I'm building a 2v, 3/4" EMT dome. Because I'm cheap, i didn't buy a hydraulic press. I bought a sledgehammer. However, I'm having a rough time getting the flats perfectly parallel- they just seem to want to turn. It doesn't help that I dont have a clamp, just an anvil and brace for the other end.
My question is, does it matter? If there is a little bit of twist (maybe 10 degrees) in the struts, will it work itself out in construction? or should I stop now before I screw myself over?
Dome strut end-squishing troubles
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trystanthegypsy
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Stop now.
If the flat ends don't align this will add torsion when assemling the dome and make it imposible to assemble.
If you are a degree or three off you could fudge it by not tightening the bolts all the way until assembled, then doing the final wrenching after the shape is settled in but not with + - 10 degrees.
Go get a 20 ton press and do it right.
If the flat ends don't align this will add torsion when assemling the dome and make it imposible to assemble.
If you are a degree or three off you could fudge it by not tightening the bolts all the way until assembled, then doing the final wrenching after the shape is settled in but not with + - 10 degrees.
Go get a 20 ton press and do it right.
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StevenGoodman
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DoctorIknow
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What's the diameter of your 2v?
The spars may just be too damn long for you to use the sledge (although, a single hand held 3lb. sledge might give you more accuracy.) Clamping the first flattened end with vise grips should help you be more accurate with the other end. Hopefully you have a good flat surface (like a concrete floor) to get it right. If you don't have an anvil, Harbor Freight Tools as a real cheapy, or maybe you can find a piece of railroad track or something like that at a metal fabricators. Pounding on cement is harder work and can really screw up the cement.
With a 2v, you "only" have 130 ends to pound. (I pounded a 4v---500 ends--- and thought it overly time consuming, but it got the job done. And, I remember reading from some Burner how even 20 ton presses can fail so I never even thought about getting one that would only be used once or break.)
On the plus side of non-perfectly aligned ends, the spars may be so long they WILL be able to be torqued down to take care of the un-parallel ends.
BTW, look very carefully for the seam in the conduit. I found that sledging the end with the seam at about 22degrees causes many less problems than if the seam is at 45 or 90degrees. If it does split at 22degrees, at least you don't have razor sharp edges as you would with a 45degree situation. If the split is in the middle of the hole (90degrees) you'll maybe have problems drilling. ALSO, a drill press, and cutting oil, is really your friend in this endeavor. It's easy to make a jig so your holes are perfectly measured.
I wouldn't get a press, especially if you don't already have a custom cover for a specific diameter dome. That way, if it doesn't work out on your assembly (ASAP!) then just cut the ends off and do it a different way.
Good luck.
The spars may just be too damn long for you to use the sledge (although, a single hand held 3lb. sledge might give you more accuracy.) Clamping the first flattened end with vise grips should help you be more accurate with the other end. Hopefully you have a good flat surface (like a concrete floor) to get it right. If you don't have an anvil, Harbor Freight Tools as a real cheapy, or maybe you can find a piece of railroad track or something like that at a metal fabricators. Pounding on cement is harder work and can really screw up the cement.
With a 2v, you "only" have 130 ends to pound. (I pounded a 4v---500 ends--- and thought it overly time consuming, but it got the job done. And, I remember reading from some Burner how even 20 ton presses can fail so I never even thought about getting one that would only be used once or break.)
On the plus side of non-perfectly aligned ends, the spars may be so long they WILL be able to be torqued down to take care of the un-parallel ends.
BTW, look very carefully for the seam in the conduit. I found that sledging the end with the seam at about 22degrees causes many less problems than if the seam is at 45 or 90degrees. If it does split at 22degrees, at least you don't have razor sharp edges as you would with a 45degree situation. If the split is in the middle of the hole (90degrees) you'll maybe have problems drilling. ALSO, a drill press, and cutting oil, is really your friend in this endeavor. It's easy to make a jig so your holes are perfectly measured.
I wouldn't get a press, especially if you don't already have a custom cover for a specific diameter dome. That way, if it doesn't work out on your assembly (ASAP!) then just cut the ends off and do it a different way.
Good luck.
Hi, we went the same route initially, first the sledge hammer, then the vice and ultimately the press. The sledge hammer was not very accurate and the vice route was equally hard, mostly on the body. I suggest you get the press, sell it when done. If you get the press, make a little guide for the polls and it will go real fast. Over all you have alot of ends to smash and bend and holes to drill. pay a little extra to make life easier.
T.
T.
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chiefdanfox
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why don't you make a wood jig with a bolt (i.e. a 2X 4 with a through bolt).
squish one end, drill it, bolt it down to the jig, then smack the other end. seems like that would keep the flat ends aligned. make sure you use a big over sized washer when bolting to the jig. One of those washers used on house foundation bolts, in addition to a cut washer that is sized to the through bolt.
If you make the jig long enough to stand on, and maybe out of 2 X 6, you might find that you aren't chasing it around the driveway/backyard/neighbor's porch/etc.
squish one end, drill it, bolt it down to the jig, then smack the other end. seems like that would keep the flat ends aligned. make sure you use a big over sized washer when bolting to the jig. One of those washers used on house foundation bolts, in addition to a cut washer that is sized to the through bolt.
If you make the jig long enough to stand on, and maybe out of 2 X 6, you might find that you aren't chasing it around the driveway/backyard/neighbor's porch/etc.
What I do to ROUGHLY align the two ends (NO, it does NOT have to be EXACTLY aligned, Drama Queen!) is to find a flat surface that the already-pounded-on end can rest on while the about-to-be-pounded-on-end is aligned with the Pounding Surface and then....whack away. Hold on to the tubing while doing so, and maybe stroke it back and forth with the hammer to insure that you're laying it down flat....Sound hard? It isn't. Just takes some getting used to. You'll be a fucking GENIUS at this by the time you've finished enough struts for a TooVee dome AND.... ONCE AGAIN...."exactly" is NOT a factor. Sweat THAT shit when you take it up a frequency or two. If things don't line up JUST RIGHT then you've made the holes too tight, or you're using bolts that are too short. DO YOURSELF A FAVOR and throw some SLACK into the equation WHILE YOU STILL CAN. I PROMISE YOU that IT WILL BE ALL RIGHT.
I'll hold your hand if you need me to- The important thing is that you MAKE YOUR DOME. You'll be REALLY proud of yourself when it's done.
I'm proud of you.
Carry on.
I'll hold your hand if you need me to- The important thing is that you MAKE YOUR DOME. You'll be REALLY proud of yourself when it's done.
I'm proud of you.
Carry on.
Howdy From Kalamazoo
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LeChatNoir
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Re: Dome strut end-squishing troubles
Hi gypsy,trystanthegypsy wrote:I'm building a 2v, 3/4" EMT dome. Because I'm cheap, i didn't buy a hydraulic press. I bought a sledgehammer. However, I'm having a rough time getting the flats perfectly parallel- they just seem to want to turn. It doesn't help that I dont have a clamp, just an anvil and brace for the other end.
My question is, does it matter? If there is a little bit of twist (maybe 10 degrees) in the struts, will it work itself out in construction? or should I stop now before I screw myself over?
Figure I’ve got to throw my two cents in here as well. Robot is right, a little misalignment isn’t going to make a real difference in a 2v. But 10 degrees might be pushing it for a 3v or more. I’m guessing that this is an estimate and that it may or may not really be 10 degrees. Likely a bit less, and using longer bolts will let you squeeze it in anyways.
Having a flat surface to reference to is important. Investing in a simple wood jig that you can use vice-grips or a clamp to hold the first end to will save you a lot of headache. If your jig and anvil face are aligned, clamp the first end and pound the second and there you go.
The New and Improved Black Cat... now with 25% more blather
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CapSmashy
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trystanthegypsy
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UPDATE!!
Thank you all for your advice, helpful or funny!
Most of the solutions mentioned are challenging for me to execute because I have almost zero access to tools or workspace. I am going to a lot of festivals this summer and I didn't want to see the cost of the damn thing climb too much higher- steel is at a premium and it cost me about $200 to buy just the raw materials.
BUT I worked it out! I went out and bought a hacksaw and some plastic clamps (one of which promptly broke.. but hey) and built a jig. My anvil is a large steel sculpture I built while I was in school, that is approximately 30" off the ground. So I balanced my jig on a ladder & tv table, and got my trusty hammer-bearing minion Thor (a.k.a. my lover & provider Rob) to smash away while I manned the proper positioning of the EMT.
As you can see, my anvil is slowly getting bent out of shape, (it's only 1/8" thick, lol. But we finished all the long pieces and some of the short pieces last night, until our neighbours started whining. Between the 2 of us, we work 9 am to 9 pm, so we figured we would get up and finish this morning, and lo-and-behold, its raining. (yes, i'm sure the steel would be fine, but I hate the rain. slippery grass + sledgehammer + wet and cold is not my idea of fun.) So, fuck the neighbours, we'll be smashing into the evening tonight.
Now for the drilling, I'm dragging all this shit down to my dad's house 3 hours away. I found a drill press on craigslist for $20, so i'll build another jig and see how that goes.
whew! no one told me this was gonna be this much work! oh wait, they did, I just didn't listen.
Thank you all for your advice, helpful or funny!
Most of the solutions mentioned are challenging for me to execute because I have almost zero access to tools or workspace. I am going to a lot of festivals this summer and I didn't want to see the cost of the damn thing climb too much higher- steel is at a premium and it cost me about $200 to buy just the raw materials.
BUT I worked it out! I went out and bought a hacksaw and some plastic clamps (one of which promptly broke.. but hey) and built a jig. My anvil is a large steel sculpture I built while I was in school, that is approximately 30" off the ground. So I balanced my jig on a ladder & tv table, and got my trusty hammer-bearing minion Thor (a.k.a. my lover & provider Rob) to smash away while I manned the proper positioning of the EMT.
As you can see, my anvil is slowly getting bent out of shape, (it's only 1/8" thick, lol. But we finished all the long pieces and some of the short pieces last night, until our neighbours started whining. Between the 2 of us, we work 9 am to 9 pm, so we figured we would get up and finish this morning, and lo-and-behold, its raining. (yes, i'm sure the steel would be fine, but I hate the rain. slippery grass + sledgehammer + wet and cold is not my idea of fun.) So, fuck the neighbours, we'll be smashing into the evening tonight.
Now for the drilling, I'm dragging all this shit down to my dad's house 3 hours away. I found a drill press on craigslist for $20, so i'll build another jig and see how that goes.
whew! no one told me this was gonna be this much work! oh wait, they did, I just didn't listen.
Nicely done! I'm stubborn about the DRILLING part too- I do it by hand (and electric drill) with a 1/8" pilot hole and then enlarge with a stepped bit to 1/2". Hard on the wrists, and hot bits of metal fall on your legs!
Hang in there...you'll be chilling in your new coolness in NO time! THEN start thinking about putting a loft in....
Hang in there...you'll be chilling in your new coolness in NO time! THEN start thinking about putting a loft in....
Howdy From Kalamazoo
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Bob
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Standard gauge is 4 ft 8-1/2 in., so if your strut length is 5 ft just leave the tubes on a railroad track and get out of the way.
Unfortunately, BART uses Indian gauge (5 ft 6 in.), which seems a little longish for dome struts.
Unfortunately, BART uses Indian gauge (5 ft 6 in.), which seems a little longish for dome struts.
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