Sewing cad software?

[Sam Farrington]

Roger,

I did not mean to imply that you were showing off; just that with the time available, a re-education in software would not be time saving.  If that implication came across, I apologize.  I expect you will resolve the issues you mention, all in good time.  But it’s the time issues that prevent me from embarking on new paths, as long as the old paths suffice.

[Roger Caffin]

Hi Sam

Complete misunderstanding! I was pre-empting any other comments, by others. Yes, I was showing off. I was not addressing any of your comments; I was a bit hampered in writing at that stage.

The lack of a JPG to illustrate appears to have been a problem with a network cable – a rather intermittent cable, from my desktop to the modem/router. It has taken me WEEKS to sort out the problem – if indeed it has been sorted out. I have replaced the whole cable; so far so good. Basically, it seems that the network was TRYING, but with <1% packet success rate!

I (cheat and) use Excel for the design. It took me in excess of 6 months to get the first version running somewhat, and probably another 6 months to get it running nicely. This shows on of my tunnel tents.

What I meant to add to my posting (but the network problems intervened) was that trying to emulate my SW would be a monumental task – and note that I have a PhD. Never mind: one can generate pretty pictures and patterns for tents, but I do not recommend that path.

One of my ‘customers’ actually took a different path to pattern generation, one I can recommend.

Cheers

[Sam Farrington]

Hi Roger,

Your last photo suggests that your ‘customer’ is going with just three of the elbowed poles,  The use of the frame in the photo is more like what I meant by ‘tailoring,’  and is similar to ones seen a few times on your FAQ section of the Aussie website.

But have learned that using flexible poles, some tent designs can change the shape of the flexible poles when the fabric is tightened over hoops or gothic arches.  So must tailor the canopy over the flexible poles to be sure that the fabric has the right bias stretch, size and shape to be taut.  Scale models can provide some idea, but only if the flex of the music wire representing the poles bends to the same extent as the carbon poles on the full size pole framework.   As it works out, the additional bend of the poles adds a few more inches of deflection that make the the canopy walls more convex, hence the tent is more spacious inside.

That may sound like the tent does not maintain its shape in wind, or is ‘floppy’; but in practice the canopy fabric actually works in conjunction with the pole framework to make the structure more rigid.  Just requires more work to get the dimensions right.  Never thought things could get this complicated, but life is for learning.

Expect you and MYOG fans have seen the repeated pix of the canopy prototype, so won’t add yet another picture.  Am also bogged down with trying to find a superlight fabric that will be competitive with DCF.  Only because DCF may not be having a come back, and want to do a tent that folks can make with fabric that is readily available, and yes, reasonably priced.  Those efforts are reported on the Gear forum in a recent thread about issues with DCF.

After my late cousin went into a nursing home, he passed on to me the work he was doing on writing the family history, work that was earlier begun by my late aunt.  My efforts waned, the project suffered, and it is now probably with the family heirlooms.  Hope the tent does not suffer the same fate.

[Roger Caffin]

All understood.
In fact, I think that what that guy made was a tent with straight poles. He sent me a photo.
Naturally, a tent with straight poles would not be as strong as one with flexed poles. But that was his choice.

Life is complex.
We have two PCs going through a modem/router to a broadband antenna. Mine has been having all sorts of drop-outs, while my wife’s PC seems to be fine.
So I replaced the ethernet cable from my PC to the router: took me most of the day. Aha – everything worked fine!
For 6 hours.
So I changed the port my cable was plugged into. Aha: working.
I await the morning to see what is happening.

Complex.
Cheers

[Sam Farrington]

Yay!  Good to hear that.

By straight poles, guess you mean alloy ones with minimal flex.  Or maybe he changed the frame.  Your elbowed hoops are unique, so never sure what to call them for short.

[Roger Caffin]

I think he bent the elbows so the poles were not curved. You can do this, but I don’t think it is nearly as strong.

Router: complex. SW inside seems to have a few bugs. I THINK it loses track and forgets to send some ACKs, so the other end stops and waits for them.

Cheers

[Sam Farrington]

OK, understood now.  If the pole sections between the elbows have virtually no flex, they must be quite heavy, though.  Nothing that would appeal to those seeking  ‘SUL’ shelters.  So it is heartening to hear that you think the more flexible poles can produce a tent that is more structurally strong.  And much lighter, I would add, especially with best quality carbon poles.

“I THINK it loses track and forgets to send some ACKs, so the other end stops and waits for them.”  Sounds a bit like ‘waiting for Godot.’

[Author]

Posts