So, with my new tool-chest I had somewhere better to put my 1/2″ extension arms. They were rattling around in the drawer. So, 30 minutes in CAD and a couple of hours in the printer, and now they have somewhere nice to sit, and they don’t rattle around anymore.
Yes, but only by printing the part, taking a mould, then infusing the part. But hey – this is the future right? Food is blue, Boris is Foreign Secretary, and I can buy things and my watch pays for them.
I’m using a Velleman Vertex bought from The Electronics Shop in Cullercoats, Whitley Bay.
Here we have the two target pieces, 60mm * 40mm * 6mm thick. I was experimenting with quality settings to see what is useable for moulding.
This is the top layer – you can see plenty of holes
This is the top layer, and you can see plenty of holes – If I was to take a mould off this I’d struggle – it’s an excellent keying surface. I may get away with a lot of brushed on thick PVA release agent, but if I was aiming for fine surface tolerances I’d not get it. Best bet would be to cover with gel-coat, polish then mould.
This is the bottom surface, which has a different setting (I don’t remember) but you can see the holes are pretty uniform and it picks up dust a bit.
This is the top surface with the number of supports in the hollow space doubled, and a thicker shell (1mm) added. If you look closely in the top picture, you can see the cross-hatching that is the support matrix, and the differences between them.
Increasing the shell thickness has also laid down a lot more plastic, making for a virtually sealed surface, but still with some tiny holes.
The Base here isn’t much better – I didn’t make any significant changes to the base, and I don’t think I would – If I design parts that are assemblies, I’d just use the base as my adhesive point. I’d use epoxy as well.
This organic looking beauty is a 3mm hole with a 1/2mm counter-sink. I wanted to see what I can do to leave dimples in the part. Dimples are important because I’d have dimples in the final part, which would make for an accurate drilling point if it needs to be demountable (such as the fuel-pump hatch in a petrol tank).
I can’t recommend the team enough here, and Anthony, with whom I dealt. They have the printer in stock, and all the consumables, spares and upgrades as well. I can’t emphasise the quality of service enough with these guys. I had a question about alignments whilst I was building the printer, and got an immediate helpful response. When I tried the printer for the first time, it printed exactly like it was meant to do, like a piece of consumer electronics, not a cutting-edge piece of manufacturing equipment.
So, NinjaTek have released a new very hard filament which is petroleum resistant – could be useful for making my composite tank. I still need to understand if the regs require foam filling, or if flap gates are adequate. I could then completely print the pump mounts, flap gates swirl pot, etc.
This comes on the back of this post about making tank bladders.
So, even though I’ve got my Velleman 8400 printer and not assembled it, I’ve been thinking of what to do with it. Needless to say, with 3D printing that started in the community there’s not only a great set of community based CAD packages, but people like Autodesk are in on it as well with TinkerCAD and a quite interesting suite of free apps as well (including using your i-device as a 3D scanner).
I think my first project (I have some 3D experience with CAD anyway) will be to rework my composite fuel tank. I had to junk the original plan – it wasn’t possible to really make a part from the moulds – I had returns greater than 90 degrees on some flanges and that just doesn’t work.
What I’ll do this time is print a framework that bolts together, and bond on to that framework a set of plastic panels. The end result will be a completed tank that can then be moulded from. I’m also going to simplify the design with far fewer faces, but some of the curves (radius curves so the carbon can go in) will be much easier to make more accurately. I think I’ll make two halves that slot into each other much like the top and bottom of a Matryoshka doll.
I will make the panels out of (maybe) 3mm polypropelene sheet. It has great release properties, but then of course, is difficult to bond to the framework. Nothing that a good keying and epoxy won’t fix. I can use other plastics of course, and if I’m a little rough with the cut, then I will fill the gaps with wax. It’s only a tank and not a display item.