototype. I was thinking that as I have the frame sorted out I could buy sheets of fabric, cut out the flat templates for each side and sew them together, but I just thought I'd ask for any advice before I start :)

The prototype doesn't need to be waterproof or anything, its more for nailing down the aesthetics at this point.

Thanks in advance!

Re: Tent Prototype

January 3rd, 2019, 7:56 am

iab
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While it could drive up the cost of your prototypes, I'd use your intended end material, which I would guess is a urethane-coated ripstop nylon. The reason being is all materials sew and stretch differently and you need to learn a lot about those characteristics earlier rather than later. How your cheap cotton muslin looks on a frame will be different from the nylon.

Re: Tent Prototype

January 3rd, 2019, 10:45 am

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louis leblanc
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As iab mentioned, different material properties might lead to a significantly different shape. Besides stretch, I would also be worried about the weight of the material. Especially as you're dealing with a flexible frame. Depending on your experience doing this and the complexity of the product, you might want to work your way up to your final material. You might want to pick a material that's cheap, easily available and easy to work with for a first stab and then make your way up to a final pattern in the intended material.

I design tensile structures in my day job. We can often go from CAD to production, simulation and computational tools help us there. We'll often test things out when we're unsure with cheap materials to get a feel for things. Though in our case messing up is easily measured in thousands of dollars of material and labor...

Re: Tent Prototype

January 4th, 2019, 9:16 am

mcpbowman
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Thank you both for your input.
My plan was to get the flat templates in a cheap material and then work with some to create a net from the final material after that. I completely get what you are saying about the different material properties and the impact they could have on the design. I'll see how much the difference is in cost of material and make a decision from there.

Out of interest Louis, what sort of CAD package do you use to design the tensile structures? I presume there are specific packages created to do this.

Re: Tent Prototype

January 6th, 2019, 9:07 pm

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louis leblanc
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Well tensile structures is a bit of a shortcut :P . Really, we design rope based playground equipment!

Image

While we share a lot of the problems of tensile fabric structures which mainly revolve around morphing an idea for a surface into a surface that can hold its shape only through tension. The term for the process is form finding if ever you want to read up on it. We run into all kinds of trickier problems as we're not building the surface out of fabric but out of individually placed ropes. We also have all kinds of safety requirements for how the ropes get placed, for example, we can't have an angle more acute than 55deg pointing up as that is a neck entrapment (asphyxiation) hazard, our connectors only allow for the rope to join at specific angles, and the list goes on...

As far as our tool-set goes. Most of the modelling is happening in Rhino. There are tools specifically for tensile fabric but they don't really generalize to what we're doing. To that end, I had the awesome opportunity to build up our in house computational tools which are mostly in Grasshopper.

Re: Tent Prototype

January 8th, 2019, 3:41 am

mcpbowman
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Thank you so much for the detailed reply! Ill definitely read up a bit more on form finding.
That sounds like a great job, I also love hearing about all the different constraints and considerations that go into products that people pass by every day and don't even think about the work that goes into them (maybe that's sad but who cares :P).

I've never used Rhino, I've only used Solidworks and NX so I'm struggling to properly simulate fabric but I'll look into it, thank you!

Re: Tent Prototype

January 9th, 2019, 2:18 pm

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FH13
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Your process seems correct. Buy cheap fabric and make your own flat patterns and sew/glue/staple yourself.
You'll probably do a few iterations learning from the previous one.
Once you are happy, then find a professional seamstress/pattern maker that can take on the project with your direction and their knowledge. I've done a few projects where I've had to sit with the seamstress/pattern maker for a few days getting details right and figuring out changes based on their expertise.

Re: Tent Prototype

January 11th, 2019, 6:48 am

mcpbowman
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Thank you FH13. I'm excited to get started on it and hopefully taking on board some of their knowledge!
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