Ah the almightly dome

[AntiM]

The positive aspect of less than stellar advice is the concept can be analyzed and understood why another method is safer/superior/desirable. A good dialog can include imperfect ideas. I might not ever build a dome, but find the whys and why nots interesting.

[LionsNzebras]

Absolutely AntiM, its not about shooting down peoples ideas, its about why and why not, what makes it a good idea, what makes it a bad idea and the bits in-between.
If I never build the dome, I have already gained more knowledge that if I would have never tried in the first place.

There are only 2 areas in the world that I have any clout, and this is not one of them

[torrey.smith]

I love your die press. That's a neato bit of reinforcement you're putting into your strut ends.

I started with a dome and everything spiraled from there into a theme camp, dome/tower/zip-line, even a Tesla Coil.

All I can say is that there's nothing trivial about building on the Playa, but it can become one of the most fulfilling experiences around.

Learn as you go, and never let yourself think you can't hit wikipedia and start learning the core details of the challenge you're facing. Lifelong Learning!

[LionsNzebras]

I love your die press. That's a neato bit of reinforcement you're putting into your strut ends.

I started with a dome and everything spiraled from there into a theme camp, dome/tower/zip-line, even a Tesla Coil.

All I can say is that there's nothing trivial about building on the Playa, but it can become one of the most fulfilling experiences around.

Learn as you go, and never let yourself think you can't hit wikipedia and start learning the core details of the challenge you're facing. Lifelong Learning!

Torrey,

Even if this does not go as planned, I will still join a camp, build, participate, enjoy helping in another camp. Just who I am.
Lifelong learning for sure.

The die design is a very very simple one, depending on how things go, the springs might be a good idea, this way I dont have to attach it to any press physically.
Just some thoughts spinning in my brain, time to break out the paper again....

[LionsNzebras]

Hello everyone, we have not forgotten about our eplaya brothers and sisters....
and or our project.

I (lion) have suffered an Achilles tendon break and am now off! yikes, zebra had her surgery and is now recovering. So a bit busy to say the least.

We have the final die constructed:

DSC06056.JPG

DSC06058.JPG

Unfortunately this die is very specific to 1 inch EMT. We are going to test 1 1/4 in it just to see. But during some of our press tests we have metal squish out on the sides. I don't like that too much as I think it reduces structure, but I have yet to talk with the engineer. I will post more pictures.

[LionsNzebras]

Here are a few pictures of our squish tests.
As you can see we got some metal squishing out of the side and might adjust the die, just not sure yet.

One:

DSC06051.JPG

Two:

DSC06052.JPG

Three:

DSC06053.JPG

The third image was our final adjustments and will most likely remain this way for all subsequent presses.

[LionsNzebras]

We did a single strut test, just to see how the metal would react to both ends being squished.

DSC06054.JPG

[LionsNzebras]

In the next image, we cut our test squishes out to work on angles of struts and bolt design.

DSC06055.JPG

I think over the next few weeks we will work on 5/6 struts, rounding off the corners and making things safe, making sure the holes and struts are to proper length etc etc.

Were using 7-10 tons of pressure for our presses as well, I forgot to mention that.

With Regards to bolts, were testing with 1 1/2 and 1 3/4 inch bolts. Using 2 SAE washers, however this might increase to 3 washers. There would be 2 washers on the top and one on the bottom, the reason for the 2 on the top would prevent the carriage bolt square from pressing itself into the EMT and possibly causing structural damage.

We have been kicking around lock washers and what not, but feel they wont be required.
There are a few nice things about the carriage bolt design.
1. it will allow a materiel to slide on the outside without ripping, we may need to reinforce the cloth a bit with a double layer but no big deal.
2. they should be easy to put on with a single socket wrench.

This week we will be finishing up the final tests and then will start putting out struts, I figure in the next few months will be our test design, but its almost winter here and we will have snow on the ground soon. Its already -10 during the day. Snow to come.

We have been watching youtube videos to work on some covering designs and such.
Stay tuned for updates.

[GreyCoyote]

Excellent work!

A couple of things:

1). Do NOT cut back the side of the flange on the strut end to clear the angle formed by the bump on the underlying struts. This massively weakens the strut assembly. Instead, make the landing area (the "squished" part of the strut) a bit longer. Give it another 1/4 inch or so.

2). Instead of having a flat surface on your die, make a 1 mm deep by 3 mm wide channel in both halves of the die where it lines-up with the folded edge of the tube when squished. What you are trying to do here is let that edge become less of a fold and more of a bend with a slight radius. This channelization increases the strength of the strut end a fair bit. It also gives the assembled strut stack some springieness (sp?) upon assembly. This is good in that the frame can give just a bit when you load it up. In doing so, it transfers the load to the surrounding members.

Other than this you have done a DAMN fine job. Want to make a copy for me? PM me please if interested!

[Jackass]

Damn, you guys ain't fucking around, smashing pipe in a vice or "hand forged" with a hammer. That's a damn fine looking die press you've got there. If you have the machine skills to make that fine piece of tooling, this dome thing is merely a cake-walk...

[GreyCoyote]

Damn, you guys ain't fucking around, smashing pipe in a vice or "hand forged" with a hammer. That's a damn fine looking die press you've got there. If you have the machine skills to make that fine piece of tooling, this dome thing is merely a cake-walk...

This. Definitely!

[LionsNzebras]

Excellent work!

A couple of things:

1). Do NOT cut back the side of the flange on the strut end to clear the angle formed by the bump on the underlying struts. This massively weakens the strut assembly. Instead, make the landing area (the "squished" part of the strut) a bit longer. Give it another 1/4 inch or so.

2). Instead of having a flat surface on your die, make a 1 mm deep by 3 mm wide channel in both halves of the die where it lines-up with the folded edge of the tube when squished. What you are trying to do here is let that edge become less of a fold and more of a bend with a slight radius. This channelization increases the strength of the strut end a fair bit. It also gives the assembled strut stack some springieness (sp?) upon assembly. This is good in that the frame can give just a bit when you load it up. In doing so, it transfers the load to the surrounding members.

Other than this you have done a DAMN fine job. Want to make a copy for me? PM me please if interested!

GC,
I was thinking of melting the ends instead of just rounding them, more like weld instead of a cut. I do like your idea though let me run it by the engineer and see what they say.
I would be happy to send you a copy of my die, there is a cost though I am not even sure what my end cost will be.
They are making it out of spare material at my sister office, and doing it on their spare time so I have not paid for any real time yet.

JackAss,
I am not doing all the work, just the research. The Fabrication is done at my sister office (we actually own them, they make our giant die press stuff, and repairs)
The engineer there is a personal friend, and its only due to that, that I have been able to do this.
I personally do not have the skills to make this happen. Once the DIE is finished, we will do the rest in a standard garage setup. It has to be easy enough to reproduce, even for a v5 dome.

[GreyCoyote]

Thats an interesting take on how to do the edges. It could be done, but using EMT would be out.

The first issue would be the galvanizing. You cant effectively weld with it around, so it would have to be removed or not present in the first place. The second would be embrittlement in the heat affected zone. You could TIG it, but you'll be there forever.

Definitely interested in one of these! Really excellent work!

[LionsNzebras]

yes EMT is galvanized so you cant weld it. The other issue is coneing when you squish it into a grove. If we were working with un-coated steel it might work. If we put groves into the die we would have to harden it, and steel would have to be hit with 50+ tons.

I think we are going to leave it the way it is and see what happens. I dont know about the trimming yet.

GC why do you think it will change strength? Side stresses? In theory there should not be any side stress on that part of the metal.

[LionsNzebras]

Just an FYI,

The final die cost has come in at 250 dollars + 15 in materials for 265 bucks Canadian. All discounted of course, I would expect this die to be around 300+ if they were charging me full prices.
its also not light, no idea on shipping costs.

Checking on bulk bolts, nuts and washers.

Were also still debating the hex bolts vs the carriage bolts.

[LionsNzebras]

So we are finally ready to purchase materials and get started.

Here are all my strut lengths.

************RAW DATA***************
30 X “A” 2.638 BEND 9.49°
35 X “B” 3.058 BEND 11.02°
80 X “C” 3.372 BEND 12.16°
20 X “D” 3.528 BEND 12.74°

*************RAW DATA CONVERTED TO INCHES**********************
Listed feet * 12

30 pieces of "A" at 2.638 = 31.656
35 pieces of "B" at 3.058 = 36.696
80 pieces of "C" at 3.372 = 40.464
20 pieces of "D" at 3.528 = 42.336

************RAW DATA + ADDITION CONVERTED TO INCHES***************

30 pieces of "A" at 2.638 = 31.656 + 1.5 = 33.156
35 pieces of "B" at 3.058 = 36.696 + 1.5 = 38.196
80 pieces of "C" at 3.372 = 40.464 + 1.5 = 41.964
20 pieces of "D" at 3.528 = 42.336 + 1.5 = 43.836

This 1.5 inches was added to cover from half hole to end of strut, this covers 3/4 an inch on both ends.

Attached is a picture of our strut testings. We will do bend tests, compression tests for each one, just for fun.
We have also not rounded the corners yet. More testing on that needed to make sure integrity stays in the strut.
There was also an odd fold in one of our test struts, we suspect this is when you dont line up the EMT fold line inside the die press.
Additional testing will be done to line up the fold properly.

Strut tests_Small.jpg

STRUT WASTE AND USE CALCULATIONS:

"A" 33.156 * 30 = 994.68 total inches, each piece of EMT is 120 inches long. 33.156 * 3 = 99.468

Using 5 pieces from the C calculation at 39.072 inches
0 pieces needed
5 pieces of waste 5.916 long

25 struts needed 33.156 inches long 2 from each 120 inch piece
9 pieces needed
9 pieces of waste 20.532 inches long


"B" 38.196 * 35 = 1,336.86 total inches, each piece of EMT is 120 inches long. 38.196 *3 = 114.588

Using 35 pieces from the C calculation at 39.072 inches

0 pieces needed
35 pieces of waste 0.876 long



"C" 40.464 * 80 = 3,237.12 total inches, each piece of EMT is 120 inches long. 40.464 *2= 80.928 - 120 = 39.072

40 pieces 10 feet long, each piece will have 39 inches of waste but can be used on strut A and B

40 pieces needed
40 pieces of waste 39.072 long




"D" 43.836 * 20 = 876.72 total inches. Each piece of EMT is 120 inches long. 43.836*2= 87.672 - 120 = 32.328

20 pieces needed
20 pieces of waste 32.328 long



TOTAL PIECES OF EMT NEEDED

A 9
B 0
C 40
D 20

69 total pieces 10 feet long.

[torrey.smith]

Beautiful work!

[LionsNzebras]

Hey Torrey,

I was looking at your images, and saw you attached pieces of cloth in each triangle, what did you use to attach them with?
Also I assume it was just a wind break type thing.

We are starting to look into coverings.

[torrey.smith]

We use mesh tarp material that passes a breeze but does offer some wind and sun protection.

We hem and sew them and use grommets along with elastic ball cords at the vertices to hold them taut.

[LionsNzebras]

Hey guys, what is the consensus on button head cap screw?

I have a quote on G5 Button soc c/s from my local bolt supply house
1/2 inch 13x 1-1/2 long quantity 100 for 54.76 + Tax or roughly 55 cents each.

They are building me a quote with 70 bolts, 70 nuts, 140 washers, both G5 and G8, will take a look at the costs and make a decision.
The difference from a 5 to an 8 in terms of strength is not a whole hell of a lot, so it will ultimately depend on the prices.

We are winding up for full dome production over the Christmas holidays!
The shop that built the die said they could cut and press the ends for 300 bucks. (this is my private 35/hr shop rate) I dont own a press, or a nice band saw with a stop.

Thoughts?

[GreyCoyote]

That crease you saw in strut #3 is due to one of two things:

1). The strut wasnt centered in the die, and it was trying to rotate during the press cycle. If so, the taper, when viewed from the end of the strut, will be lopsided. This is just an alignment issue and easy to fix.

2). The die needs a little more metal removed in the taper area. The metal has to go somewhere, and if the die is too narrow in the throat, it will fold the metal over partially, resulting in a crease.

Good show! No way I can convince you to do an F4, huh?

[LionsNzebras]

GC,

Yes I figured that on the crease. The guys must have had the fold in the press wrong.


You think it needs a little more materiel in the crease? I will take a look and see what we can do. I had a similar thought when I saw the sides bulging out a bit from the press.
How much more do you think, 2 thousandth's on the whole cup, both sides of the press?

[GreyCoyote]

GC,

Yes I figured that on the crease. The guys must have had the fold in the press wrong.


You think it needs a little more materiel in the crease? I will take a look and see what we can do. I had a similar thought when I saw the sides bulging out a bit from the press.
How much more do you think, 2 thousandth's on the whole cup, both sides of the press?

Personally I'd make my first cut about 5 thousandths all the way around, and my gut tells me it will take a bit more than this. There isnt any huge penalty for going a little big here, but the strength goes quickly to hell if you get a crease. Remember that most folks (me! Hehehe) use a couple of flat plates as our die, and get good crimps.

The area you really want to control is the transition from the round tube to where the crimp just starts. The shoulder cross-section area there tends to be oval if left unconstraineds. Ideally the die would keep it as round as possible for as long a distance as possible.

[LionsNzebras]

GC,

Yes this is what I was thinning too, the strength comes from the finger nail shape!
Flat is bad, round is good, so the girls tell me!

Will play with it a bit more when christmas holidays roll around. (man even that sounds dirty, I need to get out more, apparently i have cabin fever)
Starting to look at coverings now that the dome is mostly sorted out, to duck or not to duck.

other things...A place to hang my fan, an air conditioner and platform with my 5000 watt construction grade generator, fuel, the flat screen TV, and xbox and a king size bed!
All i need is a sherpa, a maid, butler and chef.....

muahhahahaha

[GreyCoyote]

GC,

Yes this is what I was thinning too, the strength comes from the finger nail shape!
Flat is bad, round is good, so the girls tell me!

Will play with it a bit more when christmas holidays roll around. (man even that sounds dirty, I need to get out more, apparently i have cabin fever)
Starting to look at coverings now that the dome is mostly sorted out, to duck or not to duck.

other things...A place to hang my fan, an air conditioner and platform with my 5000 watt construction grade generator, fuel, the flat screen TV, and xbox and a king size bed!
All i need is a sherpa, a maid, butler and chef.....

muahhahahaha

Yer scareing us, Lion. Tell that young sweet Zebra to evacuate ASAP if you bring the cutting torch into the bedroom.

On a serious note, do let us know what you decide on the cover materials. Personally I like the breathability of the canvas duck, but if I had to do it over again I might play with the 100% waterproof coated canvas.

[LionsNzebras]

Bolts nuts and washers have arrived, as well as ring nuts to hang hammocks n stuff!

GC, the sweet zebra is called zebra, because lions chase zebras and eat them So shes not too afraid hahaha. Its normal!
They also chase gazelles but that's another conversation.

Today I was looking at this:
http://www.princessauto.com/en/detail/1 ... -p8382764e

We haven't even talked about drilling and hole cleanup yet, or rounding the edges of my EMT.
SO....I have been looking around the interwebs for tools local to me.

I might get them to cut all my ends, but I will squish and drill them myself.

[LionsNzebras]

The above post was edited by trillobyte after my request to do so.

He removed my post with all my cost break downs under the rules of commerce.
I am in no way trying to sell my idea or to benefit from said idea, or I would not have posted the die designs themselves.

commerce and commidification is a very interesting topic, and I am happy to oblige by the rules set forth by the board.

[theCryptofishist]

That is refreshing. Thank you, and welcome to the board.

[GreyCoyote]

Bolts nuts and washers have arrived, as well as ring nuts to hang hammocks n stuff!

GC, the sweet zebra is called zebra, because lions chase zebras and eat them So shes not too afraid hahaha. Its normal!
They also chase gazelles but that's another conversation.

Today I was looking at this:
http://www.princessauto.com/en/detail/1 ... -p8382764e

We haven't even talked about drilling and hole cleanup yet, or rounding the edges of my EMT.
SO....I have been looking around the interwebs for tools local to me.

I might get them to cut all my ends, but I will squish and drill them myself.

Lion: do you have a Harbor Freight nearby? This press is half the price of the link you gave, and nearly double the capacity.

http://t.harborfreight.com/20-ton-shop-press-60603.html

I have this same press (different color, same part number) and I love it. The only mod I made was to purchase an air-over 20-ton jack and swap it for the factory cylinder. Connected to shop air at 120 psi, it takes about 10 seconds to make a complete squish. You can do a complete strut in 45 seconds or less.

You will get very tired pumping that cylinder by hand. I managed 20 struts before I said PHOOEY and went with an air-over ram. Best $99 I spent.

http://t.harborfreight.com/20-ton-air-h ... -8979.html

It comes with a squeeze valve on a 4-foot whip hose, which is precisely the right length to put the valve on the floor. This leaves both hands free and you can mash the button with your foot. Air supply pressure and length of application govern the ultimate piston force, or you can put a $20 adjustable pop-off valve downstream of the foot valve. This lets you use high volume to move the ram, and then when the crimp is formed, the pop-off valve blows. Schweet!

Anyway... Just noodling...

[LionsNzebras]

GC,

We dont have HF in Canada, so I am looking around.
One of the biggest hurdles of this project is that I do not own any tools, other than say a breaker bar, a torque wrench and some minor car stuff.
I am an Network Engineer by trade, never needed "tools" before. (if we need some cool electronic stuff, I think i could deal with that hehe)

Yes I know it totally goes against the issue and mandate of my "Man Card" but I am working on it.
The expenses for this single project are costing me more than the project itself hahaha. But hey, aint that the point of burning man?

But I believe your right, best to look for an air based one, but I dont own an air compressor! sigh.....
When I talked with my wife yesterday about the press, she said tools are a good thing, you can build a deck next year, I got the big eyes and was like huh what, no ill contract that out....

So I had the EMT delivered to the engineering company yesterday, Material arrived at 9:30 am and at 4:30 they were half done, SO...I might just spend the money on them and get them to do some of the work. They want about a buck a strut to press them, sure I could do it cheaper but would have to buy the tools. Need to weight options on setting up the tools and such in the garage.

I did find this one.
http://www.princessauto.com/en/detail/3 ... -p8246555e

It is a little more money but its air based as well as hydraulic so I could go both ways, my wife sure is going to get tired pumping that thing muhahahaha.
I am going to see if I can go to the engineering company at lunch time and see some progress.