Milling Plastazote LD33 closed cell Foam - Any milling advice?

**Foamer** · 19-11-2017

Zeeflyboy,
How did you get the caliper and knife shapes in Fusion360?

**Zeeflyboy** · 20-11-2017

Take a photo with the component you want to use, preferably with a ruler next to it for scale. Try to get things lined up as square as you can and it helps to take photo from further away with a zoom if possible to flatten the image. For best results keep the component in the centre of the image away from the border to avoid any potential issues with lens distortion.

In fusion, import the photo and scale it using either the ruler in the picture or a known distance on the component itself. Rotate and move the canvas so that it is where you want and then just draw around it using line tool and splines. I tend to hug the thing as close as possible and then do a sketch offset to achieve an acceptable tolerance.

**MPi11** · 26-11-2018

Trying to buy some of this with your initial link, but can't get through to checkout for some reason? Is this the same plastazote you used before I buy?

**Zeeflyboy** · 26-11-2018

Looks to be the same stuff!

**Tigger** · 11-01-2019

Hi Zeeflyboy, your foam cutting is impressive. We have ordered a Workbee CNC machine and are waiting for delivery, as we will be using the machine to make bespoke foam inserts for the tool, UAV batteries and parts the info you have share here will be invalueble to us.

We intend to use the LD33 foam and would like to know what cutter would be best and where did you purchase them from?

Could share the cutting speed dept of cut that you have found to be the best for the LD33?

Regards

**Zeeflyboy** · 11-01-2019

As mentioned I got the best results with single flute down cut, make sure they are nice and sharp. I used Belin but there are plenty of single flute down cut bits around... Choice is probably most limited by cutter length depending on what you want to do, although there is no problem doing 2 passes with the second pass below cutter height (as long as shank is same diameter as cutter obviously), it’s just slower. I think the Belin only go up to 38mm on a 6mm cutter.

I bought those here https://www.cncroutershop.com/uk_en/...wn-spiral.html

The most important thing I found is to use conventional milling and NOT climb.

Depth of cut is fairly unimportant. The foam is soft enough that it won’t test the rigidity of any half decent machine, same goes for width of cut and it more becomes a question of having swarf that can clear easily. I had good results using 16k rpm and 3,000mm/min on the 6mm tool, and I think around 20,000 on the 3mm.... but there’s certainly plenty of room to play around there.

For hold down I would box it in if working very close to the edge, and a vacuum plate would be the easiest way to keep it stuck down.

**Tigger** · 11-01-2019

Originally Posted by Zeeflyboy

As mentioned I got the best results with single flute down cut, make sure they are nice and sharp. I used Belin but there are plenty of single flute down cut bits around... Choice is probably most limited by cutter length depending on what you want to do, although there is no problem doing 2 passes with the second pass below cutter height (as long as shank is same diameter as cutter obviously), it’s just slower. I think the Belin only go up to 38mm on a 6mm cutter.

I bought those here https://www.cncroutershop.com/uk_en/...wn-spiral.html

The most important thing I found is to use conventional milling and NOT climb.

Depth of cut is fairly unimportant. The foam is soft enough that it won’t test the rigidity of any half decent machine, same goes for width of cut and it more becomes a question of having swarf that can clear easily. I had good results using 16k rpm and 3,000mm/min on the 6mm tool, and I think around 20,000 on the 3mm.... but there’s certainly plenty of room to play around there.

For hold down I would box it in if working very close to the edge, and a vacuum plate would be the easiest way to keep it stuck down.

Cheers, I cannot wait to get started.

**tomtailford** · 06-04-2022

Zeeflyboy / Tigger

Don't suppose either of you would be able to cut some of this foam to a spec?!

I've asked around quite a few companies, some had agreed, others can't get sorted by the required date (14th April)

If this is something either of you could potentially do, would be amazing, can pay for the service!