Tuesday, May 30, 2017

Carbon Fiber 3D Printing 2

I have so far done roughly 60 hours of printing with the carbon fiber PLA filament.

I have gone thru about a kilo at this point.

Observations:

It does not warp like the usual PLA plastic can tend to and it is much stronger.  How much stronger I do not know, but it took quite a lot of effort to break a item I was hammering on with a rubber mallet.

I had a set of files that for whatever reason the designer made the separate pieces fit together exactly and no tolerances.  53mm inside hole, meet 53mm part.  Of course it ended up being a couple tenths of a mm too tight.  The reason for that lies in the way the gcode is created and too complicated to go into here.

So it being 3am, tired and in a hurry I thought I would not check the parts with calipers first, rather fit together and hammer into place.  Of course I broke the part,  Not the part A that took 30 hours to print, rather just the part B that took 8 hours.

Interestingly it did not break at the layers, rather in a jagged line across the layers and in a very thin section of the part.  The part is still usable as it is cracked in a non critical area, however it is a commission job, so it goes into the sample bin and a new part was re-drawn with tolerances and is re-printing.

I am quite impressed with this stuff.

The finish is pretty much as advertised.  It is matte and smooth.  Stringing was about the same as regular PLA.  I am using a bowden print head on this one and it is pretty much par for the course to have to clean up the part in post processing.

It does require printing at a much slower rate than regular filament.  That is a downside.

It does clean up easier with sandpaper and wet sands better than regular PLA.  It does not really work with the wire brush cleanup trick that regular PLA works with.

I am now looking for Aramid fiber filled and higher percentage fill carbon fiber filament.  I found a 30% filled filament in China for around $50 with free shipping.

The Aramid fiber is still very exotic and not available from China.  So far I can only find 2 manufacturers of it, and they are all out of stock.

Reviews of the stuff show that it is slightly more giving than the carbon fiber and not as abrasive on the insides of the machine.

I am also searching for nylon carbon fiber filament and will be placing a order of that soon as I find someone willing to answer emails back about shipping and is not making me jump thru a series of hoops.

Note to those of you in the former USA.  The Chinese are rapidly catching up to you on customer service and reliability.

Friday I placed a order of carbon fiber filament from China, and it arrived Monday afternoon at a price less than buying from a local supplier.  $40 with shipping and 5 spare nozzles.

My latest batch of China orders was a little over $800 and shipped via various methods.  All the express shipping orders arrived within 10 days and the postal orders are all ready to pick up at the registered mail clerk with the exception of 2 small items coming from Singapore as of today.

This is from China to a turd world country, with a corrupt postal system full of thieves.

Sunday, May 28, 2017

Carbon Fiber Printing Update

I am about 1/4 the way thru my first roll of the CF(carbon fiber) filament.

I did a couple test bits with a brass nozzle, but it is highly abrasive so I did not do much until my order of stainless nozzles arrived.

I ordered the nozzles from Anycubic in China, and they usually do fast shipping.  However this time I paid for the DHL on a small item making it $20 for shipping and $6 for the nozzles.

They sent me a bogus tracking number and after a bunch of back and forth messages they coughed up the legit number.

It arrived Friday along with my new CNC control boards for the LumenLabs CNC clone and the my new design CNC machine.

So far I am liking the finish and dimensional accuracy of it.  Although, I am finding my inside  bolt holes to still be off.  The file is 3mm but a m3 bolt wont fit in it.

The good news is that it drills really nice and with a good finish vs regular PLA plastic.

I showed the fit and finish to a client and he placed a nice order of printed parts.

The plastic is 15% carbon fiber although there are brands that go up to 30 and 40%

I will be also getting some of the nylon carbon fiber in soon to print with as I have clients looking for high strength items.

It does print much slower than regular filament.  I tried going faster but my printer kind of jams up a little.

At present I am starting a 30+ hour print job and  total print for the whole project is probably 38-48 hours.

I also have to run off some more sets of printer parts as I expect more printed items orders, so I need more machines.

As I can build myself, expansion is a lot lower cost than buying finished machines.

In other news my metal foundry arrives today.  I have a Yoda head I will cast and pour as my first test.

The Yoda heads were kind of the first thing one would print back several years ago when getting into printing, it was kind of the benchmark and saying I have arrived.

Seems rather fitting.

In other news, The blowtorch hot season here has abated somewhat.

My productivity was really low once the heat season began at the end of April.

It usually lasts until monsoon arrival which was early this year.  Now its hot and humid like south Florida.

My electric bill has gone up to the $200USD a month range now with the air conditioner on and the fridge working harder.

The high heat was making me get heat exhaustion easily and I was feeling it probably 1/2 of the days I was working.  Despite drinking gallons of water and taking 3-6 showers a day.