Wed 10 Feb 2010
Fabrication Ergonomics
Posted by Marcin
We’re now in production of the open source, Compressed Earth Block (CEB) press. Here we document the fabrication ergonomics for the first steps in the build. This is for those of you considering replication.
It took 11.5 hours to cut the steel for The Liberator Beta v2.0 CEB press according to this cut list. This involved punching some of the holes, shearing, and bending – care of the local fab shop.
It took me 2 hours to build the press foot:
It took 2 hours to build the grate. Here is the grate with spacers between rebar prior to welding:
So far, the total is 15.5 hours of fabrication. If we had a hole puncher, we could probably save ourselves 2 hours of outsourced labor. So here’s our design of the hole puncher, to be built – as part of an ironworker machine:
The dxf files are here, so you can download them and continue the design if you want to get involved. This is an invitation to collaboration, starting with the wiki. First part of the ironworker is a hole puncher, and second step is metal shears for up to 12 inch wide metal, 1″ thick. The shears could save us a few more hours of outsourced labor.
There are holes on the u-channel that don’t lend themselves to hole punching, so these will be drilled using the FeF Multimachine in-the-making.
Hey, look, I found two, scrap six cylinder, in-line, 300 cubic inch Ford engine blocks in the back of the pickup.
That will be the start of the next version of the Multimachine.
Cutting out the hopper took about an hour.
If we had RepTab, the open source torch table up and running already – we could cut the 1/8″ sheet in about 5 minutes at the rated cutting speed of our 60 amp plasma cutter. So here’s a case for spending 2 dedicated weeks to get RepTab shaken down into full running condition.
In the meantime, William has been learning MIG welding in preparation for his arrival in May. Here’s a video:
He is also learning QCad, so we’ll hit the ground running on design and build of a new civilization.
February 10th, 2010 at 4:47 am
Nice to know about the progress being made, why not form a list of all the machine tools that exist and start to reverse engineer them on a priority basis? I would add how many I know to the wiki. If you all are well versed with cnc mechanism a 5 axis grinder would make all the drills and end mills you would require.
February 10th, 2010 at 11:46 am
Be careful with that MIG. The weld penetration is not deep enough to use for life or death welds.
Someone died recently due to a MIG welded lifting eye.
February 10th, 2010 at 1:48 pm
One priority list is found at http://openfarmtech.org/index.php/OS_Fab_Lab_Proposal
Tell us more about the 5 axis grinder for drills and end mills.
February 11th, 2010 at 12:42 am
Hey Marcin the way twist drills and end mills are manufactured these days is by grinding a steel bar stock which forms the flutes and tip. The grinder follows a toolpath and the workpiece is advanced indexed rotated till the job is done. http://www.youtube.com/watch?v=L4vfS1990qM I also searched for a low production type that is completely manual without luck. I envision that maybe just maybe they can be made on a milling machine to which a grinder is attached and the work piece chucked to a dividing head and connected by a gear-train to the x axis table feed. It is a true indexing head with a disengage worm gear. This is the way helical gears are made on a manual milling machine. http://www.youtube.com/watch?v=vyg0Emz4Vx4 never saw the Fab lab page will try to contribute to it. BTW we need talk or chat, this is regarding your power generation; I use google for chats and I saw your openSourceEcology@gmail.com address. Do let me know of a convenient time and please include the time zone
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February 12th, 2010 at 7:50 am
Also Marcin for the lathe why not use heavy duty plummer block or pillow block bearing? You would need a rigid piece of steel to raise the height according to your spindle level. They are real heavy duty and used in industrial application. I only mean the flange type http://www.bri-mac.co.uk/products/LOE%20picy.jpg http://www.wordsun.com/assets/baldor-1-1233917891.jpg they are standardized and available in various sizes.The way the bearings are currently mounted on your lathe can never offer rigidity as the steel would definitely flex. If you complete the furnace you can inexpensively cast your own bearing housings.
February 13th, 2010 at 5:55 am
When grinding, don’t you loose a lot of valuable metal that is polluted with lubricant? Is that easily re-usable in the furnace? For sustainability it is probably important we don’t loose too much metal.
February 13th, 2010 at 6:01 am
Ram: isn’t http://www.youtube.com/watch?v=BIsRhOQlTOs a largely manual grinder for the job (it appears to be just a single engine for driving the grinding/sharpening tool itself)
February 15th, 2010 at 2:04 am
Hi Erlend do you lose a lot of metal? Hell yeah!! But the manufacturers can always pass down the cost to customers which they do. They can use a different method but then the grinding process is perfectly suited as you need only minimum employees and you do not have to sharpen tool bits etc. Grinding is also a very precise process. Yes there is a lot of waste and no it cannot be reused. The only other alternative that i can think of is to cut them on a milling machine using a steel cutting tool and recast the scrap. The other way is to form a permanent forging die that accepts hot blanks for forming. A cheap way is to grind down a rectangular piece of metal down the metal on both sides and twist it into shape. And the video yeah its a grinder for the job of SHARPENING drills, taps etc not MAKING them. On a side note if the foundry rolling and extrusion project gets going you can have a die with necessary cross section and just twist them, it would be an extremely productive and cheap process but would not be very accurate.