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Keith Outten
10-16-2005, 11:10 PM
Not exactly woodworking but my cinder block project is a 3D sign design and a procedure that could be applied to wood or other materials. Very light and suitable for exterior service, foam shapes are often used to enhance exterior signs and will withstand the test of time when exposed to the elements.

My first attempt at machining foam sheets is my foam cinder block project. Using two inch thick foam it takes three sheets to machine eleven pieces that will produce a 44.5" by 22" by 22" cinder block. The picture below shows four pieces of machined foam on the router table. The other seven pieces are glued up, stacked with plenty of weight on the top of the stack. I ran out of glue so it will be tomorrow night before I will be able to complete the glueing process.

The next step is a very light sanding, then applying two coats of a plaster like material. Another sanding step then painting. I will post more pictures as the project moves along.

.

Gary Sutherland
10-17-2005, 4:10 AM
Keith:

Have you experimented yet with routing more complex 3D shapes by 'slicing' the design into layers in the software?

I've seen some pretty neat things cut with that process. Apparently, even the super cheap insulation foams work well for many things, when hard coated.

Like to see more pictures of your projects!

Gary

Keith Outten
10-17-2005, 7:58 AM
Gary,

At the ShopBot Jamboree there was lots of discussion concerninig slicing using AutoCad and a couple other programs. We saw some photos of several projects that others had done, it is a complex technique. The cinder block is a simple shape and did not require any complex software manipulation so I decided to give it a try as my first 3D project.

It took me awhile to identify and find a local source for brown coat, the plaster like coating everyone uses to protect foam projects. A little research turned up a local contractor who knew the product and identified a local company that sells a whole range of coating products including a top coat material. I understand that some people imbed a mesh product to reinforce the coating simular to the way fiberglass is done.

For me this is a learninig project, something I decided would be easy to build and learn to use the various materials in preparation for other foam projects in the future. I am currently working on a construction project (day job) and have found lots of business connections at work, the cinder block should prove to be quite popular and receive lots of exposure so it will be good marketing for my sign business.

Lee DeRaud
10-17-2005, 11:55 AM
Oh, come on, get ambitious!! This tool and some serious computer time looks like just the ticket for doing these things:
http://www.sawmillcreek.org/showthread.php?t=20786

Aaron Koehl
10-17-2005, 12:13 PM
Keith:

Have you experimented yet with routing more complex 3D shapes by 'slicing' the design into layers in the software?

I've seen some pretty neat things cut with that process. Apparently, even the super cheap insulation foams work well for many things, when hard coated.

Like to see more pictures of your projects!

Gary
Gary,

We're working toward more complex 3D objects-- ya gotta start somewhere. ;)

Ed Lang
10-18-2005, 10:05 AM
Looks great Keith and Aaron!

I hope to be doing something with my bot soon.

Keith Outten
10-18-2005, 1:42 PM
Ed,

I didn't have time to work on the cinder block last night, work got in the way.

I expect you have your ShopBot assembled by now. Are you runninig any practice jobs yet?

--------------------------------------------------------------------------------------
Lee,

I make signs not furniture. Occasionally I get to make things for my own personal use but the majority of my shop work is business related these days.

Ed Lang
10-18-2005, 10:57 PM
Keith,

Just came up from the shop after surfacing the spoilboard. You will see my post on here about it I am sure.

I spoke with Scott at ShopBot this morning and asked how most folks mount the MDF spoilboard and he said they glue it to the plywood. I never thought of that. So I glued it and counter sunk screws around the edges and down the middle to hold till the glue dries. I could not wait sinct I had it screwed down I fired up the computer and bot and started the surfacing. I had installed the ClearVue Cyclone but not run duct to anything yet. The Bot was the first to throw dust at it and I am sure glad I had the cyclone connected!! The MDF dust would have covered everything in sight had it not all gone into the 55 gallon drum.

So, maybe tomorrow I will get the computer work center cut and built. Then on to Santa and the deer.

The VectorArt collection #1 should be delivered tomorrow and Scott is excited about it.

I hope to see something from your way in the mail soon too;)

How did you hold down the 2" foam for the cinder block?

Take care and I gotta go to bed now the lack of sleep is catching up with me.

Bill Lewis
10-19-2005, 6:54 AM
Keith,

Can you post more information about the hard coat or brown coat material that you are using over the foam? Manufacturer name, website, and/or what sort of company carries this product?

Keith Outten
10-19-2005, 7:32 AM
Bill,

The product I am using is Imperial Basecoat Plaster. It is made by the United States Gypsum Company, 125 South Franklin Street Chicago Illinois. It is sold in a 79.4 pound bag.

I purchased it locally from a Building Specialty company, they sell commercial coatings and supplys to the construction industry.

Ed,

I used plastic toilet screws and nuts to fasten my MDF spoilboard to the plywood base. This way it is easy to replace the spoilboard when it gets thin and I don't have to sacrifice the plywood backer.

I used a plywood strip and two quick clamps to hold the foam to the table, I placed one 48" strip at the end and one in the middle of the sheet and moved them as necessary. Check the list of bits in your software, there is a selection already programmed for urethane foam.

Keith Outten
01-15-2006, 12:25 AM
I finally got the first coat of plaster on my cinder block today. Plenty of fiberglass cloth embedded in the plaster for extra strength. Tomorrow I hope to get the final coat applied and move this beast out of my workshop, I sure need the space for other projects.

My Dad and I had three concurrent jobs going today, besides the cinder block we are working on ceiling access panels that we are CNC routing using Corian and I have to create a sample door sign made from cherry to submit for a commercial building project. We actually do get to work with wood on occasion :)

Ed, when you get around to machining foam sheets and get to the plaster application you will find that when it cures it is hard as a brick (pun intended). The plaster dries in one to two hours and can be applied with a stiff brush or trowel. It can also be sanded after it cures so there is no need to fret about minor mistakes. Mix the plaster in small quantities, the working time is less than 30 minutes. I'm going to find the time soon to machine a large sign from foam, this is really cool material....except for sanding which is absolutely nasty :(

.

Michael Ballent
01-15-2006, 1:13 AM
OK call me dense, but why are you building this in the first place? Is it going to be a prop for a stage show? Although it's pretty cool that you can do this.

Keith Outten
01-15-2006, 8:05 AM
Michael,

The cinder block will serve as a sample of our 3D signage capability and will eventually be leased to a photo studio as a prop. For shows and local events it will be a real eye catcher attracting people to our booth or display. This kind of work is difficult to explain to potential customers so a picture in a brochure will be worth a thousand words :)

Various kinds of special machining jobs are often associated with theme parks when they design and build new rides. The majority of these kinds of props are made from foam sheets and shaped in various ways. Busch Gardens Williamsburg often uses local firms to build the infastructure for their new amusement rides. It's very profitable :)

Keith Outten
01-25-2010, 12:02 PM
Cruising my old files yesterday I found the cdr file for the cinder block. Not exactly a challenging project but it was certainly fun :) The cinder block has made the rounds from photo studio as a photography prop to my office where it is now being used as a book rack for catalogs which seems appropriate for an Architects Office/Sign Shop.

I'm not sure if I indicated in earlier posts that I took the cinder block to a local truck bed liner business and had them spray it with a bed liner coating. The coating made it almost indestructible and impervious to the weather.
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Bob Savage
01-25-2010, 3:50 PM
That giant cinderblock is very cool!

Keith Outten
01-25-2010, 9:02 PM
Bob,

I probably should take another picture of the cinder block since it has been coated. I wish I hadn't used the brown coat but it did add a very realistic texture. The bed liner coating is the hot setup for this kind of project, its tough and almost indestructible.

I have tried the bed liner spray cans from my local auto store on some small projects, it isn't the same as the coating you get from the truck bed coating services by a long shot.
.

Garrick David
01-26-2010, 10:39 PM
why not hot wire cut them?

Steve knight
01-27-2010, 1:45 AM
it would be a great attention getter. but it's not 3d is it? looks 2d to me.

Keith Outten
01-27-2010, 7:33 AM
Steve,

The machining is 2D but the end result is a 3D cinder block.
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Bryan Cowan
01-29-2010, 10:11 AM
Steve,

The machining is 2D but the end result is a 3D cinder block.
.

Keith,

Your cinder block really got me thinking. What else could be done in 2D slices to be made into a larger-than-life 3D object?

My aunt owns a dance studio and every June has a week-long show. Every dance/choreography uses a prop of some sort. I never got into specifics with how much her studio spends on rental props, but I wonder if it's something I could help with.

I've never looked into insulation foam for anything let alone CNC. Where could you buy it? I assume Home Depot or Lowes? That's one aisle where apparently I've never gone down :)

Keith Outten
01-29-2010, 1:41 PM
Bryan,

Lowes and Home Depot both stock styrofoam sheets in my area. I expect it is available at almost all home centers and building supply companies.

Let your imagination run wild, there must be an unlimited number of projects that you could build. Woodworkers who don't own CNC machines can cut flat sheets on their band saw and accomplish this type of project.

If you have them sprayed with bedliner material you could make lawn furniture that would be almost indestructible.
.

Bob Savage
01-29-2010, 4:24 PM
Like Bryan, this project and the other recent one building the giant guitar has me thinking about fun, GIANT projects.

I'm wondering if the insulation foam availability is regional? The Home Depot's around me have sheets but they're only about 3/8" thick, have blue plastic on them and are fairly expensive at about $30 a sheet. I'd spend eons cutting it and hundreds in material to do that cinderblock.

I'll check Lowe's next.

james mcgrew
01-29-2010, 6:05 PM
bob most building supply companies carry it it is not stocked in thickness at hd or lowes but 2" is common

call an insulation supplier

jim

Keith Outten
01-29-2010, 6:17 PM
Our local Home Depot carries the 2" thick styrofoam, it is about $24.00 per sheet.
You can get it in 2.5", 3" and 4" thick sheets at most of the commercial building supply companies.

I got two pickup truck loads of brand new 2" thick sheets that were left over from a construction project for free last year, they were about to put them in a dumpster. If you get get friendly with a Construction Superintendent on a large commercial building project he can call you when they are in the cleanup stage of the job to let you know that they have left over materials. You can get marble and a lot of other valuable materials this way.

I make small signs for a couple Superintendents and they often they need and an occasional award plaque :) Keeps them thinking about me :)
.

Steve knight
01-31-2010, 3:42 AM
can someone convert this to a dxf for a vcarve file? I just came across a sheet of foam and want to cut this out.

Bob Savage
01-31-2010, 6:29 AM
can someone convert this to a dxf for a vcarve file? I just came across a sheet of foam and want to cut this out.

See if this works.