Category: Uncategorized

Last week I finished a new video to go with my article on vacuum pump choices and options. It was a fun one to make! I got a bunch of my pumps together (and traded for one – thanks Stephan!) and thought about how to show the differences and illustrate some if the key differences between types. All the pumps I used were small single phase electric ones that you could use in a hobby or home shop – but are also at home in an industrial setting. All were bought used – most for under $200US. Here’s the video:

I am not totally clear on what pump you should buy for yourself – and that is on purpose. There isn’t any ideal pump – and it is better to understand the parameters and make the best choice for the combination of things you’re working on. If you get serious about composites and vacuum bags, you’ll want to have a few. At this time I have these plus a few larger ones – and that’s down quite a bit from when I had an actual factory! Vacuum is so important to composite processing that it is a good idea to have a variety of pumps for different types of work – and for backup.

Used pumps are a great deal and because they can be rebuilt fairly easily and composites work is not demanding of real (as these things go) high vacuum – there are lots of options. Ebay, surplus websites, auctions and local classified ads are all good places to look. Try to find a common brand that offers parts for repairs in your area. I didn’t go there in the video, but those cheap AC and refrigerant pumps you can get for under $100US are probably not going to give you as good an experience as these more industrial ones. They have lots of bad habits and can be an ok first pump or emergency backup – but you’ll be better served in the long run to find something more rugged and dependable.

Here’s the main article: HOW TO CHOOSE A VACUUM PUMP FOR COMPOSITES

I’m really excited about developments at the intersection of 3D printing and automated composites. My guess is that in the next decade the two will merge to the point of being two complementary components of the same “technology.” 3D printing (aka “Additive Manufacturing”) is already making inroads in the tooling market (see: Additive Engineering (USA) for a leading example) and ATL and AFP are well established automated composites technologies for aerospace production.

A leader in that market Electroimpact (USA) released this amazing video that shows their work combining 3D printed tooling with automated fiber placement (AFP):

In a smaller scale, ADDComposites (Finland) is building small scale automated fiber placement tools and software to bring this technology to a much more approachable scale and price point. I’m really excited to see their continued development!

And on an even smaller scale, check out the Fiber 3D printers from Desktop Metal (USA). This seems to push the Markforged (USA) type 2.5D thermoplastic technology a bit further with higher performance thermoplastics and the ability to lay wider tapes instead of fiber filament.

Do you know of any other interesting additive/automated composites efforts that should be included here? Let me know! email: [email protected]

I’m really excited to see how this technology transforms the composites industry in the coming years. One of these days I need to learn how to program robots!

I have been interested in the idea of using autoclaved aerated concrete (AAC) for composites tooling but until recently I never had a chance to test it. In fact I had never even seen in first hand! Finally got my chance thanks to Aercon AAC. They sent me a 12″ x 12″ x 4″ sample and this video shows the results of my first experiment!

It works! There is some question on how to seal the porous surface and I haven’t got a reliable number on the CTE. But it held up and seems to have come through the cooking process unharmed. The big deal is how much cheaper AAC is than most other high temperature tooling products! A pallet of AAC costs about the same as a single 50mm thick sheet of epoxy tooling board. More to come!

I am learning to make videos – and this one is about my experiences making and testing a big 3D printer made out of an old CNC router. Some things are best written, others need to be seen!

Working on rounding up and laminating some of the first test panels for the Materials Library! Starting with common hand layup, infused and pre-preg parts. Making panels oversize and trimming to 12″x12″ and 12″x1″ strips for some basic bending tests. I have an old Chatillon tension/compression tester that I’m going to try to get working – hoping to do some very basic stress/strain and failure-mode info do the line – not for actual engineering but more for comparisons between panels.

Still trying to figure out how to present the information well without having things get confusing or really hard to manage.