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Topic: Your latest purchase (Read 124675 times) previous topic - next topic

draythomp

I had to give up on hot glue.  Darn stuff gives way in the AZ heat.  Now, that epoxy putty that come in a clear cylinder; that stuff is the bomb.

And, you keep looking, I've jumped in on some of your finds and look forward to doing it again.
Trying to keep my house under control http://www.desert-home.com/

retrolefty

Quote
I've jumped in on some of your finds and look forward to doing it again.


I too have succumbed to a few of focalist's E-bay finds. The problem is I just order them because the price was so killer and put them away in a parts drawer somewhere and a month or two later I have no memory of what I bought, so It's like I don't have them at all if I don't remember I have them, right?

Darn you focalist.

Lefty

JoeN

#512
Mar 13, 2013, 08:16 pm Last Edit: Mar 13, 2013, 08:21 pm by JoeN Reason: 1

Quote
I've jumped in on some of your finds and look forward to doing it again.


I too have succumbed to a few of focalist's E-bay finds. The problem is I just order them because the price was so killer and put them away in a parts drawer somewhere and a month or two later I have no memory of what I bought, so It's like I don't have them at all if I don't remember I have them, right?

Darn you focalist.

Lefty


I have sort of the same problem.  The difference, I think, is that I keep things very well organized.  I keep smaller parts in four of the larger units shown on this page (two each of the two types):

http://www.akro-mils.com/Products/Home-Office/Hardware/Hardware-Storage-Cabinets.aspx

I label each bin.  For small quantities of small parts, I can get two into each small bin using the dividers.  For parts that will not easily fit in these cabinets, I use Sterilite stackable modular boxes from WalMart.  These are great, they stack really, really well, even different sizes because the smaller boxes stack 2 or four onto larger boxes.  A lot of thought was given to dimensioning these boxes correctly.

http://www.walmart.com/ip/Sterilite-2.7-Quart-Latch-Box-Set-of-6/20699631

WalMart stores sell these individually.

I label everything and, what's more, I go through it once every month or so just to refresh my memory of what I have and maybe some projects I intended to do and forgot.  

"Hmmm...  what were those ferrites for?"   :smiley-surprise:
I have only come here seeking knowledge. Things they would not teach me of in college.

retrolefty

Quote
The difference, I think, is that I keep things very well organized.


Well see right there is a problem, as I'm not and at my age probably never will get organized.
:D
Lefty

focalist

Lefty, that's Geekmas!

Opening a drawer and finding those five bubble envelopes you got, paid a dollar each for, and forgot-- only to open and find the inspiration for the next wildly useless portzebie.  Why do I have an industrial ultrasonic transducer designed for use in measuring the volume in tankers?  Because it was a buck (though lists for a thousand!).  What will I do with it?  Stick it on a shelf, and then pull it out when a ping sensor (at five bucks) would work.  I saved four bucks, even if it is a thousand dollar part, actually :)

It's the fact that many of these are so low cost that makes it possible or reasonable to lose things in a drawer for six months until Geekmas... it's not too hard to forget three items costing a total of two dollars that take a month to arrive, especially if you were buying them to shelve them in the first place :D
When the testing is complete there will be... cake.

GoForSmoke

I've used sawdust and carpenter's glue to make light mountings. Had a neighbor who made rockets from glass cloth and epoxy but I'd have to do major re-arranging here to begin at it.

Another mix I have yet to try is glass strands in concrete.

3D printer... a dream for me. I want one that can lay fiber and wire, maybe print sockets.

Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

JoeN


3D printer... a dream for me. I want one that can lay fiber and wire, maybe print sockets.


The first thing that I am going to print with my 3D printer is a 3D printer.  And then return the first one.
I have only come here seeking knowledge. Things they would not teach me of in college.

focalist

#517
Mar 13, 2013, 09:13 pm Last Edit: Mar 13, 2013, 10:10 pm by focalist Reason: 1

Had a neighbor who made rockets from glass cloth and epoxy but I'd have to do major re-arranging here to begin at it.

Another mix I have yet to try is glass strands in concrete.


I've recently been intrigued by the invention of Concrete Cloth.  Cloth impregnated with concrete- they even make it as bags, with an internal bladder, as an instant hardened shelter.  Leaf blower to inflate it (like a bouncy house) and then spray it with water, and it hardens overnight.  Sterilizable, hardened, drillable for utility installation, all of it.  They also can unroll it and make walkways, dams, runoff channels, you name it.  Amazingly useful invention:

http://www.youtube.com/watch?v=LBHVKFCoYFc

It's one of those "Geez, I wish I had thought of that" things, we've been doing the same thing forever with fiberglass and paper mache, why it's never been done before now with concrete is just that "Aha!" or "I wonder.." moment, I suppose.. it was invented by university students... and I look at it and instantly imagine it would be a PERFECT shop space.  Maybe it's the extremely thinly veiled desire to have a skull-shaped island with a dome, or an underground lair, but for some reason this has that "madman with a soldering iron" feel, don't you think?  Suffice to say, I think the stuff makes it worth trying out for yourself, in a poorly done hobby way.  Fiberglass matting saturated with portland cement and probably some type of latex (I would use exterior latex semigloss paint.  Always add latex to cement, imo- the cost is worth the durability.) would probably work for starters and would be cheap enough to try.  Home depot, ten to fifteen bucks you should be able to get a sack of portland cement and the cloth and a quart of noname latex paint..  Heck, they are using canvas, but multilayered.  I might consider using the fiber roll padding used for carpet backing possibly.  In any case, sounds like cheap and easy enough to try...
When the testing is complete there will be... cake.

JoeN

#518
Mar 13, 2013, 10:05 pm Last Edit: Mar 13, 2013, 10:09 pm by JoeN Reason: 1
I wonder what parts of the USA that thing would be building code compliant for a permanent installation, which I guess is the intent.  Still, very cool.  I didn't have that vid on with sound.  Are there any specs on that like how much weight it can hold on the roof before it collapses?

edit....  Found it:

Quote
Have you done any analytical testing on CCS?

The University of Bath has completed Finite Element Analysis of CCS50 structures. The result showed that the shelter can withstand all specified load cases including a person standing on the roof, uneven snow loading and Hurricane force winds. In addition it proved that the shelter can be earth-bermed with up to 0.75m of wet sand on the sides of the structure and 0.5m on the roof.


They didn't answer if adding gun ports would significantly weaken the structure though.   ]:D
I have only come here seeking knowledge. Things they would not teach me of in college.

focalist

#519
Mar 13, 2013, 10:22 pm Last Edit: Mar 13, 2013, 11:02 pm by focalist Reason: 1
Well, they say it's supposed to last ten years.. in many places that isn't considered a permanent structure.  I know here in Massachusetts, it has to have a foundation and be expected to have a certain lifespan to be considered a permanent structure as relates to property laws.  Especially considering there's no reinforcing bars or anything, that's impressive lifespan for a temporary building!  The ribbing where the fabric is stitched forms the load bearing members of the structure.

I have no idea of the price of the things, but in many cases I am sure that it is a fraction of the cost of virtually any other form of construction.  The one they show most often is something like 50 square meters... that's a pretty decent area, requiring framing and such with any other construction method.  The thing is easier to assemble than a tent.. only takes one person.

I also look at the smaller one, and having grown up in the Midwest where tornadoes are a common thing... if you anchored that thing (and I mean really anchor it) it's rounded shape makes it an almost ideal tornado shelter.  Heck, the ability to put up a feedbarn anywhere in a single day with one man... what's that worth to a farm?

I have one of the prefab steel backyard lawnmower and junk sheds, it's running down to the end of it's life- I understand it's over twenty years old.  When I looked at what it costs to replace it, you are looking at a thousand dollars or more in many cases- and I know from a mechanic friend who has done it- don't do the "assemble it yourself" kits, ever.  Even cheap sheds are five to seven hundred dollars, and even if you just set out to build one yourself out of lumber, you are looking at a few hundred for even the most rudimentary-- and a lot of labor and knowhow to do it if you want it to last a decade or two.  If one of the smaller ones was say, five hunded dollars-- it would be a real contender in that market.  I know I would think about it... and in the meantime, I take window screen and lay it across the rust holes and hit it with that spray rubber coating (or automotive undercoating spray), and it'll hold for several years.. I am up to three years on one such patch :)

Another very interesting material I have a yen to play with is UV-cure polymers.  In all honesty, I want to build a 3-d printer which utilizes this rather than extrusion.. I think managing a UV LED or laser diode is a lot easier than a feed mechanism and temperature controlled nozzles.  Just pump the liquid polymer and expose (harden) it on very precise locations, the extra runs down and is refed into the supply.  The media management becomes a simple pump, the "print head" an LED or laser diode.  All that's left is a gantry.
When the testing is complete there will be... cake.

draythomp

Quote
Another mix I have yet to try is glass strands in concrete.

I did this a couple of months ago.  A contractor I had working on my house years back didn't put enough foundation under one part and the room started to drop.  I had a crew (shovel...that much...not me) dig it out under the existing foundation and then out three feet to form a walkway.   I filled it with fiberglass reinforced 3000 lb concrete and rebar.  Really can't speak to the survivability, but the stuff has totally stopped movement on that part of the house.

But I have got to experiment with that building idea.  I'll start small, maybe a flower pot, planter, dog house, something on that scale.  It's just too cool
Trying to keep my house under control http://www.desert-home.com/

GoForSmoke


The ribbing where the fabric is stitched forms the load bearing members of the structure.


When it is done, the shell is the load bearing part.
And wow, call it a 'bomb' shelter. But it's not proper evil genius without an underground complex.

Concrete has enormous compressive strength, good but not great shear strength and very weak tensile strength. Add wire or glass fiber and suddenly you have super-crete.

I learned wire and concrete in design school. Less than 3/8" thick welding rod, stainless steel screen and concrete easily deflected a 2 1/2 lb sledge on a 2 ft wide model. Tubing, chicken wire and concrete has been used to make ocean-going 40+ ft boats with 3/4" thick hulls (except where the 2 1/2" tubing was). The stuff just gives and flexes back. If you break it, you push the loose stuff out and patch it with concrete, which is kind of like what you do with a fiberglass canoe that's been slammed into a rock.

I have to wonder how thin the glass cuttings and concrete can go. It might work for enclosures and it might not.

Oh yeah, use driveway sealer when you're done. Concrete needs some water (the term I was given is water of hydration) to maintain bonds. If it dries out, it loses strength.
Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

cyberteque

one of the best ways to waterproof concrete is PVA, water it down about 4 or 5 to 1, let it churn in the mixer for a while.
This is a great way to waterproof ponds.

Another strengthening idea the Australian Defense Force found is wood wool, sawdust isn't good enough, you need "curly" bits.
Give them a soak in a PVA/water wash, then apply them to your first layer of concrete on a "chicken wire" base, then trowel another layer of concrete over.

Other methods are polypropylene or glass fibres mixed in.

Glass reenforced concrete is really strong, they use it here on our street racing circuit curbings.


GoForSmoke

#523
Mar 14, 2013, 06:46 am Last Edit: Mar 14, 2013, 07:05 am by GoForSmoke Reason: 1
I've wondered about wood splinters as a cheap alternative to glass or wire. Shavings? Sounds good. I only use sawdust with glue to make putty, not crete.

The way I was first taught is a frame with layers of chicken wire loosely tied and the concrete pressed in taking care there's no air bubbles. It can get very thin and take high loads. That was 1974-75.

I see the use of 2 to 3 inch wire or glass fiber strands touted since. It can be poured, molded, and now erected dry and hosed down. The amount of handwork has gone way down.

Also at home supply stores, check out Hardie Board and Hardie flooring, especially the flooring.



Nick Gammon on multitasking Arduinos:
1) http://gammon.com.au/blink
2) http://gammon.com.au/serial
3) http://gammon.com.au/interrupts

westfw


I've recently been intrigued by the invention of Concrete Cloth.

Hmm.  It's not such a new idea anymore.  First shows up on the Internet in 2005, having won a prize in a 2004 design contest: http://www.wired.com/news/technology/0,1282,66872,00.html

And most recently (8 years later) looking about the same:
http://laughingsquid.com/concrete-canvas-shelter-an-inflatable-concrete-building/

So why isn't this showing up all over?  (perhaps I expect change to be too rapid, being in high-tech and all.)  A bit of searching, and it sort-of looks like the "inflatable building" isn't quite the killer app that it looks like in the demo.  Perhaps if you can deliver and position 500+lbs of concrete, provide running water for hydration and electricity for inflation, the other theoretical advantages of the scheme aren't so compelling anymore :-(  It looks like  they and other licensees are doing other neat stuff, though.  http://www.concretecanvas.co.uk/Images/ccgengallery/index.html

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