How to Cut Foam 

Hi. I work at a flight case company in Holland where I cut a lot of foam for huge flight cases to tiny presenting boxes like yours. So I thought you might like some tips. How we do it. Instead of putting the foam directly onto the suction grid we put a thin sheat of 3 millimeter mdf wood that allows the suction to go tru and then set the dept of the router to just hit the mdf so you cut al the way tru the foam. So then you get an instand smooth edge. I do like you're idea of the table router to round of the edges. Nice! We use a very fine bandsaw that you can put on a 45 degree angle. But I think you're doing it well! When the foam comes of the cnc it's always a little bit rough, that normal. So we hit it gently with a heat gun so it melts all the burs away and gives it a general smooth finish. Another thing, my personal taste, I think it looks a lot better If the egg box foam in the lid has smaller bumps. Here in Holland you can get them in all sorts of depths en thicknesses. Good luck!

If you are this thoughtful about your foam packaging, I can't imagine how AMAZING your knives must be!

I just spent 16 minutes watching foam cutting. And it was awesome.

Man the attention to detail you guys put into this is phenomenal. Your passion really shows. You guys will be very successful

You guys are too much, the attention to detail is amazing. Good job! Now I want one of your knives.

Attention to detail even on the small things mean a lot to the customer. Great job!

I spent 40 years in the machine tool industry John and you did a great job with that foam insert. I had several ideas pop up during the video only to see you use them later in your presentation, so "great minds", eh? All in all, nicely done and it was fun watching the problem solving process again.

Thank you for sharing your process of solving your problem and enjoy the commitment to your quality standard.

I love that you guys make EV-ERY-THING! Truly special

Hot damn, these foam inserts are awesome. Lot’s of useful tips for anyone wanting to cut foam on the CNC.

is a very dinamic and realistic video ... is amazing!

A trick for getting rid of the fuzzy edge is to use a heat gun. The tiny fuzz shrinks from the heat faster than the solid foam will burn. So if you do it quick enough you get a clean product.

As an Entrepreneur myself, I really appreciate your attention to detail and dedication to improving the quality of your packaging. To be honest, I had never heard of your company before today when this video showed up in my suggested videos. I'm definitely going to be looking into your products, as I am also a knife enthusiast! Keep up the great work and never stop striving to put out high quality stuff!

" How to Cut Foam " Step 1: get foam Step 2: get a $5,000 milling machine Me: LOL

I enjoy your full explanations of your thought process and then watch as you put it into action. Well done.

SO funny! Here I am looking up DIY foam cutting for fishing project and this video pops up from my grail maker. I don't have the tools Grimsmo has but hey, Im watched the whole thing any way. Good to see you guys! Beautiful work all the way around. Your attention to detials in every aspect demonstrate the pinacle of craftsmanship.

I remember when you used to ship your knives wrapped in newspaper. You've come a long way since then.

Holy crap! Such attention to detail. Great tips and great vid! Well done!

This type of foam works great for tool boxes. Making spots for every tool

Wow, everyone bashing about milling the foam yet nobody seems to care about the enthusiasm this guy talks about his work and the product... I smiled through the whole video thinking how happy I would be to work like him, being inventive about methods and then enjoying the result. You sir, made me want to buy a desktop CNC machine and make custom multi-layered foam for toolmen. Although I could probably accomplish that with my trusty Dremel, just need that Datron bit. I also understand that if you already have a milling machine, why the heck spend money on custom tools just to cut instead of milling when it's already available and doesn't need you to be there, working alone? I work in a small metal workshop and we many times have to go with what we have, not buying custom tools for one job. I liked this video a lot. Just ordered some samples from ShadowFoam by the way, being in Europe.

From experience, if you go over eva foam lightly with a heat gun it helps clean up some of the fuzz around edges. Not sure if it'd work with that foam but might be worth a shot on a scrap piece.

I just stumbled on you guys cause of this video alone. I now want one of your knives

love the development stages and thank you for all the tips!

I'm starting to carve cross link polyethylene foam, everything he's said has been correct so far. Great results so far!

I have been CNCing foam for years. I assure you that trimming the outer edge of the hole first is what we have been doing for years. With foam working from the inside out almost always works better. We have used a curved razor as well as routers to make radius edges. All in all very good job with a nice learning curve.

amazing on how much time and work that even go into just the case you obviously are a perfectionist and it shows in the quality of your knives .... don't own one yet but have handled a Norseman and fell in love! Keep up the great work John and team.

Great video, closest yet to getting perfect sides on foam

I use a 20w fibre laser to mark foam like that, and it comes out really well. Just melts the surface, very clean high resolution mark in only a few seconds (along with some nasty smoke.) I use plastizote LD45 or thereabouts for the foam, routed and then laser marked to put the logos on. its so fast, we even engrave customers names on their foam as we send stuff out. Takes seconds.

Now that's a ton of useful information right there! Thanks for sharing your experiences and solutions.. :-)

I'm impressed with your process problem-solving skill. I wouldn't have considered changing tool paths to correct the edge cutting issue. Since the material in use is just foam, I THINK it might be much less costly to cut using custom dies for each layer, before bonding them as a final sandwich/assembly. Instead of wearing out an expensive CNC router that requires several minutes per unit... a custom cutting die would simply press down and through the foam in 2 seconds. A medium durometer rummer base surface would preserve the cutting edges forever (virtually). I don't want to sound critical. Your business and presentation/marketing skills are exceptional. Thanks for posting.

Love the iterative design process for your cases. They look awesome!

You guys have come so far. Some day, I will buy a Grimsmo.

Love your attention to detail. I always look forward to your videos!!

Glad the videos are back! Great job Erin!

I decided finally to buy my own foam cutting company to make room for my cheap tools storage PVC briefcase. Thanks!

Thank you for sharing this content. Five stars.

Maybe you should make a aluminum/ Plastic template that fits inside the foam cutouts, on which the router bearing could ride. I think it would make Berry's job a little bit easier and more consistent. Regards from germany

Thanks for all the videos John!

25+ doing custom interiors,,and still using a DA with 60grit 3in flex wheel,,,Router use was a super means of removal,,love it,,nice to see you putting should detail into the cases,,Bear

Very much enjoyed your video

Very, Very informative video. Thanks guys.

The sticker looks great!

Nice work John

Just a thought, John. I totally thought at the beginning conventional milling would do the trick and was pleased ro see that's what you discovered. Another idea, why don't you machine a brand for your logo to heat stamp into the corner? Would save you tons of time on the mill.

John, adaptive clearing is ALWAYS the answer.

Love how you share the knowledge

Very nice John! I really enjoy the process.

Hi John, You can cut all the way through the product if you use a 5/32 piece of hard board with a flat closed cell (Adhesive backed) foam on it. You then can suck that down to the vacuum table and cut shallow pockets that follow the general shape of the part with just a little offset. These smaller pockets would essentially combine to form the shape of a part which you then create the array from. This forms a seamless, flat, gasket surface that will not leak. Ports are added to the jig to allow vacuum pressure to build in each pocket section. Then, you just suck down the template and your raw material at the same time. Here is the ultimate trick that makes this work. Since you now have a thickness to the foam that resides on the top of the template (bottom of the case foam), you can now cut all the way through the case foam without releasing the part as long as you only cut into the template foam but not through it. We used this method all the time and it is awesome. it would look similar to the jig set up in the link provided, but your cutter would not go all the way through the foam in the cut path below the part. This company sells the sheet goods. allstaradhesives.com/cart/category/cover_sheets

I had an idea for the back radius: A screen for the vacuum plate to put the foam inserts back on it upside down and milling the big radius on the CNC. Picture a lasercut plastic/acrylic/wood/thin aluminium "waste" lattice from your parts. With the screen you locate the inserts to the plate and cover up the exposed bits at the same time. This way you can even mill a small pocked if you need more space for things in the bottom.

Good video and good job! For the thin and small foam cutting,milling machine is suitable. Also good at engraving on the foam.

I have the exact same foam in my toolbox. Its cut specifically for my set of craftsman ratchets and sockets

Excellent job!

When you form dense foam buttstocks for guns you grind them on a belt sander to get the final shape. However they tend to struggle because the friction makes them too hot. Try putting your foam into the freezer before you use the roundover bit on them. I bet that will make the roundover easier and cleaner. The cold will make the foam more ridgid during the roundover process. Worth a try and is the go to trick for ridgid foam grind to fit shotgun recoil pads.

Sounds like Eric deserves a raise

Love the cases found video on a recommended. To put the labels on the cases to help you keep them straight you need to make a jig that will help you with the alignment and to keep them from going on wonky. Hope this helps u looking forward to seeing some of your other different videos 👌👍🤗

I love your attention to detail even on the foam inserts. Vacuum works great , I was wondering how you held it down. Like how you share your secrets.

Thanks for sharing your videos. I'm sure you have given lots of people the courage to become an entrepreneur since you fill in a lot of the mystery of all the steps it takes to run a small business. Since you have the equipment to make a mold, have you thought about just creating the exact piece through injection molding? Of course you would have to learn how to mix the chemicals to make the foam, but it would give you a nice smooth surface finish, and it would give you even more control over the process.

Dang John... You & Erick are missed. I get it though, you really are making things happen. Proud of what y'all have achieved.

In re: "Make chips" - I don't know the details of your plastic foam, but in some cases you can make soft materials like this more brittle by keeping them in the freezer until you need to machine them, or by some kind of forced air or wet process at the bit to keep them from melting by tooling friction.

Cool video, greetings from Finland

Looks cool. Only suggestion I could make that would help your throughput and may assist with your router table, is to use a profile cutter to remove your foam from your blank. Basically a razor sharp cookie cutter. Light press around each perimeter and you no longer have the remnants to work around for the bearing. Or you could use a 3m strip on the base or edge of the vacuum holes to hold the pieces to the table and then remove the material you leave. Really cool either way.

I've always found presentation to be very important it can go the extra mile adding that extra "pizzaz" really cool video THANKS!!!

Thanks, very nice work, its interesting how you guys tweek the finer details like on the woodworking table router and manual milling techniques instead of cnc climb milling.

Have you considered to cast the foam parts? Smooth-On has lots of different types of foam, that would fit your needs. This way you could cast the foam parts in ONE go. If your mould is big enough for 6 pads, you could make 6 pads in less than 5 minutes. Nice video btw. Thanks.

I just saw this video. Awesome. I highly suggest you watch (albeit totally different subject) the following channels about working with foam. Kamui Cosplay and PunishedProps. I highly suggest trying the heatgun method for heat sealing and deburring the foam... I always though about laser cutting the layers and glueing them later. So thanks for sharing. Cheers.

#BecauseGrimsmo moments watching this video: - Plastic decal stickers? Why not laser-etched aluminum? - Space in the bottom of the case for the sticker and the card? Why not a super-fancy CoA instead of just a business card? I can totally see a Grimsmo logo-embossed CoA. Maybe I'm crazy... - Why not a router table with a roun -- Oh, good, they thought of that. I would say that getting a smaller CNC for just the foam isn't wholly a bad idea -- looking at that cleanup after doing a few pallets and I can't imagine how much of a mess it would be if it's not spotless before going back to the titanium when the flood coolant comes in. None of this is criticism, I am continually staggered by your not just continuous, but relentless improvement. Keep up the amazing work, and never settle for less, it's why I enjoy watching you guys work. Maybe if the stars align, some day I'll be able to have a Grimsmo of my own.

Those injection moulded snap cases look awesome, a real pet hate of mine is the cheap all in one blow moulded cases that fold over a piece of plastic as the hinge.. I hate them with a passion they always split and break .. I like real sturdy hinges! Foam work is looking crisp! .. I cnced veg tan tooling leather for the first time a couple of months back.. works great!

At the beginning I was saying "No CNC, no CNC", and then "Crap!". Apparently everyone but me has a CNC machine, lathe, and a 3D printer.

I know its 2 yrs old, but great video, Thanks

I loved the look of your logo on the top foam. Heres a thought. A little dab of adhesive on the tips of the egg carton foam and the foam put in wavy side facing the case top. This will glue it so it wont fall out. Your logo on the flat side so you can see it or on a thin piece of denser foam adhesived to the flat side of the wavy foam. All this should give you a springy top foam that will hold everything snug when the case is shut and still have that super bad ass look of your logo on the top foam. Just a thought. Hope it makes your product better.

You can use the big cnc to make a mdf support, fit the foam in the support so it stays firm, then use the table router with the roundover bearing indexed on the mdf.

Thanks for this John. Time to do the toolbox drawers. Myself that is

Nice containers!!

The round over router bit has a bearing that needs a hard surface to follow. Make a insert that mates to the foam cut out but offers a smooth hard outline surface for the bearing to profile.

Ever looked into die cutting? It's FAST and CLEAN. Die cut the top then glue the color pad layer and die cut the outside. Emblem could be heat stamped in less than a second.

Hey John, you might want to look into a straight flute endmill instead of spirals. I use to cut plastics and wood with spiral endmills but they leave rough burred edges. With a straight flute, you should get clean pristine edges on foam all day!

Great work on the foam John. I have a suggestion that may have cleaner and safer results when routing the radius. Machine a jig that fits over the foam, just the upper half and put a smaller bearing on the bit and presto, clean, precise and no accidental radiuses on fingertips.

I'm curious as to why you wouldn't want to use laser cutters, as opposed to the carbide engraving tools that you're currently using? Lasers are so much more precise, and they are economically priced too. Lasers will also provide a much tighter fit inside the case, along with cleaner lines on the cut. Still, I admire how passionate you appear to be with the creative solutions that you've come up with for your product(s).

John, look into what's called a pin router. It will cut the same pattern every time. Make a pocket for the foam to fit in and then you can rout the the edge the same every time.

Don't know if it's been mentioned and it's only an idea but instead of the round over bit for the outside, have a template and a flush trim bit

Hey John, My thoughts on the foam Radius. Machine a positive die/male. this way the foam could be turned over and the die used as a template/pattern routing system. With a custom router Bit (lets say lakeshore), bearing on the bottom to follow the template, foam upside down on the template. This could face the edge and round over the radius. Please get your man a pair push block.

Should be able to use wood router bits in your mill. Quarter inch radius corner rounding bit with no bearing, run it like an endmill. Only trick might be fixturing and holding the foam after you finish the top and flip it upside down. Might be able to make a fixture plate that will sit on your vacuum plate and direct the vacuum to the right places to hold the individual pads once the router bit cuts them up.

Can also get rid of fuzzy edges going clockwise and counterclockwise on the outside cut. That’s what I usually do if I see on side is clean and the opposite side isn’t

I just found your channel and was very excited to see you put nano oil in the case. It's a great product. I bought some years ago and the stuff lasts forever. Christian StClaire is a super nice guy. One note though, while I was able to find it you should probably put a link to the Grimsmo Knives page in the description along with all the other links you listed. Anyhow keep up the good work.

Would you mind revealing the supplier of the case? I'm investigating doing the same thing but for a much different product. Thanks for taking all the the time to make the video. I was hanging on every word!

For such a beautiful knife you should have a walnut box with brass hinges, no plastic or foam.

Wow when i was watching the video,I could not believe you were milling the foam,I could see if you needed a one off item,but i was like screaming as i was watching more and more just thing why are they not Die cutting them,it is super easy to do Basically you just bend up thin spring steel called Die Rule,and you just insert them into a MDF pattern of your shape and use a Arbor Press or a Rubber Mallet to hit around the Parameter very simple,then you can use 3M contact adhesive to laminate the two different colors together

love the new videos thanks for sharing

Glad you put such detail in your boxing but the egg crate on the top lid is plain cheap looking. Like the first design much better, looks high end. Hope you put that much thought in the knives. Need to try one I guess.

"RUN CNC"!!! I love it ...does it play "Cut This Way"??😃😃😃😃

At our makerspace we really love using a laser cutter on foam like this - but we wouldn't be able to do the dual layer like that without manually gluing it after the fact. (cut stencil then glue to solid base) Laser foam is awesome. Looks like you tweaked this to perfection too :D

I'm surprised you don't laser engrave and laser-cut the foam, or water-jet cut it-it gets past all the pesky issues that machining the foam creates. Since you're not using abrasive media with the water jet for foam, it's actually pretty economical. Maybe for a future case revision-as is, these are still great and you've really laid out a good process to do it well with the machine tools!

You could cnc or route a zero clearance plate for the router table fence, that would allow you to push the foam up against the face of the fence rather than just a small bearing.

Thank you so much for sharing knowledge all the best wishes boss

You guys are awesome!

Hi guys nice job, that's what we call QUALITY and continuous improvement. Peoples are not always thinking and considering the hard works and the value behind the scene. One thing to ask, did you ever tried to do another pass with a rooter cutter on the computer assisted cutter to have the same nice finish than the bottom of the pad by using the rooter table? Very nice video, again, good work!

Start with a thin piece of black foam and stamp your design out with cutters...then glue the thin piece to the bottom. DONE!!!

Hey.. Thanks so much for the info.. I now realize I can save lots of $$ making my own foam product inserts.. Also I want to buy one of your knives...

might want to keep one sample in your storage with all content to check if your top filling is dissolving or starting to stick/dissolves (check like every 3 month). nice progress and thanks for the footage ;o)

For the table router setup, make a jig for the foam to insert in and then you can pass the jig around the router bit. Hard to explain in text but hopefully that could help