[msimpson99]

I did some experiments today cutting foam insulation. The pink stuff you get from various home centers. This is 1" thick insulation.

[ame=http://www.youtube.com/watch?v=ZzxBrLYrHU0]KRMx02 Cutting Foam Insulation - YouTube[/ame]

Bottom line, Cut as much foam in one pass as you can. This removes the heat quickly. Also dust collection is a must.

I started a little blog here:
Cutting Foam Insulation

I ordered a Onsrud

[harryn]

Thank you for doing the testing and posting the video of the foam cutting.

[msimpson99]

Thank you for doing the testing and posting the video of the foam cutting.

No problem. I just go in my foam cutting bit and will be doing some more tests today. I will post the vids when I am finished.

[LaughingJaguar]

I've been building composite parts for 35 years for use in many disciplines, from telescopes to aircraft.

Precision forming of the structural foam cores has always been time consuming, especially on parts that are not simple and prismatic in shape but with compound and organic surfaces. Hot wire cutters don't always work with some foams.

People have been asking me how I intend to use my new Evo when it is finished.

Now, instead of attempting to explain, I'll simply give them a link to your video.

Thanks

L.J.

[msimpson99]

Just put the Onsrud foam cutting bit to the test.
It cuts like butter. It has different geometry than your standard up spiral bit.

See it in action here:

[ame=http://www.youtube.com/watch?v=grq7EPkMNy4]Cutting Foam Insulation - YouTube[/ame]

You can get more information on my foam testing here:
Cutting Foam Insulation



[ame="http://www.amazon.com/gp/product/B0020AUG70/ref=as_li_tf_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B0020AUG70&linkCode=as2&tag=kronosrobotic-20"]You can get the Onsrud bit here[/ame]

[msimpson99]

I though you might want to see the fruit of my labors.

[ame=http://www.youtube.com/watch?v=Bvaa5RRJ2jM]Quadcopter Prototype - YouTube[/ame]

I ordered some new props that will workout much better than the nasty toy ones I am using here. Also I can use foam for the standoffs. It will be more rigid and weigh less.

When I get the new props I will cut a smaller body out of 2" foam that will include the standoffs.

[LaughingJaguar]

That four blade copter would drive my cats crazy but looks like an easy build!

What I am interested in is the name of the manufacturer of the fixturing plate you use for your hold-downs.

Thanks

L.J.

[msimpson99]

The fixture used to hold the booms was MDF. The clamps are Baltic birch with 5/16" T bolts. The table top is 80/20.

The slot in the MDF was cut to hold a 3/8" square x 13" strip. It’s a tight fit so knockout holes were added at three points.

My first attempt at cutting the booms failed, as I was just using the clamps to hold it against the fence. One end was off center. I thought my fence was out of adjustment, but it turned out to be spot on.

The problem was that the wood strip was slightly twisted on one end. The fixture holds the wood at the correct position regardless of warpage.

[msimpson99]

Just cut some 2" foam insulation. I only took 1" cuts as I needed this part quickly.

[ame=http://www.youtube.com/watch?v=0Dn6CrkHtf0]Quad Mod - YouTube[/ame]

It's a replacement for the standoff hardware I was using. Using the foam created a stronger frame and was almost 40 grams lighter.

[LaughingJaguar]

The fixture used to hold the booms was MDF. The clamps are Baltic birch with 5/16" T bolts. The table top is 80/20.The slot in the MDF was cut to hold a 3/8" square x 13" strip. It’s a tight fit so knockout holes were added at three points.

I am really pleased to learn that the floor plate with all those "T" slots is an 80/20 product.

I'm building a 4 x 4 EVO and considering using 80-20 extrusions for the frame.

Now that I know they have a fixturing plate, it furthers my commitment to using their components.

The four-rotor RC chopper is a hoot! Will you be offering plans? Components?

Thanks

L.J.

[msimpson99]

Here you can get a better look at the construction of the top.

[ame="http://www.youtube.com/watch?v=MOv88lMDWAA"]Modular CNC Table - YouTube[/ame]

Here is a smaller version of the same machine. Same design, but the table top is connected to a piece of MDF so that the whole table top can be removed.

[ame="http://www.youtube.com/watch?v=TRPwpK-J2FE"]Making Dust KRMx02 Demo Machine - YouTube[/ame]





The idea is to write a book that features three multi-rotor craft. A small quad one like the one I am playing with here. A mid sized quad, and a large hex or octo.

Im supposed to do a multi-article series in Servo Magazine as well. It will feature the mid sized quad.

The thing is I can build them and fly them so-so. For the fancy stuff I have to get my buddy to take control of the craft. On the mid sized and large craft I can add FPV cameras so they are fairly easy to fly. Also the kind of computer that is controlling them makes a big difference. IE the mid and large will have presure sensors and GPS for holding position and coming home if they get out of range.

Im having a lot of fun cutting the foam on this small one. The speeds and feeds I have, make is easy to slap the foam down and cut the part. On the large one I will be cutting aluminum plate with the CNC. It will have aluminum booms, legs, and some sort of aluminum gible for one of the cameras.

[msimpson99]

Did a little 3D profile today.

[ame=http://www.youtube.com/watch?v=V_UVdGe-h_0]KRMx02 doing 3D Profile in Foam Insulation - YouTube[/ame]

The only bit I could get my hands on in short notice as a little 1/4" round nose bit. The results were not bad concidering.

This is actualy slice 1 in a two slice part. I would have prefered to cut it all in one pass. I need to purchase a set of extended bits so I can carve 2" foam.

[msimpson99]

Some more foam cutting. I did a little 3D rosette using a 1/16" straight bit.

[ame=http://www.youtube.com/watch?v=wwkOc16NjXk]3D Foam Profile - YouTube[/ame]

I pretty much reached the maximum resolution of foam insulation.

You can see all the foam insulation notes here:
Cutting Foam Insulation

[Shalecnc]

Why don't you pick up some polyurethane foam insulation boards from Home Depot or Lowes (it should be next to the pink extruded polystyrene, but will probably have a foil backing on both sides)?

As I understand it, its much easier to shape on a router. It [should] turn into dust rather than melt at high spindle speeds, which is what you're looking for a surface finish.

[msimpson99]

I saw this. I was wondering about it. It looks a little tighter as well so it may work for making molds.

[Shalecnc]

Please do try it and post a comparison video -- Loving these clips!

[msimpson99]

Any recomendations on handling the foil skin?

One is to just ignore it. When using Cut3D it taks a very small pass at all surfaces so its possible its mute.

[Shalecnc]

Couple ideas:

You could experiment with a heatgun or hairdryer to weaken the adhesive bond (if there is one). But I would be very careful there -- you can potentially "cook" the top layer of polyurethane, which gives off dangerous (potentially fatal) gases.

I'd just try milling through it.

If it starts to clog up the bit and pieces of AL swag hit the part, you could do a single facing pass, taking off .1" over the entire board before starting. Though that would be time consuming.

Still... lots cheaper than blocks of Urethane tooling foam.

[msimpson99]

Cut a 3D face today. I got the face off this forum.

Im using a 1/8" four flute ball nose bit.

[ame=http://www.youtube.com/watch?v=l8qfXo6CDu8]KRMx02 Cutting 3D Face - YouTube[/ame]

[msimpson99]

I thought I would show you why I started working with foam in the first place. I wanted to create a protective body for a QuadCopter I built.

[ame=http://www.youtube.com/watch?v=a724Z8ffQ7U]QuadCopter Body - YouTube[/ame]