newbie dome builder looking for sound advice :)

system error · Post by **system error** » Thu Apr 27, 2006 8:04 am

ello there, im new here, been looking for a geodesic dome help forum for a while, and never though of looking on the nurbing man forum.Doh!
Anyway im building my 1st dome here in UK 3/4" conduit and 2v--2.50m radius..
Im busy getting my tools together abd I have 2 questions i need help with ok>>>>>

1. I bought a old drill press for $7 :wink: but it will only take a 4mm drill drill, is my best plan still to use the press to make the initial holes, and then work my way up to the correct size using an electric drill?

2. Im looking to buy an arbor press, but not having a lot of spare cash a 1 ton one is all i can aford. Will this be up to the job of crushing the conduit
or do i need 2 --3 ton press.

Thanks for all the tips i read already, super happy i found this place incase i run into problems.bOOOM!

i love desertdomes site
this is very valuble info! all newbies chek it! :arrow: :arrow:
_________________
Om namah Shiva<> 8)

Bob · Post by **Bob** » Thu Apr 27, 2006 9:20 am

Isn't there a shoppe where you can rent real tools over there? Plan ahead, make a jig for marking/drilling accurately, and have at it. Buy multiple drill bits, decent brands, not the cheap Asian stuff.

system error · Post by **system error** » Thu Apr 27, 2006 10:01 am

thanks, but that hasn't anwsered any of my questions now has it!

anyone else? :roll:

Paolo · Post by **Paolo** » Thu Apr 27, 2006 1:10 pm

Hey System Error,

Like you, I am a first time dome builder. I am still planning my 2V, 18' foot diameter dome and so far, it seems pretty straight forward. Just do a google search using the words: "conduit geodesic dome" and you will find LOTS of information. I bet if you search this forum, you will come up with lots of added instruction.

I figure that I will cut the 3/4" EMT conduit with my skill saw. I think they sell metal cutting wheels for these saws but if not, then I guess I will use a pipe cutter. (I just love to see sparks fly!!!)

Last weekend, I went to "Harbor Freight tools" and picked up a 12 ton shop press for about $100 bucks. I plan on using it to squash the ends, (forget hammering!). The next "Harbor Freight" purchase that I make will be a small drill press, good bits and lots of cutting fluid.

A good work bench, vice, and some clamps will also be necessary. Wish me luck!

I am a BM virgin so I am not sure about this one, but I heard that they have held a "Tour of domes" in the past. I wonder how that works? Sounds fun!

Paolo

Dork · Post by **Dork** » Thu Apr 27, 2006 1:31 pm

If you can't afford a decent arbor press, a good sledge hammer will work. Precision is not critical in that step.

I'm curious about this drill press than only accepts one size bit. Can you post a picture or describe it a little further? There may be a cheap way to outfit it with a real chuck unless it's simply too tiny to be able to drill holes larger than 4mm. Barring that, what you're planning should work. In either case, be sure to center punch where you want the hole to be so the bit doesn't wander around too much, and use cutting oil.

DVD Burner · Post by **DVD Burner** » Thu Apr 27, 2006 1:35 pm

Hey there.

You can always go to my blog http://playacast.blogspot.com and find things about Domes I linked to eplaya and other sites about things other than domes also.

You may have to do some searching through the blog but it is there.

Hope that helps. Bob also has good info on his site I belive.

dragonfly Jafe · Post by **dragonfly Jafe** » Thu Apr 27, 2006 3:23 pm

check out this thread also (I searched eplaya on "domes")

http://eplaya.burningman.org/viewtopic. ... light=dome

good luck! I agree with the advice about quality bits and good tools. Rent the right tools if you have to rather than try to get by with cheaper stuff...your body will thank you!

falk · Post by **falk** » Thu Apr 27, 2006 3:38 pm

Hmmm, a few random notes based on my own experience:

Construction photos from my 32' dome:

http://www.efalk.org/OasisDome/photos.html

If you haven't designed the dome yet, you should definately visit the dome calculator at http://www.desertdomes.com/domecalc.html and experiment with frequency and diameter until you find a design that uses the available EMT sticks (which come in 10' lengths) most efficiently. Don't forget to allow 3/4" margin at each end for the bolt hole.

(I'll leave it to you to convert to metric if that's appropriate.)

http://geodome.sourceforge.net/orig/bend.jpg

I second the question: what kind of drill press only takes one size bit?

I think you should make the investment and get a decent drill press (or borrow one). American-made (other than Sears) are the best. Don't get chinese. Ask around under "Share Resource"; you might be able to borrow one. Or better yet, a Roper-Whitney hole punch. It's like a cross between a paper punch and a pair of bolt cutters. Takes a lot of upper-body strength to use, but makes a hole in 1/10 the time and 1/100 the mess of a drill press. They cost as much as a drill press though :(

I built my dome with 1/4" bolts, but most people prefer 3/8". You want your holes about 1/32" bigger than the bolts.

Ordinary nuts and bolts and washers are good if you have a power driver to tighten them up. If not, consider wingnuts instead of hex nuts.

A pipe cutter is the best tool for cutting the EMT as it leaves no flash (sawdust), but it's slow. If you have a power chop saw or band saw, the cutting will go faster.

I don't think a 1-ton arbor press will cut it for squashing pipe ends. A sledge hammer will do an adequate, if sloppy, job. You need an anvil too; don't try to use the sidewalk. See if you can't borrow a decent hydrolic press instead; it does an excellent job (see my photos).

Make at least two extra struts of every size, just in case. Get at least 20 spare bolts and nuts.

Start thinking about how you'll cover your dome. I used cotton canvas, but it's expensive, requires a lot of sewing, it shrank, and then it mildewed. Sailcloth is better, or you can use tarps or billboard vinyl.

BadDawg · Post by **BadDawg** » Thu Apr 27, 2006 6:26 pm

I use a Port-A-Band (portable bandsaw) for cutting the conduit. I made my own conduit smasher by using a 3 or 4 ton bottle jack and a set of dies made from 3/8" or 1/2" plate steel and some 2x2 square tubing to make the frame it sits in. A drill press makes short work of the drilling duties. when drilling use the next size up from 3/8", I believe the one I use is 25/64", makes fitting the dome together a little easier.
Also I use 5/16" washers when constructing the dome, they fit on the bolts nice & snug. Hope this helps and have fun.

Bob · Post by **Bob** » Thu Apr 27, 2006 9:08 pm

system error wrote:thanks, but that hasn't anwsered any of my questions now has it!

Given the piffle you've provided wrt to tools you actually own, I thought it appropriate.

Cheaper to rent than buy, usually, and cheap enough to rent heavy-duty tools you would never consider owning if you have a one-off project.

Or you could trot down to King's Cross and flop your rod on the rail at platform 9 3/4.

Token · Post by **Token** » Thu Apr 27, 2006 9:31 pm

If you already have a press, why drill? Would it not be easier to just use a punch in the press? Just curious.

system error · Post by **system error** » Fri Apr 28, 2006 1:46 am

the drill press was made for putting holes in ciruit boards i belive hence only trake 4mm, thanks for all the sound advice guys, most helpful. Well apart from BOb, but theres always "one" on every forum isn't there...lol...........get a grip m8..........if u got nowt usefulto say, dont waste ya finger energy typing ok....peace....

system error · Post by **system error** » Fri Apr 28, 2006 2:02 am

plus i never said it wasa "1 off project" thats why i want my own tools as i plan on making a few to sell also........anywayzzz peace out.

dragonfly Jafe · Post by **dragonfly Jafe** » Fri Apr 28, 2006 7:46 am

system error wrote:...as i plan on making a few to sell also........anywayzzz peace out.

Then you DEFINATELY want the right tools for the job, so the job will be done right and look right. Taking shortcuts/compromises on YOUR dome is one thing, but doing so on something you plan to sell to someone (possibly ignorant of such issues) is negligence at the least...at least make it clear if you decide to proceed with makeshift tooling that this is the case before you make the sale (ie-show pictures of how crude the ends are, etc) - and price them accordingly. Just a another thought...

Almost · Post by **Almost** » Fri Apr 28, 2006 11:13 am

1 ton press will get you through one dome, but it will start to bend by the very end. If you plan more than one dome definetly get a larger 2-3 ton press.

The drill press will work some what, but chances are you'd be better off using a corded/cordless hand drill with the proper bit and just skip over the whole drill press altogether.

Bob · Post by **Bob** » Fri Apr 28, 2006 11:41 am

system error wrote:the drill press was made for putting holes in ciruit boards i belive hence only trake 4mm, thanks for all the sound advice guys, most helpful. Well apart from BOb, but theres always "one" on every forum isn't there...lol...........get a grip m8..........if u got nowt usefulto say, dont waste ya finger energy typing ok....peace....

system error wrote:plus i never said it wasa "1 off project" thats why i want my own tools as i plan on making a few to sell also........anywayzzz peace out.

Bite my crank, mate. Why is it the "peace out" types who turn out to be utterly hostile fuckwits? You could have found your answers in the existing dome threads here instead of double-posting your vague query. This isn't your personal forum -- any answers provided are for the benefit of all, not just yourself. You act like a dissatisfied consumer, but maybe that's the trend at Burning Man.

My advice is still to find a little shoppe that rents heavy-duty tools, and make a jig to drill quickly & accurately so as to not waste rental time. This advice is based on watching too many buhrnurz struggling with cheap-ass underpowered Home Borg crappy so-called tools. As the rental outfits usually have the most durable tools, you might be well advised to start your home shop selections based on those and your experience using them.

Hope this helps.

Dork · Post by **Dork** » Fri Apr 28, 2006 12:16 pm

system error wrote:the drill press was made for putting holes in ciruit boards

Sounds like a great recipe for frustration. The forces exerted by the conduit (especially when not flattened well) will be orders of magnitude more than those of a circuit board. You need a real drill.

Well apart from BOb, but theres always "one" on every forum isn't there

Yeah, there's always that one guy who reacts to people giving them good advice by insulting them. Even if you are eventually able to build professional looking domes it will take a professional demeanor in order to actually sell them. Might want to work on that.

Token · Post by **Token** » Fri Apr 28, 2006 9:51 pm

Sheesh, everyone getting stuck in a flame...

I'd still like to get opinions on using a punch in the press to create the holes.

What are the estimates on the size of press needed to punch through flattened conduit? Anyone try it before?

For that matter, what is the gauge of 3/4 and 12 inch conduit?

This might be a big time saver if building a higher frequency dome.

robotland · Post by **robotland** » Sat Apr 29, 2006 7:54 am

I've dreamed of a Super Dome Die that could flatten, bend to 18 degrees AND, if not actually punch the hole, at least make a dimple to guide the drillpress. It certainly is POSSIBLE, at least.
Along with all the other waste that my current employer produces, they also chuck lots of heavy cardboard tubes....This year, I've decided to make a disposable dome. Probably not too impressive in scale, since most of the fabric scrap that they also chuck is 32" wide and the plan is to cover each triangle with its own piece of pretty-colored Sunduck and this constrains the strutlength to just over two-and-a-half feet.
I've been amassing HUGE mounds of this Sunduck fabric, and plan to bring as much with me as I'll have room for in the car after everything else is packed....Available on a first-come basis, so come see me EARLY in the week in Hushville...or look for a heavyset guy in a green kilt with a big smile on his face, over in Apokiliptika territory....

SystemError- If you're planning to make your fortune by selling geodesics I suggest that you come up with a quick, easy, durable AND economical covering-solution first. THEREIN lies the rub.

falk · Post by **falk** » Tue May 02, 2006 2:43 pm

Some friends of mine built a 24' dome two years ago. They took the cut struts to a metal shop in Redwood City that had a big hydraulic press that flattened the ends and punched the bolt hole all in one operation. I think they were charged $300 for their 3V dome (I think that's 165 struts).

As for a hand punch, I bought a Roper Whitney 7a

http://www.vansantent.com/Hand_punch_7A.htm

I think they're about $175 new, but you can get them used for much less. They take a lot of upper body strength to use, but they do a beautiful job.

To center, all you'd need to do is use a small punch to put a small dimple in the metal where you want the hole, and the big punch should center pefectly.

newbie dome builder looking for sound advice :)

newbie dome builder looking for sound advice :)

Why Drill?

Let me try again