Lots of things went wrong this weekend, now beer

So, the cunning plan was to get the short engine built this weekend, and I wasn’t far away until I had a mild issue that turned into a disaster. Well, a recoverable disaster, but not without effort and maybe cost.

I have been time slicing between getting the printer working how I want it, and doing the jobs on the engine. The major job this weekend was getting the head on, with the ARP studs set. The head had been modified and professionally built for me, but you can’t put it on the block with the cams in place – they obscure the head-bolts.

So, off came the cams, and in went the studs (threads lube’d of course) and on went the gasket and head (including the two small dollops of gasket). All the threads were painstakingly painted with the correct graphite paste and done so with an artist’s toothbrush. I’ve learned there’s no use really caking it on – it just squeezes out.

All the pressure washers went on, and as I was putting the last bolt in to hand tighten it before the torquing sequence, I fumbled it and it went down an oil gallery. Mildly frustrating I thought, but no big deal – just take the sump off (only finger tight on three bolts) and it should have dropped down. I turned the engine over on the stand, and this is where it all went arse. Four of the cam buckets fell off on to the floor. I managed to turn the engine over before more did.

Each cam-follower-bucket-type-of-thing is separately chosen for the correct valve clearance, and you guessed it, they’re all different. So, I don’t have a record of which is on which valve, and I’m just hoping my engine builders did keep a record. If not, I will have to take it back to them to be reset. Not a major deal, but hours wasted.

Then I went to do just a simple job – put the cam-chain guides on. The supplied bolts are socket-headed cap screws (my favourite of all the bolts) and they are to be torqued to 9.75Nm. No problem there – I have small torque wrench just for this, and it’s a 1/4 square. Arse. I have step-down from 1/2″ to 1/4, but no step up. By then it was 5pm and Halfords was of course closed. Then I went to my magnificent box of shiny bolts, and found a pair of flanged bolts that were the right size, and shiny. Did I mention how pretty they looked?



3d prints under the microscope

3D Printing – Can I Get That in Carbon Fibre?

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.

The Target Pieces


Here we have the two target pieces, 60mm  * 40mm * 6mm thick. I was experimenting with quality settings to see what is useable for moulding.





Lower Quality Settings (the default)

  • Support Matrix: 10%
  • Wall Thickness 0.7mm
  • Speed (max) 48mm/s

This is the top layer – you can see plenty of holes

0714_1This 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.



0714-2This 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.


Higher Quality Settings

  • Support Matrix: 20%
  • Wall Thickness 0.1mm
  • Speed (max) 43mm/s


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).

Praise for The Electronics Shop and Velleman

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.

3d printed plastic that is petroleum resistant

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.